(70) Is the Magnitude of Maxillary Advancement Associated With Relapse in Patients With Cleft Palate Via Conventional Le Fort I Osteotomy?

Abstract: Le Fort I maxillary advancement is a well-established treatment modality for correcting acquired midface hypoplasia among patients with cleft palate (CP). Despite widespread use, there remains concern over obtaining stability among large maxillary advancements. The specific impact of the distance of advancement on horizontal relapse requires further investigation as studies have shown contradictory results (Fahrayadan et al, 2018; Watts et al, 2015, Bhatia et al, 2016). This study aimed to assess the relationship between the magnitude of maxillary advancement and horizontal relapse among cleft palate patients following Le Fort I orthognathic surgery. We hypothesized that the magnitude of sagittal advancement of the cleft maxilla would not influence stability at 6 months post-operatively.

This was a retrospective study of skeletally-mature patients with cleft palate ± cleft lip (CP ± L) who underwent maxillary advancement at a tertriary-referral hospital over a 4-year period. All subjects were treated by a single surgeon using standard technique for Le Fort I osteotomy. Patients were included as study subjects if diagnostic imaging at 3 time points: preoperative (T0), immediately postoperative (T1), and 6-month postoperative (T2) follow-up. All patients had computer assisted virtual surgical planning, rigid fixation with or without bone grafting, and cephalometric data traced by expert orthodontic observers. Secondary variables included age, sex, cleft type, history of velopharyngeal surgery, intraoperative segmentation, bone graft placement, concurrent fistula repair, and complications. The outcome of interest was linear or angular change in maxillary sagittal position between T2 and T1; change < 1.5 mm or < 1.5 degrees was considered stable.

The study included 48 cleft patients with a mean age of 18.6 years. 70.8% (34) had a primary diagnosis of unilateral cleft. The mean horizontal advancement was 8.3 mm ± 2.3 mm (range: 4-14 mm). No otherwise eligible subjects were lost to follow-up. At T2 compared to T1, maxillary position was stable (relapse < 1.5 mm, < 1.5 degrees). Mean horizontal relapse at T2 was 1.1 mm ± 0.4 mm among subjects with advancements ≥ 10 mm and 0.9 mm ± 0.4 mm among those with < 10 mm of advancement. Mean SNA change at T2 was 1.1 ± 1.4 degrees for movements < 10 mm and 1.2 ± 0.6 degrees for movements < 10 mm. There was no significant difference in the amount of relapse between these two surgical groups (P > .05). Magnitude of advancement was weakly correlated with relapse (Pearson r = 0.4, P < .01).

The results of this study support the notion that the magnitude of maxillary advancement does not significantly influence horizontal relapse in patients with CP undergoing conventional Le Fort I advancement. These results provide further evidence that advancements of 10 mm or more can be completed safely and stably, and do not necessarily require distraction osteogenesis.

References:
Bhatia S, Bocca A, Jones J, Sugar AW. Le Fort I advancement osteotomies of 1 cm or more. How safe or stable? Br J Oral Maxillofac Surg. 2016 Apr;54(3):346-50.
Fahradyan A, Wolfswinkel EM, Clarke N, Park S, Tsuha M, Urata MM, Hammoudeh JA, Yamashita DR. Impact of the Distance of Maxillary Advancement on Horizontal Relapse After Orthognathic Surgery. Cleft Palate Craniofac J. 2018 Apr;55(4):546-553.
Saltaji H, Major MP, Alfakir H, Al-Saleh MA, Flores-Mir C. Maxillary advancement with conventional orthognathic surgery in patients with cleft lip and palate: is it a stable technique? J Oral Maxillofac Surg. 2012 Dec;70(12):2859-66.
Watts GD, Antonarakis GS, Forrest CR, Tompson BD, Phillips JH. Is Linear Advancement Related to Relapse in Unilateral Cleft Lip and Palate Orthognathic Surgery? Cleft Palate Craniofac J. 2015 Nov;52(6):717-23.