Effect of vertical malocclusions on root crown ratio of maxillary teeth-A cross-sectional radiographic study

Root resorption is the loss of apical root tissue which is implicated by decrease in root-crown ratio. It usually effects from external surface to pulp chamber if not identified in the early stage. Several natural conditions place roots at risk of resorption without any pathology. Knowing the pressure or etiology of the resorption will help the orthodontist in the treatment aspect. To date literature regarding root resorption due to various malocclusions is deplete in Indian population. To measure and assess the root crown ratios of maxillary incisors with vertical malocclusions, deleterious habits, and validate by two different radiographic techniques.90 Patients enrolled for the orthodontic treatment were allocated to three groups - open bite, deep bite & control groups and were subdivided based on nail biting habit. Panoramic radiographs, Periapical radiographs (by paralleling technique) for maxillary incisors (360 teeth) were taken and traced. Length of the root & crown were assessed and root crown ratios were calculated and the results substituted to statistics using SPSS. Comparison of Root-crown ratios in vertical malocclusions, revealed statistically significant (P < 0.001) differences in Open bite group for all maxillary incisors in both panoramic and periapical radiographs. No statistical significant differences were found in the deep bite group. Significant association was found between nail biting habit and Root-crown ratio. Gender predilection was found to be absent.Decreased Root- crown ratios were observed in open bite patients. Nail biting patients show significant root resorption. Both panoramic radiographs and periapical radiographs with paralleling technique can be used for assessing root resorption.