[Secondary retention of permanent molars. II. Therapy]

The efficacy of 5 treatment modalities for secondary retention of permanent molars was evaluated in 62 patients with 92 affected molars. The results showed that a prosthetic build up is a proper treatment if secondary retention develops late in or after the growth spurt. In these cases the extent of infraocclusion is slight and relatively stable. If secondary retention starts before the growth spurt, immediate removal of the retained molar followed by orthodontic treatment to close the diastema gives maximal success. When secondary retention develops during the growth spurt, the tooth affected has to be observed at six monthly intervals. In such cases, no active treatment is indicated if the extent of infraocclusion is minor and stable. In all other cases the affected molar should be removed, followed by orthodontic closure of the diastema.