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Objectives This study aimed to evaluate the effect of labiopalatal inclination of maxillary right central incisor on palatal bone width using cone-beam computed tomography (CBCT). Methods The angle formed between the longitudinal axis of the right central incisor and the palatal plane was measured on 75 CBCT images, and classified into three groups of labially-inclined, lingually-inclined, and normal groups. The total palatal bone thickness in the apical region of the upper right central incisor was linearly measured perpendicular to the tooth axis on sagittal slices. The intraclass correlation coefficient, Kolmogorov-Smirnov test, one-way ANOVA, and Pearson’s and Spearman’s correlation coefficients were used for data analysis (alpha=0.05). Results A significant difference was noted among the groups in the total apical palatal bone thickness (P<0.05). The labially inclined group had significantly lower bone thickness than the other two groups (P=0.002, 95% CI: 5.5-7.38); however, this correlation was inverse (Pearson’s R=-0.58), which means that as the angle between the upper central incisor axis and the palatal plane increased, the bone thickness significantly decreased. No correlation was found between the palatal bone thickness (cancellous or cortical) and tooth inclination (P>0.05). Arch length was not correlated with any group either (P>0.05). Conclusion Labial inclination of upper central incisor causes the root apex to be closer to the palatal alveolar bone, resulting in less apical bone support in the palatal area. [ABSTRACT FROM AUTHOR]

Background: The myosin 1H (MYO1H) gene, located on chromosome 12, encodes the unconventional MYO1H protein, which is involved in the intracellular movement and morphology of chondrocytes, and plays a vital role in the prognathism or retrognathism of the mandible., Objectives: The objective of this study was to assess the relationship between the polymorphisms of the MYO1H gene and mandibular prognathism in the Iranian population., Material and Methods: The current project evaluated 64 patients with mandibular prognathism requiring orthognathic surgery and 60 controls with skeletal class I occlusion. Genome amplification was performed using specific primer pairs to assess the rs10850110 and rs11611277 polymorphisms of the MYO1H gene through the polymerase chain reaction (PCR). The restriction fragment length polymorphism (RFLP) technique was used to detect single-nucleotide polymorphisms. The data was analyzed using the χ2 test., Results: The patient and control groups were not significantly different in terms of age or gender (p > 0.05). In all, 3.1% of patients and 6.7% of controls had the rs10850110 polymorphism (p = 0.680), and 1.6% of patients and 5% of controls had the rs11611277 polymorphism (p = 0.602)., Conclusions: No significant correlation was noted between the rs10850110 and rs11611277 polymorphisms of the MYO1H gene and mandibular prognathism in the Iranian population. However, the lower frequency of these polymorphisms in the patient group suggests a possible association with mandibular retrognathism, which needs to be investigated with a larger sample size.