LeFort I Horizontal Osteotomy: Defining the Feasibility of the “High Osteotomy”

BACKGROUND: Patients with cleft lip and palate (CLP) commonly develop midface deficiency, and up to 35% of affected patients undergo a LeFort I osteotomy to improve facial aesthetics and occlusion(1). A “high’ LeFort I osteotomy can improve aesthetics by transposing more superior aspects of the midface compared to a traditional LeFort I(2,3). However, the inferior turbinates are the upper limit for this cut, and variance in the vertical location of this structure affects the feasibility of a “high-osteotomy.” The purpose of this study was to quantify the relationship between the inferior turbinates and superior ala in cleft patients undergoing LeFort I osteotomy to determine the frequency with which the osteotomy was performed above the superior ala and attempt to define the height at which this “high osteotomy” would need to be performed. METHODS: The surgical records of 35 non-syndromic patients with unilateral CLP who had undergone LeFort I osteotomy between 2013 and 2022 were retrospectively analyzed. Patients were included if cone-beam computed tomography (CBCT) scans were completed pre- and post-operatively. Rhinoplasty prior to post-operative imaging and patients with a bilateral cleft were excluded. Two reference planes ensured standardization of CBCT head orientation(4). Dolphin Imaging Software was used for CBCT visualization and measurement. The most inferior point of the piriform aperture on the non-cleft side defined the piriform base. The osteotomy height was defined as the most anteromedial point of the osteotomy along the lateral piriform rim. The level of the inferior turbinate was used as the most anterior point of the inferior turbinate at its attachment to the lateral nasal wall. The most superior aspect of the soft tissue ala was superimposed onto the hard tissue for measurement. Descriptive statistics were performed. RESULTS: The sample included 27 males and 8 females, and 13 right-sided clefts and 22 left-sided clefts. One (2.86%) of the osteotomy cuts was above the level of the cleft side superior ala, and no osteotomy cuts were above the level of the non-cleft side superior ala. On average, the superior ala was located 2.83mm (95% CI 1.70-3.96) above the inferior turbinates. The average distances between the non-cleft piriform aperture to the mean height of the bilateral superior ala is 12.24mm (95% CI 11.29-13.19) with a variance of 16.41 and from the non-cleft piriform aperture to the mean height of the bilateral inferior turbinate is 15.07mm (95% CI 13.81-16.34) with a variance of 29.11. CONCLUSION: Given that the superior ala is often positioned above the inferior turbinate, completing an osteotomy above the level of the superior ala is usually not possible. Thus, the feasibility of a clinically useful “high” LeFort I osteotomy is called into question. Furthermore, significant variation in the location of these structures makes it impractical to define a standard measurement for a “high osteotomy.” References: 1. Good PM, Mulliken JB, Padwa BL. Frequency of Le Fort I osteotomy after repaired cleft lip and palate or cleft palate. Cleft Palate Craniofac J. 2007;44(4):396-401. 2. Davidson, E., & Kumar, A. R. (2015). A preliminary three-dimensional analysis of nasal aesthetics following Le Fort I advancement in patients with cleft lip and palate. Journal of Craniofacial Surgery, 26(7), e629-e633. 3. Yun, Y. S., Uhm, K. I., Kim, J. N., Shin, D. H., Choi, H. G., Kim, S. H.,... & Jo, D. I. (2015). Bone and soft tissue changes after two-jaw surgery in cleft patients. Archives of plastic surgery, 42(04), 419-423. 4. Lonic D, Sundoro A, Lin HH, Lin PJ, Lo LJ. Selection of a horizontal reference plane in 3D evaluation: Identifying facial asymmetry and occlusal cant in orthognathic surgery planning. Sci Rep. 2017;7(1):2157. Published 2017 May 19.