Effect of Maxillary Central Incisor Inclination on Palatal Bone Width

This study aimed to evaluate the effect of labiopalatalinclination of maxillary right central incisor on palatal bone width using cone-beam computed tomography (CBCT).

The angle formed between the longitudinal axis of the right central incisor and the palatal plane was measured on 75 CBCT images, andclassified 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).

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 wasinverse (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).

Labial inclination of upper central incisor causes the root apex to be closer to the palatal alveolar bone, resulting in lessapical bone supportin the palatal area