Endodontic access to maxillary lateral incisors.

One hundred thirty-one maxillary lateral incisors were radiographed from a mesiodistal vantage point. Projections of the buccal and lingual walls onto the incisal showed that 16 percent opened to the buccal of the incisal edge; 32.9 percent were buccal and inclusive of the incisal edge, 43.5 percent were buccal and lingual to the incisal edge, 6.9 percent were inclusive of the lingual to the incisal edge, and 0.8 percent were entirely to the lingual of the incisal edge. Theoretically, the highest success rate that could be achieved for that portion of endodontic therapy that depends upon canal débridement would be gained by having the occlusal access opening in the most direct path to the long axis of the root canal. In this study it has been shown that, for maxillary lateral incisors, that path would necessitate that out occlusal opening be made inclusive of and slightly buccal to the incisal edge.