One-Piece Le Fort I Osteotomy Versus Segmental Le Fort I Osteotomy

Le Fort I osteotomy is often used in orthognathic surgery for patients to solve midface retrusion. It is known that post-surgical stability of Le Fort I osteotomy can be influenced by single jaw or bimaxillary procedures, fixation techniques or interpositional grafting. In patients with cleft lip and palate, the postoperative instability of Le Fort I osteotomy can be even worse due to scar tissue resulted from palate surgery. Segmental LeFort I osteotomy is another useful surgical modifications that can be easily done through the alveolar cleft. It is performed to allow the correction of differences in the occlusal planes, correction of transverse discrepancy or to facilitate an optimal occlusion. The most important benefits is that the alveolar cleft in patients who have not had alveolar bone graft surgery or failed to have successful result can be narrow down or even closed by approximation of two separating alveolar segments. However, there are limited previous studies comparing the stability of segmental versus one-piece Le Fort I osteotomy especially in patients with cleft. It is our aim to investigate whether one-piece Le Fort I osteotomy or segmental Le Fort I osteotomy can provide a better stability after surgery.

Measurements Skeletal movement Skeletal Surgical movement from T2 to T1 positional change of landmarks in vertical from constructed Frankfurt plane positional change of landmarks in horizontal plane in relative to constructed coronal plane through Sella point Post-Surgical skeletal movement (Stability) from T3 to T2 positional change of landmarks in vertical from constructed Frankfurt plane positional change of landmarks in horizontal plane in relative to constructed coronal plane through Sella point Skeletal angular measurement change on mid-sagittal plane from (T2 to T1) and (T3 to T2) Dental change measured from digital maxillary cast in transverse direction from (T2 to T1) and (T3 to T2) Facial Height / Facial Proportion changes from (T2 to T1) and (T3 to T2) Alveolar cleft width changes from (T2 to T1) and (T3 to T2)

Cleft lip and palate, Cone-Beam Computed Tomography, Le Fort I Osteotomy, Segmental Osteotomy, Stability

For some cases that bone filling over cleft site is not good enough for tooth movement, it is possible that we put them into this group which means by using Segmental Le Fort I Osteotomy to approximate two dental alveolar segments.

For patients having ideal bone graft result over cleft site, traditional One-piece Le Fort I Osteotomy will be performed.

comparison the stability of segmental Le Fort I osteotomy with conventional approach of one-piece Le Fort I osteotomy

to compare the stability and relapse rate in vertical, horizontal and transverse among two kinds of different surgical techniuques

Inclusion Criteria: Cleft lip/palate patients Non growing Taiwanese adults, at least 18 years old for men and 16 years old for women Patients with midface retrusion and malocclusion that will need Le Fort I osteotomy Rigid fixation with bone plates Patients who signs the informed consent form Exclusion Criteria: Association with craniofacial anomalies Patient without complete 3D imaging records including CBCT scans and digital dental models