Orthodontics & Craniofacial Research最新文献

Objective: To evaluate the related factors for alveolar bone changes surrounding maxillary central incisors in extraction cases with clear aligner therapy, including tooth displacement and movement pattern.

Materials and methods: A total of 94 patients were included. Pre-treatment (T0) and post treatment (T1) cone beam computed tomography was obtained to calculate tooth displacement and labial bone thickness (LBT), palatal bone thickness (PBT), labial bone height (LBH) and palatal bone height (PBH) at different root levels. Paired-t test and Wilcoxon signed-rank test were performed to compare tooth movement and bone changes between T0 and T1. The two-sided Welch's t-test and Mann-Whitney U test were applied for comparison between movement patterns. Multiple linear regression with backward elimination was used to investigate possible factors related to bone changes.

Results: Defect of palatal bone was significant, while labial bone basically maintained. Different bone dimensional changes were found between uncontrolled tipping and controlled tipping. Tooth retraction was associated with the decrease of PBT and the increase of LBT. Crown retraction was a dominant factor related to the reduction of PBH. Incisor intrusion resulted in the increase of PBT, the decrease of LBT and the bone defect of both LBH and PBH. Root distal movement was associated with the resorption of LBT and LBH. Lingual inclination was evidently related to LBT loss.

Conclusion: Three-dimensional tooth displacements and movement pattern acted as risk factors for maxillary anterior bone changes after retraction. Treatment planning deign should be aware of predicted tooth movement, preventing alveolar bone defect.

Trial registration: Clinical Study Registration Number: HGGC-227.

Objectives: To validate the quantitative case analysis (QCA) method study as an effective tool for assessing orthodontic tooth movements induced by clear aligners in a controlled experimental setting.

Materials and methods: The validation process consisted of two main components: first, evaluating the dimensional accuracy of planned movements using metrology techniques via ZEISS INSPECT, and second, assessing ten simulated treatment scenarios to determine QCA's accuracy in identifying treatment discrepancies.

Results: Verifying the dimensional correctness of the QCA method, it demonstrated high accuracy in reproducing planned translations with measurement inaccuracies below 0.01 mm. Rotational movements showed deviations of 0.16°-0.17°, within clinically acceptable limits. Testing realistic scenarios, the highest average measurement inaccuracy observed was 0.23 ± 0.34 mm for mesiodistal translation of molars and 0.29 ± 0.68° for axial rotations of anterior teeth.

Conclusions: The QCA method has been validated as an effective tool for accurately assessing the achieved orthodontic tooth movement performed with clear aligners, demonstrating potential for improving clinical outcomes through precise treatment monitoring.

Crouzon and Apert syndromes are rare syndromic craniosynostoses frequently associated with craniofacial and dental anomalies, including tooth agenesis. Although individual studies have reported tooth agenesis prevalence data in specific populations, no attempts have been made to systematically synthesise these data. This systematic review and meta-analysis evaluated the prevalence and patterns of permanent tooth agenesis in patients with Crouzon or Apert syndromes. The study followed a pre-registered protocol (PROSPERO CRD42024581856). Two independent investigators conducted a literature search in MEDLINE (via PubMed), Web of Science, Embase, ProQuest, and Google Scholar to identify studies on permanent tooth agenesis in individuals with Crouzon or Apert syndromes. Studies were deemed eligible if they reported on permanent tooth agenesis in patients diagnosed with Crouzon or Apert syndromes. Risk of bias was assessed using the Joanna Briggs Institute tool. Random-effects and inverse variance heterogeneity meta-analysis models were used for data synthesis. After database search, deduplication, and screening, seven studies were included, comprising a total of 89 individuals with Apert and 77 with Crouzon syndrome. The estimated overall prevalence of permanent tooth agenesis, excluding third molars, was 37% (95% CI: 28%–48%) in individuals with Apert and 31% (95% CI: 17%–46%) in those with Crouzon syndrome. In Apert syndrome, the most common tooth agenesis pattern was the bilateral absence of the mandibular second premolars, followed by the absence of the left maxillary lateral incisors and the bilateral absence of the maxillary lateral incisors. In Crouzon syndrome, the most frequent tooth agenesis pattern was the absence of the right mandibular second premolar, followed by the bilateral absence of the mandibular second premolars. Individuals with Crouzon or Apert syndrome present a high prevalence of tooth agenesis. Early diagnosis of missing permanent teeth is essential to optimise long-term treatment planning and improve functional and aesthetic outcomes. However, the evidence is limited by small sample sizes and heterogeneity across included studies.

Objectives: The purpose of this study was to determine if there are any clinically significant differences between direct, virtual indirect, and artificial intelligence (AI) bonding techniques.

Materials and methods: This in vivo study analysed 840 teeth selected from 14 patients undergoing orthodontic treatment with full fixed appliances. Anatomical superimpositions were performed, and data were collected as both numerical values and colour-coded deviation maps to assess the differences between direct, AI, and virtual indirect bonding techniques.

Results: The intraclass correlation coefficient test showed good correlation (0.894). The Kruskal-Wallis comparison showed a statistically significant difference when comparing direct to virtual indirect and direct to AI. Descriptive statistics showed 4 values with clinically significant differences when comparing direct to virtual indirect. Descriptive statistics showed 3 values with clinically significant differences when comparing direct to AI. Root mean square (RMS) discrepancies exceeding 0.50 mm were found in four tooth types (AI vs. Direct) and three (Clinician vs. Direct).

Conclusions: We found statistically and clinically significant differences between AI and virtual indirect when compared to direct bonding. With our data, we could infer that if we compare AI versus virtual indirect, there might not be any clinically significant differences since the differences between them fall below 0.25 mm.