The Angle orthodontist最新文献

Objectives: To evaluate the skeletal and dental effects of Class II correction in growing patients using clear aligners, with either elastics or mandibular advancement (MA).

Materials and methods: The study included 66 growing Class II patients: 45 patients treated with clear aligners (20 using Class II elastics and 25 with MA) and 21 untreated controls observed over a comparable time period. Nine cephalometric and three study cast measurements were evaluated initially (T1) and the end of treatment (T2) to assess skeletal and dental changes.

Results: The control group maintained a Class II molar relationship and overjet, whereas both treatment groups corrected to Class I. In the MA group, statistically significant skeletal changes from T1 to T2 were observed, including reduction in SNA (-1.09°) and ANB (-1.69°), in addition to dentoalveolar Class II correction. The elastic group showed no statistically significant changes in SNA and ANB compared to the control group. Linear regression revealed 5.28° of lower incisor proclination with Class II elastics, whereas lower incisor inclination was maintained with MA treatment.

Conclusions: Clear aligner treatment with Class II elastics and MA were effective for correcting Class II malocclusion in growing patients that would have otherwise been maintained without intervention. Although Class II correction was mainly due to dentoalveolar changes, a skeletal component was observed with MA treatment.

Objectives: To evaluate dentoskeletal effectiveness of deciduous molar anchorage in rapid maxillary expansion (RME) during mixed dentition.

Materials and methods: A comprehensive search was conducted across PubMed, MEDLINE, Scopus, and Cochrane Library databases from January 2000 to March 2025, adhering to PRISMA guidelines. Included studies comprised randomized controlled trials (RCTs) and non-RCTs assessing RME anchored to deciduous molars in patients with mixed dentition. Risk of bias (ROB) was assessed using ROB2 for RCTs and ROBINS-I for non-RCTs. Data were synthesized using a random-effects meta-analysis, focusing on dental and skeletal expansion.

Results: Seventeen studies (six RCTs, 11 retrospective) met the inclusion criteria. A meta-analysis of 12 studies demonstrated significant transverse changes in all evaluated areas: deciduous canines (4.27 mm), deciduous molars (5.51 mm), permanent molars (3.93 mm), and skeletal expansion (2.59 mm). Notably, dental expansion significantly exceeded skeletal expansion. Subgroup analyses comparing Haas and Hyrax expanders revealed no statistically significant differences in dentoskeletal expansion outcomes. However, heterogeneity across studies ranged from moderate to high. ROB assessments indicated moderate risk in all RCTs, whereas non-RCTs ranged from low to serious risk. Funnel plot inspection revealed no substantial asymmetry, suggesting a low likelihood of publication bias.

Conclusions: This meta-analysis confirms that deciduous molar anchorage in RME significantly increases dentoskeletal transverse dimensions. No significant differences emerged between appliance designs (Haas vs Hyrax). Despite consistent expansion effectiveness, variability in study design and ROB must be considered when interpreting these results.

Objectives: To evaluate agreement between the tooth landmark localization patterns of artificial intelligence (AI) and those from human examiners.

Materials and methods: Three-dimensional (3D) digital dental model images were obtained from 284 participants. On a total of 5583 permanent teeth, six landmarks per tooth were manually identified and annotated using custom-made 3D annotation software. To develop an AI model capable of automatically identifying tooth landmarks, a deep-learning algorithm was applied to a training dataset consisting of 4519 teeth. To select the optimal AI model, datasets of 556 and 508 teeth were used as validation and test datasets, respectively. For intraexaminer and interexaminer reliability tests, 280 teeth from 10 participants were randomly selected, and two human examiners identified the same six landmarks on two separate occasions.

Results: The mean error in tooth landmark localization of the AI model ranged from 0.01 mm to 1.68 mm. The intraclass correlation coefficient between the AI model and human examiner for all landmarks was excellent, ranging from 0.97 to 1.0. The landmark localization error from the AI model was smaller than human interexaminer differences for mesial and distal proximal points. However, errors for the cusp tip and facial axis points were greater in the AI model than the interexaminer differences.

Conclusions: AI exhibited localization accuracy for tooth landmarks comparable with that of human examiners for specific measurements related to tooth size. Nonetheless, its accuracy still needs improvement to match that of orthodontic clinicians in identifying cusp tips and facial axis points.

Objectives: To develop and validate a standardized protocol for clear aligner (CA) thickness measurement using a three-dimensional (3D)-printed auxiliary device to improve measurement reliability.

Materials and methods: 24 pairs of digital dental models (D0s) were included and 3D-printed into physical models (P0s), from which CAs were thermoformed using 0.75-mm polymer sheets. Measurement auxiliary devices (MADs) were designed on D0s through measurement point selection, direction determination, electronic gauge mapping, and base shaping, and then 3D-printed. Two operators measured CA thickness (40 points per CA, 48 CAs) using an electronic gauge both directly (direct measurement, D-M) and with MADs (auxiliary measurement, A-M) across three sessions. Measurement precision (repeatability and reproducibility) of D-M and A-M were analyzed using intraclass correlation coefficients (ICCs) and repeated-measures analysis of variance (ANOVA) or Friedman tests. Bland-Altman plots were used to evaluate intersession agreement.

Results: A-M demonstrated superior intersession repeatability with ICC > 0.90 at all points and high intersession agreement with a narrow 95% limit of agreement (LoA) and minimal outliers. Interoperator reproducibility for A-M was also higher, with ICCs above 0.75 at all points, compared to D-M, which showed ICCs below 0.75 at almost all points.

Conclusions: The 3D-printed auxiliary device-based protocol provides a precise and operator-independent method for CA thickness measurement, offering a tool for quality control and providing a foundation for future research on material advancement and design optimization to improve aligner functionality.

Objectives: To compare the profile attractiveness of skeletal Class III patients treated with either a surgery-first approach (SFA) or a conventional surgery approach (CSA), as perceived by surgeons, orthodontists, and laypersons.

Materials and methods: Thirty-four patients were assigned to either the SFA or CSA group retrospectively based on the surgical protocol performed and were evaluated by three distinct groups: oral and maxillofacial surgeons, orthodontists, and laypersons (n = 23 per group). Profile images before (T1) and after orthodontic-surgical treatment (T2) were analyzed using a 5-point Likert scale. Then participants answered the following question: "Which surgical technique was used, CSA or SFA?" Statistical analyses including the Spearman correlation coefficient, the Friedman test, the κ test, independent t-tests, and one-way analysis of variance were conducted to assess correlations and comparisons among evaluator groups (P < .05).

Results: A high and positive correlation (r = 0.86, P < .001) was demonstrated for scores between surgeons and orthodontists, and a low correlation was demonstrated between laypeople and specialists (r = 0.55, P = .01 and r = 0.48, P = .03). No statistically significant relationships were found between esthetic perceptions and the surgical approach regardless of the level of expertise of the evaluators, and it was also not possible to differentiate between the surgical approaches used.

Conclusions: In this study, we indicate that the choice of orthognathic surgical protocol, whether surgery-first or conventional, did not significantly influence the perceived facial profile attractiveness of skeletal Class III patients. These findings support the clinical viability of the SFA protocol, particularly in cases where treatment time or patient preference are factors in decision-making.

In this case report, we present the treatment of a 28-year-old patient with lip incompetence and vertical maxillary excess (VME), using a combination of a midpalatal miniscrew-anchored cantilever clip appliance and submerged buccal shelf miniscrews. The patient exhibited a convex profile, long face, gummy smile, and protrusion, with a Class II skeletal relationship and mentalis strain. The patient declined conventional orthognathic surgery, leading to an orthodontic camouflage treatment plan involving extraction of four first premolars, maximum retraction, and active vertical control with skeletal anchorage devices. Treatment included the use of infrazygomatic crest miniscrews, anterior subapical miniscrews, and a cantilever clip appliance for molar intrusion, resulting in significant improvement in facial profile, reduction of gummy smile, resolution of lip incompetence, and alleviation of mentalis strain. This case demonstrates the effectiveness of a nonsurgical orthodontic intervention in managing a complex case of VME and lip incompetence.

Objectives: To compare the effect of postsurgical orthodontic treatment between using clear aligners (CA) or fixed appliances (FA) on the postsurgical stability of patients with mandibular prognathism in the surgery-first approach (SFA).

Materials and methods: This retrospective study included 54 patients with mandibular prognathism who underwent surgical orthodontic treatment with isolated mandibular setback surgery. The patients were divided into two groups according to the mechanics of postsurgical orthodontic treatment: the CA group included 27 patients treated with clear aligners, and the FA group included 27 patients treated with brackets during postoperative orthodontic treatment. Cone beam computed tomography scans were taken before, immediately after, and at 3, 6, and 12 months postsurgery to assess mandibular relapse. The measurements of postsurgical mandibular relapse including horizontal and vertical positions were compared according to the treatment progress and groups.

Results: Total postsurgical mandibular relapse at pogonion was 3.2 mm in the CA group and 2.2 mm in the FA group. Relapse was higher at 3 months postsurgery in both groups, with an average forward movement of 1.4 mm in the CA group and 1.7 mm in the FA group. Relapse in the CA group showed no significant changes over time, indicating persistence beyond the initial period. In contrast, the FA group showed a significant reduction in relapse by 3 months. Overall, the CA group tended to have greater and more persistent relapse than the FA group.

Conclusions: Careful consideration of skeletal relapse is needed in the postsurgical management of patients treated with clear aligners in SFA treatment.

Objectives: To determine failure rates of orthodontic-surgical treatment for maxillary and mandibular impacted canines and identify patient- and treatment-related risk factors of failure, increased duration, and need for surgical reintervention.

Materials and methods: Panoramic radiographs and clinical records of patients who consecutively visited the Postgraduate Clinic of the Department of Orthodontics of the Aristotle University of Thessaloniki, Greece, were retrospectively retrieved and analyzed. Two statistical analyses were conducted, using canine and patient as units of analysis, respectively, to account for bilaterally impacted canines, resulting in multiple observations per individual. Linear and logistic regression models were employed.

Results: A total of 84 patients with 106 impacted canines were included. An overall failure rate of 11.3% was reported. With canine as the analysis unit, age was the only significant risk factor for failure, while both age and exposure technique were linked to the need for reintervention. In the mixed-effects regression model, age remained the only significant risk factor for both failure and reintervention. Regarding increased duration, an association was detected with increased angulation, proximity to midline, and closed exposure.

Conclusions: Increased age is a significant risk factor for treatment failure and surgical reintervention of impacted canines, while greater angulation, proximity to midline, and closed over open exposure may be associated with prolonged treatment.

Objectives: To examine whether clinical cone-beam computed tomography (CBCT) images can be used to assess three-dimensional bone mineral density (BMD) distribution changes in the alveolar bone (AB), reflecting the biological outcomes of orthodontic treatment in adolescent patients.

Materials and methods: CBCT images of 40 patients (28 females and 12 males; initial mean age = 14.42 ± 1.34 years, range, 11.9-17 years) taken before and after orthodontic treatment with full fixed appliances (treatment duration = 20.50 ± 4.03 months) were collected retrospectively. The AB at maxillary first molar locations (FDI 16 and 26) was digitally isolated using imaging software. A frequency plot of gray values proportional to BMD was developed for each AB region. The mean as well as the fifth percentile low and high gray values (low5 and high5) were computed. Changes in AB morphological parameters and cervical vertebral gray values of the same patient were also compared. A paired test was used to compare the parameters before and after orthodontic treatment.

Results: The gray values of the AB and cervical vertebrae significantly increased after orthodontic treatment (P < .02). Changes in AB parameters before and after orthodontic treatment showed significant but weak positive linear relationships with changes in cervical vertebral parameters (0.12 < r2 < 0.48, P < .04).

Conclusions: Rapid growth and bone mineralization in adolescent patients partially contribute to increased AB BMD following orthodontic treatment. These findings provide baseline information for planning orthodontic treatment specific to adolescents.

Objectives: To evaluate the influence of self-esteem on oral health-related quality of life (OHRQoL) in the occlusal transition from childhood to adolescence.

Materials and methods: This longitudinal observational study involved 785 children, ranging from mixed to permanent dentition, over a 4-year follow-up period. OHRQoL was assessed using the Child Perceptions Questionnaire (CPQ) for two age groups: 8 to 10 years for those in mixed dentition and 11 to 14 years for permanent dentition. Clinical variables related to malocclusion were evaluated using the Dental Aesthetic Index (DAI), and children's self-esteem was measured using the Global Negative Self-Evaluation (GSE). Poisson regression analyses were conducted, with regression models adjusted to estimate relative risks and their respective 95% confidence intervals. A significance level of P < .20 was used for individual analyses, with an overall significance set at 5%.

Results: Individuals with low self-esteem had an 11%, 12%, 21%, and 20% higher risk of reporting a negative impact on OHRQoL in functional limitation, emotional well-being, social well-being, and total OHRQoL, respectively (P < .05).

Conclusions: Self-esteem may contribute to decreased OHRQoL in the transition from childhood to adolescence. The findings suggest that the need for orthodontic treatment does not significantly alter this relationship in childhood and does not affect OHRQoL.