Journal of the World Federation of Orthodontists最新文献

Objectives: This randomized two-arm parallel trial aimed to compare the effectiveness of standard anterior bracket positioning with the smile arc protection (SAP) method in terms of occlusal and smile morphometric indices, and perceived post-treatment smile aesthetics.

Methods: Patients needing nonextraction orthodontic treatment were randomly assigned to either the SAP or standard bracket placement group. Inclusion criteria were ages 11 to 25 years, nonextraction treatment, and good oral hygiene, all treated using the Roth 0.018 system. Primary outcomes assessed occlusal and smile morphometric changes using cephalograms, study models, and photographs. Perceived smile aesthetics was evaluated with the Visual Analogue Scale (VAS). Statistical analyses included independent t-tests, paired t-tests, Mann-Whitney U test, Wilcoxon signed rank test, and analysis of covariance.

Results: Forty-two patients (mean age, 19.5 ± 5.5) were randomized evenly between the SAP and standard groups. Baseline characteristics were similar, and one patient from the SAP group was excluded. No significant differences were found between the groups for occlusal and smile morphometric variables before and after treatment (P > 0.05). Post-treatment, the smile arc significantly improved in the SAP group compared to both the standard method (P = 0.005) and its pretreatment state (P = 0.005). VAS scores from orthodontists and laypersons showed no significant differences (P > 0.05), but general dentists rated the SAP group's smiles as more attractive (P = 0.002).

Conclusions: The SAP method was more effective in achieving a consonant smile arc than conventional bracket positioning. While other occlusal and morphometric changes showed no significant differences, general dentists found the SAP group's smiles more attractive. Further research is needed to confirm these results.

Registration: The research was registered in the Iranian Registry of Clinical Trials (IRCT) database with the identification code IRCT20220108053669N3.

A 15-year-old female sought multidisciplinary treatment for hypodontia, three-dimensional problems, deep overbite, multiple occlusal interferences, and collapse of the occlusion. Through virtual-digital design with objective decomposition, this patient underwent five steps of orthodontic treatment under the guidelines of the principles: removal of occlusal restriction is a prerequisite; transverse problems are solved first; then sagittal problems; and vertical correction runs through the treatment. After orthodontic and prosthetic treatment, aesthetic appearance and functional occlusion were achieved. In complex multidisciplinary cases with three-dimensional problems, which makes it difficult to formulate the final goal, virtual-digital design under objective composition and standardized comprehensive principle are effective and necessary.

Background: DNA methyltransferase 1 (DNMT1) is responsible for epigenetic remodeling of the genome during spermatogenesis and maintenance of DNA methylation. The current study aimed to assess the possible association between paternal polymorphic variants of the gene encoding DNMT1 enzyme and the risk of nonsyndromic cleft lip with or without cleft palate (NSCL/P) expression in offspring.

Methods: Nine DNMT1 polymorphic single nucleotide polymorphism (SNP) variants were analyzed in 101 fathers of NSCL/P Chilean cases and 187 fathers of controls. Single marker association for additive, dominant, and recessive models was performed using logistic regression analysis. The haplotype-based association was assessed using 3-SNPs sliding windows with a likelihood-ratio test. Multiple comparison corrections were applied using false discovery rates.

Results: None of the DNMT1 SNPs remained significant for any genetic models for single marker association. However, after false discovery rates correction, rs2228611-rs2228612-rs16999714 (q = 0.0042) and rs2228612-rs16999714-rs17291414 (q = 0.0014) haplotypes showed association with the phenotype, based on the dominant model.

Conclusions: Paternal haplotypes, sharing the rs2228612 and rs16999714 DNMT1 SNPs, are associated with NSCL/P expression in the Chilean population. The absence of in vitro/in vivo experimental evidence about the role of these variants on gene expression or protein function opens the opportunity for further investigations.