Main Instructor Hsin-Yi Lo
Department / Institution Division of Orthodontics, Veteran General Hospital, Taichung
Classification Case report
「Case」: A 10 year-old male presented Skeletal Class III relationship(ANB:-3。), Class III molar relationship and negative overjet. The stage I treatment started at the age of 10. With facemask treatment, the maxilla and upper dentition were protracted. After 2-year treatment, we superimposed the lateral cephalometric film and found 2mm forward displacement of A point, ANB 0。, mandible clockwise rotation and occlusal plane change. The stage II treatment started at the age of 15. By four bi-cuspid extraction and space closure under maximum anchorage, we retracted upper anterior teeth, decreased overjet, relieved crowding and achieved class I molar relationship. Post treatment lateral cephalometric film revealed ANB 2.5。.
「Discussion & Summary」: The biomechanical effect of the facemask includes maxilla protraction, mandible clockwise rotation and occlusal plane change. However, the amount of clinical effect is still controversial because growth also influences the skeletal change. Moreover, patient’s cooperation plays an important role.
In this case, superimposition of the cephalometric films after 8–year treatment and showed 6mm forward displacement of N point and A point, 7mm downward movement of palatal plane, more vertical than horizontal growth of mandible and clockwise rotation of mandibular plane.
The Effect of Stage I Treatment with Facemask in Class III Malocclusion : A Case Report.