Comparison of Prevalence of Oxis Contact in Primary Maxillary and Mandibular Teeth: A Retrospective Cohort Study

Aim: The purpose of the present study was to evaluate four different types of OXIS contact areas (open [O], point [X], straight [I], and curved [S]) in primary teeth using cone beam computed tomography (CBCT) among 3- to 9-year-old children.

Methods: A retrospective cohort study was performed using cone-beam computed tomography images of children, available from January 1, 2022, to July 31, 2023 in Mathura district showing the presence of caries-free contact area between primary right maxillary and mandibular 1st and 2nd molar. In this study, 65 selected contacts using OXIS criteria from the occluso-cervical and axial view at coronal level using CBCT.

Result: Based on the shapes observed, the results showed four distinct types of contact regions between the primary molars, namely, O type, X type, I type, and S type; hence, the suggested categorization is known as OXIS. I type was the most prevalent pattern in the maxilla (47.06%), while O type was the most prevalent pattern in the mandible (50%).

Conclusion: There are four types of intact interproximal contact areas between primary molars, which can be evaluated in three dimensions. These types are O, X, I and S. In maxilla, pattern was

I > O > X > S whereas in mandible pattern was O > X > I = S.