Most Class III malocclusion patients manifest a concave profile. However, the skeletal pattern could be in different forms. It may be caused by underdeveloped maxilla, overgrowth of the mandible or both. Knowing the skeletal pattern is important as it may influence the treatment options. Objective: To asses the skeletal pattern of Class III malocclusion patients who attend orthodontic clinic in Faculty of Dentistry, University of Indonesia. Methods: 108 patients who seek orthodontic treatment during 1990-2004 were selected and divided into 3 different age groups according to somatic growth curve which were below 10, 10-18 and above 18 years old. There were 30 males and 78 females in the study. Lateral cephalometric of each patient was taken and measured with Mc. Namara criteria where the length of the mandible, length of the maxilla, point A to N Prep and Pogonion to N Prep. The data was analysed using descriptive statistics. Result:
|
|
GROUP A <10Years |
GROUP B 10-18Years |
GROUP C >18Years |
Total |
|||
|
Male |
Female |
Male |
Female |
Male |
Female |
||
|
Maxilla Normal, Mandible protruded |
2(7.7%) |
0 % |
4(15.4%) |
9(34.6%) |
7(26.9%) |
4(15.4%) |
26 |
|
Maxilla retruded, Mandible normal |
1(2.2%) |
5(11.4%) |
4(9.1%) |
20(45.5%) |
2(4.5%) |
12(27.3%) |
44 |
|
Maxilla retruded, Mandible protruded |
0 % |
1(2.6%) |
5(13.2%) |
17(44.7%) |
5(13.2%) |
10(26.3%) |
38 |
Conclusion: The main skeletal pattern observed in Class III malocclusion patients for 10-18 age group were retruded maxilla with normal mandible and retruded maxilla with protruded mandible.