Orthodontics & Craniofacial Research最新文献

Background: Molar bands, essential for orthodontic anchorage, may negatively influence periodontal health. Custom bands are expected to provide better adaptation and supragingival positioning compared with standard bands.

Objectives: The primary objective was to evaluate differences in bleeding on probing (BOP) between custom and standard bands after 12 months. Secondary objectives included comparison of plaque control record (PCR) and probing depth (PPD).

Methods: This retrospective clinical study analysed 60 orthodontic patients treated between May 2023 and February 2025. Participants were divided into two cohorts: custom bands (n = 30) and standard bands (n = 30). PCR, BOP and PPD were measured at baseline, 6 months and 12 months. Data normality was tested with the Shapiro-Wilk; intergroup comparisons used Mann-Whitney or t-test; intragroup changes were analysed with Friedman/ANOVA as appropriate.

Results: At 12 months, BOP increased by 28% in the Standard group versus 16% in the Custom group (between-group difference: -12%, 95% CI: -18 to -6; p = 0.01). PPD increased by 0.5 mm in the Standard group versus 0.2 mm in the Custom group (between-group difference: -0.3 mm, 95% CI -0.5 to -0.1; p = 0.03). No significant differences were observed for PCR (p = 0.47).

Conclusions: Both band types negatively affected periodontal health over time, but Custom bands were associated with reduced bleeding and probing depth. Customised design and supragingival placement may represent a preventive strategy during fixed orthodontic therapy.

Objectives: To validate the third palatal rugae as stable reference landmarks for the superimposition of maxillary digital models in premolar extraction cases.

Materials and methods: Maxillary intraoral scanning digital models of 22 extraction patients, obtained before (T0) and after approximately 4 months of incisor retraction (T1), were superimposed using the automated best-fit of the third palatal rugae and palatine raphe. Voxel-based registration of CBCT scans served as the gold standard. Point-to-point displacements between T0 and T1 of the central incisors and cuspids were calculated for both methods.

Results: The mean differences (mismatch) between methods in the combined vertical and horizontal perspectives of the central incisors were 0.08 mm (right) and 0.12 mm (left), respectively. For the cuspids, the mean 2D differences were 0.02 mm (right) and 0.07 mm (left). The pure horizontal displacement differences of the maxillary central incisors were 0.13 mm (right) and 0.04 mm (left). For the cuspids, the differences were: 0.05 mm (right) and 0.03 mm (left). No statistically significant differences were found between the intraoral-scan and CBCT measurements for either the central incisors or cuspids after maxillary superimpositions. The differences between the two methods were smaller than 0.2 mm in all comparisons.

Conclusions: Digital superimposition of the third palatal rugae of models obtained with intraoral scans is a valid method for the 3D evaluation of the short-term (4-month) dental changes in the anterior region of the maxilla in cases of premolar extraction followed by incisor retraction.

Trial registration: ClinicalTrials.gov: NCT03089996 and NCT05281588.

Objectives: Alveolar bone defects, such as fenestration and dehiscence, induced by orthodontic treatment represent significant complications that can impact treatment outcomes and long-term health. This study aims to develop a machine learning-based predictive model for classifying the risk grade of alveolar bone defects following orthodontic treatment.

Methods: This study utilised a retrospective cohort design, involving 354 patients who had completed orthodontic treatment. Participants were divided into a training set and a validation set in an 8:2 ratio. The outcome indicator was a three-category risk grade (low, medium, high) based on the length of bone defects. From an initial pool of 100 predictor variables, 23 key features were selected using LASSO regression. Five machine learning models were then constructed: Extreme Gradient Boosting (XGBoost), Support Vector Machine (SVM), Multilayer Perceptron (MLP), Multivariate Logistic Regression, and Decision Tree. Model performance was comprehensively evaluated using metrics including accuracy, precision, recall, specificity, F1-score, and the area under the receiver operating characteristic curve (AUC). The best-performing model, XGBoost, was compared with conventional methods and further interpreted using Shapley Additive exPlanations (SHAP) to assess feature importance.

Results: LASSO regression identified 23 critical predictors. Among all models, XGBoost, which ultimately incorporated 20 variables, demonstrated the most superior predictive performance, achieving an accuracy of 0.9429 and an AUC of 0.9955. SHAP analysis indicated that the primary risk factors influencing the model's decisions included the pre-treatment bone defect score, the width of the basal bone arch in the middle maxilla, and the length of the posterior mandible, among others. The XGBoost model demonstrated significantly superior performance compared to conventional evaluation methods.

Conclusion: This study successfully developed an XGBoost machine learning model incorporating 20 variables to predict the risk grade of alveolar bone defects following orthodontic treatment. The model demonstrated excellent predictive performance, significantly outperforming conventional assessment methods and other commonly used machine learning models. Core variables such as the pre score, lower posterior length, and upper mid base width were found to substantially enhance its predictive capability. This model shows potential as a clinical decision-support tool to assist orthodontists in pre-treatment risk assessment and personalised treatment planning.

Objective: This cross-sectional study examined differences in orofacial features and oral health-related quality of life in previously treated young adults with either idiopathic condylar resorption (ICR) or TMJ involvement from juvenile idiopathic arthritis (JIA).

Material and methods: The study included 17 patients with ICR and 15 patients with JIA-related TMJ involvement, all treated at the Section for Orthodontics, Aarhus University Craniofacial Clinic, Denmark and the Department of Oral and Maxillofacial Surgery, Aarhus University Hospital, Denmark. Data compared came from a standardised radiological examination with cone-beam computed tomography, a standardised clinical orofacial examination and a completed oral health-related quality of life questionnaire (OHIP-14). Validated methodologies were used to evaluate TMJ and dentofacial morphology.

Results: The ICR patients reported a markedly higher number of TMJ pain symptoms, affected jaw function and difficulties in chewing food. The ICR group showed significantly more pronounced aberrant dentofacial morphology in relation to mandibular inclination, anterior/posterior face height ratio and mandibular sagittal position. No statistically significant differences were detected in the severity of condylar deformity between ICR and JIA patients. The oral health-related quality of life was significantly more negatively affected in the ICR group compared to the JIA group in the following domains: physical pain, psychological discomfort and psychological disability.

Conclusion: The present study illustrates more severe TMJ signs and symptoms, a greater degree of dentofacial deformity and negatively affected oral health-related quality of life in the ICR group when compared with the JIA group. The same degree of TMJ deformity was found in both groups. Our findings contribute valuable insights towards establishing diagnostic criteria for ICR patients and improving the differential diagnosis of JIA-related TMJ involvement.

Objective: This study aimed to provide age-related osseous measures of the temporomandibular joints (TMJs) and mandibular ramus in asymptomatic children and adolescents and to develop percentile reference data for ramus height.

Material and methods: A retrospective cross-sectional study was conducted on 133 asymptomatic participants (67 males, 66 females; age range 0-19 years) who underwent magnetic resonance imaging of the head, including the TMJs and posterior parts of the mandible. Mandibular ramus height, glenoid fossa depth, articular eminence inclination angle, and condylar dimensions (mediolateral and anteroposterior) were measured. A single observer assessed 266 TMJs, and a second observer repeated measurements for 80 TMJs to evaluate intra- and inter-observer reliability using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Age-related growth curves were estimated using the Box-Cox Cole and Green (BCCG) distribution, modeling median, coefficient of variation, and skewness as cubic spline functions of age. The optimal spline degrees of freedom were selected using the Bayesian information criterion. Percentile curves were derived, and biannual lookup tables were provided.

Results: Ramus height, glenoid fossa depth, articular eminence angle, and condylar width increased with age, whereas condylar depth exhibited variable patterns during adolescence. Intra-observer reliability was excellent for all measurements. Ramus height and condylar width measurements demonstrated excellent inter-observer reliability, while glenoid fossa depth, articular eminence inclination angle, and condylar depth measurements showed good inter-observer reliability.

Conclusion: This study provides age-related osseous measures of the TMJs and mandibular ramus in asymptomatic children and adolescents aged 0-19 years. The percentile curves for mandibular ramus height may aid in assessing growth in children with juvenile idiopathic arthritis for monitoring disease activity and treatment responses.

Objective: To evaluate the impact of seven key facial features on the perceived attractiveness of varying buccal corridor (BC) widths, aiming to inform personalied orthodontic treatment planning for enhanced smile aesthetics.

Methods: A cross-sectional design was employed, using image manipulation software to alter BC widths (10%, 15%, 20%, and 25%) and modify seven key facial features: vertical facial type, upper and lower facial width, interpupillary distance, eye fissure width, ala nasi width and maxillary central incisor (MCI) width. Online questionnaires were used to assess aesthetic preferences for each BC width. Statistical analysis was performed using chi-square tests and multivariable logistic regression.

Results: A total of 511 valid questionnaires were collected, BC widths of 15% and 20% were consistently rated as the most attractive, while extremely narrow or wide BCs were less preferred. Aesthetic suitability varied by age, gender, and facial features: slightly wider BCs were perceived as more harmonious for middle-aged individuals and dolichofacial males, especially when upper facial width was narrow. In contrast, broader ala nasi suited smaller BCs, while variations in interpupillary distance, eye fissure width, and MCI width had limited impact.

Conclusions: Aesthetic preferences for BC are influenced by both demographic and facial soft tissue characteristics. These findings offer clinical guidance for personalised orthodontic treatment planning to enhance smile aesthetics.

Clear aligners are increasingly preferred for their aesthetics and convenience, particularly amongst adults. This systematic review aims to highlight the effect of various materials of aligners on aligner retention. An electronic search was made up to March 2025 using different databases, which include: LILACS, Cochrane, MEDLINE (via PUBMED). Four independent reviewers conducted the study selection, data extraction and risk of bias evaluation. The quality of the included studies was assessed using the JBI tool. Eligibility criteria include peer-reviewed prospective and retrospective clinical studies, including randomised trials, cohort and case-control studies. Results were analysed by evaluating various relevant parameters: retention efficacy, measured via fit, resistance to dislodgement and material adaptation over time. Amongst 343 articles, six were finally selected after full text reading and risk assessment. Literature shows that the retention in aligner therapy is primarily influenced by material properties such as modulus of elasticity, fatigue resistance, and structural behaviour rather than thickness alone. High-modulus materials like TC-85 and BENQ PET offer superior retention and force control, making them ideal for complex tooth movements. Aligner retention is primarily influenced by material properties such as modulus, elasticity, and fatigue resistance, with high-modulus materials like TC-85 and BENQ PET offering the most consistent and effective performance.

Objective: The notion that clear aligners alone can distalize upper molars without affecting anterior teeth is inaccurate. Although strategies such as Class II elastics, tooth-movement sequencing, and attachment variations have been investigated to mitigate unwanted side effects, temporary anchorage devices have demonstrated potential for maintaining anchorage during molar distalization. This study used Finite Element Analysis to evaluate different setups for distalizing one or both upper molars, comparing passive anchorage (ligature tie) and active anchorage (1.66 N), and assessing the presence of vertical attachments.

Materials and methods: Six models were generated with 0.2 mm distal activation for molar distalization. These models varied by premolar/M attachments and anchorage type-active (1.66 N) or passive-applied from extra-alveolar screws to canine buttons.

Results: All setups distalized the second molars, but passive anchorage demonstrated greater efficiency and fewer side effects. Passive systems achieved over 90% distalization-to-anchorage loss ratios, compared with 65% with active forces. Passive setups also minimised unintended anterior movement and enabled distal canine movement following molars-an advantageous outcome. Vertical attachments had minimal impact. X-axis (midline) movement predominantly affected canines, particularly with active anchorage. Anterior intrusion on the Z-axis was reduced with passive systems.

Conclusion: Active anchorage forces may deform aligners and compromise control, whereas passive anchorage-similar to a ligature wire applied to anterior teeth-supports planned movement without disrupting biomechanics.

Objective: This retrospective study aimed to evaluate interproximal contact tightness (ICT) at completion of maxillary canine retraction in first premolar extraction cases treated with In-office Clear Aligner (IOCA).

Materials and methods: The study sample comprised 18 subjects who underwent maxillary first premolar extractions. All cases were treated using a multi-stage intraoral scanning protocol, followed by digital laboratory set-up for the fabrication of IOCA. Recorded data of both virtual and actual stereolithography models at completion of canine retraction were collected. The ICT between the maxillary canine and second premolar was evaluated using (1) virtual residual extraction space (VRS) and (2) actual residual extraction space (ARS). Using superimposed models, canine distalization was assessed through (1) virtual canine distalization (VCD) and (2) actual canine distalization (ACD). All measurements were performed using GOM Inspect Suite. Statistical analysis involved the Wilcoxon signed-rank test and paired t-test.

Results: Interproximal contact tightness of the actual group (median 0.46 mm; 95% CI: 0.41-0.58 mm) demonstrated statistically significant larger residual space than the virtual group (median 0.11 mm; 95% CI: 0.10-0.21 mm). The median difference between ARS and VRS was 0.28 mm (95% CI: 0.26-0.42 mm). The mean VCD was significantly greater (7.41 ± 0.89 mm) than the ACD (7.18 ± 0.97 mm).

Conclusion: The actual interproximal contacts were not completely closed, in contrast to the complete contact predicted by the 3D virtual setup. To prevent this remaining gap, it is recommended to perform fake interproximal stripping or tooth collision during the virtual planning stage.

Objective: To evaluate the effects of Presurgical Infant Orthopaedics (PSIO) using Nasoalveolar Moulding (NAM) on the maxillomandibular complex in growing children with Unilateral Cleft Lip and Palate (UCLP) during the mixed dentition phase.

Methodology: This retrospective Cone Beam Computed Tomography (CBCT)-based study included 40 patients (aged 7-11 years), divided into two groups (n = 20 each): Group 1-UCLP who underwent PSIO using Modified Grayson's NAM technique; and Group 2-UCLP patients who did not receive PSIO. Maxillomandibular craniofacial structures along with the Temporomandibular Joint (TMJ) were evaluated in transverse, sagittal, and vertical planes using linear and angular parameters. Descriptive statistics were calculated, and intergroup comparisons were performed using one-way ANOVA. Post hoc analysis (Bonferroni correction) was conducted for pairwise comparisons to identify specific group differences.

Results: The PSIO group exhibited significantly greater dimensions in Greater Palatine Foramen (p < 0.001), nasal cavity lateral wall (p < 0.001), and Intra Orbital Foramen (IOF) axial measurements (p = 0.002) compared to the no-PSIO group. Mandibular transverse widths were significantly narrower in the PSIO group (p < 0.001). Ramal height was significantly higher on both cleft and non-cleft sides in the PSIO group (p = 0.001 for both). No significant differences were noted in IOF sagittal dimension (p = 0.189), palatal plane sagittal length (p = 0.061), palatal height (p = 0.789), mandibular length (p = 0.714), TMJ parameters (p > 0.2), or ANB angle (p = 0.712).

Conclusion: In growing children with UCLP, PSIO using the Modified Grayson's NAM technique was associated with craniofacial development by influencing vertical, transverse, and sagittal dimensions. These early findings highlight the need for long-term studies to further evaluate developmental outcomes over time.