Progress in orthodonticsAliaa A Khadre, Mohamed Elkorashie, Mostafa Magdy Elzahar, Christoph Bourauel, Ahmed Mahmoud Fouda
BACKGROUND: Torque control of anterior teeth remains a major challenge in clear aligner therapy. Power ridges have been introduced to improve buccolingual root control; however, their biomechanical performance in directly printed aligners remains insufficiently investigated. The aim of this study was to compare the torque efficiency of power ridges in thermoformed and directly printed aligners. METHODOLOGY: A controlled in-vitro study was conducted using a standardised maxillary model requiring incisor torque correction. Four aligner groups were evaluated: Zendura Flex thermoformed aligners (Bay Materials LLC, USA) with (ZF-PR) and without (ZF-C) power ridges, and two directly printed aligners with power ridges fabricated from TA-28 (Graphy Inc., Seoul, South Korea) and DCA (LuxCreo Inc., Bellevue, WA, USA) resin materials. Power ridges were digitally positioned on the labial gingival third of the maxillary central incisors. Biomechanical testing was performed using the Orthodontic Measurement and Simulation System (OMSS) to assess torque expression, root displacement, and force-moment systems under controlled temperatures (25 °C and 37 °C). RESULTS: Torque expression demonstrated a clear material-dependent pattern. ZF-C, used as the baseline, showed moderate and consistent torque expression (38-39% of the programmed torque) across temperatures, with no significant temperature-dependent differences. DCA exhibited the highest torque expression, reaching 62% at 25 °C and 47% at 37 °C. ZF-PR showed intermediate performance (32-42%) with moderate temperature-related variation. TA-28 demonstrated the lowest torque expression (10-17%) with no significant temperature effect. Secondary outcomes supported these findings, with moment generation and displacement patterns correlating with torque expression, whereas force magnitude did not. CONCLUSIONS: Torque expression in clear aligner systems is primarily governed by material properties and thermomechanical behaviour. Design features alone cannot fully compensate for limitations in material performance. Effective torque delivery depends on the generation and transmission of an appropriate force-moment system rather than on force magnitude alone.
European journal of orthodonticsMaryam Elyasi, Babak Bohlouli, Akriti Tiwari, Maryam Amin
BACKGROUND: Poor adherence in orthodontic care is a complex issue involving both children and their parents. The study aimed to expand the theory of planned behavior (TPB) by integrating sense of coherence (SOC) to predict appointment attendance in adolescent orthodontic patients. MATERIALS AND METHODS: This prospective cohort study recruited adolescents from the University of Alberta Graduate Orthodontic Clinic. Baseline questionnaires captured sociodemographic data, TPB constructs, and SOC. Appointment attendance and oral hygiene were monitored over 1 year. Structural equation modeling (SEM) was used to examine relationships between TPB constructs and appointment adherence, with model fit assessed using χ2, chi-square/degrees of freedom ratio (CMIN/DF), root mean square error of approximation (RMSEA), and comparative fit index (CFI). RESULTS: A total of 168 adolescent-parent pairs participated, and 57% of participants missed at least one appointment during the first year of treatment. SEM demonstrated moderate model fit (CMIN/DF = 1.74; RMSEA = 0.06; CFI = 0.84). Within the TPB constructs, only perceived behavioral control (PBC) significantly predicted intention (P < 0.05), whereas attitude and subjective norm were not significant predictors. SOC did not significantly predict intention, TPB constructs, or appointment adherence in either the adolescent or parent models. Intention also failed to significantly predict actual attendance. CONCLUSION: Within the expanded TPB-SOC framework, PBC was the sole psychosocial predictor of orthodontic appointment-adherence intention. However, neither intention nor SOC translates into actual clinical attendance. The moderate model fit indicates that psychosocial constructs alone are insufficient to fully explain orthodontic appointment adherence. To build more effective adherence models, future research and clinical strategies must look beyond psychology and account for structural, logistical, and environmental barriers.
BMJ case reportsTanu Sharma, Shruti Sharma, Anshul Singla, Amrita Puri
This case report discusses the genetic influence and treatment of class III malocclusion in identical twin sisters, in their early 20s, who presented with mandibular prognathism. Both exhibited concave profiles with hypodivergent growth patterns, but Sister A had a more pronounced concavity. Diagnosis revealed skeletal class III malocclusion with mandibular prognathism and negative overjet (9 mm in Sister A, 6 mm in Sister B). Treatment involved pre-surgical orthodontics, bilateral sagittal split osteotomy (BSSO) with mandibular setbacks (7 mm for Sister A, 5 mm for Sister B), followed by post-surgical orthodontics and retention. Both sisters achieved improved facial aesthetics, class I occlusion and functional stability. However, Sister B experienced transient paraesthesia and a bad split, leading to temporary splinting of the second molar. The case highlights the genetic basis of mandibular prognathism, the effectiveness of BSSO and the importance of meticulous surgical planning and interdisciplinary management for optimal long-term results.
International journal of oral scienceBo Zhang, Zhihang Song, Yige Zhang, Jingyi Cai, Guanyin Zhu, Zhihe Zhao
The metabolism and remodeling of alveolar bone are highly active, which dynamically respond to mechanical force. However, the mechanism of how alveolar bone responds to mechanical force remains elusive. Orthodontics is essentially a physiological process of mechanical force-driven alveolar bone remodeling. Here, we demonstrated that orthodontic tension promoted the expression of glycolysis-related genes in periodontal ligament (PDL) fibroblasts. The mechanoactivated glycolysis subsequently enhanced lactylation on histone H3 lysine 18 (H3K18la) in PDL fibroblasts. CUT&Tag analysis revealed that H3K18la was enriched at the promoter region of CXCL1 to upregulate its transcription. 3PO inhibited glycolysis and attenuated stretching force-induced H3K18la and CXCL1 levels in PDL fibroblasts. CXCL1 subsequently augmented oxidative phosphorylation in macrophages and promoted M2 macrophage polarization. Additionally, in vivo inhibition of glycolysis by periodontal injection of 3PO disrupted the CXCL1-mediated CXCR2+ macrophage infiltration and inhibited bone formation during orthodontic tooth movement. Furthermore, the blockade of the CXCL1/CXCR2 axis in vivo, using Cxcr2 knockout (Cxcr2-/-) mice, impaired tension-induced M2 macrophage polarization in PDL, disrupting the pro-resolving microenvironment conducive to bone formation during orthodontic tooth movement. Overall, the results reveal that the tension-induced glycolysis-H3K18la axis in PDL fibroblasts plays a critical role in creating the pro-resolving periodontal immune niche and facilitating alveolar bone formation during orthodontic tooth movement.
Clinical and experimental dental researchChristianna Iris Papadopoulou, Nusha Paschaei, Giulia Brunello, Rebecca Jungbauer, Kathrin Becker
OBJECTIVE: The aim of this systematic review was to evaluate the skeletal and dental effects of skeletally-anchored (SA) maxillary protraction compared with conventional facemask (FM) therapy in growing patients with Class III malocclusion, while controlling for the confounding effect of rapid maxillary expansion (RME). MATERIALS AND METHODS: A systematic literature search (MEDLINE, Cochrane Library, Virtual Health Library, Web of Science, Google Scholar), which involved two screening stages, was performed until January 2026 and identified prospective clinical trials comparing SA with conventional tooth-borne FM therapy. Only studies in which expansion protocols were applied uniformly across groups were included. Risk of bias was assessed with RoB 2 and ROBINS-I tools, and random effects meta-analyses were conducted for cephalometric outcomes. The certainty of the evidence was evaluated according to the grading of recommendations, assessment, development, and evaluation (GRADE) approach. RESULTS: Five prospective trials (3 RCTs, 2 CCTs; n = 194 participants) met the inclusion criteria. Random-effects meta-analyses showed a modest but significant greater increase in SNA for SA (MD 0.65°; 95% CI 0.18-1.13, I2 = 0.0%) and consistently fewer dental side effects with SA: upper-molar mesialization (-1.14 mm; -2.12 to -0.17, I2 = 10.3%), molar extrusion (-0.74 mm; -1.07 to -0.40, I2 = 0.0%), and maxillary incisor proclination (-2.47°; -4.14 to -0.80, I2 = 0.0%). The mandibular plane rotation did not differ significantly (-0.38°; -1.67 to 0.91, I2 = 45.6%). Risk of bias was assessed as "some concerns" in RCTs and "serious" in non-randomized studies. The certainty of evidence ranged from very low to moderate according to GRADE. CONCLUSIONS: Within the limitations of the available short-term evidence, and given the low-to-moderate certainty of the pooled estimates, SA was associated with fewer dental side effects and a statistically significant, though not clinically relevant, gain in skeletal efficacy. Future long-term, age-stratified randomized trials are needed to confirm the long-term stability of these findings.
Clinical and experimental dental researchFazli Rabi, Naveed Sadiq, Muhammad Jamil, Sadia Asif Samdani, Waqas Naseem, Ferdous Bukhary, Umar Hussain, Alessandra Campobasso, Nikolaos Pandis
OBJECTIVE: This study aimed to compare the clinical effects of chlorhexidine (CHX) and essential oil-containing mouthwash (EOM) on periodontal health in patients undergoing fixed orthodontic treatment over a 3-month follow-up period. MATERIAL AND METHODS: This double-blinded, parallel-arm randomized-controlled clinical trial with a 1:1 allocation ratio was conducted at the Department of Orthodontics, Saidu College of Dentistry, Swat, Pakistan. Sixty participants aged 13-40 years undergoing fixed orthodontic treatment were randomly allocated to receive either 0.12% chlorhexidine mouthwash or Listerine essential oil mouthwash, dispensed in identical coded containers to ensure blinding. Participants were instructed to rinse with 10 mL of the assigned mouthwash twice daily for 30 s for 3 months while maintaining routine oral hygiene practices. The primary outcomes were the plaque index and the gingival index. Tooth staining was assessed as a secondary outcome (harm). Clinical outcomes, including the plaque index, the gingival index, and the stain index, were recorded at baseline, 1, 2, and 3 months by a calibrated examiner. Data were analyzed using generalized estimating equation models to evaluate longitudinal changes between groups, with statistical significance set at p ≤ 0.05. RESULTS: The gingival index showed a significant change over time (Wald p = 0.02), with no statistically significant overall difference between the CHX and Listerine groups (Wald p = 0.07). The plaque index was significantly higher in the CHX group than in the Listerine group (Wald p < 0.001). The stain index was also significantly higher in the CHX group than in the Listerine group (Wald p < 0.001). CONCLUSION: Both mouthwashes were associated with changes in periodontal health during fixed orthodontic treatment. Compared with CHX, EOM was associated with significantly lower plaque index and stain index scores, whereas no statistically significant overall difference between groups was observed for the gingival index. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov (Identifier: NCT07119840).
International journal for numerical methods in biomedical engineeringMouhamad Abou Hamdan, Delphine Wagner, Hamdi Jmal, Siham Touchal
Orthodontic tooth movement results from alveolar bone remodeling induced by mechanical loads applied to the teeth over extended periods during the unloading phase of arch wires. In clinical practice, orthodontic arch wires are inserted into bracket slots without precise knowledge of the forces transmitted to individual teeth. Excessive loads may lead to undesirable side effects, whereas insufficient forces may fail to initiate bone remodeling and tooth movement. This study aims to develop a 3D numerical approach based on finite element method to simulate orthodontic tooth movement during the alignment phase while quantifying the loads applied by the superelastic nickel titanium arch wire. A common clinical case of buccal infraposition of the maxillary canine was selected. Patient-specific geometries of the teeth and alveolar bone were reconstructed from cone-beam computed tomography scans. A coupling strategy between the arch wire unloading response and an external bone remodeling model was implemented to predict teeth movement over a one-month treatment period as orthodontic appointments are typically scheduled every 4 weeks. During recovery to its initial shape, the arch wire delivered light and constant forces, leading to extrusion of the canine and intrusion of the adjacent first premolar and lateral incisor. This numerical framework captured the mechanical behavior of the superelastic nickel titanium arch wire and predicted teeth movement consistent with clinical ranges reported in the literature. This approach provides an efficient tool for orthodontists to predict patient-specific orthodontic outcomes and optimize treatment design during the leveling phase.
Progress in orthodonticsLyn Jiang, Alex Simon Chan, Maurice J Meade, Elissa Freer, Hisham Mohammed
BACKGROUND: Laypeople can choose from a variety of orthodontic care pathways. It is in the clinician's best interest to understand their preferences in order to tailor consumer engagement. This scoping review maps the evidence concerning laypeople's preferences for orthodontic providers and appliances. METHODS: The review follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Two reviewers conducted a systematic search and an independent screening process across five electronic databases until December 2025. RESULTS: A total of 56 studies (48 cross-sectional questionnaires; seven qualitative; one mixed methods) comprising 16,271 laypeople across 17 countries were included. Forty-two studies examined perspectives for orthodontic appliances, and 20 studies investigated providers. Specialist orthodontists were consistently the most preferred treatment providers, primarily associated with perceived higher quality and expertise. Direct-to-consumer (DTC) treatment appealed to a minority and was associated with lower cost, self-perceived easier-to-treat malocclusion and convenience. Adults preferred and were willing to pay more for aesthetic appliances, whereas children and adolescents perceived metallic braces as more aesthetic. Pragmatic appliance features such as effectiveness, comfort, and treatment outcomes often outweighed appearance, especially among informed or experienced patients. Common public misperceptions included confusion between general dentists and orthodontists, and overestimation of DTC safety and effectiveness. CONCLUSION: While DTC and aligners appeal to the public demand for aesthetics and convenience, preference for orthodontists and fixed appliances remains strong, driven by perceived quality and the social acceptability of metal braces in children and adolescents. Better public and in-chair education is recommended to address misperceptions and guide better-informed decision-making.
Journal of Indian Prosthodontic SocietyMansi Dhiran, Ajay Sabane, Abhijit Ashok Patil, Arti Gachake, Darshana Mundhe, Rupali Patil
AIM: This study aims to evaluate and compare the scanning accuracy of three IOSs and measuring the vertical marginal fit of three-dimensional (3D) printed resin retainers for single crown, three-unit, and cross-arch fixed partial denture situations. SETTINGS AND DESIGN: Comparative In Vitro Study. MATERIALS AND METHODS: A maxillary Nissin typodont with prepared abutments at #13, #23, #25, #27, and #16 served as the master model. A calibrated Shining 3D laboratory scanner provided the reference standard tessellation language (control). Each IOS generated six scans ( n = 6/scanner; 18 test scans). Trueness and precision were derived by best-fit superimposition in Geomagic Design X. Fifty-four single-unit, three-unit, and cross-arch retainers were 3D-printed. Vertical marginal discrepancy was measured at mid-buccal and mid-lingual sites using a digital stereomicroscope (×20). STATISTICAL ANALYSIS USED: One-way ANOVA with Tukey's post-hoc test was used for comparisons among scanners and prosthesis spans. Pearson's correlation was used to assess the relationship between trueness and marginal fit, and Chi-square test was used to assess clinical acceptability. A P value ≤0.05 was considered statistically significant. RESULTS: 3Shape TRIOS 3 showed the highest trueness (28.5 ± 5.2 µm) and precision (18.2 ± 3.1 µm), followed by Medit i700 and Shining 3D Aoralscan 3 ( P < 0.001). Marginal discrepancy was lowest with 3Shape TRIOS 3 (52.4 ± 6.5 µm) and increased with span. A positive correlation was found between trueness and marginal fit ( r = 0.82; P < 0.001). Clinical acceptability was 100%, 94.4%, and 77.8% for 3Shape TRIOS 3, Medit i700, and Shining 3D Aoralscan 3, respectively ( P = 0.041). CONCLUSION: All three scanners delivered clinically acceptable results; 3Shape TRIOS 3 yielded the highest accuracy and best marginal adaptation. Accuracy and marginal fit deteriorated as prosthesis span increased.
American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of OrthodonticsP Emile Rossouw, Anthony M Puntillo, Daniel J Rejman, Meenakshi Vishwanath, Onur Kadioglu, Timothy Tremont, Paul M Kasrovi, Jose A Bosio, Roberto Hernandez-Ors…
As a credentialing organization, the American Board of Orthodontics (ABO) has the responsibility to continually evaluate and refine its format and structure to ensure that they remain relevant to its stakeholders, including examination candidates, current board-certified orthodontists, and the general public. This article describes how the ABO's current credentialing process has evolved to align with contemporary credentialing trends, particularly within the broader healthcare field. Furthermore, the ABO explains its role regarding the concepts of standardization, curriculum validation, public protection, certification, and licensure. This article highlights the ABO's collaborative efforts with orthodontic educators and residency programs to develop fair, defensible, and evidence-based examination criteria. Examination development, psychometric analyses, and operational demands are outlined, along with future considerations and options to provide increased value during the certification renewal process.
Journal of Indian Prosthodontic SocietyP S Prakhyath, Bharath Prabhu, Shijal Narayan Suvarna
AIM: This study aimed to evaluate and compare the vertical marginal discrepancy of DMLS copings fabricated from stone dies scanned using an intraoral scanner (IOS) and a laboratory scanner. SETTINGS AND DESIGN: An in vitro comparative study was conducted to evaluate the influence of intraoral and laboratory scanning systems on the vertical marginal discrepancy of DMLS copings. MATERIALS AND METHODS: A customised stainless-steel model simulating a prepared tooth with a shoulder finish line was fabricated. Impressions of the model were made using elastomeric impression material. Forty dies ( n =40) were poured using type IV dental stone and divided into two groups ( n =20). Group 1 dies were scanned using a 3Shape TRIOS IOS and Group 2 dies were scanned using a 3Shape extraoral laboratory scanner. Copings were fabricated using CAD/CAM software. Marginal gap between the die and the coping was measured at 4 predetermined points (buccal, lingual, mesial, and distal) using a stereomicroscope at ×40 magnification. STATISTICAL ANALYSIS USED: Data were analysed using SPSS (version 21, IBM Corp., Armonk, NY, USA). Student's unpaired t-test was used to compare the tested groups. The collected data were analysed at a significance level set at P < 0.05. RESULTS: The mean marginal gap between the die and coping was 11.44 μm for Group 1 and 29.62 μm for Group 2. The difference between the groups was statistically significant ( P < 0.001). CONCLUSION: Copings fabricated from dies scanned using IOS demonstrated significantly lower vertical marginal discrepancies compared to those scanned using the laboratory scanner. However, the marginal gaps observed in both groups were within clinically acceptable limits.
Journal of Indian Prosthodontic SocietySmruti Nanda, Mirna Garhnayak, Abhijita Mohapatra, Sangram Panda, Abhilash Mohapatra, Gopal Krishna Choudhury
AIM: This study aimed to compare the marginal and internal adaptation of monolithic computer-aided design and computer-aided manufacturing (CAD/CAM) zirconia crowns and heat-pressed ceramic-veneered zirconia crowns fabricated using a standardized digital workflow. SETTINGS AND DESIGN: An in vitro laboratory study was conducted using standardized epoxy resin dies and zirconia crowns fabricated by two different laboratory workflows. MATERIALS AND METHODS: Twenty zirconia crowns were fabricated from a single STL dataset with a 50-µm cement space and divided into two groups ( n = 10): monolithic CAD/CAM zirconia (MZ) and bilayer heat-pressed ceramic-on-zirconia (PVZ). All crowns were fabricated on epoxy resin dies replicated from a CAD/CAM-milled stainless-steel master die. After cementation with glass ionomer cement under a controlled seating load of 50 N, the specimens were sectioned buccolingually. Marginal and internal gaps were measured using scanning electron microscopy at eight predetermined sites. STATISTICAL ANALYSIS USED: Data were evaluated for normality using the Shapiro-Wilk test. Intergroup comparisons were performed using the Mann-Whitney U-test, with statistical significance set at P < 0.05. Bonferroni adjustment was applied for exploratory multiple comparisons. RESULTS: For the primary outcome, composite internal adaptation was lower in the monolithic CAD/CAM zirconia crown group than in the heat-pressed ceramic-veneered zirconia crown group (103.07 vs. 111.38 µm; P = 0.019), with a moderate effect size ( r = 0.53). Composite marginal adaptation did not differ significantly between the groups (88.90 vs. 95.73 µm; P = 0.226). CONCLUSION: Both fabrication workflows produced zirconia crowns with marginal and internal adaptations within clinically acceptable limits. Monolithic CAD/CAM zirconia crowns showed slightly smaller internal discrepancies than heat-pressed ceramic-veneered zirconia crowns; however, the magnitude of this difference is unlikely to affect clinical seating or cementation.
Clinical and experimental dental researchMohammadreza Nakhaei, Hossein Dashti, Arsalan Shahri, Mahsa Rahmani, Ali Kazemian, Saeid Sabzevari, Masih Rezaee
OBJECTIVES: To quantify the occlusal adjustment required for two-unit, implant-supported polymethyl-methacrylate (PMMA) crowns with either digital or conventional impression techniques, using full-arch and half-arch workflows. MATERIAL AND METHODS: An acrylic maxillary-mandibular model carrying two bone-level implant analogs (sites 46-47) was mounted on a semi-adjustable articulator. Twenty impressions were made (n = 5 per group): digital full-arch, digital half-arch, conventional full-arch, and conventional half-arch. PMMA crowns were designed using computer-aided design (CAD) software, milled, and surface-scanned before adjustment. Occlusal contacts were refined on the articulator with 21 µm film while recording adjustment time. Pre- and post-adjustment scans were superimposed and analyzed using three-dimensional surface analysis software to quantify mean material reduction (µm). Data were analyzed with one-way ANOVA and independent-samples t-tests (α = 0.05). RESULTS: Digital workflows required significantly less occlusal reduction (146 ± 35 µm vs. 226 ± 35 µm; p = 0.035) and shorter adjustment times (144 ± 36 s vs. 385 ± 36 s; p < 0.001) than conventional, with no effect of arch span (full vs. half; p > 0.05). Within protocols, the digital half-arch group showed the smallest adjustment (127 ± 37 µm) and fastest finishing (98 ± 33 s), whereas the conventional half-arch group required the longest time (456 ± 21 s). CONCLUSION: Fully digital impressions reduce both the amount of occlusal adjustment and the chairside time needed to seat implant-supported crowns compared with conventional silicone impressions. Reducing the scan to a half-arch does not compromise occlusal precision, making the digital half-arch workflow an efficient alternative for posterior, free-end implant restorations. CLINICAL RELEVANCE: In implant posterior PMMA crowns, the impact of impression/workflow choice on occlusal adjustment is unclear. This in-vitro study measured occlusal reduction and chairside time across digital versus conventional and full- versus half-arch workflows. Digital, especially half-arch, required less adjustment and shorter time. Clinically, a digital half-arch approach may streamline delivery and reduce unnecessary material removal, pending confirmation in patient-based settings.
Revue medicale suisseSibylle Chatelain, Gianmarco Widmer, Dominik Ettlin, Nenad Lukic, Michael Adler, Sandra Van Den Broecke, Martin Broome, Raphaël Heinzer, Karma Lambercy
Obstructive sleep apnea syndrome (OSAS) remains widely underdiagnosed, despite its well-established cardiovascular and cognitive consequences. Although continuous positive airway pressure (CPAP) remains the first-line treatment for severe OSAS and for moderate OSAS associated with comorbidities, adherence often remains suboptimal. Custom-made mandibular advancement devices (MAD) therefore represent an attractive therapeutic alternative for patients with symptomatic mild to moderate OSAS. Generally better tolerated than CPAP, they are associated with better adherence. This article guides clinicians through the different stages of patient management with MAD : indication, fabrication and treatment follow-up.
Swiss dental journalAdrian C Frey, Noah C Walser, Patrick R Schmidlin
Pathologic tooth migration (PTM), tooth flaring, and severe mobility are frequent clinical problems in stage IV periodontitis and can cause major aesthetic and functional impairment. Conventional correction often requires prolonged interdisciplinary periodontal-orthodontic treatment. This case series introduces the PIANO protocol (Periodontal Immediate Adhesive Nonsurgical Orthorepositioning), a splint-assisted approach combining orthorepositioning with immediate stabilization during step 2 periodontal therapy. Three patients with generalized stage IV, grade C periodontitis, anterior PTM, and grade III mobility were treated. Before local anaesthesia, the affected teeth were moved with gentle digital pressure towards the closest passively achievable functional and aesthetic position. Movement was discontinued if resistance or discomfort occurred. The teeth were then adhesively splinted, premature occlusal contacts were adjusted, and nonsurgical periodontal therapy was performed. At 6 months, all treated teeth remained clinically stable and responded positively to pulp sensibility testing. Periodontal inflammation had resolved, no residual pathological probing depths were detected, and radiographs showed defect fill compatible with osseous repair. Patient-reported outcomes were favourable, particularly for aesthetics, function, and willingness to undergo the procedure again. No pulpal complications or splint failures occurred. Within the limitations of this three-patient case series, the PIANO protocol provided rapid aesthetic and functional improvement while facilitating periodontal treatment of grade III mobile teeth. It may represent a minimally invasive adjunct for selected patients seeking rapid aesthetic improvement and a time- and cost-efficient treatment option.
Clinical oral investigationsİsmail Burak Halat, Zeynep Gümrükçü, Taha Emre Köse
OBJECTIVES: This study aimed to evaluate the association between pterygomaxillary separation (PMS) performed during surgically assisted rapid maxillary expansion (SARME) and three-dimensional morphological and morphometric changes of the mandibular condyle using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This retrospective CBCT-based study included 50 independent adult patients who underwent SARME, with 25 patients in each PMS group. Both condyles of each patient were segmented and measured separately to preserve side-specific morphological information, yielding 100 condylar imaging observations from 50 patients. Preoperative and postoperative CBCT data were used to perform condylar segmentation and generate three-dimensional models. Condylar volume, surface area, root mean square distance (RMS), mean signed distance (MSD), minimum and maximum surface distances, apposition/resorption distribution, and right-left condylar asymmetry were assessed. To account for the correlation between bilateral condyles from the same patient, the principal condyle-level outcomes were analyzed using generalized estimating equations (GEE) with patient as the clustering unit and robust standard errors. Condylar volume and surface area were evaluated longitudinally using the PMS group × time interaction, and a patient-level sensitivity analysis based on bilateral condylar averages was additionally performed. RESULTS: Baseline condylar volume and surface area values were generally similar between the PMS(+) and PMS(-) groups (p > 0.05). After SARME, measurable morphological and morphometric changes were observed in the condyle in both groups. After accounting for within-patient clustering, the estimated between-group difference in longitudinal condylar volume change was 47.61 mm³ (95% CI, - 1.31 to 96.53; p = 0.056). Nominal cluster-adjusted between-group associations were observed for RMS (estimated difference, 0.067 mm; 95% CI, 0.004 to 0.131; p = 0.038; q = 0.113) and minimum surface distance (estimated difference, - 0.240 mm; 95% CI, - 0.434 to - 0.046; p = 0.015; q = 0.092). However, neither remained statistically significant after Benjamini-Hochberg FDR correction. Moreover, these surface-distance estimates could not be demonstrated to exceed imaging and measurement uncertainty and were therefore regarded as exploratory observations of uncertain methodological and clinical significance. The longitudinal condylar volume interaction was also not statistically significant after correction (p = 0.056; q = 0.113), and no statistically detectable differences were observed for surface area change, MSD, or maximum surface distance. Patient-level sensitivity analysis based on bilateral condylar averages yielded a similar overall pattern. Apposition/resorption distributions were summarized descriptively without formal condyle-level inference. CONCLUSIONS: After accounting for within-patient clustering and multiple comparisons, none of the principal imaging outcomes remained statistically significant. Nominal between-group associations were observed for RMS and minimum surface distance before FDR correction, but their adjusted q values exceeded 0.05. Patient-level sensitivity analyses yielded a similar overall pattern. These findings should therefore be interpreted as exploratory imaging observations of uncertain methodological and clinical significance rather than established evidence of condylar remodeling; moreover, they should not be attributed specifically to PMS because residual confounding by indication cannot be excluded. CLINICAL RELEVANCE: Exploratory CBCT-based surface-distance observations differed nominally according to PMS status, but none of the principal imaging outcomes remained statistically significant after FDR correction, and the observed surface-distance differences could not be demonstrated to exceed imaging and measurement uncertainty. Their clinical significance remains uncertain, and residual confounding by indication precludes attributing these observations specifically to PMS.
Clinical oral investigationsRupa J Nimbai, Kapil M Sonar, Hema Yadav, Uday Hemant Barhate, Vilas D Samrit, Riyaz Ahmad Mir, Vikender S Yadav, Rajiv Balachandran, Prabhat Kumar Chaudhari, …
OBJECTIVES: Orthodontically induced root resorption (OIRR) is a common adverse effect of orthodontic treatment, and early detection remains challenging. This randomized controlled trial aimed to evaluate the biological effect of injectable platelet-rich fibrin (i-PRF) on OIRR using dentin sialophosphoprotein (DSPP) levels in gingival crevicular fluid (GCF) as a biomarker during orthodontic tooth movement. MATERIALS AND METHODS: Thirty patients requiring bilateral maxillary first premolar extraction were randomly allocated to an i-PRF group (n = 15) or a control group (n = 15). In the intervention group, i-PRF was administered submucosally before incisor alignment. GCF samples were collected from maxillary central and lateral incisors at baseline (T0) and monthly for six months (T1-T6). DSPP concentrations were quantified using an enzyme-linked immunosorbent assay. Longitudinal changes in DSPP levels were analyzed using linear mixed-effects models to account for repeated measurements. RESULTS: DSPP levels showed a significant time-dependent increase in both groups for central and lateral incisors (p < 0.001). However, the pattern of DSPP release differed significantly between groups. From the fourth month onward, DSPP levels were significantly lower in the i-PRF group compared with controls (p < 0.05). Lateral incisors consistently exhibited higher DSPP concentrations than central incisors. CONCLUSIONS: Administration of i-PRF before incisor alignment was associated with lower DSPP expression during orthodontic tooth movement, suggesting a possible biological effect of i-PRF on OIRR. CLINICAL RELEVANCE: The study provides preliminary biological evidence that i-PRF may influence processes associated with OIRR. If confirmed by future studies, i-PRF could serve as a minimally invasive adjunct to help reduce the risk of root resorption during orthodontic treatment. TRIAL REGISTRATION NO: CTRI/2023/08/056931 (Clinical Trial Registry of India).
PURPOSE: This study compared the outcomes of clear aligner-based expansion screw (CAE) and nickel-titanium palatal expanders in mixed dentition patients with elevated sleep questionnaire scores. METHODS: A randomized clinical trial was conducted on 24 UCLP patients presenting with transverse maxillary deficiency and elevated sleep questionnaire scores. Participants were allocated to treatment with either CAE or NiTi palatal expander. Cone-beam computed tomography (CBCT) and polysomnography (PSG) were performed before and after expansion. Changes in airway volume and sleep parameters were assessed. Correlation analyses were conducted to determine associations between expansion characteristics and airway or PSG outcomes. RESULTS: Pre- and post-expansion Cone-Beam Computed Tomography (CBCT) and polysomnography (PSG) showed that both modalities significantly improved pharyngeal airway volume and sleep parameters. Both groups demonstrated significant improvements in pharyngeal airway volume and PSG parameters. CBCT-based transverse measurements confirmed significant increases in intercanine width, intermolar width, basal bone width, and buccal tipping of molar in both groups, with group1 showing significantly greater gains in intercanine and intermolar width than group 2. Correlation analysis revealed statistically significant positive correlations between the change in intercanine width and increases in nasopharyngeal, oropharyngeal, and total pharyngeal airway volume, and between the change in intermolar width and oropharyngeal airway volume; no significant correlations were observed for J-J' width, basal bone width, or buccal tipping of molar with airway or PSG parameters. A statistically significant negative correlation was observed between skeletal expansion and Δ minimum SpO₂ in the NiTi group. CONCLUSION: Both CAE and NiTi palatal expanders significantly improved airway dimensions and sleep parameters in UCLP patients. Anterior transverse widening (intercanine and intermolar width) correlated positively with airway volume gains, whereas basal skeletal widening (J-J' width, basal bone width) and molar inclination did not, suggesting that the overall expansion effect rather than its mechanistic subtype may be the primary driver of functional benefit. Both appliances demonstrated comparable clinical effectiveness.
Sleep & breathing = Schlaf & AtmungIzabella P Manetta, Bruno B Duarte, Michel B Cahali
PURPOSE: To map the existing evidence on the impact of transverse craniofacial alterations on mandibular advancement device treatment outcomes in adults with obstructive sleep apnea, with the objective of identifying knowledge gaps and informing future research and clinical decision-making. METHODS: A systematic literature search was conducted in six databases. Additionally, gray literature sources were searched, and clinical trial registries, including ClinicalTrials.gov, were screened for RCT protocols. The reference lists of all included sources of evidence were also screened, and experts in the field were consulted. RESULTS: The literature search yielded a total of 1,508 references after duplicate removal. Nine studies and one conference report were found eligible for inclusion. The literature demonstrated heterogeneous associations between transverse craniofacial characteristics and mandibular advancement device treatment outcomes. Most studies (n = 7) did not identify significant associations between isolated transverse craniofacial measurements and treatment response. Greater mandibular transverse dimensions were associated with better therapeutic outcomes in two studies, whereas one study reported better treatment response in individuals with smaller mandibular transverse dimensions. Reduced maxillary width and unfavorable anatomical balance were more frequently associated with greater obstructive sleep apnea severity or poorer treatment outcomes. CONCLUSIONS: While some studies suggest that the response to mandibular advancement devices in obstructive sleep apnea is associated with transverse mandibular dimensions, most investigations have not identified this relationship. Future standardized and well-designed studies are needed to clarify the influence of this anatomical characteristic on the outcomes of this common treatment for obstructive sleep apnea.
Clinical oral investigationsHui Shan Boo, Norhidayah Nor Zahidah Mohd Tahir, Mohd Shahriman Adenan, Alia Amani Abdul Aziz, Nur Izzah Harith Sherifuddin, Aufa Dahlia Bahar, Simon J Littlew…
BACKGROUND: This study aimed to evaluate and compare the surface roughness, surface morphology, and mechanical properties of direct 3D-printed retainers (3DPR) and thermoformed retainers (TFR) after six months of intraoral use. METHODS: This study reports a secondary laboratory objective of a previously published randomised controlled trial (Boo et al. 2026) and included a subset of 10 participants (n = 5 per group). TFRs were fabricated using 1.0 mm Erkodur blanks, while 3DPRs were designed with a uniform thickness of 0.75 mm and printed using NextDent Ortho Flex resin. For each participant, unused upper and lower retainers served as controls, while the corresponding retainers were retrieved after six months of intraoral use. Surface roughness parameters (Ra and Rq) were measured on the cameo and intaglio surfaces using contact profilometry. Surface morphology was evaluated using scanning electron microscopy. Mechanical properties were assessed by instrumented indentation testing. Upper- and lower-arch measurements were averaged at the participant level for statistical analysis. RESULTS: The 3DPR group generally exhibited higher surface roughness values than TFR, with statistically significant differences observed at the intaglio surface at both time points and at the cameo surface after six months (Ra and Rq, p < 0.05). No significant within-group changes in Ra or Rq were observed over time. Surface morphology analysis demonstrated more pronounced surface irregularities in 3DPR compared with TFR, which showed relatively smooth surfaces. For mechanical properties, TFR demonstrated statistically significantly higher Martens hardness, indentation modulus, and indentation hardness than 3DPR at baseline (all p < 0.05), with further increases after six months, whereas 3DPR showed declines in these properties (p < 0.05). CONCLUSIONS: In this pilot laboratory study, 3DPR showed higher surface roughness and more significant decreases in indentation-based mechanical properties after six months of intraoral use compared to TFR, indicating potentially lower mechanical durability under these conditions. However, these findings should be interpreted cautiously given the small sample size.
The Chinese journal of dental researchLe Bei Wang, Ting Dong, Nian Song Ye, Lun Guo Xia, Bing Fang
OBJECTIVE: To investigate the clinical application of clear aligner therapy (CAT) among Chinese dental practitioners, focusing on case selection, treatment strategies, aligner change intervals and recall schedules, and compare CAT with fixed appliances in clinical decision making. METHODS: A nationwide online cross-sectional survey of licensed dental practitioners in China was conducted from June to November 2024. A structured questionnaire collected information on demographics, CAT case selection, treatment strategies and clinical management practices. Descriptive statistics were conducted. RESULTS: CAT was the choice of 87.74% of respondents (n = 1,066), mainly driven by patient demand and expected compliance (88.84%). The high cost was identified as the main hindrance. CAT was most commonly prescribed to adult patients, especially those aged 26 to 30 years. For dental crowding, clinicians more often preferred arch expansion or molar distalisation over interproximal enamel reduction or extraction. In extraction cases, four-premolar extraction was the most common pattern. Rotation and root control were perceived to be the most difficult tooth movements. Most respondents reported aligner changes every 7 to 14 days (n = 608 [57.04%], every 7 to 10 days; n = 389 [36.49%], every 10 to 14 days). Recall visits were typically every 6 to 12 weeks (n = 389 [36.49%], every 6 to 8 weeks; n = 355 [33.30%], every 8 to 12 weeks). CONCLUSION: CAT has been widely adopted by Chinese dental practitioners, especially for the treatment of adult patients with mild to moderate malocclusion. Standard clinical protocols most often require aligner changes at 7- to 10-day intervals and patient recall visits at 6 to 8 weeks.
The Chinese journal of dental researchYou Sheng Jiang, Lin Feng, Jun Xin Zhu, Xiao Yan Wang, Xue Jun Gao
OBJECTIVE: To explore how central retainer depth affects stress distribution and fracture resistance in endocrown-restored premolars. METHODS: A 3D finite element (FE) model of an intact maxillary premolar was established as a negative control. Five endocrown-restored FE models were established, differing in the extension of the central retainer inside the pulp chamber: 0, 2, 3, 4 and 5 mm. The remaining pulp cavity was filled with composite resin. Stress distributions were analysed under oblique loads. Thirty freshly extracted human maxillary premolars were randomly divided into three groups after endodontic treatment. The extension of the central retainer was set to 0 (G0), 2 (G2) or 4 mm (G4). After endocrown manufacturing and cementation, all specimens were subjected to oblique loads in a universal testing machine until fracture occurred. Fracture resistance was analysed by one-way analysis of variance (ANOVA). Fracture patterns were analysed using a Fisher exact test (α = 0.05). RESULTS: The FE analysis showed that within a range of 0 to 4 mm, increasing retainer depth led to decreased peak von Mises Stress (VMS) values in the cement layer and tooth cervix. At a retainer depth of 5 mm (without base material), peak VMS values were higher than those parameters at a depth of 4 mm. The mean fracture resistance values increased with the increasing retainer depth. G4 exhibited significantly higher fracture resistance than G0. The proportion of irreparable fractures increased with retainer depth. CONCLUSION: A central retainer with composite resin used as base material and extending approximately 1 mm apical to the cementoenamel junction is recommended for endocrown-restored premolars.
Lasers in medical scienceAndira Mar-Ramírez, Laura Emma Rodríguez-Vilchis, Rogelio José Scougall-Vilchis, Motohiko Nagayama, Rosalía Contreras-Bulnes
This study aimed to evaluate the shear bond strength and surface roughness of the enamel after removal of ceramic brackets with CO2 laser. Thirty extracted premolars were randomly assigned to three groups (n = 10): Untreated enamel (GI), Conventional debonding (GII), and CO2 laser debonding (GIII). Polycrystalline ceramic brackets were adhered on the buccal surface of GII and GIII groups, using 35% phosphoric acid and Transbond Plus Color Change resin (3 M Unitek; Monrovia, California, USA); shear bond strength was evaluated with a universal testing machine (EZ Graph; Shimadzu, Kyoto, Japan). Prior to debonding, brackets in the GIII group were irradiated with a CO2 laser (Yoshida Dental MFG; Tokyo, Japan) at a wavelength of 10.6 μm, power output of 6 W, for 5 s, at 5 mm. Each specimen was evaluated for adhesive remnant index score, and enamel surfaces were polished to assess roughness (with and without the CO2 laser) under atomic force microscopy. Ra, Rq, and Ry roughness parameters were analyzed. Statistical analysis was carried out using Student's t-test to evaluate shear bond strength, the Mann-Whitney U to assess the adhesive remnant index, and the Kruskal-Wallis and Dunn's post hoc to examine enamel roughness. GIII group showed statistically significant differences, with a reduction in shear bond strength (p < 0.001) and enamel roughness (p < 0.0083) compared to GII. These findings indicate that CO2 laser irradiation can be considered as an alternative in debonding ceramic brackets in orthodontic treatments.
BACKGROUND: Maxillary molar mesialization with clear aligners is challenging because achieving controlled root movement without excessive mesial tipping remains difficult. Although power arms can modify the force system, the combined effects of power-arm length and attachment configuration on molar displacement and tipping remain insufficiently characterized. This study evaluated the effects of 6-, 8-, and 10-mm power arms combined with two attachment configurations during maxillary first molar mesialization using three-dimensional finite element analysis. METHODS: The attachment configurations were selected to represent two clinically distinct approaches to integrating a vertical attachment with a power arm: a palatal vertical attachment combined with a buccal cut-out and a buccal vertical attachment with direct power-arm integration. Six three-dimensional finite element models were constructed by combining three power arm lengths (6, 8, and 10 mm) with two attachment configurations: a palatal vertical attachment with a buccal cut-out, and a buccal vertical attachment without a cut-out. A mesial force of 200 g was applied from a temporary anchorage device (TAD) to the power arm. Displacements were measured along the X (bucco-palatal), Y (mesio-distal), and Z (occluso-gingival) axes. Peak von Mises stress values in the periodontal ligament and aligner deformation were evaluated. RESULTS: In all models, maxillary first molar displacement occurred predominantly in the mesial and gingival directions. Mesial crown displacement ranged from 0.068 to 0.074 mm, while distal displacement at the root apex ranged from 0.011 to 0.012 mm. Mesial tipping angles ranged from 0.155° to 0.170°, with higher tipping observed in models with shorter power arms. Increasing power arm length was consistently associated with reduced mesial tipping and lower periodontal ligament stress, but with reduced mesial crown displacement. Shorter power arms generated higher periodontal ligament stress, whereas longer power arms were associated with greater aligner deformation. CONCLUSIONS: Power arm length and attachment configuration were associated with differences in initial tooth displacement patterns, periodontal ligament stress distribution, and aligner deformation during maxillary first molar mesialization with clear aligners. Longer power arms were associated with reduced mesial tipping and lower periodontal ligament stress, but also with reduced mesial crown displacement. The buccal vertical attachment configuration consistently produced lower mesial rotation than the palatal vertical attachment with buccal cut-out configuration at each corresponding power-arm length; this difference should be interpreted as a configuration-dependent finding within the initial biomechanical response.
Clinical oral investigationsZihan Meng, Ting Ma, Erkang Tian, Jiaxin Yang, Qingchen Feng, Chaoran Xue, Xianglong Han, Juan Li
OBJECTIVE: The objective of this study was to describe the distribution of final incisor position in orthodontically treated Chinese patients with acceptable profile outcomes across different sagittal and vertical skeletal patterns. MATERIALS AND METHODS: Posttreatment lateral cephalograms of 727 patients aged ≥ 16 years were analyzed. Patients were stratified according to pretreatment sagittal skeletal classification (Class I, II, III) and vertical skeletal pattern (low, normal, high angle). Incisor inclination, anteroposterior position (AP position) and vertical level were compared among groups. RESULTS: Incisor inclination differed significantly across both sagittal and vertical skeletal patterns, with angular differences reaching 12.09° (d > 1.0). Sagittal skeletal classification exerted a dominant influence on maxillary incisor AP position, with intergroup differences in U1-NA exceeding 2.3 mm (d > 1.14), whereas mandibular incisors demonstrated limited AP displacement (< 2 mm) despite marked angular variation. Pogonion-referenced indices (U1-Pog, L1-Pog) differed significantly across sagittal and vertical patterns (P < 0.001), reflecting systematic variation in incisor position relative to facial projection. CONCLUSIONS: Final incisor position did not converge toward a single common reference. Incisor inclination varied with both sagittal and vertical morphology. Anteroposterior position was associated mainly with sagittal pattern, especially in the maxillary incisors, whereas mandibular incisors showed limited anteroposterior displacement. Chin-referenced measurements provided additional information on final incisor position in relation to facial projection. These findings provide descriptive skeletal-pattern-conditioned reference distributions, rather than universal reference values or evidence-based optimal treatment targets.
BACKGROUND: STELA is a newly introduced auto-cured bulk-fill composite proposed as an alternative to amalgam. It does not require light activation and provides an unlimited depth of cure, in addition to acceptable esthetic and mechanical properties. OBJECTIVES: To evaluate cuspal displacement, marginal adaptation, and nanoleakage in mesio-occluso-distal (MOD) Class II preparations of maxillary premolars restored with an auto-cured bulk-fill composite compared with a light-cured bulk-fill composite. MATERIALS AND METHODS: Sixty maxillary human premolars extracted for orthodontic purposes were randomly assigned to two groups (n = 30) according to the bulk-fill composite used. Standardized MOD Class II preparations were made and restored using either Group 1: STELA Capsule (SDI, Australia) or Group 2: Tetric N-Ceram Bulk Fill (Ivoclar Vivadent, Liechtenstein). Each group was subdivided into three subgroups (n = 10) based on the test performed. In Subgroup 1, cuspal displacement was recorded after post-cavity preparation and at (5 min, 24 h) post-restoration using a digital microscope. The remaining restored specimens underwent thermocycling and mechanical loading. Subsequently, marginal adaptation (Subgroup 2) was examined using scanning electron microscopy. Nanoleakage (Subgroup 3) was evaluated using silver nitrate tracing. Statistical analysis was performed using the independent-samples t-test and Fisher's exact test (P ≤ 0.05). RESULTS: STELA Capsule demonstrated significantly lower cuspal displacement at both 5 min and 24 h post-restoration compared with Tetric N-Ceram Bulk Fill (P < 0.001). Following thermocycling and mechanical loading, STELA Capsule also exhibited better marginal adaptation (P = 0.033) and reduced nanoleakage (P < 0.001) compared with the Tetric N-Ceram Bulk Fill. CONCLUSIONS: The STELA composite with its dedicated primer showed favorable laboratory outcomes compared with Tetric N-Ceram Bulk Fill used with Tetric N-Bond. This restorative protocol can serve as a viable clinical alternative to light-cured bulk-fill composites, particularly for restoring MOD Class II preparations in maxillary premolars. CLINICAL RELEVANCE: The novel auto-cured bulk-fill composite with its dedicated primer demonstrated excellent performance in reinforcing weakened premolars. It exhibited superior results in reducing cuspal displacement, improving marginal adaptation, and minimizing nanoleakage compared to a light-cured bulk-fill composite, indicating its potential for clinical use.
BMC oral healthGiacomo Scuzzo, Giuseppe Scuzzo, Elena Calzadilla-Suárez, Mario Alvarado-Lorenzo, Laura Criado-Pérez, Adrián Curto, Alfonso Alvarado-Lorenzo
BACKGROUND: Although the twin block is the most commonly used appliance for the treatment of Class II malocclusion, the clear aligner industry has developed systems with integrated mandibular advancement. The purpose of this study was to evaluate and compare the effects of Twin block appliances, standard AngelAligner clear aligners and AngelAligner A6 mandibular advancement clear aligners as early orthodontic interventions for patients who develop Class II division 1 malocclusion. METHODS: The study sample comprised 60 patients with a mean age of 12.4 ± 1.3 years, who were divided into three homogeneous groups of 20 patients each and received different treatments: Twin Block (GTB), AngelAligner aligners (GAA) and AngelAligner A6 for mandibular advancement (GA6). Clinical and radiographic assessments were performed at baseline (T0), immediately prior to appliance placement, and repeated after the completion of treatment objectives (T1). RESULTS: Class II malocclusion was corrected with all three appliances. The GA6 and GTB groups showed similar mandibular advancement, with an increase in the SNB angle of 2.1° and 2.3° respectively, and correction to Class I in 85-90% of cases, outperforming the GAA group, which showed an increase in the SNB angle of 1.2° and correction to Class I in 70% of cases. The duration of treatment was shorter in the GA6 group (15.2 months). CONCLUSION: These findings suggest that the AngelAligner A6 MA and Twin Block are superior for skeletal correction, whereas the standard AngelAligner is effective for milder cases with aesthetic priorities. CLINICAL TRIAL NUMBER: ClinicalTrials.gov, NCT07591025. Registered 6 May 2026. Retrospectively registered.
Clinical oral investigationsAscensión Vicente, Antonio J Ortiz-Ruiz, Clara Serna-Muñoz, Inmaculada Cabello, Yolanda Martínez-Beneyto
OBJECTIVES: To evaluate the effect of two remineralizing systems (Regenerate™ and Orthocare™) on the mineral recovery of demineralized enamel and on the shear bond strength (SBS) of brackets. METHODS: 180 bovine teeth were divided into four groups: 1)Intact enamel, 2)Demineralized enamel, 3)Demineralized enamel/Regenerate™, and 4)Demineralized enamel treated/Orthocare™. Groups 2 to 4 were demineralized. All samples were brushed three times daily; groups 1 and 2 without toothpaste, and groups 3 and 4 were treated with Regenerate™ or Orthocare™. Outcomes were assessed by SBS, adhesive remnant area, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, surface microhardness, and micro-computed tomography (micro-CT). Parametric or non-parametric tests according to data distribution (α = 0.05). RESULTS: Demineralized enamel showed significantly lower SBS, adhesive remnant, surface microhardness, mineral density, calcium and phosphorus content, and phosphate-related Raman parameters than intact enamel (p < 0.05). FE-SEM revealed increased porosity. Neither remineralizing system significantly restored SBS compared with untreated demineralized enamel. However, both treatments promoted partial enamel remineralization, improved calcium (Ca) and phosphorus (P) levels (p < 0.001), increasing surface microhardness and mineral density (p < 0.05). Raman showed greater recovery of phosphate (I960) and carbonate (I1070) peaks in the Regenerate™ group, indicating better mineralization and crystallinity recovery than Orthocare™. CONCLUSIONS: Both agents partially remineralized enamel without fully restoring sound enamel properties. Regenerate™ demonstrated better mineral recovery than Orthocare™. However, the newly formed hydroxyapatite appeared immature, and bond strength was not significantly improved compared with demineralized enamel. CLINICAL RELEVANCE: Remineralizing agents may improve demineralized enamel before orthodontic bonding without significantly affecting bracket bond strength.
BMJ case reportsKeerti Kaushik, Anshul Singla, Naomi Laldinmawii, Amrita Puri
Skeletal Class III malocclusion, or mesiocclusion, is characterised by maxillary deficiency, mandibular excess or both, resulting in a reversed or edge-to-edge incisor relationship. It often reflects underlying skeletal discrepancies in the maxillary or dentoalveolar components and may be worsened by functional mandibular shifts. Treatment options depend on severity and growth status, ranging from orthopaedic correction in growing patients to orthodontic camouflage or orthognathic surgery in adults. Accurate diagnosis and case selection are critical to ensure favourable outcomes.The introduction of temporary anchorage devices has expanded the scope of non-surgical management for Class III cases by allowing controlled distalisation of the mandibular dentition with minimal reciprocal effects and reduced reliance on patient compliance. Micro-implants placed in the infrazygomatic crest or buccal shelf regions provide stable anchorage for en masse distal movement without proclination of the anterior teeth.This case report presents the successful orthodontic management of a patient with bilateral Angle Class III molar relationship, an edge-to-edge bite, 0 mm overjet and reduced overbite, accompanied by mild skeletal discrepancy and a slightly concave facial profile. The patient declined orthognathic surgery and a non-extraction, camouflage approach was pursued. Using miniscrew anchorage, controlled en masse distalisation of the mandibular dentition was achieved, resulting in improved occlusion, facial balance and patient satisfaction.This case demonstrates that skeletal anchorage-assisted distalisation can serve as an effective, minimally invasive alternative for adult Class III patients unwilling to undergo surgical correction, achieving functional and aesthetic harmony through precise biomechanical control.
Progress in orthodonticsGraziana M Sala, Burcu Aydin, Nicoline C W van der Kaaij
AIM: The aim of this retrospective cohort study was to investigate the association between New-T-appliance activator wear time, as measured by a Theramon microsensor, and overjet reduction in patients with a Class II Division 1 malocclusion and to determine whether this association is related to age or sex. METHODS: This study included patients with a Class II Division 1 malocclusion treated with a New-T-appliance activator equipped with a Theramon microsensor in a private orthodontic practice between 2011 and 2023. Mean daily wear time was recorded using the temperature-sensitive microsensor, while overjet was measured at baseline and during treatment. Multivariable linear regression analysis was performed to evaluate the association between wear time and overjet reduction, with age and sex included as covariates. RESULTS: In total, 705 patients were included. The daily mean wear time was 8.3 h/day. Statistically significant associations were found between overjet reduction and mean wear time (p < 0.001). Patients younger than 12 years showed significantly greater overjet reduction than older patients. However, no significant sex-related associations were found. CONCLUSIONS: Higher functional appliance wear time was associated with greater overjet reduction. Patients who start orthodontic treatment at a younger age have a higher appliance wear time and greater overjet reduction. These findings suggest that starting orthodontic treatment with functional appliances before the age of 12 could be beneficial. The patient's sex has not been identified as an influencing factor.
BACKGROUND: This study aimed to compare three-dimensional displacements of the maxilla and mandible, and upper airway changes, following tooth-borne rapid palatal expansion (TB-RPE) (Hyrax) and tooth-bone-borne miniscrew-assisted rapid palatal expansion (TBB-MARPE). Additionally, the correlation between skeletal movements and upper airway changes was evaluated. METHODS: This was a secondary analysis of a previous randomized clinical trial (RCT), recruiting patients with transverse maxillary deficiency and allocating them to TB-RPE or TBB-MARPE. Low-dose cone-beam computed tomography images obtained at pre-expansion and after 3 months of consolidation post-expansion were analyzed for 32 patients (TB-RPE group: n = 13, mean age = 13.15 ± 3.85; TBB-MARPE: n = 19, mean age = 13.68 ± 4.20). Skeletal displacements and changes in airway volume and cross-sectional area of the nasal cavity, nasopharynx, and total upper airway were assessed. Intergroup comparison and correlation analysis were performed. The level of statistical significance was set at 0.05. For multiple comparison correction of skeletal movements and upper airway changes, the significance level was determined using false discovery rate (FDR) adjusted p-values < 0.05. RESULTS: TBB-MARPE resulted in significantly greater maxillary expansion than TB-RPE; however, no significant difference was observed in maxillary and mandibular displacement between groups. Both groups demonstrated a slight forward and downward displacement of the maxilla (FDR-adjusted p < 0.05), with no significant mandibular position changes (FDR-adjusted p > 0.05). Significant increases were observed in anterior and middle airway cross-sectional areas, nasal cavity volume, and total upper airway volume in both groups, with greater improvement in the TBB-MARPE group (FDR-adjusted p < 0.05). No significant changes were found in the posterior cross-sectional area or nasopharynx volume (FDR-adjusted p > 0.05). Maxillary expansion were positively correlated with the increase in nasal cavity volume and total upper airway volume (p < 0.05). CONCLUSIONS: TBB-MARPE facilitated greater maxillary expansion and upper airway enlargement after consolidation; however, both approaches presented similar skeletal displacement patterns, characterized by slight forward and downward maxillary movement and insignificant mandibular position changes. Within the limitations of this study, orthopedic maxillary expansion positively enhances the nasal airway but has minimal influence on the nasopharynx. TRIAL REGISTRATION: The original trial was retrospectively registered at the WHO International Clinical Trial Registry Platform (Registration number: KCT0006871 / Registration date 27/12/2021).
Acta odontologica ScandinavicaKhalid Ayidh Alqahtani, Hamod Alqahtani, Abdullah Saad Alqahtani, Mahmud Uz Zaman, Wajdi A Mohammed Bin, Saleh Alhindi, Nasser Raqe Alqhtani
The relative contribution of radiographic methods and characteristics of the orthodontic intervention to orthodontically induced root resorption (OIRR) remains unknown. The aims of this systematic review and meta-analysis were to (1) estimate the pooled OIRR effect across orthodontic intervention versus comparator contrasts, (2) compare pooled estimates by radiographic method (2D [two-dimensional] vs. 3D/CBCT [three-dimensional/cone-beam computed tomography]), and (3) explore whether force mechanics (intrusive versus nonintrusive) modified OIRR magnitude. Seven randomized controlled trials and one prospective study (January 2010-October 2025) were included. Only OIRR was the outcome, reported as correlation coefficients (r). The primary analysis combined within-study intervention-versus-comparator estimates. Subgroup analysis of 2D versus 3D/CBCT imaging was prespecified, whereas post-hoc analysis of intrusive versus nonintrusive mechanics was performed. The pooled analysis for the primary outcome showed a small, nonsignificant OIRR effect (r = 0.07; 95% confidence interval [CI]: -0.12 to 0.27; p = 0.372) with high heterogeneity (I2 = 84.0%). Radiographic method did not change the pooled estimates significantly (p = 0.331). Force-mechanics analysis showed that intrusive mechanics was related to significantly higher root resorption than nonintrusive mechanics (r = 0.40; 95% CI = 0.15 to 0.65 versus r = -0.03; 95% CI = -0.16 to 0.10; p < 0.001). This accounted for 87.1% of the between-study variance. The average orthodontic intervention effect on OIRR was small and not significant; however, the OIRR magnitude was strongly affected by force mechanics, particularly by intrusive forces. There was no significant difference in pooled estimates by radiographic method; however, 3D/CBCT provides superior volumetric quantification and should be used judiciously according ALARA (as low as reasonably achievable) principles.
Brazilian oral researchCinthia Oliveira Lisboa, Sergio Luiz Mota-Júnior, José Thiers Carneiro Junior, Eduardo Luis de Sousa Cruz, Lucia Helena Soares Cevidanes, Eduardo Franzotti San…
This study evaluated three-dimensional (3D) soft tissue changes and their correlations with hard tissue movements after combined bimaxillary orthognathic surgery. A retrospective analysis was performed using cone-beam computed tomography scans obtained from 22 adults before surgery (T1) and at least 6 months after surgery (T2). Participants were divided into two groups according to the surgical procedure performed: mandibular setback combined with maxillary advancement (MdSet + MxAdv; n = 10) or mandibular advancement combined with maxillary impaction (MdAdv + MxImp; n = 12). Three-dimensional displacements of hard and soft tissue landmarks were assessed using ITK-SNAP and 3D Slicer software. Pearson's and Spearman's correlation coefficients were used to identify associations between hard and soft tissue changes. Significant correlations between anteroposterior hard and soft tissue movements were observed in the subnasal region in the MdSet + MxAdv group (% = 75/70; r = 0.768/0.875) and in the upper lip (% = 83/87/71; r = 0.689/0.760/0.812) and lower lip (% = 54; r = 0.755) regions in the MdAdv + MxImp group. Soft tissue responses in the lower lip and chin regions were significantly correlated with underlying hard tissue movements in both groups; however, the MdAdv + MxImp group demonstrated greater soft tissue response magnitudes (% = 123/136; r = 0.975/0.982) than the MdSet + MxAdv group (% = 75/70; r = 0.810/0.727). Significant vertical correlations in the MdAdv + MxImp group were identified at point A' (% = 86; r = 0.851) and mandibular landmarks (% = 67/109/108; = 0.855/0.981/0.996), whereas the MdSet + MxAdv group showed significant correlations at the lower lip and Pog' point (% = 137/73; r = 0.785/0.921). Both groups demonstrated stronger correlations for mandible-related soft tissues in the anteroposterior and vertical directions. These quantified soft-to-hard tissue ratios may improve the prediction of facial soft tissue changes and contribute to more accurate planning of combined bimaxillary orthognathic procedures.
Medical engineering & physicsYahong Wang, Daniel R Mesghena, Zhenyu He, Jing Xiong, Ning Zhao, Zeyang Xia
Accurate measurement of tooth displacement is essential for orthodontic treatment planning and outcome evaluation. In routine practice, however, commonly used methods such as manual caliper measurement are constrained by limited resolution, marked operator dependence, and low efficiency when repeated measurements are required. This study proposes a fully automated image-based measurement framework in which orthodontic brackets are detected as anatomical reference markers using a YOLOv11-based detection model. The detected brackets are then automatically sorted, classified into maxillary and mandibular groups, and used for scale-normalized distance calculation, enabling high-precision displacement measurement. The method can support real-time longitudinal monitoring during orthodontic treatment and retrospective quantitative analysis of archived clinical images. Evaluation on an intraoral clinical dataset from six orthodontic patients showed that the model achieved an average mAP@0.5 of 95.4% and a precision of 97.9% in patient-level cross-validation, with an average processing time of 40 ms per image. The system measurement resolution reached 0.01 mm. In 140 clinical gauge-block validation measurements, the mean absolute error was 0.028 mm, and all errors were within 0.05 mm. These results indicate that the proposed system provides a rapid, accurate, and repeatable solution for clinical assessment of orthodontic tooth displacement.
Sleep & breathing = Schlaf & AtmungNicolas Charnallet, Simon Valentin, Nicolas Carpentier, Maxime Patout, Ari Chaouat, Bruno Ribeiro-Baptista
BACKGROUND: Sleep apnea has become an increasingly important condition to address, given its growing prevalence in the general population with positive airway pressure (PAP) and mandibular advance device (MAD) as the main treatment. This study aims to describe the evolution of PAP and MAD prescriptions in France over the past ten years, the associated healthcare costs, and the changing characteristics of both beneficiaries and prescribers. METHODS: This study is based on open access reimbursement data from the national health care system (Open LPP) between 2014 and 2023, which provide data on all PAP and MAD prescriptions within the French population. RESULTS: The number of PAP prescriptions has increased by an average of 16% per year, rising from 986,784 in 2014 to 3,362,040 in 2023. Despite reductions in reimbursement rates, healthcare expenditures have doubled, reaching 934 million euros in 2023 for PAP. Private care specialists contributed the most to the increase in prescriptions. Regarding beneficiaries, 64% of prescriptions in 2023 were for male patients compared to 70% in 2014. Meanwhile, adherence to PAP therapy have decreased with 67.6% of patients having an adherence > 4 h/day in 2018 vs. 63.6% (p = 0.03). MAD prescriptions in France increased from 8,110 in 2014 to 29,546 in 2023, representing an average annual growth of 17%. CONCLUSION: PAP and MAD prescriptions have risen markedly over the past decade in France, alongside increasing healthcare expenditures and shifting patterns of prescribers and beneficiaries.
BACKGROUND: Posterior open bite (POB) may develop as an occlusal adverse effect of long-term oral appliance (OA) therapy for obstructive sleep apnea (OSA). However, its frequency, time to clinical documentation, and associated skeletal and dental factors remain insufficiently characterized. This study investigated the frequency and clinical characteristics of POB and explored factors associated with its development during OA therapy. METHODS: This retrospective study included 96 patients with OSA who received OA therapy between August 2015 and May 2025 and had sufficient clinical and cephalometric data for analysis. Patients were categorized into POB and non-POB groups. Patient characteristics, treatment-related factors, dental variables, and cephalometric parameters were compared using unpaired t-tests and Fisher's exact tests, as appropriate. Variables meeting the prespecified screening criterion of p < 0.20 in univariate analyses were entered into a multivariable logistic regression model. RESULTS: POB was documented in 16 of 96 patients (16.7%). The mean interval from the initiation of OA therapy to the first documentation of POB was 1,265.3 days (approximately 3.5 years), with considerable variation among patients. Seven of the 16 patients (43.8%) reported awareness of occlusal changes when POB was first documented. Initial apnea-hypopnea index, number of remaining teeth, overjet, SNA, and SNB met the prespecified screening criterion in univariate analyses, with higher SNB showing a statistically significant unadjusted association with POB. However, none of these variables reached statistical significance in the multivariable analysis. CONCLUSIONS: POB was documented in 16.7% of patients in the final analytical cohort and was first identified at variable times during OA therapy. Although no statistically significant independent predictors were identified, higher SNB may be associated with POB. These exploratory findings require confirmation in larger prospective studies. Careful occlusal monitoring is warranted throughout long-term OA therapy.
BACKGROUND: Periodontal diseases are common chronic inflammatory conditions that may compromise the planning, safety, and outcomes of orthodontic treatment, particularly in adults and in patients with reduced periodontal support. In such patients, orthodontic care requires accurate periodontal diagnosis, confirmation of disease stability before treatment initiation, careful biomechanical adaptation, and close coordination with periodontal maintenance. However, the extent to which dentists providing orthodontic care integrate these principles into routine practice remains insufficiently documented, particularly in North African settings. This study assessed the knowledge, attitudes, and practices of Moroccan dentists providing orthodontic care regarding the diagnosis and management of patients with periodontal diseases. METHODS: A nationwide cross-sectional online survey was conducted in Morocco between September 2025 and February 2026. Eligible participants were dentists practicing orthodontics exclusively or within general practice. The questionnaire included demographic variables, 8 knowledge items, and 9 attitude/practice items covering diagnosis, screening, treatment timing, interdisciplinary collaboration, and periodontal maintenance. Item-level descriptives used available-case denominators. Knowledge (0-7), attitude (0-2), practice (0-6), and total KAP (0-15) scores were calculated. Associations with periodontitis-case management were explored using logistic regression; correlates of KAP scores were examined using linear regression, with candidate variables selected from univariable analyses (p < 0.20). RESULTS: Of 418 platform entries, 118 blank entries were excluded; 300 practitioners from 11 regions provided at least 1 valid response, including 190 complete questionnaires. Only 18.3% correctly defined periodontitis and 46.3% identified the radiographic criterion for bone loss, whereas 81.1% recognized apical displacement of the center of resistance and 70.4% identified intrusion as the movement associated with bone gain. Pre-orthodontic periodontal screening was reported by 63.0%, but systematic full-mouth 6-site probing by only 16.5%. Among periodontitis cases, 44.4% reported formal periodontal stability confirmation before treatment initiation and 35.9% waited 3 months after active periodontal therapy. Median knowledge, attitude, and total scores were 2 (interquartile range (IQR) 0-3)/7, 1 (IQR 0-1)/2, and 6 (IQR 1-7)/15; mean practice score was 2.36 ± 1.25/6. A total of 84.0% expressed a need for continuing education. CONCLUSIONS: Moroccan dentists showed suboptimal ortho-periodontal performance, with limited comprehensive periodontal assessment and variable interdisciplinary coordination. Training should prioritize periodontal diagnosis, full-mouth assessment, and structured co-management pathways.
Nederlands tijdschrift voor tandheelkundeJ W Nolte, P C M Zuurbier, M Gilijamse, J A Groen, I Sparreboom, N C W van der Kaaij
Orthodontics and prosthodontics in orthognathic surgery In complex care, such as for growth disorders and congenital anomalies, multidisciplinary collaboration is essential and begins even before the actual treatment starts. Systematic evaluation of dental, skeletal and soft tissue parameters prevents the correction of one aspect from creating new discrepancies in another area. Through backwards planning, the desired fi nal outcome is fi rst determined collaboratively, after which the treatment process is mapped out step by step in reverse. The process consists of 5 phases: 1. determining desired outcomes and psychosocial context, and collaborative decision-making; 2. pre-operative orthodontics and any necessary dental preparation; 3. surgical planning and osteotomy; 4. fi nishing; 5. follow-up. To prevent misunderstandings and suboptimal outcomes, clear communication, alignment of roles, and shared responsibility are crucial. Digital planning and multidisciplinary consultation support predictable, aesthetic and functional results. Within this multidisciplinary pathway, an orthodontist, a maxillofacial surgeon and a prosthodontically trained dentist each contribute equally to the overall treatment plan.
Progress in orthodonticsNabeel Almotairy, Fahad Aleisa, Abdulrahman K Alshammari
BACKGROUND: Clear aligner (CA) therapy has experienced rapid use over the past two decades to treat orthodontic malocclusions. However, evidence on CA material degradation in the oral environment remains limited and often focuses on single brands or isolated material properties. OBJECTIVES: To investigate CA ageing characteristics across different materials and brands and evaluate the chemical, physical, mechanical, and morphological changes following simulated or intraoral ageing. SEARCH METHODS: Five databases (PubMed, Web of Science, MEDLINE [Ovid], ProQuest, and Scopus) were searched to 18 March 2026, with no restrictions. ELIGIBILITY CRITERIA: Studies assessing CA properties after intraoral use or simulated ageing (thermocycling, cyclic loading, or liquid immersion) were included. DATA COLLECTION AND ANALYSIS: Study selection followed PRISMA 2020. RoB was assessed using QUIN for purely in vitro studies, JBI for cohort in vivo studies, and Cochrane RoB 2 for RCTs. Results were synthesised narratively and organised by property domain, as substantial methodological heterogeneity precluded formal meta-analysis. Where protocols were comparable, a simple pooled weighted mean was calculated and presented graphically. RESULTS: Ninety-five studies were included. RoB was low in eight studies, moderate in sixty-two, and high in twenty-five. Chemical composition remained largely stable during ageing, though some brands showed trace elemental release. Physical, mechanical, and morphological properties showed material-dependent deterioration. Pooled discolouration was greatest with coffee (weighted mean ΔE = 70.9), versus tea (ΔE = 18.4) and red wine (ΔE = 11.5), with Invisalign® consistently exceeding the clinically perceptible threshold. Force decay of 40-90% typically occurred within 48 h. Thermoplastic polyurethane (TPU)-based and directly printed aligners (DPAs) generally showed greater susceptibility than polyethylene terephthalate glycol-modified (PETG)-based aligners, though findings on hardness, roughness, and stiffness were inconsistent. CONCLUSIONS: CA materials undergo clinically relevant degradation during use, particularly in TPU-based and DPAs aligners. Clinicians may need to prioritise material-specific protocols, reinforce dietary and cleaning instructions, and consider force decay when determining aligner replacement intervals. PROSPERO number: CRD420251110248.
JMIR research protocolsAishwarya Atey, Rizwan Gilani, Shefali Singh, Abhijeet Kadam
BACKGROUND: Stainless steel (SS) orthodontic archwires are widely used because of their mechanical properties, affordability, and biocompatibility; yet, prolonged intraoral exposure can cause electrochemical corrosion and release of metal ions (eg, Ni and Cr) that may affect clinical performance and patient safety. Surface coatings such as silver dioxide have been proposed to improve corrosion resistance, but comparative data for silver dioxide-coated versus uncoated SS orthodontic archwires across clinically relevant simulated oral environments are lacking. OBJECTIVE: This study aimed to compare the corrosion susceptibility of silver dioxide-coated and noncoated 0.019"×0.025" SS orthodontic archwires in four simulated oral solutions by measuring electrochemical behavior, cumulative metal ion release, and mass lossthereby testing our null hypothesis (H₀) that no difference exists between coated and noncoated wires. METHODS: This in vitro protocol uses 40 SS archwire specimens divided into two main groups (20 silver dioxide-coated, and 20 uncoated) and four immersion subgroups (n=5 per subgroup): (1) 0.9% NaCl, (2) phosphate-buffered solution acidified with lactic acid (pH ~6.75), (3) phosphate-buffered solution with 0.1 wt% NaF, and (4) phosphate-buffered solution with 0.1% w/v bovine serum albumin. Coatings will be deposited by radiofrequency magnetron sputtering to achieve a 15- to 20-nm silver oxide (Ag₂O/AgO) layer; coating quality will be verified through scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and profilometry. Specimens will be incubated individually at 37 °C with orbital agitation; immersion solutions will be sampled at baseline, 14 days, and 28 days. The primary outcome is corrosion current density (Icorr, µA/cm²) from potentiodynamic polarization. Secondary outcomes include pitting potential (Epit, mV vs SCE), cumulative ion release (Ag, Ni, Cr, Fe; expressed µg/mm²) analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES) after acidification, percent weight loss normalized to surface area (mg/cm²), and SEM/EDS surface analyses. Electrochemical tests will follow a standardized three-electrode setup (SCE reference). Statistical analyses will be used to assess normality; we will use independent-samples tests or nonparametric equivalents for between-group comparisons and mixed-effects models for time-dependent measures. Tests were evaluated at α=.05, with effect sizes and 95% CIs reported throughout. RESULTS: Institutional ethical approval was obtained in April 2024 (DMIHER(DU)/IEC/2024/253). Coating parameters and quality control procedures have been established, and 40 specimens have been prepared and characterized. Immersion and electrochemical experiments are scheduled between June and December 2025, followed by ICP-OES analysis and statistical evaluation, with study completion planned by December 2025. CONCLUSIONS: This protocol will generate comparative data on electrochemical corrosion, ion release, and material degradation of silver dioxide-coated versus uncoated SS orthodontic archwires under multiple simulated oral conditions. Our findings will inform the potential of silver dioxide coatings to enhance the durability and biocompatibility of orthodontic archwires and will guide future in vivo or clinical investigations.