Potential attachment area of the fourth maxillary premolar in dogs.

Tooth root and root trunk surface area measurements were made on 20 permanent fourth maxillary premolar (P4) teeth randomly harvested from canine cadaver specimens. Mean root surface area for all 20 teeth was 562.8 +/- 124.9 mm2. Cumulative surface areas of the mesiopalatal, mesiobuccal, and distal roots were 113.8 +/- 29.0 mm2, 138.5 +/- 34.6 mm2, and 180.8 +/- 39.9 mm2, respectively. The mesial root trunk and distal root trunk surface areas were 60.0 +/- 17.5 mm2 and 72.1 +/- 33.2 mm2, respectively. There was not a significant difference between the root surface area of the mesial root trunk and distal root trunk; however, all other root surface area measurements were significantly different (P less than 0.01). Cumulative individual root surface area (distal root + mesiobuccal root + mesiopalatal root) was 76% of total root surface area. The distal root surface area contributed most to total root surface area (32.1%) and cumulative individual root surface area (41.7%). Observation of the linear variation of percentage of root surface area revealed 40.8% of the total root surface area to be in the portion located between 5 and 9 mm apical to the most coronal aspect of the cementoenamel junction. The mesiobuccal root and distal root were cylindrical compared with the flattened, concave shape of the mesiopalatal root.