Effect of Interceptive Strategies on the Clinical Outcome of Impacted Maxillary Permanent Canines

Canine impaction is a sign of abnormal dental development with potentially far-reaching consequences (such as significant root resorption and loss of lateral incisors. This compromises both aesthetics and function of the teeth, making the prediction of canine tooth impaction increasingly important. Interceptive orthodontic measures, such as extraction of deciduous canines or molars or maxillary expansion aim to create extra space in the dental arch, allowing the canines to position themselves better and normalizing their eruption pattern.

This study corresponds to the second phase of an RCT, based on the results of the first phase, published in July 2023 (S59030) (Willems G, Butaye C, Raes M, Zong C, Begnoni G, Cadenas de Llano-Pérula M. Early prevention of maxillary canine impaction: a randomized clinical trial. Eur J Orthod. 31;45(4):359-369). The first phase compared the effect of 3 interceptive strategies (expansion, extraction and no intervention) on the position of impacted maxillary canines, finding that maxillary expansion provides the most improvement on impacted canine position. In second phase, 8-year-old patients without posterior crossbite and lack of space in the dental arch are randomized to treatment with 'slow maxillary expansion with removable plates' or 'no treatment'. These groups are additionally compared with patients with a crossbite and lack of space, which always receive expansion treatment. All selected patients will be followed up for at least 18 months. The primary endpoint is to investigate the effect of maxillary expansion with removable plates on the position of maxillary canines prone to impaction during early mixed dentition, assessed on panoramic X-rays. The secondary endpoint is the assessment of the need for additional orthodontic treatment.