A Modified Minimally Invasive Approach Towards Le Fort I Osteotomy: a Prospective Study

Study Overview
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Brief Summary
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Nowadays, maxillary Le Fort I osteotomy is a safe and routinely performed procedure. The conventional approach is characterized by a vestibular incision extending from molar-to-molar, associated with a pterygomaxillary disjunction performed with a curved chisel. Adequate mobilization of the maxilla during Le Fort I osteotomy requires an effective separation of the maxillary tuberosity from the pterygoid plates of the sphenoid bone. However, as initially described by Precious (1991) and later by Hernandez-Alfaro (2013), a true pterygomaxillary osteotomy is not necessary to achieve successful disjunction. Furthermore, Hernandez-Alfaro combined his technique of pterygomaxillary disjunction, the so-called Twist technique, to a minimally invasive protocol, performing the complete Le Fort I osteotomy through a 20 to 30 mm long horizontal vestibular incision. Although promising, the technique remains highly sensitive from a technical standpoint, and its true accuracy has not been comprehensively evaluated. The purpose of this study is to present and validate a minimally invasive approach towards Le Fort I osteotomy, using a modified pterygomaxillary (PTM) disjunction technique. The primary outcome is to evaluate the accuracy of the technique using rigid voxel-based registration of the 3D virtual treatment planning and the 4 weeks postoperative CBCT images. Secondary outcomes include the surgical time necessary to complete the procedure and the presence of intraoperative and early postoperative complications.

Conditions
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Jaw Abnormalities

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients of all ages Patients of all genders A Le Fort I osteotomy is planned, as part of a bimaxillary orthognathic procedure The surgery is planned with 3D Virtual Treatment Planning (Maxilim v. 2.3.0.3.0.) The planning is transferred with 3D CAD/CAM tooth-borne splint and vertical internal bony reference landmarks The maxilla is repositioned first during the surgery (maxilla first sequence) Exclusion Criteria: Patients not eligible according to abovementioned criteria Simultaneous extraction of impacted teeth 18 and/or 28 Previous maxillary orthognathic surgery Previous Surgical Assisted Rapid Palatal Expansion (SARPE) Syndromic condition, including cleft lip and palate Segmental Le Fort I osteotomy Adjuvant Zygomatic osteotomy Maxillary impaction higher than 3 mm Maxillary advancement greater than 5 mm
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| accuracy of the minimally invasive approach in comparison to conventional approaches, based on 3D virtual CBCT superimposition of planning CBCT and postoperative CBCT |  | at 4 weeks postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgical time necessary to complete the procedure |  | perioperative | 
| Intraoperative and early postoperative complications |  | within 4 weeks postoperative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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minimally invasive, le fort I osteotomy, 3D virtual treatment planning, accuracy