Abstract
Although several reports have discussed the effect of two-jaw surgery on the nasal tip and upper lip region, few have mentioned changes in the cheek line, and no quantitative analysis of the cheek line was performed.
In this study, the morphological changes of the soft tissue profile (mainly the cheek line) were examined in skeletal Class III patients who had undergone two-jaw surgery. The subjects were 12 skeletal Class III patients (four females and eight males) on whom two-jaw surgery was carried out at Niigata University Dental Hospital. The controls were 12 skeletal Class III patients (eight females and four males) who had undergone mandibular setback only.
Preoperative and postoperative cephalograms were traced, and analyses of hard tissue, soft tissue, and the cheek line were done. On the cheek line, three angular measurements were made:∠C1, ∠C2, and ∠C3, in addition to the anteroposterior movement of the cheek line (C4, C5).∠Cl is the angle made between the cheek line and parallel line with the FH plane at the intermediate point between the FH plane and Pronasale.∠C2 is the angle made between the cheek line and a horizontal line located below Subnasale.∠C3 is the angle made by the lines connecting the intersection points of the cheek line on the parallel line with the FH plane at the intermediate point between the FH plane and Pronasale.
The results were that, in two-jaw surgery patients, changes of Pn and Sn were similar to those of previous studies. The upper part of the cheek line moved in a forward direction and ∠C1 tended to increase, the lower part of the cheek line changed to convex countor and ∠C2 tended to decrease. As a result, the cheek line tended to become more convex in the two-jaw surgery group than in the one-jaw surgery group.
In conclusion, two-jaw surgery was considered to be quite effective for the esthetic correction of skeletal Class III patients, especially those with maxillary deficiency.
