PURPOSE: Ectopic second premolars may lead to impaction and loss of space in the jaws, and in rare cases even to resorption of the first permanent molar. The aim of this study was to analyse different treatment strategies of ectopic second premolars and if possible give guidelines on when to favour different treatment approaches.

MATERIALS AND METHODS: The study was a retrospective, non-randomised, outcome analysis of treatment on 41 ectopic second premolars in 37 patients (24 females and 13 males). In all cases oral examination, radiographs (pre-, peri-, and post) and full medical history were obtained. The treatment options included: (a) spontaneous eruption, (b) spontaneous eruption + extraction of primary tooth, (c) surgical exposure, (d) surgical uprighting, and (e) surgical uprighting + orthodontic extrusion. For evaluation each tooth was scored according to: (1) stage of root development, (2) distance between edges of the premolar and first permanent molar, (3) depth of impaction, (4) inclination, (5) horizontal position of the tooth. The level of significance was set to 5%.

RESULTS: Only mild cases of ectopic second premolars are self-correcting. Based on the position of the tooth in the jaw different treatment options may be chosen, these may include: extraction of primary predecessor (impaction depth < 5 mm, inclination < 55°), surgical exposure of tooth germ (impaction depth < 5.5 mm, inclination < 95°) or surgical uprighting (impaction depth > 5.5 mm with no inclination limit).

CONCLUSION: If there is no sign of self-correction after a short observation period, it is important to consider active treatment to help guiding the tooth into the correct eruption pathway.