Study of the gubernacular canal on CBCT: a contribution to understanding its role in the eruptive process

Abstract

The gubernacular cord, or gubernaculum dentis, is a structure composed of fibrous connective tissue contained in a bony canal called gubernacular canal (CG). The gubernacular cord connects the dental follicle to the lamina of the suprajacent gum, thus, the GC extends from the bone crypt to the alveolar bone crest, usually by the lingual / palatine aspect of the predecessor tooth. Although GC has been revisited in current imaging research, studies with this structure are relatively scarce in the literature. Presently, it is considered that the gubernacular cord plays a role as a guide for erupting teeth. However, such a function of the gubernacular cord can be questioned, since there is no consensus about the presence of this structure in deciduous teeth and permanent molars, and its characteristics in teeth with eruption failures are not well known. This work aims to verify if there is an association in the presentation of the GC imaging characteristics in teeth with and without eruption failure and to evaluate the presence of GC in permanent molar teeth. Cone-beam computed tomography images from Ribeirão Preto School of Dentistry - USP will be analyzed for the selection of examinations containing intraosseous teeth. Teeth will be divided into 2 groups: G1- Teeth within normal process of eruption and G2- Teeth with failure of eruption. For each tooth, the following data will be recorded: age and sex of the patient, tooth group, rhizogenesis stage, follicular space status (normal or enlarged), presence or absence of the GC, GC shape, thickness, length, location of the GC extremity in the alveolar ridge and in follicular space. For G2, type of eruption failure and positioning of the tooth in the bone will also be recorded. The presence of GC in permanent molars and the characteristics evaluated by group will be presented through descriptive statistics. The evaluated characteristics will be compared between groups G1 and G2 (the categorical variables by Fischer test, Dz or Scheffe test; CG thickness by ANOVA). The level of statistical significance adopted will be 5%. It is expected to determine the prevalence of GC detection in permanent intraosseous molars and to describe the GC presentation in teeth in normal eruption process and with failure of the eruption process, contributing to the study of the role of the gubernacular cord as a guide for eruption of the teeth. (AU)