The Angle orthodontist最新文献

Objectives: To compare the treatment effects of pushing or pulling force mechanics applied to bimaxillary miniplates with those of deferred treatment control patients to evaluate mandibular skeletal growth changes in growing patients with skeletal Class II malocclusion due to mandibular deficiency.

Materials and methods: Thirty-nine patients (24 males, 15 females; mean age = 11.59 ± 0.56 years) were equally and randomly assigned to one of three groups: Group A, skeletally anchored fixed-functional appliance (pushing mechanics); Group B, skeletally anchored Class II spring (pulling mechanics); and Group C, deferred treatment skeletal Class II control patients. Pretreatment and posttreatment cone-beam computed tomography scans were used for assessment of measurements (time interval: 11.52 ± 0.32, 11.53 ± 0.31, and 9.63 ± 0.22 months for groups A, B, and C, respectively).

Results: Relative to the control group, both intervention groups showed significant increases in effective mandibular length (Co-Gn), with mean differences of 5.08 ± 2.25 mm in Group A, and 3.83 ± 2.79 mm in Group B. A significant improvement in the sagittal relationship was observed in both groups, with reductions in ANB angle by 4.31° in Group A, and 5.5° in Group B. The mandibular plane angle was increased significantly in Group B by 1.83 ± 0.72°.

Conclusion: Mandibular growth was enhanced using either pushing or pulling skeletally anchored force mechanics. The use of pulling force mechanics, specifically, was associated with increases in lower facial height.

Objectives: To assess and compare the accuracy of infrazygomatic crest screws (IZC) placed with and without a dynamic navigation system.

Materials and methods: Preoperative cone-beam computed tomography (CBCT) and intraoral scan of the maxillary arch were obtained for 12 patients requiring therapeutic first premolar extraction after leveling and alignment. Virtual planning of the final IZC screw position on both sides was done using Evalunav software. Maxillary left and right arches for each patient were randomized into experimental and control sides. A 12 × 2 mm dimension IZC screw was positioned with and without use of a dynamic navigation system randomly on either side. A postoperative CBCT was taken immediately to assess the final screw position. Preoperative and postoperative CBCTs were compared for deviation in the entry point, apical point, and angular point for experimental and control sides. Mean value deviations obtained were subjected to statistical analysis using SPSS 20.0 to describe the data.

Results: Paired t-tests were used to analyze the comparisons. Dynamic navigation showed a statistically significant difference in entry point and angular point compared to the freehand approach during implant placement.

Conclusions: IZC screws implanted with the dynamic navigation system offered better control with less deviation and greater accuracy in all three planes of space. However, further studies are necessary to determine the stability and anchor value of implants placed with a dynamic navigation system.

Severe vertical maxillary excess (VME) is a skeletal abnormality that typically requires orthognathic surgery for correction. Nonsurgical orthodontic treatment has been a fascinating but challenging alternative, especially when adverse anatomic factors hamper or pose risks for intrusive tooth movement. Despite well-documented efficiency of temporary anchorage device (TAD)-aided nonsurgical treatment for VME, evidence is scarce regarding the treatment efficacy and safety for cases with adverse anatomic traits. In this case report, we present nonsurgical treatment of a patient with severe VME, maxillary protrusion, and retrognathism. Additional challenges included compromised periodontal health, low maxillary sinus floor, short roots with axes deviating from the center of basal bone, and thin labial cortical bone with partial deficiencies. With anchorage from a transpalatal arch (TPA) and TADs and elaborate biomechanical control strategies, significant maxillary full-arch intrusion and anterior retraction with adequate root torque control were achieved, resulting in counterclockwise mandibular rotation and notable profile improvement. One-year follow-up showed stable treatment results. This case provided evidence on how balance may be achieved between treatment efficacy and anatomical limitations using biomechanical control strategies.

Objectives: To investigate the prevalence of bullying in schoolchildren and its relationship with malocclusion, accounting for demographic and psychosocial factors.

Materials and methods: This was a cross-sectional study on 10-14-year-old schoolchildren in the United Kingdom. Clinical examination was undertaken measuring Index of Orthodontic Treatment Need (IOTN), overjet, overbite, and crowding or spacing. Questionnaires were used to measure bullying, oral health-related quality of life (OHRQoL), self-esteem (SE), loneliness, and behavioral and emotional difficulties.

Results: Of 698 participants, 68 reported being bullied (9.7%). No difference was found in prevalence for gender, ethnicity, or age. Increased prevalence was found in participants with overjet > 6 mm (P = .02) and great need for treatment (IOTN Dental Health Component 5 P < .001, Aesthetic Component 9-10 P = .008). Bullied participants reported lower OHRQoL (P < .001) and SE (P < .001) and higher levels of loneliness (P < .001), emotional symptoms (P < .001), conduct problems (P = .002), and peer problems (P < .001). Multivariate analysis showed that being bullied was related to higher levels of loneliness (P = .007), poor peer relations (P < .001), and increased overjet (P = .032).

Conclusions: Accounting for psychosocial factors, risk of being a victim of bullying was related to malocclusion, specifically an increased overjet.

Objectives: To compare the accuracy and time required for orthodontic miniscrew placement using a dynamic computer-assisted surgery (d-CAS) system vs the conventional freehand (FH) approach. The effect of side, location, and operator experience was also evaluated.

Materials and methods: A randomized, in vitro experimental study was conducted using 10 maxillary resin models. After virtual planning, 40 miniscrews were randomly placed by one experienced and one novice operator. Twenty miniscrews were placed using a d-CAS system (test group) and 20 using the conventional FH method (control group). Preoperative and postoperative cone beam computed tomography scans were superimposed to measure deviations between the planned and final miniscrew position, and placement time was recorded.

Results: The d-CAS group showed less deviation at the entry point (95% confidence interval [CI] = 1.79 mm to 0.16 mm; P = .019) and less angle deviation (95% CI = 8.5° to 1.7°; P = .004). No significant differences were observed in other variables. Both operators achieved similar accuracy. Placement time was significantly longer in the d-CAS group, with a mean difference of 6.3 minutes (P < .001).

Conclusions: Dynamic computer-assisted surgery improves the accuracy of orthodontic miniscrew placement vs the traditional FH method. However, d-CAS takes significantly longer. Clinician experience does not seem to significantly affect accuracy.

Objectives: To provide a comprehensive critique of the diagnosis of root resorption using panoramic and periapical radiography, including discussion of the various methods of measurement, severity spectrum, and to shed light on a significant factor predisposing to resorption: treatment duration.

Materials and methods: The articles reviewed involved human subjects undergoing buccal fixed orthodontic treatment, diagnosed by panoramic or intraoral radiographs at the beginning and end of treatment. Treatment duration and external apical root resorption (EARR) had to be recorded to be included in the study. Relevant sources were searched using various platforms including PubMed, Scopus, and WoS. All sources of evidence, regardless of language, were included in the study.

Results: The search strategy yielded 704 studies; screening by title and abstract yielded 389 articles for full-text review. Forty studies were finally included and categorized according to the type of radiograph used to diagnose EARR: authors of 18 studies used panoramic radiographs, and authors of 22 studies used intraoral radiographs.

Conclusions: In this study, we revealed a lack of agreement among authors concerning the diagnosis and measurement methods of external apical root resorption, resulting in inconsistencies in the results. Additionally, patient- and treatment-related factors, including treatment duration, were found to be inconsistently associated with the development of EARR. Standardization of diagnostic protocols and refinement of measurement techniques are essential to improve the accuracy of orthodontic care.

Objectives: To assess mandibular lingual bone thickness changes after molar distalization with microimplants and during retention.

Materials and methods: Twenty-one patients (10 men, 11 women; mean age: 20.5 ± 4.9 years) who underwent mandibular molar distalization with microimplants were included. Cone-beam computed tomography images at pretreatment (T0), posttreatment (T1), and retention (T2) were used to measure posterior space available and lingual bone thickness distal to the mandibular second molar at 0-, 2-, 4-, and 6-mm levels apical to the root furcation. Repeated measures analysis of variance with Bonferroni correction was applied to compare T0, T1, and T2 measurements. Pearson's correlation analysis assessed the relationship between lingual bone thickness change and other variables.

Results: The mandibular second molar moved distally by 3.0 mm at crown level, and 1.2-1.8 mm at root level, after treatment. Posterior space available decreased significantly with root-cortex contact or radiographic lingual bone dehiscence observed at 6-mm root level. After retention, reduced cortical bone thickness increased significantly; however, T2 lingual bone thickness was less than T0. Although the decrease in lingual bone thickness at 6-mm root level correlated with crown and root distal movement after treatment, the increase in bone thickness during retention was not associated with tooth movement, patient age, or retention duration.

Conclusions: Mandibular lingual bone thickness noticeably decreased after molar distalization with microimplants. After retention, significant bone recovery formation was observed at the thinned lingual cortex or radiographic bone dehiscence.

Objectives: To investigate transverse treatment outcomes in patients with skeletal Class III malocclusion treated with a surgery-first orthognathic approach (SFA) vs conventional orthognathic surgery (COS).

Materials and methods: This retrospective cohort study included 128 patients, divided into four groups of 32 based on the inclusion of presurgical treatment and extraction of the maxillary premolars: (1) COS with extraction, (2) COS without extraction, (3) SFA with extraction, and (4) SFA without extraction. CBCT scans were taken before and after treatment, with an additional scan after presurgical orthodontic treatment for the COS group only. The primary outcome variable was transverse decompensation, assessed through changes in maxillary and mandibular molar inclination and intermolar width. Predictor variables included treatment approach (SFA vs COS) and extraction status (extraction vs nonextraction). Transverse measurements were compared among the four groups throughout the treatment process.

Results: Maxillary molar inclination relative to the occlusal plane increased after treatment, whereas the mandibular molar inclination decreased after treatment, indicating transverse decompensation in the COS and SFA groups, and the extraction and nonextraction groups. There were no statistically significant differences in transverse changes between the COS and SFA groups.

Conclusions: Although the difference in transverse decompensation between the COS and SFA groups was not statistically significant, clinicians may still need to consider careful management of transverse decompensation during postsurgical treatment, particularly in SFA cases.

Objectives: To compare efficacy and treatment duration of early versus late Class II elastics in patients with Class II malocclusion.

Material and methods: Forty patients were randomized into two groups based on the timing of elastics use: early and late. In the early group, light short elastics were used from the day of placement of fixed preadjusted edgewise appliances. In the late group, elastics were inserted once 0.016 × 0.022-inch stainless steel archwires were in place. Lateral cephalograms and standardized smile photographs were taken before treatment and after achieving a Class I buccal segment relationship. Treatment duration, dental, skeletal, and soft tissue measurements were then compared between the two groups.

Results: Maxillary central incisors were retroclined relative to the SN plane (95% confidence interval (CI): 3.75°-11.99° and 3.96°-9.18° in the early and late groups, respectively) with clockwise rotation of the occlusal plane (95% CI: 3.75°-11.99° and 3.96°-9.18° in the early and late groups, respectively). Treatment duration to level and align and reach Class I buccal occlusion was significantly less in the early group (95% CI: 4.74-10.8 months). Comparison between groups revealed no significant differences for all measurements except MP/SN and PP/SN angles (P < .05).

Conclusions: Class II elastics were equally effective and more efficient in the early group with significantly less time needed to level and align and reach Class I buccal occlusion compared to the late group.

Objectives: To evaluate the accuracy of three fully automated software systems compared to nonautomated cephalometric analysis software tested using cephalograms featuring correct and incorrect head positions.

Materials and methods: The study sample consisted of 40 lateral cephalograms retrieved retrospectively from a larger pool of pretreatment orthodontic records. Cephalograms were recruited and divided into correct head posture group (CHP) and incorrect head posture group (IHP). Cephalometric data were obtained by manual landmarking (Dolphin software), which served as a reference, and by fully automated AI software (WebCeph, Ceph Assistant, and AudaxCeph). Intraclass correlation coefficients (ICC) and paired t-tests were used for intragroup comparisons, whereas analysis of variance and post-hoc analysis were used to compare performance among artificial intelligence (AI) based software applications.

Results: The tested software exhibited a good level of consistency for angular measurements whereas linear measurements were more error-prone. AudaxCeph demonstrated the most consistent accuracy, achieving excellent agreement (ICC > 0.90) for several skeletal parameters; however, it failed in detecting soft tissue accurately. WebCeph and Ceph Assistant showed greater variability, especially for linear measurements (ICC < 0.50). Positional errors drastically reduced measurement accuracy, with linear parameters such as Go-Me showing the poorest agreement across all software.

Conclusions: AI-based cephalometric software demonstrated variable accuracy depending on the cephalometric measurement, and this pattern was exacerbated under conditions involving positional errors in cephalograms. Accordingly, oversight by expert clinicians is still required to minimize marginal error.