The canalis sinuosus is a passage within the maxilla through which the anterior superior alveolar nerve, artery and vein pass. The proximal opening of the canal occurs near the mid-point of the infraorbital canal.[1]: 616
From its proximal opening, the canalis sinuosus first passes infero[1]: 616 laterally[1]: 653–654 within the maxillary orbital floor where it is situated lateral to the infraorbital canal. It then turns[1]: 616 to pass inferomedially[1]: 653–654 and anteriorly[1]: 699 while passing through the anterior wall of the maxillary sinus[1]: 616 (the canal is marked by a groove upon the internal surface of the anterior wall of the sinus[1]: 699 ). It then courses to the inferior to the infraorbital foramen (of the infraorbital canal) and anterior to the anterior extremity of the inferior nasal concha to reach the margin of the anterior nasal aperture. Thereupon, it passes along the inferior rim of the anterior nasal aperture[1]: 616 between the nasal cavity (superiorly), and the tooth sockets (dental alveoli) of the canine and incisor teeth (inferiorly).[1]: 653–654 It ends distally by opening near the nasal septum[1]: 616, 653–654 anterior to the incisive canals.[1]: 616 The canal may be up to 55 mm in length.[1]: 653–654
The anterior superior alveolar nerve turns inferior-ward in the canal and ramifies to innervate the incisor and canine teeth.[1]: 656