Analysis of course of canalis sinuosus on cone-beam computed tomography and in osteological specimens: a systematic review

BACKGROUND: The canalis sinuosus (CS) is an anatomical structure within the maxilla that encloses the anterior superior alveolar nerve (ASAN), artery (ASAA), and vein (ASAV). Since its first description in 1939, understanding the course of the CS has become essential, especially for clinical outcomes involving facial surgeries and interventions, due to variations in its path. MATERIALS AND METHODS: In this review, conducted according to PRISMA guidelines, Web-of-Science and PubMed databases were comprehensively searched using key words related to the CS and its anatomical components. Both cadaveric investigations and radiological studies using computed tomography (CT) and cone-beam CT (CBCT) were included. RESULTS: The prevalence, diameter, and trajectory of the CS were assessed. Thirteen of the 897 records met the inclusion criteria, revealing CS prevalence in most subjects. The mean CS diameter was 1 mm, and clinically significant trajectory variations with significant implications for clinical practice were observed. The segmented anatomical analysis revealed that the course of the CS was divided into three distinct parts, i.e. the initial segment near the infraorbital foramen, the intermediate segment extending to the pyriform aperture, and the end segment near the tooth root apices. The CS pathway began at the infraorbital foramen, curving towards the nasal aperture before bending again near the inferior nasal concha. DISCUSSION AND CONCLUSIONS: Further studies are needed to clarify the complex end segment and precise anatomical details of the CS. Existing studies have notable limitations and inconsistencies, underlining the urgent need for uniform methodologies and consistent terminology.