Anatomical study of pterygoid implants: artery and nerve passage through bone dehiscence of the greater palatine canal.

Purpose: Pterygoid implants are an alternative approach to avoid sinus-lifting or other grafting procedures. During pterygoid implant placement, dental surgeons risk damaging the greater palatine canal (GPC). However, they do not have sufficient reasons to avoid GPC injury. This study performed a detailed morphological analysis of the GPC to determine susceptibility to damage during pterygoid implant surgery.

Methods: To understand the detailed morphology of the GPC, gross anatomical analysis, histological analysis, and bone morphometry via micro-computed tomography were performed.

Results: We found that the medial wall of the GPC communicated with the nasal cavity through the bone dehiscence. The dehiscence appeared near the inferior nasal concha in 72.4% of the cadavers. The nerve and artery passed from the GPC to the nasal mucous membrane through the dehiscence. Given that the greater palatine nerve passed medial to the descending palatine artery in the GPC, the descending palatine artery is damaged first rather than the greater palatine nerve during pterygoid implant surgery.

Conclusions: Dental surgeons who penetrate the GPC using an implant body may extend the bleeding to the nasal mucosa, which seems to spread the inflammation to the nasal cavity.