American Journal of Orthodontics and Dentofacial Orthopedics最新文献

Introduction: This study aimed to assess whether sagittal maxillary-mandibular skeletal relationships influence perceived facial esthetics in patients with varying sagittal skeletal discrepancies.

Methods: We analyzed 3-dimensional facial models from cone-beam computed tomography scans of 40 patients (17 males and 23 females aged 14-48 years; ANB = 0°-10°), lacking skin color or hair, to isolate shape. A total of 100 laypeople rated these for esthetics and sexual dimorphism using visual analogue scales. Procrustes-based 3-dimensional geometric morphometrics quantified shape, and multivariate linear regression estimated vectors for visual analogue scales ratings. Linear regression tested correlations between shapes linked to the ANB angle and esthetics.

Results: Perceived attractiveness was unrelated to age, asymmetry, or deviation from the population average shape. Esthetics correlated with lower facial third shape (r² = 0.473, P = 0.058, 4.5% variation), particularly with anterior or inferior gnathion and pogonion displacement, with consistent patterns across sexes (r_v = 69.2°, P <0.0001). Shapes associated with higher ANB angles (indicating convexity) showed a negative association with attractiveness (r² = 0.494, P <0.001). Sexual dimorphism was linked to cheek placement, facial roundness, and nasal tip position (r² = 0.558, P = 0.001, 9.0% variation).

Conclusions: Sagittal maxillary-mandibular relationships, as measured by the ANB angle and sagittal skeletal discrepancy, modestly influence facial esthetics, with straighter profiles and prominent chins rated more attractive. These findings suggest a partial biological basis for esthetic preferences, though individual and cultural factors, including smile esthetics and dental symmetry, also play a role. The study informs orthodontic treatment planning by highlighting the esthetic impact of jaw alignment.

Introduction: The objective of this study was to systematically evaluate cortical bone remodeling and mandibular incisor movement during presurgical orthodontic decompensation in patients with severe skeletal Class III malocclusion and explore more suitable indicators for determining the decompensation range.

Methods: Cone-beam computed tomography images of 46 patients with severe skeletal Class III malocclusion who underwent presurgical orthodontic treatment were analyzed. Vertical bone loss (sagittal view) was measured, and cortical bone remodeling and mandibular tooth movement (coronal view) were assessed at the crestal, midroot, and apical levels. Patients were grouped by their degree of alveolar bone deterioration. Mandibular incisor inclination angle (the angle between the long axis of the mandibular central incisor [MCI] and the long axis of the mandibular symphysis) and incisor mandibular plane angle (the angle between the long axis of the MCI and the mandibular plane) were compared between groups using t tests.

Results: MCIs exhibited tipping movement, with prominently increased lingual alveolar bone defects after decompensation. The mean mandibular incisor inclination angles were as follows: (1) pretreatment was 4.45° for group 1 (with better alveolar bone conditions) and 2.99° for group 2 (with worse alveolar bone conditions) (P = 0.252), and (2) posttreatment (after decompensation) was 10.91° for group 1 and 19.31° for group 2 (P <0.001). The mean incisor mandibular plane angles were as follows: (1) pretreatment was 77.63° for group 1 and 71.64° for group 2 (P <0.05), and (2) posttreatment was 85.95° for group 1 and 84.84° for group 2 (P = 0.624).

Conclusions: Instead of decompensating until the mandibular incisors are nearly upright relative to the mandibular plane, the relationship with the mandibular symphysis should be prioritized for healthier considerations.

Introduction: Miniscrew-assisted rapid palatal expansion (MARPE) is a predictable option for nongrowing patients with maxillary transverse deficiency manifesting as posterior crossbite. However, recent evidence suggests a high frequency of asymmetrical expansion as a complication of MARPE.

Methods: Retrospective analysis of 9 patients (mean age: 21.7 years; 65% female; average Yonsei Transverse Index: -4.6 mm) included superimposition of pre (T1) and posttreatment (T2) cone-beam computed tomographies using a voxel-based technique on the anterior cranial base. T1 and T2 cone-beam computed tomographies were digitized in a common Cartesian plane, enabling linear and angular measurements using T1 landmarks as the reference to compare T2 landmarks. Geometric analyses included linear Euclidean left vs right and transverse distances, 3-dimensional (3D) angulation, and 3D matrix rotations to quantify asymmetry. Asymmetry thresholds were set at 2 mm or 2°. Stepwise regression was used to determine the association between potential explanatory variables and asymmetry.

Results: There was no statistically or clinically significant asymmetry of the ANS-PNS vector. Linear, angular, or zygomaticomaxillary roll of jugale, keyridge, or zygomaticofrontal suture around the ANS-PNS vector was found (P >0.05). Statistically but not clinically significant linear asymmetry of keyridge (0.9 ± 0.9 mm; P = 0.02) and first molar furcation (0.7 ± 0.8 mm; P = 0.02) was found. Stepwise regression did not find any potential explanatory variables explaining the keyridge and the first molar furcation linear asymmetry.

Conclusions: Under the conditions of this study and 3D analyses, MARPE resulted in statistically significant linear asymmetry of the keyridge and the first molar furcation. Statistical significance does not equate clinical significance or relevance.

Introduction: Improvement in facial and dental esthetics is a motivator for orthodontic treatment. An update in the preferences of clinicians and patients is necessary because beauty standards are constantly evolving and extraction and nonextraction decisions impact soft tissue and incisor position. This study aimed to update facial profile and incisor inclination preferences among orthodontists (ORs), general dentists (GPs), and laypeople (LPs) and correlate these preferences with objective soft tissue and incisor changes.

Methods: This retrospective study used discriminant analysis to identify 30 borderline patients with Class I and mild Class II treated with extractions and 30 treated with nonextraction. Assessment of profile and incisor inclination was performed by 90 LPs, 40 ORs, and 40 GPs using a 200 mm visual analog scale and rankings on a web-based survey. The degree of preference between the profile esthetics and incisor inclination was compared using the Cohen d value for standardized mean difference.

Results: Survey results indicated ORs' preference for extraction profiles (mean difference = 5.52 mm; 95% confidence interval = 1.64-9.40), GPs' preference for nonextraction profiles (mean difference = 3.67 mm; 95% confidence interval = 0.43-6.92), and all groups showing a stronger preference for more upright incisors. LPs' preferences are more aligned with GPs.

Conclusions: GPs preferred protrusive lips and acute nasolabial angles (typical in nonextraction treatment), while strongly preferring upright incisors (typical in extraction treatment). These discrepancies in preferences highlight the importance of communication of treatment objectives and expectations among ORs, LPs, and GPs.

Introduction: Patients in the orthognathic surgery process frequently turn to social media to obtain information and share their experiences. Accordingly, the present study analyzed YouTube comments to evaluate patient satisfaction, emotional tendencies, and social interactions, aiming to draw implications for improving communication and psychological support strategies.

Methods: A total of 250,582 comments from 8044 YouTube videos on orthognathic surgery were collected using Mozdeh (University of Wolverhampton, Wolverhampton, UK) and R software (version 4.2.2, Posit, PBC, Boston, Mass). After preprocessing, 111,953 comments remained. Sentiment analysis (AFFIN/NRC lexicons), structural topic modeling, and manual thematic analysis (10% sample) were performed. Gender-based discourse differences were examined using Chi-square tests with Benjamini-Hochberg correction.

Results: Ten main themes were identified through structural topic modeling and thematic analyses. Positive emotions were mostly expressed, though fear and negativity were also observed. Esthetic and emotional expressions were used more often by women, whereas cost-related terms were used more often by men. Thematic qualitative analyses revealed that YouTube videos and comments were perceived by patients as a source of psychological support, whereas certain misleading content was also found to have the potential to misguide patients during the treatment process.

Conclusions: This study has transcended the limited scope of traditional surveys, which are confined to specific time periods and small sample sizes, by making it possible to access patient experiences shared on the YouTube platform without temporal or spatial constraints. The analyses revealed prevalent misconceptions on social media and assessed patients' expectations, concerns, and psychological states. The findings serve as a practical guide for healthcare professionals in developing patient-centered communication and care strategies.

Introduction: Mental health is a key component of overall well-being. Adolescents often experience gradual changes in their mental health, which can go unnoticed and undiagnosed. The aims of this study were as follows: (1) to assess the feasibility of implementing mental health screening for adolescent patients in the orthodontic setting and (2) to examine the difference between guardian and patient responses.

Methods: The Pediatric Symptom Checklist (PSC), a questionnaire used to identify emotional and behavioral issues, was employed as a screening tool in the orthodontic setting. Participants included children aged 12-17 years and their legal guardians. Measures of feasibility included the following: survey acceptance rate, survey completion rate and duration, and patient and guardian responses to questions related to the importance of screening and willingness to participate again. Analysis of overall and subscale checklist scores, as well as concordance between patient and guardian responses, was used to assess the difference in checklist responses.

Results: A total of 100 orthodontic patients and their legal guardians completed a modified version of the PSC in an average of 3-4 minutes. Overall, 14% patients had scores ≥15, indicating significant problems with emotion and behavior, compared with just 2% guardians. There was a significant difference between the mean PSC score for participants (8.22) and guardians (5.45) (P <0.01). Concordance of responses between participant and guardian was low to moderate for many factors on the PSC.

Conclusions: Screening for mental health in the orthodontic setting is easily implemented and can help identify patients who require additional support and intervention.

Introduction: This study aimed to analyze 3-dimensional (3D) tooth movement patterns during mandibular molar intrusion using finite element analysis, with a particular focus on the effects of temporary skeletal anchorage devices positioning and archwire constriction bend (ACB).

Methods: A 3D finite element model of the mandibular dentition was constructed. Intrusive forces of 2.0 N were applied to the archwire either mesial (M6 model) or distal (D6 model) to the first molar, whereas bilateral forces of 1.0 N were applied in the MD6 model. An ACB force of 1.0 N was applied lingually to both ends of the archwire. Tooth displacement, angulation change, and occlusal plane rotation were evaluated in 3 dimensions after 100 cycles of bone remodeling simulation, both with and without ACB during molar intrusion.

Results: Mandibular molars exhibited intrusion accompanied by mesial tipping in the M6 model, distal tipping in the D6 model, and minimal tipping in the MD6 model, regardless of the presence or absence of ACB. The mandibular central incisor (Mn1) demonstrated labioversion in the M6 model and linguoversion in both the D6 and MD6 models without ACB. With ACB applied, Mn1 consistently showed labioversion across all models, with the greatest intrusion and labioversion observed in the M6 model. The occlusal plane angle (OPA) rotated counterclockwise in all models except the M6 model with ACB, which exhibited a slight clockwise rotation. Mandibular posterior teeth showed buccal tipping in all models except the M6 model with ACB, where molars tipped lingually. ACB application reduced buccal tipping of the mandibular posterior teeth and mitigated counterclockwise rotation of the OPA, while promoting intrusion and labioversion of Mn1. Notably, OPA remained nearly stable during molar intrusion in the M6 model with ACB.

Conclusions: The appropriate force direction for mandibular molar intrusion, combined with ACB, facilitates controlled 3D tooth movement patterns.