The Angle orthodontist最新文献

Objectives: To evaluate the influence of personalized aligner replacement, with or without physical methods of acceleration using low-frequency vibration combined with a low-level laser, on the tooth movement rate and accuracy of clear aligners.

Materials and methods: Forty participants were randomly allocated to three groups. Fourteen participants used the standard replacement protocol in Group A, Group B included 14 participants using a personalized replacement protocol, and 12 participants in Group C followed the personalized replacement protocol and used a physical device that combined low-frequency vibration and low-level laser. Aligner replacement cycles of the first 12 steps were recorded, and GOM inspect suite software 2022 (GOM; Braunschweig, Germany) was used to evaluate maxillary molar movement accuracy using digital models collected before treatment and at the end of the 12th step.

Results: No significant difference was found in the accuracy of maxillary molar movement between Groups A and B, but the tooth movement rate in Group B was significantly greater. The accuracy of maxillary molar movement was similar in Groups B and C, and the tooth movement rate in Group C was significantly increased.

Conclusions: The personalized replacement protocol decreased the number of aligner replacement cycles without impacting the accuracy of tooth movement. With personalized replacement, a physical method of acceleration combining low-level laser and low-frequency vibration significantly accelerated orthodontic tooth movement and had little influence on the accuracy of tooth movement.

Objectives: To compare mandibular incisor root length (RL) and root volume (RV) changes after 6 months of wearing either a removable anterior bite plane (RABP) during meals (F + M) or not during meals (F - M). Additionally, changes in incisal maximum bite force (IMBF) and their correlation with RL and RV changes were assessed.

Materials and methods: Thirty-six children with deep bite using RABPs full time were randomly assigned in equal numbers to either the F + M group or F - M group. Cone-beam computed tomographic radiographs and IMBF were recorded at baseline (CT0) and after 6 months (CT1). Within and between group comparisons of RL and RV were performed (P = .05) with Bonferroni correction applied for segmental RV differences (P = .008). Relationships between IMBF changes and RL and RV changes were analyzed (P = .05).

Results: Both groups showed significant reductions in RL and RV. RL decrease in the F + M group (0.25 ± 0.14 mm) was significantly greater than in the F - M group (0.21 ± 0.14 mm). Reduction in RV was not significantly different between the groups, but IMBF significantly increased in both groups. Significant correlations were observed between IMBF changes and RL (r = 0.56) and RV (r = 0.86) changes.

Conclusions: Deep bite correction using RABPs for 6 months with F + M protocol resulted in a greater decrease in mandibular incisor RL compared to the F - M protocol. However, RV changes were comparable between protocols. IMBF may influence the degree of RL and RV changes.

This case report describes correction of maxillary constriction using a maxillary skeletal expander (MSE) in a 15-year-old female with a skeletal Class III pattern and asymmetry. The maxillary expansion device with four mini-implants was used to correct the constricted maxilla, bilateral crossbite of the posterior teeth, and crowding of the dentition. Comparison of cone-beam computed tomography scans before and after treatment showed that the majority of maxillary expansion was orthopedic, with minimal alveolar bone bending and tooth tipping. Fixed appliances were used to correct the crowding and malocclusion. Stable and satisfactory maxillary expansion was obtained by using MSE non-urgically.

Objectives: To assess case outcomes using the American Board of Orthodontics (ABO) Objective Grading System (OGS) in patients treated with lower incisor extraction.

Materials and methods: Discrepancy indices (DI) were used to stratify patients into mild, moderate, and complex categories and overjet, overbite, and buccal occlusion were examined. Nineteen subjects were included in the study, among which 52.6% were females.

Results: The average (SD) age was 28.5 (15.1) years, and the average (SD) DI was 15.2 (8.6) with an even distribution of mild, moderate, and complex cases. The mean post-treatment OGS was 31, with 52.6% of the patients achieving passing ABO clinical scores. 31.6% achieved normal post-treatment overjet. A total of 52.6% achieved normal post-treatment overbite, and 84.2% achieved normal post-treatment buccal occlusion.

Conclusions: An increase in overbite and overjet, and a decrease in buccal occlusion measurement, were found after lower incisor extraction treatment. The ABO-OGS scores obtained were high, indicating that they may not pass the ABO criteria established.

Objectives: To evaluate the effects of rs1799750 1G/2G polymorphism of the MMP1 gene and rs1800470 T/C polymorphism of the TGF-ß1 gene on temporomandibular disk displacement and vertical facial development.

Materials and methods: Sixty-six individuals were examined radiographically prior to evaluation of the signs/symptoms of temporomandibular disorders according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Class II, hyperdivergent individuals with TMD (+) were assigned to Group 1, and individuals with TMD (-) were included in Group 2; while Class I, normodivergent individuals with TMD (-) were included in Group 3. For genetic analysis, oral mucosa swab samples were collected, and genotype analysis was performed.

Results: The incidence of 2G alleles in Group 2 (72.7%) was significantly higher than the other groups (P < .05). ANB angle and mean Wits of the 1G/1G genotype of the MMP1 gene were significantly lower than 1G/2G and 2G/2G. Mean Go-Gn of the 1G/1G genotype was significantly higher than that of 1G/2G. The mean SNB of the TGF-β1 TT genotype was significantly higher than TC. The mean Co-Gn of TT was significantly higher than CC.

Conclusions: A relationship was found between the 2G allele of rs1799750 1G/2G polymorphisms of the MMP1 gene and the risk of individuals developing disk displacement. Also, it was found that TGF-ß1 gene rs1800470 29 T/C polymorphisms had a detrimental effect on mandibular development.

Objectives: To evaluate the perception of orthodontists and laypeople of facial attractiveness during aging in participants with acceptable, untreated occlusion.

Materials and methods: Frontal and profile facial photographs of 24 participants (13 male, 11 female) with acceptable, untreated occlusion, taken during adolescence (mean age = 13.3 years) and late adulthood (mean age = 61.2 years) were used. Groups of 30 orthodontists and 30 laypeople scored the facial attractiveness using a scale from 1 (unattractive face) to 10 (very attractive face). Raters indicated the apparent age at T2 and the most and least pleasing facial structures. Three-way analysis of variance was used to assess the influence of sex, age, and rater group on facial attractiveness. Mann-Whitney test was used to compare males and females regarding the apparent age perceived by raters at late adulthood (P < .05).

Results: Mature age was judged with lower scores on facial attractiveness (mean = 5.43) by both groups compared with adolescence (mean = 6.51). Facial attractiveness was not affected by sex. At late adulthood, females were considered younger by both groups of raters, while men were perceived more similar to their actual age. Laypeople were slightly more critical than orthodontists in the assessment of facial attractiveness. Thirty percent of the raters indicated the eyes as the most pleasant region and the chin and nose as the least pleasing structures.

Conclusions: Facial attractiveness slightly decreased from adolescent to mature ages. Women appeared younger than their actual age at late adulthood.

Objectives: To evaluate changes in the width of five circummaxillary sutures after miniscrew-assisted maxillary protraction (MAMP) and to identify which of them are most significantly affected.

Materials and methods: Cone-beam computed tomography (CBCT) performed before and after MAMP treatment was used to assess the sutural and cephalometric changes in growing patients with skeletal Class III malocclusion (n = 17). CBCT-generated lateral cephalograms were analyzed for skeletal and dental changes. Width changes in the five circummaxillary sutures (frontomaxillary, pterygomaxillary, zygomaticofrontal, zygomaticomaxillary, and zygomaticotemporal) were measured before and after MAMP. Suture widths were measured using ImageJ software on CBCT images. The pre- and post-MAMP mean values of the bilateral width changes were compared. The magnitude of the width changes of the five circummaxillary sutures were ranked to identify the most substantially altered sutures. Statistical significance was determined using the Friedman test.

Results: In the CBCT-generated lateral cephalometric analysis, statistically significant increases were observed in SNA and ANB values, with the most pronounced results seen in overjet (P < 0.05). After MAMP, all five circummaxillary sutures demonstrated a statistically significant increase in width. The zygomaticofrontal, pterygomaxillary, and zygomaticotemporal sutures exhibited significant changes, with the zygomaticofrontal suture showing the greatest increase in width.

Conclusions: Among patients with Class III malocclusion treated with MAMP, the most pronounced width increase was observed in the zygomaticofrontal suture, whereas the frontomaxillary suture exhibited the least change.