Stability after Cleft Maxillary Distraction Osteogenesis or Conventional Orthognathic Surgery

OBJECTIVES: To compare stability of maxillary advancements in patients with cleft lip and palate following distraction osteogenesis or orthognathic surgery. MATERIAL AND METHODS: Inclusion criteria: 1) cleft lip and palate, 2) advancement > 8 mm. Eleven patients comprised the distraction osteogenesis group (DOG). Seven patients comprised the orthognathic treatment group (CONVG). Skeletal and soft tissue points were traced on lateral cephalograms: T1 (preoperatively), T2 (after surgery), T3 (follow-up). Group differences were analyzed using Students t-test. RESULTS: At T1-T2, advancement of 6.98 mm (P = 0.002) was observed in DOG. Horizontal overjet increased 11.62 mm (P = 0.001). A point-nasion-B point (ANB) angle increased 8.82° (P = 0.001). Aesthetic plane to upper lip was reduced 5.44 mm (P = 0.017) and the naso-labial angle increased 16.6° (P = 0.001). Vertical overbite (VOB) increased 2.27 mm (P = 0.021). In T2-T3, no significant changes were observed in DOG. In T1-T2, horizontal overjet increased 8.45 mm (P = 0.02). The ANB angle, 9.33° (P = 0.009) in CONVG. At T2-T3, VOB increased, 2.35 mm (P = 0.046), and the ANB angle reduced, 3.83° (P = 0.003). In T2-T3, no parameters changed in CONVG. At follow-up (T3), VOB increased in CONVG compared with DOG, (P = 0.01). Vertical position of A point differed between the groups (P = 0.04). No significant intergroup differences between soft tissue parameters occurred. CONCLUSIONS: Distraction osteogenesis resulted in a stable position of the maxilla and movement upwards in vertical plane, however in case of orthognathic treatment sagittal relapse and a continued postoperatively downward movement was registered.