The aim of this study is to investigate the effect of different instrument modifications on the customized osteotomy of the lateral nasal wall in Le Fort I surgery, focusing on the level of lateral nasal wall fractures and the separation pattern of the pterygomaxillary junction.

The primary hypothesis is blade osteotome is useful and facilitate the fracture line in ideal level both for lateral nasal wall and the pterygomaxillary junction.

While there are numerous studies in the literature evaluating various parameters related to maxillary down-fracture in Le Fort I osteotomy, studies specifically focused on lateral nasal osteotomy are very rare. There is no study in the literature has addressed customized lateral nasal osteotomy using different instruments. In our study, the lateral nasal wall osteotomy will be performed 2 mm shorter than the measured descending palatine ater distance in the axial computer tomography plane. One group (n=23) will use the routinely employed Nievert osteotome (single guided osteotome), while the other group (n=23) will use a blade osteotome (no guided tip). This study aims to evaluate parameters such as the fracture pattern of the lateral nasal walls and the separation pattern of the pterygomaxillary junction by using different instrument modifications for lateral nasal wall osteotomy.

Inclusion Criteria:

• Patients requiring Le Fort I or bimaxillary surgery
• Patients who have not previously undergone Le Fort I or bimaxillary surgery (revision)
• Patients without cleft lip or palate
• Patients with no history of midface fractures or craniofacial trauma

Exclusion Criteria:

• Patients with cleft lip and/or palate requiring orthognathic surgery
• Patients with a history of trauma needing orthognathic surgery for malocclusion correction
• Patients who have previously undergone orthognathic surgery and require revision surgery