Does mandibular osteotomy affect the infraorbital nerve? a prospective study.

OBJECTIVES: The aim of this study was to evaluate the sensory function of the infraorbital nerve after orthognathic surgery (OS). MATERIALS AND METHODS: Patients who underwent Le Fort I osteotomy with or without BSSO for dentofacial deformity treatment were studied. Two groups were created according to whether BSSO was performed. Class A tests were performed to determine the degree of peripheral nerve damage. The Class B test was performed if decreased sensation was detected in at least one of these tests. A Class C test was performed if abnormal sensation was detected. RESULTS: Twenty-eight patients (n=56) who underwent OS were included in this prospective study. Of the patients, 57.1% were female, 42.9% were male, and the mean age was 24.6 (±3.8). Seven patients were in group 1 (n=14), and 21 patients were in group 2 (n=42). In both groups, there were statistically significant differences between T1 and T2 (p<0.001), and the mean NSD score at T2 was higher than that at T1. The mean NSD score in the single jaw group was higher than that in the double jaw group at all time points. CONCLUSIONS: Bimaxillary surgeries had a negative effect on the somatosensory changes that developed in the early period. The upper lip's somatosensorial recovery was faster than IOR and single jaw recovery was faster than double jaw. CLINICAL RELEVANCE: Maxillofacial surgeons performing orthognathic surgery should be aware that in double jaw operations, changes in the somatosensory function of the ION are more severe.

Effect of Orthognathic Surgery on Movement of the Cheilion.

The cheilion (Ch), corner of the mouth, is the soft-tissue landmark where the upper and lower lips intersect. Orthognathic surgery can modify Ch position, which can affect facial esthetics. The aims were to evaluate Ch movements resulting from Le Fort I maxillary advancement with maxillary impaction or downgrafting, and with mandibular advancement or setback, and to investigate relationships between surgical movements and Ch movements. The 45 patients had undergone bilateral sagittal split ramus osteotomy with Le Fort I advancement surgery. They were divided into 4 groups according to surgical movement direction. Preoperative and postoperative photographs were calibrated. Standardized methods were used to identify and measure preoperative and postoperative Ch positions. Significant correlations were detected between extent of maxillary downgrafting and inferior movement of the Ch in group 1 ( r =0.988, P =0.001) and group 3 ( r =0.915, P =0.001). Also, significant correlations were detected between extent of mandibular advancement and anterior movement of the Ch in group 3 ( r =0.561, P =0.046) and group 4 ( r =0.661, P =0.005). The findings indicate that, in patients who undergo bilateral sagittal split ramus osteotomy/Le Fort I surgeries, mandibular advancement moves Ch anteriorly and maxillary downgrafting moves Ch inferiorly.

Comparison of scleral show alterations following Le Fort I osteotomy with either maxillary impaction or lengthening.

This study aimed at evaluating changes in scleral show following Le Fort I osteotomy with either impaction or lengthening of the mid face. Patients who underwent Le Fort I osteotomy were included. The patients were divided according to the direction of the movement: group 1 underwent maxillary advancement and impaction, while group 2 underwent maxillary advancement and lengthening. Standardized preoperative and 6-month postoperative photos were superimposed using Microsoft PowerPoint. The inferior visible scleral area was assessed with landmarks and measured separately using ImageJ software. Marked scleral surface area was determined using pixel count. A total of 36 consecutive patients were included. The mean maxillary advancement in the patients was 4.16 ± 2.14 mm. The mean impaction in group 1 (n= 21) was 1.06 ± 1.49 mm, while the mean vertical lengthening in group 2 (n = 15) was 1.54 ± 1.65 mm. The difference in improvement in the inferior scleral show between the groups was not statistically significant. Preoperative (180 ± 118.2 mm) and postoperative (147.75 ± 92.2 mm) scleral show significantly improved (p = 0.012) in both groups. Scleral show can be overlooked for movements under 6 mm while planning for maxillary orthognathic movement, as it improves regardless of the desired movement.

Effect of Horizontal Osteotomy Level on Complication Rates and Neurosensory Deficits After Sagittal Split Ramus Osteotomy.

Horizontal osteotomy is one of the most critical step at sagittal split ramus osteotomy (SSRO) and determination of the ideal height of this horizontal osteotomy is essential to avoid nerve and vessel injury. PURPOSE: The aim of this study was to evaluate the level of the medial horizontal ramus cut as a risk factor for unfavorable outcomes in the SSRO. MATERIALS AND METHODS: Sixty-four patients with dentofacial deformity who applied to Oral & Maxillofacial Surgery Department between August 2018 and August 2019 and undergone orthognathic surgery were evaluated. Out of 64, 49 patients had SSRO with or without maxillary surgery and genioplasty. Twenty-six patient had postoperative computed tomography scan with 6-months follow-up. Finally, 26 patient with 52 SSRO sides were included in this study. Computed tomography scans were evaluated and classification according to osteotomy levels was made. Postoperative neurosensory deficit, bleeding, and intraoperative complications such as bad split, visible damage to inferior alveolar bundle were assessed. Age, gender, neurosensory deficit, bad splits were analyzed and correlated with the level of the osteotomies. RESULTS: Fifteen osteotomies were above lingula, 24 between apex and base of lingula, and 14 below lingula. One bad split occurred, and no visible damage to the inferior alveolar bundle was seen. There was no significant difference between osteotomy groups in terms of visual analogue scale (VAS) scores (P > 0.05) but in all groups; women's VAS scores are statistically significantly higher than men. (P: 0.036). CONCLUSION: There is no correlation between the horizontal osteotomy level and intraoperative or postoperative complications. The low medial horizontal osteotomy can be safely performed in SSRO.