The main objective of the investigators' study is to assess the efficacy of a course of treatment using skeletal anchorage (MINISCREW) as compared with treatment involving dental anchorage (reference) during dentofacial orthopedic treatment.

Multicenter prospective study on patients aged between 12 and 50 years, requiring orthodontic treatment with premolar extractions and closure of the extraction spaces by distalization of the 6 anterior teeth. In the experimental group (50 patients) distalization will be performed using skeletal anchorage (MINISCREW). In the control group (50 patients), distalization will be by dental anchorage.

The main evaluation criterion will be extraction space closure after 8 months of treatment. Angle class I cuspid and the parallelism of the dental axes will also be taken into account. Evaluations will be made by very precise radiological analysis using 3D CT-scan. Examinations will be done before and after closure of the extraction sites and will assess treatment efficacy using skeletal anchorage versus dental anchorage. Patients will also be requested to complete a satisfaction questionnaire. The study will comprise an inclusion appointment during which patient consent will be obtained and a regular monthly appointment during the 8 months of active treatment and space closure.

Inclusion criteria:

• Aged from 12 to 50 years old
• Patient need orthodontic treatment with extraction of 2 maxillary bicuspid
• Patient has signed informed consent

Exclusion criteria:

• Patient younger than 12 and older than 50 years old
• Patient without social security affiliation
• Patient with a medical condition that indicates against orthodontic treatment