Incisor root length in individuals with and without anterior open bite: a comparative CBCT study.

Luis Ernesto Arriola-Guillén,Guillerme Janson,Aron Aliaga-Del Castillo,Yalil Augusto Rodríguez-Cárdenas,Gustavo Armando Ruíz-Mora,Ivy Samantha Valera-Montoya

doi:10.1590/2177-6709.25.4.23.e1-7.onl

Luis Ernesto Arriola-Guillén, Guillerme Janson + Show 4 more

Open Access

https://doi.org/10.1590/2177-6709.25.4.23.e1-7.onl

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Abstract

ABSTRACTObjective: This study aimed to compare the root length of maxillary and mandibular incisors between individuals with open bite versus matched individuals with adequate overbite. Methods: This comparative, matched and retrospective study included 48 cone beam computed tomographies (CBCTs) obtained at a university radiological center. Scans belonged to 24 individuals with open bite (overbite ≤ 0 mm) and 24 individuals with adequate overbite (controls). Both groups were matched by age, sex, malocclusion classification and skeletal characteristics (ANB and FMA angles). Root length of each maxillary and mandibular incisor was measured in millimeters (mm) in a sagittal section from a perpendicular line to the enamel cement junction until the root apex (384 length measurements were made). The means of root length in both groups were compared using t-tests. In addition, correlations between variables were evaluated with the Pearson correlation coefficient (α = 0.05). Results: In both groups, the root length of the upper central incisors was approximately 12 mm and the root length of the maxillary lateral incisors was approximately 13 mm (p˃ 0.05). Likewise, the root length of lower central incisors in both groups measured approximately 12 mm (p˃ 0.05). However, the mandibular lateral incisor roots of open bite patients were significantly longer than in the normal overbite patients (approximately 1 mm, p= 0.012 right side, p= 0.001 left side). Conclusions: Root length of maxillary incisors and central mandibular incisor is similar in individuals with or without open bite, but the mandibular lateral incisor roots in open bite patients were significantly longer than in the normal overbite patients.

Highlights

Some authors found shorter maxillary central incisor length in open bite patients compared to controls without open bite,[8] or with deep bite[9], based on lateral cephalogram evaluation
Root lengths ranged from 12.29 mm to 13.20 mm for the maxillary incisors, and did not show significant intergroup differences (Table 2)
For the mandibular central incisors, the root lengths ranged from 11.49 mm to 11.71 mm, and only the root lengths of the open bite mandibular lateral incisors were significantly greater than the normal overbite group

Summary

Introduction

It has been reported that individuals with open bite have greater incisor dentoalveolar height, compared with balanced facial pattern subjects.[1,2] Based on the increased vertical skeletal and dentoalveolar dimensions that open bite individuals present,[1,3,4,5,6,7] it could be speculated that the root lengths of anterior teeth would be greater in open bite individuals, when compared to those without open bite.Contrarily, some authors found shorter maxillary central incisor length in open bite patients compared to controls without open bite,[8] or with deep bite[9], based on lateral cephalogram evaluation. The root length was not directly measured.[8,9] In addition, only two studies that evaluated dental root length in panoramic radiographs[10] and root area in CBCT11 concluded that patients with open bite, especially those with a high mandibular plane angle, have shorter dental roots and smaller root areas of the maxillary incisors, when compared to individuals with normal overbite. These studies mention that their findings may be related to the loss of occlusal contact in the anterior teeth. These results should be evaluated in other samples for better consistency.[15]

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