Thickness of the buccal bone wall and root angulation in the maxilla and mandible: an approach to cone beam computed tomography

BACKGROUND: The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. METHODS: CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4 mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. RESULTS: A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2 mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had < 1 mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67 ± 6.37° for incisors, 16.88 ± 7.93° for canines, 13.93 ± 8.6° for premolars, and 9.89 ± 4.8° for molars. In the mandible, the mean values were 10.63 ± 8.76° for incisors, 10.98 ± 7.36° for canines, 10.54 ± 5.82° for premolars and 16.19 ± 11.22° for molars. CONCLUSIONS: The high incidence of a buccal wall thickness of less than 2 mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns.