Targeted Endodontic Microsurgery: Implications of the Greater Palatine Artery

Targeted Endodontic Microsurgery (TEMS) combines trephine burs and 3D-printed guides to make flapless maxillary palatal root-end surgery possible. This study assessed the location of the greater palatine artery (GPA), the relationship of the GPA to maxillary molar root ends, and the feasibility of flapless palatal-approach TEMS.

Three endodontists analyzed 250 cone-beam computed tomographic images of maxillary molars for (1) transition morphology between the hard palate and the alveolar process adjacent to first and second molars as an indication of the most likely location of the GPA, (2) the superior-inferior relationship between the GPA and root ends, and (3) the feasibility of palatal-approach TEMS.

Palatal transition morphology included 20% Spine, 72% Bridge, and 8% Smooth. GPA position as related to palatal root ends was classified as 34% superior, 40% adjacent, and 21% inferior. Five percent of classifications were undefined. TEMS was deemed feasible for 47% of maxillary first molars and 52% of second molars, and was significantly more feasible with GPAs superior to palatal root ends. Reasons for infeasibility included GPA proximity and unfavorable resection angle or level. Maxillary first molar palatal roots were 11.13 ± 2.68 mm from the greater palatine foramen (GPF) and 2.37 ± 1.46 mm from the GPA. Second molar palatal roots were 4.94 ± 2.55 mm from the GPF and 2.53 ± 1.77 mm from the GPA.

Palatal transition morphology and GPA position adjacent to maxillary molars, as manifested in cone-beam computed tomographic coronal views, suggested maxillary palatal root TEMS could be accomplished with a 2-mm safety margin in 47% of first molars and 52% of second molars. Historical paradigms that do not consider flapless palatal surgical approaches may need to be revised.