Prevalence of delayed emergence of permanent teeth as a result of local factors.

Delayed emergence of permanent teeth as a result of local etiologic factors was found in 45 of 1,032(4.3%) persons ages 8 through 18 in a dentally indigent population. In 36 persons (3.4%) delayed emergence resulted from causes other than those associated with premature primary molar extraction. This statistic probably approximates the potential for this problem in a treated population group. Teeth most commonly involved were mandibular second premolars, maxillary canines, and maxillary central incisors. The most common causes, respectively, were space loss, palatal position, and mesiodens. Supernumerary, malformed, and congenitally missing teeth were more frequent in persons with delayed emergence than in the rest of the population sampled. The difference was statistically significant. No correlation was found between delayed emergence and sex of the patient. In this study, teeth delayed in emergence behaved as other teeth in that they exhibited normal root development and did not contribute to resorption of adjacent roots. Except for maxillary canines, enlarged follicular spaces did not develop after eruption