Marginal bone support and tooth lengths in 19-year-olds following orthodontic treatment.

Abstract

The study was performed in 19-year-olds who on the average had completed orthodontic treatment 5.7 years prior to the examination. An untreated group of 19-year-olds served as controls. The distance from the cemento-enamel junction to the intradental alveolar crest was estimated on bitewing radiographs of the upper and lower premolars, molars and canines. The same measurements were carried out on periapical radiographs of the upper incisors. The tooth and crown lengths of the upper incisors were measured and the root lengths were calculated. The data demonstrated, that individuals in a rural community, subjected to orthodontic treatment, on average experience a small loss of marginal bone support, compared with untreated persons. Forty-five per cent of the treated individuals experienced one or more sites with bone loss ≥ 2 mm compared with 23 per cent in the control group. The reduction in tooth lengths was mainly due to shorter roots in the central incisors and shorter crown lengths in the lateral incisors. No statistically significant correlation was found between marginal bone loss and reduction in tooth lengths.