The Influence of the Hourglass Form of the Neck on Perceptions of Frontal Esthetics.

The purpose of this investigation was to evaluate the effect of the neck concavity angle (NCA) on different occupational groups' perceptions of frontal esthetics. An online survey was developed using Google Forms and sent to the observers through WhatsApp. Male and female frontal silhouettes were created, and NCAs that comprise the hourglass form of the neck were altered in 5 degrees increments from 120 degrees to 170 degrees. Observers were asked to score the images using 0 to 10 numerical rating scale. In all, 279 observers (97 orthodontists, 92 oral-maxillofacial surgeons, and 90 laypeople) participated in this study. For the male and female silhouettes, an NCA of 145 degrees was perceived as the most esthetic, while an NCA of 170 degrees was perceived as the least esthetic by all groups. Generally, an NCA greater than 145 degrees was perceived as less esthetic than an NCA smaller than 145 degrees. There was no significant difference between the scores of the observer groups for the silhouettes except for the female silhouettes with an NCA of 125 degrees or 150 degrees and the male silhouettes with an NCA of 145 degrees or 150 degrees. For both the female and male silhouettes, the further the NCA increased or decreased from 145 degrees, the less esthetic it was perceived to be. A significant increase in NCA was perceived as less esthetic than a significant decrease. The range of NCAs perceived as esthetic varied between 120 degrees and 145 degrees for women and between 130 degrees and 150 degrees for men. These ranges of variability of NCA may provide clinicians with useful information for orthognathic surgical planning.

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.

The Assessment of External Nasal Valve Efficiency After Le Fort I Surgery.

BACKGROUND: The present study investigated how external nasal valve function is affected after Le Fort I osteotomy using external nasal valve efficiency (ENVE) index. MATERIALS AND METHODS: Twenty-one patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in the retrospective study. Preoperative and postoperative standardized videos of basal view of the nose during breathing were recorded, and 2 screenshots were taken, 1 in the resting position and the other after deep inspiration. External nasal valve efficiency was calculated at preoperative and postoperative periods for each patient. RESULTS: Of the 21 patients, 12 were women and 9 were men (mean age, 26.63 ± 8.20 years). The mean ENVE index was 0.75 ± 0.16 for the preoperative period and 0.82 ± 0.17 for the postoperative period. There was a significant difference between these values ( P = 0.002). When the correlation of the ENVE with maxillary movements was analyzed, the ENVE was negatively affected by maxillary impaction ( P = 0.011, r = -0.540). CONCLUSIONS: These findings imply that Le Fort I osteotomy positively affects the ENVE index. However, because of the antagonistic relation between maxillary impaction and ENVE, higher maxillary impaction amounts or isolated maxillary impaction should be carefully planned in patients with low ENVE index.

Safe Limits of Lateral Nasal Wall Osteotomy at Le Fort I Surgery.

INTRODUCTION: The aim of this study was to define the difference between lateral nasal wall anatomy and variations as linear and angular in patients with class II and class III dentofacial deformities and to determine a surgical margin for safe entry by establishing an ideal osteotomy line for lateral nasal wall osteotomy during Le Fort I surgery. MATERIALS AND METHODS: Eighty-five patients with dentofacial deformities, who were admitted to Medipol Mega University Hospital between September 2018 and February 2021, and 170 regions, including the right and left, were evaluated. In the axial image taken from coronal sections 5 mm above the deepest point of the nasal floor, lateral nasal wall angulations and linear and angular distances to the descending palatine canal were measured. Class II and class III patients were evaluated according to the right and left regions and gender. RESULTS: The angled right distance values to the descending palatine artery of class III patients are higher than the values of the angled left distance to the descending palatine canal (p = 0.034). The right second angulation levels of class II female patients are higher than those of class II male patients (p = 0.037). Class III male patients have a significantly higher right linear distance to the descending palatine canal and right second angulation levels compared to class III female patients (p1 = 0.009; p2 = 0.003). The right second angulation levels of class II male patients are significantly lower than those of class III male patients (p = 0.003). CONCLUSION: This study described the mean angulations and linear distances between anatomic structures of the lateral nasal wall in patients with class II and class III dentofacial deformities for the purpose of a safe osteotomy. The location of the descending palatine canal and the morphology of the lateral nasal wall are not significantly associated with dentofacial deformity.

Analysis of Inferior Nasal Morphology and Nostrils following Le Fort I Osteotomy.

OBJECTIVE: This study aimed to investigate the soft tissue parameters related to inferior nasal morphology and nostril shape and investigate the change at nostril types according to the Modified Topinard System following maxillary surgery. MATERIALS AND METHODS: Thirty-five patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Presurgery (T1) and postsurgery (T2) measurements which were the angle between the longitudinal axis of left and right nostril, nostril length, nostril width, alar width, alar base width, columella length, and columella width, were measured on computed tomography images. Nostril types according to Modified Topinard System and nostril shapes were also examined. RESULTS: Following Le Fort I surgery, there was a significant increase in alar base width, alar width, and angle between the longitudinal axis of the left and right nostril (P<0.05). Nasal tip protrusion was decreased with significance (P=0.022). Multiple linear regression analysis showed that every 1 mm maxillary impaction amount leads to a 3.34° increase in the angle between the longitudinal axis of the left and right nostrils (P=0.03, adjusted R2=0.21). Nostril type classification according to Modified Topinard System was changed significantly (P=0.000). CONCLUSION: Surgeons should be aware of the risk of postoperative nonaesthetic results in Modified Topinard System's borderline cases. Modified Topinard classification may be included in preoperative orthognathic planning from the bottom view.

The Effect of Orthognathic Surgery on the Hourglass Appearance of the Neck.

In frontal view, the transition from the upper aspect of the neck to the inferior border of the mandible has a subtle hourglass appearance. The aim of this study was to evaluate the effect of the orthognathic surgery on the hourglass appearance of the neck in patients with Class II dentofacial deformity. Twenty-six patients with Class II dentofacial deformity who underwent bilateral sagittal split osteotomy alone or in combination with Le Fort I osteotomy and/or genioplasty were included in this study. The width of the most upper part, the width of the narrowest part, the length of the upper part, the height of the upper part, the depth, and the angle of the hourglass were measured on frontal facial photographs obtained preoperatively and at sixth months postoperatively. The decrease in the width of the narrowest part ( P =0.012) and the right ( P <0.001) and left ( P <0.001) angles of the hourglass were statistically significant. Also, increase in the right ( P =0.036) and the left ( P =0.004) depths of the hourglass were statistically significant. Orthognathic surgery procedures performed to correct Class II dentofacial deformity positively affects the hourglass appearance of the neck, therefore neck esthetics should also be considered in the preoperative evaluation of facial esthetics.

Evaluation of parameters related with upper lip aesthetics and dynamic smile following Le Fort I osteotomy.

OBJECTIVE: The present study aimed to investigate how upper lip aesthetic and dynamic smile parameters are changed following a Le Fort I osteotomy. METHODS: Twenty-seven patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Upper lip aesthetic parameters which were Cupid's bow angle, lip angle, lip length, lip width, philtrum width and lip corners were evaluated on pre and postoperative rest photos using Image J software. Lip corner movement direction, buccal corridor area with respect to canine and last visible tooth were also measured on posed smile photos with respect to dynamic smile evaluations. Measured variables were submitted to statistical analysis and significance level was determined as 0.05. RESULTS: There was a significant reduction in buccal corridor area according to last visible teeth for right and left side at postoperative period. However, buccal corridor area with respect to canine for the right and left side was not significant. The angle between the lip corner movement direction and Y-axis of the face for the right and left sides was not significant between pre and postoperative period. The changes in this angle were not also correlated with the changes in buccal corridor area and maxillomandibular movements. Not only the Cupid's bow angle, lip angle but also lip length, lip width, philtrum width and lip corner have not been changed significantly. CONCLUSION: Buccal corridor area investigated in dynamic smile shows significant improvement after orthognathic surgery especially in the means of maxillary impaction. Lip corner movement during smile was not associated with the changes in buccal corridor area. Landmarks around perioral area in static state were affected clinically with no statistical significance following the surgery.

Analysis of Gull in Flight Appearance and Related Parameters Following Le Fort I Osteotomy.

ABSTRACT: The present study aimed to investigate how "Gull in Flight" appearance and alar-columellar relationship change following maxillary surgery. Thirty-three patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Measurements which were angle of columella triangle, alar-rim angle, columella lobular angle, and distance of points forming "Gull in Flight" appearance were evaluated on pre and postoperative frontal and lateral photos of patients. Data was submitted to statistical analysis and significance level was determined as 0.05. Following Le Fort I surgery, distance of points forming "Gull in Flight" appearance with respect to canthus was decreased significantly (P < 0.05). Positions of these points to each other were not changed (P > 0.05). Every 1 mm maxillary impaction led to 0.58 mm reduction in y3 (the distance from the point that illustrates Gull's body) (P = 0.032). There was a decrease in angle of columella triangle, alar-rim angle and increase in columella lobular angle. However, these changes were not found significant (P > 0.05). Angle of columella triangle was increased 2.51 degree for every 1 mm maxillary advancement (P = 0.028). In conclusion, maxillary surgery had an impact on nasal region from frontal view. However, "Gull in Flight" appearance which is one of the aesthetic parameters in nose was not changed following maxillary surgery.

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.

Changes of Stress Distributions Around Pterygomaxillary Junction With Different Osteotome Angulations.

The aim of this study was to investigate how the alteration of the angulation of osteotome at pterygomaxillary junction affects lateral pterygoid plate, maxillary tuberosity, palatal surface of maxilla, palatine bone and body of sphenoid bone. Following reconstruction of 3D modelling of maxilla, Osteotomes' tip was angulated 45 and 90 to sagittal plane to simulate pterygomaxillary osteotomy. Finite element analyses (FEA) was performed and Von Misses stress distributions were analyzed for two different angulations. Independent sample t test was used to compare differences between 45 and 90 angulations. Von Misses stress values on lateral pterygoid plate were higher in 45 angulation (0.71 ±â€Š0.21 MPa) than 90 angulation (0.54 ±â€Š0.28 MPa). This difference was statistically significant (P < 0.01). Placement of osteotome's tip with 90 angulation had higher stress value than 45 angulation on maxillary tuberosity region. However; difference wasn't significant (P = 0.44). Stress values on body of sphenoid bone were 0.45 ±â€Š0.17MPa for the case of 90 angulation and 0.19 ±â€Š0.09MPa for 45 angulation. Difference between these values were statistically significant (P < 0.01). Possible risk of unfavourable lateral pterygoid plate fracture and complications related with body of sphenoid bone during pterygomaxillary osteotomy was remarkably increased in case of narrow angulation (45). Keeping osteotome at right angle with sagittal plane may avoid these complications.

Surgical Protocol for a Safe Lateral Nasal Wall Osteotomy.

PURPOSE: The purpose of this study was to define the anatomy and anatomic variations of the lateral nasal wall area to identify safe access points, determine the optimum osteotomy line for Le Fort I osteotomies, and define a surgical protocol. MATERIALS AND METHODS: The angulations and widths of 160 lateral nasal walls and the distances of the greater palatine canal were measured on axial images from coronal sections 5 mm over the deepest point of the nasal base. RESULTS: The average angle between the anterior lateral nasal wall and the medial maxillary sinus wall was 160 degrees in females and 165.67 degrees in males for the right and 155.90 degrees in females and 163.22 degrees in males for the left side. Statistically significant differences were found in the lengths, angulations, and widths of the lateral nasal walls between females and males. CONCLUSION: This study described the mean angulations and linear distances between anatomic structures of the lateral nasal wall and it defines the "Medipol protocol" for a safe osteotomy.