Bonding positional accuracy of attachments and marginal adaptation of in-house aligners - A quality improvement laboratory study.

OBJECTIVES: To evaluate the 3D accuracy of attachment positioning and the adaptation of aligners to attachments using in-house templates made with either polyethylene terephthalate glycol (PETG) or ethylene-vinyl acetate (EVA) and either pressure or vacuum thermoforming machines. MATERIALS AND METHODS: Overall, 140 test specimens were resin-printed. Templates for the attachment bonding were made with 1-mm EVA or 0.5-mm PETG laminates. Orthodontic aligners were manufactured with 0.75-mm PETG. The thermoplastification process was carried out using either vacuum or pressure machines. The positional differences between the virtual and bonded attachments were assessed in the X, Y and Z coordinates. The marginal adaptation between the aligners and the attachments was measured. RESULTS: Minor inaccuracies in the positioning of the attachments were observed in all combinations of thermoforming machines and plastic laminates used to fabricate the templates, mainly in the superior-inferior (Z) dimension. PETG performed better than EVA in the anterior region (p < .05). No association was found between thermoplastification machines and the accuracy of the positioning of the attachments (p > .05). While small misadaptations between the aligners and the attachments were observed, the EVA templates performed better than the PETG templates. CONCLUSIONS: The inaccuracy of the attachment positioning and the misadaptation of the aligners to the attachments were slight. The vacuum and pressure thermoplastification machines showed no difference in attachment positioning accuracy. The PETG template was better than the EVA template in the anterior region, but the EVA attachments presented a better adaptation to the aligners than the PETG attachments.

Human diprosopus: Case report of a rare congenital abnormality.

Diprosopus is a congenital anomaly in which partial or complete duplication of craniofacial structures occurs. Because it is rare, the mortality rate is high, and information concerning this anomaly is scarce. This study describes a case of human diprosopus in a 9-year-old male individual, who has severe complications associated with the central nervous, cardiovascular, respiratory, and digestive systems. Since birth, he has been monitored in a specialized hospital environment, where he has undergone several surgeries and multidisciplinary treatments. Regarding the craniofacial aspects, he had agenesis of the corpus callosum, floor of the nasal cavity, and floor of the anterior cranial fossa, in addition to the presence of bone dysplasia, ocular hypertelorism and cleft palate with nasal and oral teratoma. Regarding dental characteristics, the patient has duplication of the maxilla, mandible, tongue, and some teeth. After complementary imaging exams, several supernumerary teeth were found, with some being impacted and in complex regions, with an indication for extraction due to the risks of impaction, irruptive deviation, root resorption, and associated cystic or tumoral lesions. Because of the numerous complications, knowledge, and preparation of the entire team is necessary for the correct management of the case.

Prevalence of ankyloglossia according to different assessment tools: A meta-analysis.

BACKGROUND: Prevalence of ankyloglossia may vary depending on the assessment tool. This systematic review aimed to evaluate the prevalence of ankyloglossia in distinct age groups according to different assessment tools. TYPES OF STUDIES REVIEWED: Nine electronic databases were searched from inception through November 2021 without restrictions of language or year of publication. Paired independent reviewers selected cross-sectional and cohort studies reporting the diagnosis of ankyloglossia, extracted data, and assessed methodological quality. The number of patients with ankyloglossia and the sample were extracted to calculate the overall prevalence of ankyloglossia and 95% CI. The authors calculated the prevalence of ankyloglossia per assessment tool, age group, and sex. They assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Seventy-one studies were included. Seven different diagnostic tools were used. The overall prevalence of ankyloglossia was 5% (95% CI, 4.0% to 5.0%) and ranged from 2% (using an unspecific tool) to 20% (Coryllos classification). The prevalence per age group was higher in infants (7%). The prevalence ratio was 1.34 (95% CI, 1.17 to 1.54) for boys, with very low certainty of evidence. PRACTICAL IMPLICATIONS: The prevalence of ankyloglossia is higher among infants and differs depending on the assessment tool used for the diagnosis. It is uncertain whether boys are more affected by ankyloglossia than girls.

Methodological Quality of Systematic Reviews Addressing Orthodontic Interventions: Methodological Study

ABSTRACT Objective: To assess the methodological quality and characteristics of systematic reviews (SRs) of interventional studies in orthodontics and assess how the certainty of the evidence is reported using the GRADE approach. Material and Methods: Six electronic databases were searched, followed by a hand search of the reference lists of eligible studies (PROSPERO #CRD42020180852). The required study design was randomized and nonrandomized studies of interventions published between January 2019 and May 2020. The Assessing the Methodological Quality of Systematic Reviews (AMSTAR 2) tool was used for the quality appraisal of the included SRs. Paired reviewers independently screened the studies, extracted data, and appraised the methodological quality. Results: The study included 46 SRs; 19.5% had moderate to high methodological quality, and the remaining had low to critically low methodological quality. Fifty-four percent of the reviews assessed the certainty of evidence using the GRADE approach, and 34.8% followed all GRADE criteria. Conclusion: Most reviews had a good judgment of the AMSTAR2 items, although some critical items contributed to decreased overall quality. Half of the reviews used the GRADE approach to assess the certainty of the evidence, and this approach should be included in future systematic reviews of interventions.