Correlation between maxillary central incisor crown form and maxillary dental arch form: A Model-Based morphometric, cross-sectional study

The crown form of maxillary central incisor tooth is one of the vital phenomenon for a person's esthetics. Its crown form has been compared with other anatomical parameters such as arch form and facial form. Three different classes of tooth forms which relate to square, tapered, and ovoid forms are identified. The aim of this study was to morphometrically evaluate the correlation between maxillary dental arch form and the maxillary central incisor crown form. Dentate cast models of fifty male and fifty female normal occlusion controls in the age group of 18–23 years were analyzed. The mesiodistal (MD) dimensions of the maxillary central incisors were measured at incisal (MD_I) and at gingival (MD_G) levels. The transverse widths of maxillary casts were measured at the first molar and at the first premolar levels. The measured data were statistically analyzed using the SPSS software. The MD dimensions of maxillary central incisor were significantly greater in males than females. The ratio between the two MD dimensions also varied significantly among genders. The intermolar width (IMW) and inter first premolar width (IPmW) between males and females were highly significant (P < 0.05), whereas the ratio between these two parameters in males and females was not significant (P = 0.43). Eighty-eight percentage of the participants were found to have an ovoid type of maxillary arch, while only 45% of them had the ovoid form of maxillary central incisors. The MD_I and the IMW were found to be in the ratio of 1:5.5 in both genders. The MD_G and the IPmW were in the ratio of 1:4.7 in males and 1:4.5 in females. There was a weak positive correlation between MD_I and IMW (r2 = 0.146) and between MD_G and IPmW (r2 = 0.05). No significant concordance between the maxillary central incisor crown form and the maxillary arch form was found in this study.