Investigação tomográfica da fissura petrotimpânica: método para localização e classificação com base em aspectos morfológicos

Abstract

The objectives of the present study were to describe the morphological aspects of petrotympanic fissure (PTF) in cone-beam computed tomography (CBCT) images, establish a standardized protocol for its analysis and classification, determine the prevalence of its different types and evaluate their association with the variables sex and age. This is an observational, retrospective, and cross-sectional study in which CBCT examinations of 121 participants (242 TMJs) were done. Two examiners, previously calibrated by a specialist in Dental Radiology, performed the tomographic analyses. For the localization and classification of PTF, three consecutive sagittal slices were selected from a reference axial slice. The classification followed the model proposed by Sato et al. (2008), which categorizes PTF into: type 1 (wide along its entire length), type 2 (wide entrance with progressive thinning), and type 3 (narrow exit). The data were presented using absolute and relative frequencies of the types of PTF. The Chi-square test was applied to verify associations between PTF types and sociodemographic variables. The sample was predominantly female (67.8%), with a higher concentration of individuals in the 18-29 age group (26.4%). Among the 242 TMJs evaluated, type 1 was the most prevalent (38.8%), followed by types 2 (34.7%) and 3 (26.5%). No significant association was identified between the PTF type and age group; however, a significant association with sex was observed: type 1 was more frequent among women, while types 2 and 3 predominated among men. It is concluded that the proposed protocol represents an important contribution to the standardization of PTF identification and classification in CBCT images, reducing possible methodological variability and favoring comparability between studies. Further research is recommended to investigate the possible relationships between the morphology of the PTF, temporomandibular disorders, and otological symptoms.