A study of post-operative changes in facial height and width of mandibular prognathic patients

Kim, Eun Joo; Moon, Cheol Hyun

Abstract

If a mandibular prognathic patient has an extremely unnatural anteroposterior and vertical maxilla or keen esthetical perception for facial profile, orthognathic surgery must be performed along with orthodontic treatment, which alone cannot provide satisfactory
results
in this case. Esthetical improvement becomes an important factor in the satisfaction level of the patient's treatment result, but an attempt to objectively measure beauty holds many problems. Therefore, in the end, the patient submits the final esthetical evaluation based on his/her subjective viewpoint. Because Korean People have a tendency to prefer the facial appearance of westerners, they favor an oval shaped face over the traditional round face. This research was conducted in response to the complaints raised by patients who claim that their face had become more round from widening of facial width after the orthognathic surgery for manidubular prognathism than before the surgery. The following results were obtained on the changes in facial appearance and patient satisfaction level by analyzing the skull P-A analysis of total of 14 patients (8 male and 6 female) who underwent orthognathic surgery primarily chief complaint for manidibular prognathism and from their responses on questionnaires. These results are to be used in the research on the pre- and post- operative changes in facial height and width from orthognatic surgery. 1. There (21.4%) of 14 patients said their face had widened. 2. The A group showed no change in mandibular width but B group showed a 0.7mm reduction. The facial width increased by 0.45mm and 0.66mm in groups A and B, respectively, after the orthognathic surgery. 3. After the surgery the facial length changed by an 0.52mm increase in upper facial height, 1.19mm reduction in lower facial height, and 0.7mm reduction in mandibular height in group A. In group B group, there was a 0.67mm reduction in upper facial height, 3.66 mm reduction in lower facial height, and 5mm reduction in mandibular height. 4. In reference to facial width, the facial height showed 1.5% reduction in group A and 3.6 reduction in group B after the surgery. 5. In reference mandibular height-to-facial width ratio, there was a 1.3% reduction in group A, and 4.4% reduction in group B after the surgery. 6. In reference to the mandibular height-to-width ratio, there was a 1.3% reduction in group A 4.3% reduction in group B after the surgery. 7. Although the change in the facial width due to surgery can be ignored, sufficient explanation should be provided to the patient before surgery on the fact that the face can appear to be relatively wide because of the reduced facial length as result of the surgery.