Dento-maxillary abnormalities included in Angle class III are dismorphic entities with multifactorial aetiology and different clinical manifestations1- 5. They can develop from simple forms (reverse interlocking) to major modifications in the facial harmony (mandibu protrusion with macrognathism) 6-9. Aim of the study: to assess the frequency of Angle Class III malocclusion in a group of children, with emphasis on early therapeutic methods that can prevent the evolution of severe anatomical forms9-12.
Materials and method: The study group comprised 355 children (200 females, 155 males), aged 4-6 years, with dento-maxillary abnormalities. Investigations were conducted over a period of 3 years (2007-2010) by analyzing patients’ records from the Department of Orthodontics, Tg. Mures The children were examined both clinically and radiologically. On clinical examination, the facial form was evaluated from the frontal and side view, while medical history established the involvement of genetic factors in patients with Class III abnormalities. Paraclinical examinations included study design (perimeter and sagittal arrow), lateral cephalometric examination (to assess bone deviations) and panoramic radiography (to assess Bjork’s structural signs of mandibular growth rotation).
The retropulsion test made possible the differential diagnosis between different clinical forms2,5,13-15.
Results and discussion: The study first evaluated the gravity of malocclusion Class III out of the total dentomaxillary abnormalities, the 2.81% percent obtained, ranking between 2.82% and 3.5%,corresponding to the values published by Schapira in literature