Morphologic analysis of upper lip area following maxillary osteotomy via the tunneling approach.

Preservation of favorable upper lip morphology is a critical factor in assessing the success of maxillary osteotomy surgery. Unesthetic postsurgical lips often appear thin and tight, with the vermilion border shortened and rolled inward. Clinical observation of patients who had undergone total maxillary alveolar process osteotomies by means of vertical buccal incisions and a tunneling approach suggests that presurgical lip morphology is minimally changed. This study investigates the presence and degree of change in upper lip morphology following this technique. Pre- and postoperative cephalometric radiographs of ten patients were compared by superimposition of acetate tracings on cranial base landmarks. Cross-sectional lip area was calculated by compensating polar planimetry presurgically and at four intervals following intervention: 1 to 3 days, 1 to 3.5 months, 6 to 9 months, and more than 10 months. Analysis showed the cross-sectional upper lip area, compared to the presurgical baseline, to be as follows: Immediately following surgery, the area increased by a mean of 27.8% (range, 15.0% to 36.9%; SE = 4.72). At 1 to 3.5 months postsurgery, the increase was reduced to 3.3% (range, 0 to 7.7%; SE = 0.82). At 6 to 9 months, lip area remained minimally increased, at + 0.78% (range, -5.0% to 7.6%; SE = 1.68). At 10 months or longer, the mean increase from preoperative values was 0.61% (range, -6% to 6.4%; SE = 1.38). The results of this study indicate that the upper lip cross-sectional area returns to its presurgical value at 6 months following surgery and remains constant at subsequent measurements. The performance of maxillary surgery with this flap design appears to preserve presurgical lip morphology.