• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.6
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• pp.365-368
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• 2023

The mentum plays an important role in the aesthetics of the face, and genioplasty is performed to improve an unbalance of the mentum. Among the various surgical approaches, setback genioplasty is used to create an aesthetic jaw-end appearance by moving the mentum backward when it protrudes more than normal. However, conventional setback genioplasty may be aesthetically disadvantageous because the profile of the mentum could become flat. This case study attempted to overcome the limitations of conventional setback genioplasty by rotating the position of the menton and pogonion. We devised a new method for setback genioplasty by rotating the segment anteroinferiorly. Using virtual surgery, we were able to specify the range of surgery more accurately and easily, and the surgery time was reduced. This case report showed the difference in chin soft tissue responses between conventional setback genioplasty and setback genioplasty with rotation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.413-420
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• 2012

Purpose: The purpose of this setback genioplasty study is to develop a prediction method for the calculated osteotomy angle using horizontal and vertical changes as well as to evaluate the proportion of hard and soft tissue changes. Methods: Twelve patients who had received setback genioplasty with other maxillofacial surgery were examined. Three lateral cephalograms were taken just before surgery, immediately after surgery, and 3 months later surgery. A reference line was established to the reference point of the inner most point of the lingual symphysis cortex, incisor tip, and 2nd molar cusp tip. Measuring was conducted from pogonion (Pg), menton (Me), labrale inferius (Li), Mentolabial fold, soft tissue pogonion (Pg'), and soft tissue menton (Me') to the reference lines. Results: In setback genioplasty, the skeletal Pg moved posteriorly 5.07 mm. The ratios of soft tissue to hard tissue movement were 36% posteriorly and 62% inferiorly at Pg', 67% posteriorly and 104% inferiorly at Me', and 34% anteriorly and 164% posteriorly at Li. In reduction & setback genioplasty, skeletal Pg moved posteriorly 4.63 mm and skeletal Me moved superiorly 3.63 mm. The ratios of soft tissue to hard tissue movement were 76% posteriorly and 18% superiorly at Pg', 68% posteriorly and 42% superiorly at Me', and 44% anteriorly, 124% posteriorly at Li. The calculated mean slope angle, based on ${\Delta}H/{\Delta}V$ ratio, was 61.25 and the measured mean slope angle was 60.17. Thus, the calculated and measured slope angles have a similarity. Conclusion: In setback genioplasty, soft tissue moves posteriorly and inferiorly. In particular, at the Me' and Pg', the inferior movement of the soft tissue is greater than the posterior movement. Also, the predictable results (measured slope angle) after operation can be achieved by the calculated slope angle. Thus, the relationship of soft and hard tissue changes must be considered as the results are predictable.

• The korean journal of orthodontics
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• v.38 no.1
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• pp.41-51
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• 2008

Objective: The aim of this study was to compare the initial lateral cephalometric characteristics in two groups of patients: those that had mandibular setback surgery only and those that had mandibular setback surgery with advancement genioplasty. Methods: The lateral cephalograms of thirty-one patients were studied. Twenty-one Class III patients (group A) had only madibular setback surgery Twelve Class III patients (group B) had mandibular setback surgery with advancement genioplasty. Results: Differences between two groups were found in N-Me, ANS-Me, Occlusal Plane angle, Palatal Plane to U1, Mandibular Plane to L1, Mandibular Plane to L6, SN to U1, Sn-Stms, and Pog' projection. Compared to group A, group B showed more linguoversion and extrusion of upper incisors, more extrusion of lower incisors and lower first molar, and more steepness of the occlusal plane. N-Me, ANS-Me, and Sn-Stms were also longer in group B. But Pog' projection was shorter than group A. Conclusion: We conclude that certain initial lateral cephalometric characteristics may help indicate the inclusion of advancement genioplasty when mandibular setback surgery is planned in skeletal Class III patients.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.343-355
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• 2000

The purpose of this study was to evaluate the amount and interrelationship of hard and soft tissue changes after mandibular setback osteotomy and reduction genioplasty in mandibular prognathism with long anterior facial height. The control group (Group A) consisted of 20 patients who had severe horizontal discrepancy. They experienced Presurgical orthodontic treatment and orthognathic surgery via mandibular setback. The experimental group (Group B) consisted of 20 patients who had severe horizontal and vertical discrepancy. They experienced presurgical orthodontic treatment and orthognathic surgery via mandibular setback and reduction genioplasty. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was tarried on with EXCEL 97 program. The results were as follows : 1. The correlation of hard and soft tissue horizontal changes in lower 2/3 of lower anterior facial height were high for both groups. The correlation coefficients of hard tissue changes and Ls, Stm, Li changes in Group B were moderately higher than Group A. 2. The correlation of hard and soft tissue vortical changes in Group B were lower than Group A. (except for pointB-Ils, Me-Me') 3. The ratio for soft tissue to Pog in Group B was lower than Group A. The ratios of hard and soft tissue vertical changes were 32% at Ils, 54% at Pog', and 60% at Me'. 4. The ratio of lower anterior facial height to total anterior facial height was reduced for both groups. But ratio of upper 1/3 of lower anterior facial height to total anterior facial height did not changed significantly in Group B. 5. Reduction genioplasty combined with mandibular setback procedure showed no change in upper one third(Sn-Stm) and significant decrease(Stm-Me') in the lower two thirds of the soft-tissue anterior lower facial height

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.4
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• pp.239-246
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• 2017

Objectives: This paper proposes Han's ratio as an objective and quantitative comparative result obtained from pre and postoperative data in patients with a mandibular angle reduction. Materials and Methods: Thirty patients, 12 men and 18 women, who visited the Department of Oral and Maxillofacial Surgery with the chief complaints of skeletal mandibular prognathism and prominent mandibular angle were selected. The subjects were classified into 3 groups according to the types of surgical procedures involved. Group A consisted of patients who underwent mandibular angle resection and mandibular setback. Group B was comprised of patients with mandibular angle resection, mandibular setback and genioplasty. Group C consisted of patients with mandibular angle resection, mandibular setback, Le Fort I osteotomy, and genioplasty. The landmarks placed in pre and postoperative frontal photographs were used to obtain the Han's ratio in each group. The Han's ratios were compared pre- and postoperation and according to the surgical techniques applied. Results: Of the 3 groups who had undergone a mandibular angle resection, all showed a statistically significant increase in Han's ratio. On the other hand, there was no statistically significant difference based on the surgical techniques used. Conclusion: The ratio of the lateral lower face proposed in this study is a potential indicator of postoperative esthetic enhancement in mandibular angle reduction surgery.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.104-120
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• 2008

Purpose: The purpose of this study was to assess the hard and soft tissue changes associated with mandibular bilateral sagittal split osteotomy and genioplasty. Methods: This is a retrospective study of 40 patients who underwent either bilateral sagittal split osteotomy for mandibular setback (BSSO group, n = 20) or in combination with advancement genioplasty (Genio group, n = 20). Lateral radiographs, were taken before and immediately after surgery, and at least 6 months after surgery. Results: Comparing hard and soft tissue changes between the BSSO group and Genio group, there were significant differences in the lower incisor, soft tissue B point (B'), and soft tissue Pogonion (Pg') (p < 0.5). The mean ratio of hard and soft tissue changes for B/B', Pg/Pg', and Menton/soft tissue Menton after surgery in the BSSO group was 0.997, 0.965, and 1.022 respectively, and 0.824, 0.602, and 0.887 respectively in the genio group. Significant differences were found between the two groups. There were significant differences in lip thickness (B-B', Pg-Pg') in the Genioplasty group between pre and postsurgery, but not in the BSSO group. Pogonion to Labrale inferior and B' had a correlation coefficient of 0.833, 0.922, respectively for the BSSO group, and 0.775, 0.799 for the Genio group. Conclusions: The results indicate that there is a significant difference between bilateral sagittal split osteotomy with or without genioplasty in the lower facial esthetics values. The combination of mandibular setback and genioplasty had a smaller change in soft tissue thickness of the symphysis area after surgery than that of mandibular setback only.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.1
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• pp.9-13
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• 2012

Introduction: To evaluate the 3-dimensional changes in the pharyngeal airway of skeletal class III patients after bimaxillary surgery. Materials and Methods: The study sample consisted of 18 Korean patients that had undergone maxillary setback or posterosuperior movement and mandibular bilateral sagittal split osteotomy setback surgery due to skeletal class III malocclusion (8 males, 10 females; mean age of 28.7). Cone beam computed tomography was taken 1 month before and 6 months after orthognathic surgery. Preoperative and postoperative volumes of the nasopharyngeal, oropharyngeal, and laryngopharyngeal airways and minimum axial areas of the oropharyngeal and laryngopharyngeal spaces were measured. Moreover, the pharyngeal airway volume of the patient group that had received genioplasty advancement was compared with the other group that had not. Results: The nasopharyngeal and laryngopharyngeal spaces did not show significant differences before or after surgery. However, the oropharyngeal space volume and total volume of pharyngeal airway decreased significantly (P<0.05). The minimum axial area of the oropharynx also decreased significantly. Conclusion: The results indicate that bimaxillary surgery decreased the volume and the minimum axial area of the oropharyngeal space. Advanced genioplasty did not seem to have a significant effect on the volumes of the oropharyngeal and laryngopharyngeal spaces.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.5
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• pp.185-191
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• 2014

Purpose: Although there have been several studies of reduced airway space after mandibular setback surgery using the sagittal split ramus osteotomy technique, research on the risk factors for changes of the airway space is lacking. Therefore, this study was performed to examine airway changes and the position of the hyoid bone after orthognathic surgery, and to assess possible risk factors. Methods: In this retrospective study, 50 patients who underwent posterior displacement of the mandible by the bilateral sagittal split ramus osteotomy technique were included. Changes of the position of the hyoid bone and the airway space were analyzed over various follow-up periods, using cephalometric radiography taken preoperatively, immediately after surgery, eight weeks after surgery, six months after surgery, and one year after surgery. To identify risk factors, multiple regression analysis of age, gender, body mass index (BMI), posterior mandibular movement, and the presence of genioplasty was performed. Results: Inferor and posterior movement of the hyoid bone was observed postoperatively, but subsequent observations showed regression towards the anterosuperior aspect. The airway space also significantly decreased after surgery (P<0.05), and increased slightly up until six months after surgery. The airway space significantly decreased (${\beta}=0.47$, P<0.01) as the amount of mandibular setback increased. However, age, sex, BMI, and presence of genioplasty were not associated with airway reduction. Conclusion: The amount of mandibular set back was significantly associated with postoperative reduction of airway space. It is necessary to establish a treatment plan considering this factor.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.184-188
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• 2001

Horner's syndrome as a complication of orthognathic surgery is given little attention of head and neck surgery and is a relatively benign and transient condition. A 18-year-old male referred to our department with long and anteriorly projected chin. The cephalometric evaluation revealed a skeletal Class III relationship. A 10-mm setback of the mandible to eliminate Class III relationship and 4-mm vertical reduction genioplasty were performed. Three weeks after operation, the patient was recognized anhidrosis in left face and the head, and ptosis of left eye. The trauma to cervical sympathetic nerve during left sagittal split ramus osteotomy was thought to be the cause of Horner's syndrome. Patient was treated by dermatologic and opthalmologic care. Follow-up examination 8 months later, he was recovery of horner's symptom.

• The Journal of the Korean dental association
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• v.47 no.11
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• pp.750-757
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• 2009

Purpose : The purpose of this study is to evaluate the clinical availability of submentoplasty for esthethic improvement of the cervico-facial region of patients with obtuse chin-neck angle. Materials and methods : Case 1. We evaluate the changes of submental line length and chin-neck angle of 35-year-old woman with skeletal Class III and mandibular excess with excessive submental fat before and after surgery: Bilateral sagittal split ramus osteotomy(BSSRO) setback(5mm), Mandibular Angle Reduction, Reduction Malarplasty and Submentoplasty. In this case, It was done simultaneously with orthognathic surgery. Case 2. The changes of submental line length and chin-neck angle of 20-year-old man with skeletal class III and maxillary defiency were evaluated before surgery, at first surgery : Lefort I osteotomy(6mm posterior Impaction), BSSRO setback(9mm), Paranasal Augmentation and at second surgery: genioplasty(6mm advanced) with submentoplasty. In this case, submentoplasty and advancement genioplasty were done after 2 months post-operative periods. Results : Case 1. In case of the Skeletal Class III mandibular excess with submental fat deposit, It showed the improvement of submental angle and length of submental line after simultaneous submentoplasty. Submental angle is changed from $177^{\circ}$ (pre-op) to $151^{\circ}$ (post-op) and submental line length is changed from 8mm(pre-op) to 36mm(post-op). Case 2. The improvement of submental angle and length of submental line after delayed submentoplasty was aquired in case of the skeletal class III maxillary defiency. Submental angle is changed from $154^{\circ}$ (pre-op) to $161^{\circ}$ (first surgery) and to $153^{\circ}$ (second surgery) and submental line length is changed from 25mm(pre-op) to 19mm(first surgery) and to 23mm(second surgery). Conclusion : The results suggest that Submentoplasty is useful surgical procedure for esthethic improvement of the cervicofacial region of patients with obtuse chin-neck angle.