Juvenile periodontitis. Localization of bone loss in relation to age, sex, and teeth.

The distribution of bone loss in 156 patients, 12-32 years old, with juvenile periodontitis was analyzed according to age, sex, and teeth affected. The criteria for bone loss were: vertical or horizontal bone loss involving more than one-third of the root as judged by radiographs. Three age groups were established: 12-18, 19-25, and 26-32 years old. Three types of bone loss localization were defined: I. First molars and/or incisors. II. First molars, incisors and some additional teeth (total less than 14 teeth). III. General involvement . There was a dominance of female patients. The ratio females: males decreased from 5.3:1 in the youngest age group to 1.5:1 in the oldest. The mean number of involved teeth increased with age from 5.3 teeth in the youngest group to 11.6 in the oldest. The frequency of type I bone loss decreased from 55% in the youngest group to 7% in the oldest. Type II occurred with the same frequency (55-58%) in all three age groups. Type III was not seen in the youngest group whereas it increased from 17% in the middle to 35% in the oldest group. Of the total number of involved teeth, the first molars were most frequently affected, followed by the incisors. Maxillary teeth were involved to a slightly higher degree than mandibular teeth, and there was a strong "mirror effect" between involved teeth of right and left jaw halves.