CBCT‐Guided Analysis of the Accessory Foramina of the Canalis Sinuosus: Morphological Variants and Their Significance for Implant Surgery

The canalis sinuosus in the premaxillary region often has accessory canals palatal to the central and lateral incisors. These small anatomical structures are of increasing interest due to numerous case reports of postoperative complications following surgery in the upper anterior region. On the one hand, this study examined the number, position and extent of the accessory foramina of the canalis sinuosus in 210 patients. Furthermore, the study looked at the distances to neighboring teeth and to the buccal cortical bone in edentulous patients. The three-dimensional tomographic images (CBCT) were created with a resolution of 0.2 voxels and evaluated using the Osirix MD program. Results showed a prevalence of 97% for accessory foramina, confirming it as a clear anatomical structure. Males had significantly more terminal openings of the canalis sinuosus than females, with a clustering in the fourth to sixth decade of life. The foramina had a mean extension of 0.9 mm and a mean distance of 4.6 mm to adjacent teeth. This narrow position is particularly relevant for surgical procedures. Greater attention should be paid to larger foramina in implant planning, as postoperative complications are increasingly being described. Foramina and accessory canals should be detected in three-dimensional, navigated implant planning in order to minimize the risk of injury during oral surgery.