Anatomical study on the posterior alveolar canal in maxillary tuberosity region using computed tomography

Objective: This study aimed to identify the anatomical characteristics of the posterior alveolar canal (PAC) and related maxillary bone using computed tomography (CT). Methods: The study included 40 Japanese cadavers (70 hemi-heads), comprising 23 males (41 hemi-heads) and 17 females (29 hemi-heads). Simple CT data of the maxillary bone region of the specimens were obtained and analyzed using a measurement software with reference to the Frankfurt horizontal (FH) plane to identify the PAC in the maxillary tuberosity region, alveolar crest (AC), and corner of the inferior crest of the zygomatic process (CICZP). The shortest distances between the PAC and the respective landmarks and the smallest width of the posterior wall of the maxillary sinus (WPWMS) at the PAC level were calculated and analyzed statistically. Results: Of all specimens, the mean and SD of AC-PAC: 21.4 f 3.32 mm, horizontal PAC-CICZP: 15.1 f 2.89 mm, vertical PAC-CICZP: 5.70 f 3.15 mm, WPWMS: 0.81 f 0.31 mm, and the coefficients of variation ranged 15.5-55.3%. In the WPWMS, the mean value was statistically smaller in the female group (0.59 mm) than in the male group (0.96 mm) (p < 0.001). Conclusions: The results showed certain tendencies in the distances between the PAC and the respective anatomical landmarks with large variations. The thickness of the posterior wall of the maxillary sinus was thinner in females than in males. However, it is < 1 mm in both sexes, and external forces caused by trauma or surgery may fracture the posterior wall of the maxillary sinus and damage the posterior superior alveolar artery regardless of sex.