[Interceptive treatment with the DAC appliance: structural analysis]

The aim of this retrospective short and middle term study was to evaluate dental and skeletal effects during early class II treatment. Thirty subjects were treated with DAC appliance, 32 children were not treated. Data were collected at the start of the study (t(1)), after the active treatment (t(1')) and 28 months after t(1) (t(2)). L.D.V. and Tweed cephalometric analyses were applied on the lateral roentgenograms of the three groups. Differences for all the variables from t(1) to t(1') and t(2) were calculated and compared by t-test. Results suggested that DAC appliance was able to achieve twice more mandibular growth in the treated group than in the non treated group. Anterior total skeletal and matricial rotations were similar to control group. Early DAC appliance achieved overjet correction thanks to major skeletal participation (89%) and little dental participation (11%). During following-up stage, overjet relapsed partially as shown in other articles with other appliances. As a conclusion, DAC appliance may be an orthopedic appliance indicated to achieve correction in class II skeletal pattern without maxillary prognathism and with mandibular retrognathism.