Evaluation of Greater Palatine Canal and Foramen Anatomical Variation on Cone-beam CT Radiography

Introduction: A known method for maxillary nerve block is through the greater palatine canal (GPC). Poor knowledge about the anatomy might result in undesired conditions such as perforation of the arteries, nerve damage and blindness. This study aimed at determining variations of the GPC and greater palatine foramen (GPF) on cone beam computed tomography (CBCT) images. Materials and Methods: This cross-sectional descriptive study was carried out at Islamic Azad University dental school and private clinics of Isfahan in 2018. A total of 92 CBCT images of adults over 18 years old were evaluated and GPC length, GPF diameter and its distance to the anterior nasal spine (ANS), posterior nasal spine (PNS) and mid-maxillary suture (MMS) were measured. The data were analyzed using SPSS 18. Results: The mean distance of GPF to ANS (47.96 mm in men and 45.36 mm in women), to PNS (18.9 mm in men and 17.21 mm in women), and to MMS (15.93 mm in men and 14.73 mm in women), as well as the diameter of the GPF (6.07 mm in men and 5.01 mm in women) were significantly higher in men on both right and left sides (P<0.05). The mean GPC length in men and women was 34.36±2.5 and 31.39±1.9 mm, respectively, which was significantly larger in men. The more common canal pathway in sagittal plane was inferior/inferior-anterior (70%) in both genders. The inferior/inferior-anterior pathways were more common in both genders in coronal plane; however, this difference was not significant (P>0.05). Conclusion: Since the maxillary nerve block technique might cause irreparable complications through GPC, it is very important to know the position of the foramen and the canal direction. Therefore, it is advisable to use CBCT in order to better understand the GPF and GPC anatomy