Clinically significant oroantral communications--a study of incidence and site.

The incidence of clinically significant oroantral communications (OACs) after simple tooth extraction during the period 1980-9, at the Faculty of Dentistry, Mahidol University, Bangkok, Thailand, was studied retrospectively. The total number of OACs was 87. The tooth most frequently involved was the upper first molar, followed by the second and third molars. The difference, however, was not statistically significant (P > 0.05). The sockets of the palatal roots of the first and the second molars were most frequently involved. There was no statistically significant difference between the incidence of OACs on the right and the left sides (P > 0.05).