The Introduction of a Novel PAOO Technique

Inclusion Criteria: * tooth crowding exceeding a 5mm lack of space (originating from the discrepancy between the overall mesiodostal length of the teeth and the length of the dental arch present at the time of the evaluation) * thin bone morphotype (buccal width of the cortical layer must be under 1mm) * incisor proclination in order to eliminate crowding without compensatory extractions. * informed consent Exclusion Criteria: * ongoing periodontitis * Pregnant women. * Participation in another clinical study within 30 days prior to study start. * Alcoholism, drug dependency, heavy smoking (\>5 cigarettes/day). * Known infection with HIV, HBV, or HCV. * Patients requiring chemo- or radiotherapy. * Previous or current radiotherapy of the head. * Uncontrolled or insulin-dependent diabetes mellitus * Clinically relevant osteoporosis or systemic disease affecting bone metabolism * Clinically relevant cardiovascular disease e.g., decompensated cardiac insufficiency, hemodynamically relevant heart valve defects, or myocardial infarction during the last three months. * Clinically relevant blood coagulation disorder. * Previous or current treatment with systemic corticosteroids (within 2 months prior to screening visit) of more than 5 mg/day prednisone equivalent. * Previous or current therapy with bisphosphonates at least for 30 days within the last 12 months before screening visit