Cervical enamel projections as an etiologic factor in furcation involvement.

Two thousand molars in 200 East Indian skulls were examined for the occurrence, location, and grade of cervical enamel projections. The relationship between the enamel projections and furcation involvements was studied. Several findings resulted. The incidence of cervical enamel projections in molars was 32.6%. The incidence of cervical enamel projections varied between molars. The mandibular second molars showed the highest incidence of enamel projections (51.0%), followed by the maxillary second molars (45.6%). The lowest incidence was seen in the maxillary first molars (13.6%). Grade 1 enamel projections were the most frequently encountered. Cervical enamel projections occurred most frequently on the buccal surfaces of teeth. There was a positive, statistically significant relationship between tooth surfaces with grade 2 and 3 enamel projections and periodontally involved furcations. However, no etiologic relationship was found between grade 1 projections and furcation involvements. There seems to be a physiologic relationship between bone and enamel projections. The alveolar crest has a tendency to follow the outline of the enamel projection, and a channel much wider than a normal periodontal membrane space accommodates the enamel projection as it extends toward the furcation. The results indicate that when cervical enamel projections are severe enough to approach or enter the furcation area (grades 2 and 3), they may be an etiologic factor in the breakdown of these furcations.