American Journal of Orthodontics and Dentofacial Orthopedics最新文献

Introduction: SmileMate (SmileMate, Dental Monitoring SAS, Paris, France) is an artificial intelligence (AI)-based Web site that uses intraoral photographs to assess patients' dental and orthodontic parameters and provide a report. This study aimed to investigate the ability of an AI assessment tool (SmileMate) for orthodontic and dental parameters.

Methods: A United Kingdom-based prospective clinical study enrolled 35 participants in the study. The participants' occlusal and dental parameters were assessed, and standardized orthodontic photographs were taken and uploaded to the SmileMate Web site to produce an AI-generated assessment. A total of 19 parameters were evaluated: 9 orthodontic parameters and 10 dental parameters covering both soft and hard tissues. A crosstabulation for AI and clinician assessments was reported using Fisher exact tests. Cohen's kappa was calculated to provide an agreement between the gold standard (clinician assessment) and SmileMate (AI assessment). Finally, the sensitivity, specificity, and area under the curve were calculated.

Results: Statistically significant differences between a direct in-person assessment and the SmileMate AI assessment were noted across 9 of the 19 parameters (P <0.05, Fisher exact test). The overall kappa value was fair (0.29), with a variety of agreements between AI and clinician assessments; the level of agreement ranged from poor in 2 parameters (lateral open bite and teeth fracture) to almost perfect for missing and retained teeth. The level of agreement ranged from slight to moderate for the other variables in this study. The overall sensitivity of the AI-generated assessments was 72%, and the specificity was 54%. The specificity of AI was very low for gingivitis and oral hygiene, indicating a very high probability of false-positive findings for those parameters.

Conclusions: The overall agreement between SmileMate and the clinician's assessment was slight to moderate. AI-generated assessments are inadequate for evaluating malocclusion.

Introduction: Four (2 maxillary + 2 mandibular) premolar (4P) and 2 maxillary premolar (U4) extractions are commonly employed for Class II malocclusion with excessive overjet. Although upper lip changes have been widely investigated, lower lip changes remain unclear. The soft-tissue responses after maxillary and mandibular incisor movements in each protocol were investigated.

Methods: A total of 90 pretreatment and posttreatment lateral cephalograms were digitized and allocated to 3 groups (n = 30 each) according to the initial overjet and treatment: normal overjet with 4P (NJ-4P), excessive overjet with 4P (EJ-4P), and excessive overjet with U4 (EJ-U4). The cephalometric parameters were compared, and the lip-to-incisor change ratios (upper lip-maxillary incisor, lower lip-mandibular incisor, and lower lip-maxillary incisor) were determined.

Results: Soft-tissue parameters revealing significant changes among the groups included upper lip and lower lip positions, mentolabial area, and vermilion lip thickness. Significant differences were observed between NJ-4P/EJ-U4 for lower lip-mandibular incisor ratio and between NJ-4P/EJ-U4 and NJ-4P/EJ-4P for lower lip-maxillary incisor ratio but not for upper lip-maxillary incisor ratio.

Conclusions: Reduction in upper lip protrusion was smaller, whereas that in lower lip protrusion was greater after maxillary incisor and mandibular incisor retraction, respectively, in patients with excessive overjet and skeletal Class II malocclusion undergoing the 4P extraction than in those with normal overjet. Moreover, a reduction in lower lip protrusion can be expected with minimal retraction of the mandibular incisors in patients undergoing U4 extraction. The potential impact of the maxillary incisors on the lower lip, especially in excessive overjet malocclusion, should be noted during clinical examination.

Introduction: This study aimed to evaluate the bone mineral density (BMD) and anatomic limitations of miniscrew placement at buccal interradicular sites.

Methods: Virtual miniscrews were placed at the interradicular sites from the canines to the second molars of 139 patients who underwent quantitative computed tomography. Mixed-effects modeling and logistic regression were used to test the differences in BMD and the odds of root proximity, sinus invasion, and bicortical perforation according to sex, growth status, and interradicular site.

Results: No significant interradicular BMD differences were observed between the sexes. Adults had higher interradicular BMDs than adolescents only in the mandible. There were no significant BMD differences among the maxillary interradicular sites, whereas the mandibular interradicular BMD tended to increase from the anterior to the posterior regions. All interradicular bones belonged to the same category according to Misch's classification, and BMD differences of <0.05 g/cc were observed in most sites except between mandibular molars. The interradicular BMD measurements were unavailable for 41.9% and 24.6% of the maxilla and mandible, respectively, mostly because of root proximity. The most anatomically favorable site was between the mandibular premolars, whereas the most unfavorable site was between the maxillary molars. The odds of anatomic limitations were not significantly affected by growth state or sex.

Conclusions: Regarding BMD, all interradicular sites from the canines to the second molars may be adequate candidates for miniscrew placement, regardless of growth state and sex. Anatomic limitations should be carefully considered when placing miniscrews, specifically between the maxillary molars.

Introduction: This study evaluated the esthetic perception of the mandibular anterior teeth during speech by comparing the assessments of laypeople (LP) and orthodontists (ODs).

Methods: A Class I occlusion model was filmed pronouncing "Czechoslovakia" and smiling. Dynamic smile and speech images were extracted and digitally manipulated to create various dental conditions: ideal alignment, mandibular canine extrusion, mandibular incisor crowding, inclined mandibular occlusal plane, mandibular incisor diastema, and mandibular incisor extraction simulation. Forty-eight participants from each group (LP and ODs) evaluated images using visual analog scales. Statistical analysis employed repeated measures analysis of variance with a 5% significance level.

Results: No significant differences appeared between evaluator group means except for the dynamic smile image. Dynamic smile images received the highest scores, followed by aligned and leveled teeth, both showing significant differences (P <0.05) from each other and the remaining images. Inclined occlusal plane and diastema images received the lowest scores. Group evaluations showed distinct patterns: ODs did not significantly differentiate between canine extrusion, crowding, inclined occlusal plane, and diastema images, whereas LP showed no significant differentiation between incisor extraction, canine extrusion, crowding, and diastema images.

Conclusions: Speech images received lower attractiveness ratings than ideal occlusion in both groups. No significant differences appeared between LP and OD evaluations except for the dynamic smile image assessment.

Introduction: This study aimed to assess the anchorage loss in the premolars and anterior teeth during maxillary molar distalization using clear aligners combined with miniscrews, provided that no virtual movement was designed for these teeth.

Methods: A total of 38 maxillary quadrants of 21 participants were analyzed. Digital models were gathered before and after the designed initial movement of the premolars and anterior teeth and superimposed using the palatal rugae area. The predicted, achieved, and unachieved molar distal movements, as well as the linear, anterior, and lateral movements of premolars and actual movement of anterior teeth, were compared and analyzed.

Results: Approximately 0.8 mm of maxillary molar distalization was unachieved. The unachieved distalization of the first and second molars (0.53 ± 0.41 mm and 0.82 ± 0.64 mm, respectively), the lateral and anterior movement of the first (0.14 ± 0.28 mm and 0.32 ± 0.37 mm, respectively) and second (0.25 ± 0.31 mm and 0.29 ± 0.32 mm, respectively) premolars were significantly greater than 0. There were significant positive linear regression relationships between the unachieved distal movement of molars and the anterior movement of premolars, as well as between the unachieved distal movement of molars and the actual movement of the anterior teeth (P <0.05). In addition, significant positive linear regression relationships were found between the anterior movement of the premolars and the actual movement of the anterior teeth.

Conclusions: Significant anterolateral movement tendencies were observed in premolars. Premolar anterior anchorage loss may mediate the interactions between molar distalization and anchorage loss in the anterior teeth.

Introduction: This study aimed to examine and compare the cytotoxic and genotoxic effects of Hawley and Essix removable retainers on tissues.

Methods: A total of 50 patients who had completed fixed orthodontic treatment were randomly assigned to 1 of 2 groups based on the type of retainer they would use for retention: Essix group (n = 25) or Hawley group (n = 25). For biochemical evaluation, saliva samples were collected at 3-time points: before appliance use, 1 month after appliance use (TB1), and 3 months after appliance use. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), nuclear factor erythroid 2-related factor 2, and Kelch-like ECH-related protein 1 (Keap1) were then analyzed. For cytologic evaluation, swab samples were collected before and 14-21 days after the use of the appliance, and the occurrence of micronucleus, pyknosis, karyorrhexis, and karyolysis were analyzed.

Results: Biochemical evaluation revealed that the 8-OHdG level was higher in the Hawley group at TB1 and TB2. Conversely, no significant differences were observed in nuclear factor erythroid 2-related factor 2 levels between the groups. Although no significant difference in Keap1 value was observed between the 2 groups at TB1, a notable elevation in Keap1 levels was evident in the Hawley group at TB2. A cytologic evaluation revealed that the levels of micronuclei, pyknosis, karyorrhexis, and karyolysis were higher in the Essix group at 14-21 days after appliance use.

Conclusions: The application of both appliances was observed to increase the number of findings indicating nuclear degeneration. However, the Hawley retainer increased the 8-OHdG level, whereas the Essix retainer showed a decrease in this 8-OHdG level.