Evaluation of Extension Type of Canalis Sinuosus in the Maxillary Anterior Region: a CBCT Study.

Objective: To evaluate the extension of canalis sinuosus (CS) into the alveolar crest for surgical reference in the anterior maxilla.

Methods: In this cross-sectional study, 485 CBCT images were evaluated in three orthogonal planes (axial, coronal and sagittal). The type of extension of CS into the alveolar ridge in the anterior maxilla was evaluated. The alveolar ridge was divided into four equal parts in a vertical and horizontal direction. In a vertical direction from apical to incisal and in a horizontal direction from labial to palatal, the four parts were designated as types 0, I, II and III, respectively. The extension of CS into the alveolar ridge was then traced.

Results: CS was present in 380 subjects (78.35%), and the extension type was unilateral in 217 of them (57.11%) and bilateral in 163 of them (42.89%). There was no significant relationship between incidence of CS and sex. Regarding the distribution of vertical and horizontal types, type II (the third quadrant of the ridge from apical to incisal and from labial to palatal, respectively) was significantly more prevalent than other types.

Conclusion: The most common location of CS into the alveolar ridge in both horizontal and vertical directions was type II (which is not close to the cortex). Awareness about the presence and possible locations of CS helps to reduce the risk of unjustifiable postoperative complications.