Readmission after orthognathic surgery.

OBJECTIVE: To evaluate the readmission rate after orthognathic surgery and identify associated risk factors. STUDY DESIGN: Retrospective analysis of patients who underwent orthognathic surgery and had an unexpected hospital admission, with or without return to the operating room (OR), within the first postoperative year. Study variables included sex, age, American Society of Anesthesiologists (ASA) status, type of surgery, concomitant third molar extraction, concomitant genioplasty, duration of surgery, first assistant experience, and duration of hospitalization. Bivariate associations were calculated between variables and readmission status. Chi-square and Fisher's Exact tests were used to compare categorical variables, and a 2-sample t test was used to compare continuous variables. RESULTS: There were 701 patients included in the study. The readmission rate was 9.70%. Twelve patients were managed non-surgically, and 56 patients required an OR procedure. The most common reason for readmission without return to the OR was an infection, and for reoperation was hardware removal. Age, sex, type of surgery, third molar extraction, genioplasty, duration of surgery, and experience of first assistant were not found to be predictors for readmission. CONCLUSIONS: Only ASA classification and duration of initial hospitalization were significant risk factors for readmission of patients within the first postoperative year after orthognathic surgery.

Vascular Anatomy for the Prevention of Sublingual Hematomas: Life-Threatening Complication of Genioplasty.

After genioplasty, the occurrence of bleeding is rare; however, rapid enlargement or displacement of the tongue secondary to lingual or sublingual hematoma can lead to life-threatening airway obstruction, necessitating prompt recognition, and immediate management. Therefore, the investigators aimed to evaluate the underlying etiologies of sublingual hematoma and relevant anatomy to facilitate early recognition of the initial presentation of these hematomas and appropriate management. The authors conducted a literature review on cases of delayed sublingual hematoma after genioplasty. The authors also report a case of delayed hematoma after performing genioplasty. The anatomical structures involved with the development of rare and serious hematomas therein are the sublingual and submental arteries, which are located in the sublingual area, rendering them susceptible to injury during genioplasty. The results of this study suggest that submental artery ligation should be performed for proper management of airway obstruction, if symptoms of sublingual bleeding are observed during the surgical procedure. If there is continuous bleeding despite the submental artery ligation, sublingual artery ligation should be performed.

Effect of concentrated growth factor on lower lip hypoesthesia after osseous genioplasty: a prospective, split-mouth, double-blind randomized controlled trial.

Lower lip hypoesthesia is the most common complication following osseous genioplasty. Concentrated growth factor (CGF) has recently been shown to improve neural regeneration. The aim of this study was to evaluate the effect of concentrated growth factor on neurosensory recovery after osseous genioplasty. Patients who underwent osseous genioplasty between June 2017 and February 2020 were enrolled. CGF was applied to the mental nerve on one side. The treatment side was randomized, and the other side was considered as the control. Lower lip hypoesthesia was assessed preoperatively and postoperatively (1 week, 1, 3, 6, and 9 months) using the two-point discrimination test and a 10-point visual analogue scale (self-reported paresthesia). The assessor was blinded. Twenty-six female patients completed the study. At 1 and 3 months, both the mean two-point discrimination value and mean visual analogue scale score were significantly lower in the CGF group than in the control group (P < 0.001). At 3 months, the percentage of patients with lower lip hypoesthesia in the CGF group was significantly lower than that in the control group (P < 0.001). Both groups showed resolution of lower lip hypoesthesia at 6 months. Concentrated growth factor may accelerate the recovery of long-standing sensory nerve impairment following mental osteotomy.

Osseous Genioplasty: Prevention of Witch's Chin Deformity with No-Degloving Technique.

BACKGROUND: Osseous genioplasty is a powerful procedure that can correct chin dysmorphology; however, traditional techniques may result in chin ptosis or a "witch's chin" deformity. Iatrogenic chin ptosis is thought to be caused by excessive degloving of soft tissue with a failure to reattach the mentalis muscle. In the authors' study, they compared the "no-degloving" technique (using a 90-degree plate with lag-screw fixation) to the "traditional" technique, for minimization of chin ptosis. METHODS: The authors compared genioplasty techniques for consecutive patients: group 1 (traditional) underwent degloving for fixation of a stair-step plate, whereas group 2 (no-degloving) underwent lag-screw fixation (n = 50; 25 patients per group). The authors compared operating room time, advancement, complications, preoperative-to-postoperative vertical height change of the pogonion and menton (obtained through cone beam computed tomographic scans), surgeons' assessment of witch's chin, and FACE-Q surveys. RESULTS: No-degloving versus traditional groups had similar age and sex distributions, horizontal/vertical change (5 mm/2 mm versus 6 mm/2 mm), length of surgery, and complication rate (5 percent). The traditional group had more deviation from expected position for both the pogonion (3.4 mm versus 1.2 mm; p ≤ 0.05) and menton (2.9 mm versus 0.8 mm; p ≤ 0.05), and more occurrences of witch's chin (six versus zero). No-degloving was superior for several FACE-Q scales, including Chin Appearance, Quality of Life, Satisfaction with Decision to Undergo Procedure, and Satisfaction with Outcome. CONCLUSION: No-degloving osseous genioplasty is a safe, reproducible technique that results in decreased soft-tissue ptosis and increased patient satisfaction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

A New Concept of Narrowing Genioplasty: Home Plate-Shaped Sliding Osteotomy.

BACKGROUND: Narrowing genioplasty is commonly performed among East Asian populations, as a broad and/or square chin can be aesthetically unappealing. This study was aimed to introduce the home plate-shaped sliding osteotomy technique for narrowing genioplasty and to evaluate the results of this technique. METHODS: A retrospective chart review of 117 patients who underwent home plate-shaped sliding osteotomy alone between 2011 and 2019 was performed. The angles of oblique osteotomy lines and measurements of caudal repositioning, which significantly affect the postoperative chin shape, were evaluated. RESULTS: The home plate-shaped sliding osteotomy technique was successfully accomplished for narrowing genioplasty as an isolated procedure. The mean distance of caudal repositioning was 3.9 ± 0.8 mm, and the mean angles of oblique osteotomy lines were 23.3 ± 4.8 degrees on the right and 21.8 ± 3.5 degrees on the left. This produced an aesthetically pleasing rounded and proportionately narrow chin. The incidence of minor complications was 6.0 percent. There were no major complications. In particular, the risk of inferior alveolar nerve injury was obviated, as an additional mandibular border osteotomy was not typically used with this technique. CONCLUSIONS: This new surgical procedure for narrowing genioplasty provides improved aesthetic results by altering the chin shape, rather than reducing the transverse width of the chin. The versatility of this procedure allows the chin shape to be adjusted with respect to narrowing, vertical lengthening, anterior advancement, and asymmetric or cleft chin correction. The present study suggests that home plate-shaped sliding genioplasty may be an excellent alternative for correcting broad and/or square chins and more complex chin deformities. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Orthognathic Hardware Complications in the Era of Patient-Specific Implants.

BACKGROUND: Patients undergoing orthognathic skeletal correction present with a variety of comorbidities that may affect surgical outcomes. The purpose of this study was to determine how patient risk factors and operative technique contribute to complication rates after orthognathic surgery in the era of patient-specific implants. METHODS: Retrospective cohort analysis was conducted of pediatric patients undergoing Le Fort I osteotomy, bilateral sagittal split osteotomy, and/or genioplasty from 2014 to 2018. Patient risk factors, operative characteristics, and postoperative outcomes were gathered and compared with appropriate statistics. RESULTS: Ninety-four patients met inclusion criteria, with an overall 1-year complication rate of 11.7 percent (11 of 94). Patient-specific mandibular plates are significantly associated with infection (p = 0.009; OR, 8.8), occurrence of any complication (p = 0.003; OR, 8.3), readmission (p < 0.001; OR, 11.1), and reoperation (p < 0.001; OR, 11.4). In patients with syndromes or history of cleft lip/palate, patient-specific mandibular plates are associated with infection (p = 0.006; OR, 10.3), readmission (p < 0.001; OR, 21.6), and reoperation (p < 0.001; OR, 22.9). In multivariate regression controlling for age, sex, syndrome status, and orofacial cleft history, use of patient-specific mandibular plates was associated with infection (p = 0.017; adjusted OR, 12.5), any complication (p = 0.007; adjusted OR, 11.8), readmission (p = 0.001; adjusted OR, 17.9), and reoperation (p = 0.001; adjusted OR, 18.9). CONCLUSIONS: In the era of patient-specific orthognathic surgery, syndromic status and use of patient-specific mandibular plates are associated with increased infection, readmission, and reoperation because of hardware-related complications. The authors' data support increased caution and counseling with use of patient-specific mandibular implants in patients with syndromic status, history of orofacial cleft, and history of previous maxillomandibular surgery given increased risk of hardware-related complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Feminization of the Chin: Genioplasty Using Osteotomies.

Chin reshaping can provide a more identifiable female appearance for transitioning male to female patients undergoing facial feminization. The "sliding" genioplasty has the most potential for dramatically reshaping the chin, while also avoiding many of the issues that may occur with implants. A chin should be evaluated radiologically and by physical examination to determine what changes should be made to any particular chin. When performing osseous genioplasty, the mental nerve can be protected by performing any osteotomies at least 6 mm below the inferior border of the mental nerve canal.

Osteotomy in Genioplasty by Piezosurgery.

BACKGROUND: The chin is the most prominent and median sector of the lower third of the face giving harmony to nose and lips. The authors present the application of piezoelectric scalpel for the correction of different chin deformities. The distinctive characteristics of this device allow the authors to avoid or reduce the immediate genioplasty complications. METHODS: Fifty-five patients of defective chin have been treated from January 2006 to April 2008. Intraoral genioplasty was performed during the correction of dentofacial dysmorphisms or associated with nasal surgery. The authors used a piezoelectric cutting device to perform different osteotomies and if necessary, interpositional graft was used to stabilize bony segments. RESULTS: Piezosurgery has been associated with a fewer number of postoperative complications, especially as regard intraoperative bleeding, nerve injuries (immediate and late), hematomas and seromas, asymmetry (immediate and early). The mean time for completing the complete procedure of genioplasty with piezosurgery was almost the same compared with the saw and drill. CONCLUSION: Genioplasty represents one of the most common ancillary procedures and may be associated with corrective surgery of dentofacial dysmorphisms. Mental nerve injuries, asymmetries, intraoperative bleeding are the main immediate complications of genioplasty. Distinctive characteristics of ultrasonic piezoelectric osteotomy are selective cut of mineralized structure with less risk of vascular and nervous damage (microvibrations), intraoperative precision (thin cutting scalpel and no macrovibrations), blood free site (cavitation effect). In the authors' experience, piezoelectric scalpel, compared with saw and drill, enables them to reduce or avoid immediate complications of chin surgery, helping the surgeon to reach patients' satisfaction.

Face-neck lifting and ancillary procedures: A series of 203 cases.

Various methods and ancillary procedures have been defined in the era of face-lifting surgery.The purpose of this study was to evaluate the esthetic outcomes of our face-neck cases and the importance of adding ancillary procedures based on individual assessment.We conducted a retrospective review of 203 face-neck cases, basically following the endoscopic and open principles of Vasconez. The ancillary procedures added in selected cases included genioplasty, augmentation with autologous facial superficial fascial tissue or fat injections, upper lip shortening, perioral dermabrasion, ear lobe reduction, buccal fat reduction, mentum lifting, and upper orbital rim shaving. Complications, postoperative follow-up, esthetic outcomes, and contribution of the ancillary procedures were recorded.Our esthetic face complication rates were comparable to those of previous studies and included chemosis, hematoma, cyst on the eyelid suture line, skin sloughing, scar abnormalities (hypertrophic scar and widespread scar), pseudoparalysis of the marginal mandibular branch, temporary hypoesthesia of the forehead, irregularity of the glabella after endoscopy, and asymmetry. We did not observe any comorbidity owing to genioplasty and augmentation with autologous tissue except for a case with infection after fat injection.More improvement can be obtained with careful planning of ancillary procedures in face-neck lifting surgery.

Strategies of Mandibular Revision: A Retrospective Study of Revisional Mandibular Surgery for Unaesthetic Results of Previous Mandibular Reduction.

BACKGROUND: Mandibular reduction has been developed and popularized in Asia for decades. Despite the technical advancement and experience accumulation, complications and unaesthetic results still occur, and some need a revision surgery. This study aims to introduce the experience of revision surgery to reshape the unaesthetic mandibular contour after previous mandibular reduction. METHODS: From May 2011 to September 2017, patients dissatisfied with the result of previous mandibular reduction and who received a secondary mandibular revision were retrospectively reviewed and analyzed. RESULTS: Twenty-five patients were included in this study. Under-correction (88%, 22/25) was the most common aesthetic problem requiring revision, followed by asymmetry (56%, 14/25), broad chin (40%, 10/25), second mandibular angle (32%, 8/25), and over-correction (8%, 2/25). As revision techniques, long-curve mandibular reduction, simple mandibular reduction, and mandibular grinding were performed on 60% (15/25), 36% (9/25), and 4% (1/25) of the patients, respectively. All the patients were satisfied with the results. Cephalometric measurements indicated a significant bone removal after revision. CONCLUSIONS: When performing a revision surgery to reshape the mandibular contour, the surgeon should have a clear surgical plan based on comprehensive evaluation, focus on the balanced harmony of the entire face, use proper technique and instruments, and avoid concomitant injury and complications. The one-staged technique that treats the whole mandible as an entirety is superior than multistaged techniques to improve the aesthetic outcomes to the largest extent. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Facial Implants: Controversies and Criticism. A Comprehensive Review of the Current Literature.

BACKGROUND: Polyethylene (Medpor) and silicone are two of the most popular materials used today for facial skeleton implantation. Previous studies have identified common complications with the use of these implants, but patient follow-up has been short. This review of the literature examines complications and patient follow-up in cases using Medpor and silicone implants for reconstructive and aesthetic operations of the mid and lower face over the past 20 years. METHODS: A literature search was conducted through the PubMed database. Keywords used were as follows: ("mandible implants" or "malar implants" or "chin implants") AND ("reconstruction" or "augmentation") AND ("Medpor" or "silicone"). RESULTS: There were nine studies with 626 patients in the Medpor group and five studies with 365 patients in the silicone group. The silicone group had a higher incidence of infections and displacements. The Medpor group showed a higher incidence of prominence problems. Exposure/extrusion rates were low for both implant types. Chin and mandibular implants were the safest, whereas malar implants had a high incidence of prominence problems. The average follow-up for Medpor was 36.6 months and 24 months for silicone. There were wide ranges of follow-up times, from 2 weeks up to 15 years. A limited number of articles included an averaged time within their ranges. Reported follow-up times were not linked to specific complications. CONCLUSIONS: Medpor implantation is more common than silicone. Complication rates are low with the use of both materials. Patient follow-up is deficient and has not improved in the past 20 years, raising questions on the reliability of complication rates.

Intraoral Prosthetic Chin Augmentation With Vertical Incisions.

To explore a new surgical approach for chin augmentation using a prosthesis with 3 intraoral vertical incisions whereby placement of the prosthesis is more convenient and accurate, with fewer postoperative complications. Following the anatomic characteristics of the chin, a bilateral mucosal vertical incision and a median observation incision are made. The V-shaped mark on the upper side of the prosthesis can be seen through the observation incision after it is placed from the lateral incision into the predesigned compartment. The incision can be sutured if there is no bleeding in the operation area. Surgery performed in all 19 patients with mild microgenia with 6 to 12 months of follow-up resulted in satisfactory chin and face shape without any complications. The application of this novel method can correct McCarthy type I microgenia with more accurate positioning, less possibility of bilateral sideways and/or up/down movement, and fewer complications.

Split-Overlapping Genioplasty: Surgical Technique, Morphological and Radiological Long-Term Outcomes.

BACKGROUND: The overlapping bone flap genioplasty, described by Tessier, was developed to treat major retrognathia or long and retruded chins. For 15 years, we have used a modified version of this technique to avoid its drawbacks. The aim of this article is to describe our modification and evaluate the long-term morphologic and radiologic outcomes. PATIENTS AND METHOD: The authors included every split-overlapping genioplasty performed in our department between 2004 and 2014. Demographics, surgical data, and complications were recorded. Radiologic bone resorption was evaluated comparing preoperative, day-1 postoperative, and year-1 postoperative cephalometric x-rays. Morphologic outcomes were evaluated on standardized pre- and postoperative views using an analogic Likert scale. SURGICAL TECHNIQUE: The main modification of the procedure consists in separating the posterior cortex of the transplant using a reciprocating saw. After overlapping the reduced transplant onto the mandible, the posterior cortex is used as an apposition graft to soften the labiomental crease. RESULTS: Forty-seven patients were analyzed during this period. In 44 patients, the procedure was combined with mandibular and/or maxillary osteotomy. The average reduction of symphysis height was 5 mm, and the average pogonion advancement was 4.3 mm. After 1 year, we recorded 7% average bone resorption. No major complications (nerve injury, hematoma, among others) were reported. Morphologic outcomes were deemed satisfactory or very satisfactory in the vast majority of cases. CONCLUSION: Split-overlapping genioplasty is a safe and reliable procedure with stable, long-lasting outcomes. This versatile technique is particularly useful for the correction of a massive symphysis or high and retruded chins.

[PLASTIC CLOSURE OF THE WOUND DEFECT IN PATIENTS, SUFFERING THE ORAL AND ORO-PHARYNGEAL CANCER STAGES ІІІ - ІV].

Results of treatment of 124 patients, suffering locally-advanced oral and oropharyngeal cancer were analyzed. In these patients after wide excision of tissues the defect has occurred, which would be impossible to close using simple suturing. To these patients a primary plasty, using musculo-cutaneous or adiposo-cutaneous flap, was performed. The defect, occurring after resection of the oral cavity floor together with the mandibular anterior fragment, constitutes the most complex one for the plasty performance. The main principles of the defects plasty were determined. The plastic material choice depends on peculiar clinical situation, the surgical intervention volume, the defect localization and its size.

Effect of Genioplasty on the Pharyngeal Airway Space Following Maxillomandibular Advancement Surgery.

PURPOSE: To evaluate the effect of genioplasty on the size of the pharyngeal airway space (PAS) in a sample of patients without obstructive sleep apnea syndrome (OSAS) undergoing maxillomandibular advancement (MMA) surgery. MATERIALS AND METHODS: Lateral cephalometric radiographs of 52 patients who underwent orthognathic surgery for MMA were obtained before (T1) and after (T2) surgery. The radiographs were digitized and the anteroposterior dimensions of the PAS were measured at the nasopharynx, oropharynx, and hypopharynx levels. The sample was divided into 2 groups: MMA with genioplasty (n = 27; average age, 30.81 yr) and without genioplasty (n = 25; average age, 37.64 yr). Comparisons were made between T1 and T2 in patients with and without genioplasty. Horizontal and vertical changes of the maxilla, mandible, and chin were correlated to changes in the PAS. RESULTS: MMA resulted in an increased anteroposterior PAS at the 3 levels analyzed (P < .05), except in the hypopharynx, in cases without genioplasty (P = .141). When the groups with and without genioplasty were compared, there were no significant differences (P > .05) in the PAS. There was a statistically relevant correlation between horizontal mandibular change and the oropharynx (r = 0.484 and r = 0.509, respectively) and between vertical chin change and the hypopharynx (r = 0.434 and r = 0.455, respectively) for groups with and without genioplasty. There was a statistically relevant correlation between horizontal chin change and the hypopharynx (r = 0.586) for surgeries without genioplasty. CONCLUSION: Considering the limitations inherent to retrospective study designs, the results suggested that MMA surgery, with and without advancement genioplasty, can promote immediate gains to the PAS. A larger gain was possible in the hypopharynx for MMA with genioplasty. MMA without genioplasty could represent a greater gain in the nasopharynx and oropharynx. Further studies should evaluate functional parameters in patients with OSAS to measure the possible benefits of this increase in the PAS.

A Patient With Aspiration Pneumonia After Mandibular Osteotomy With Genioplasty.

Orthognathic surgery including maxillary osteotomy, mandibular osteotomy, and genioplasty is a reliable treatment strategy for jaw deformity. However, there are some complications associated with these surgeries, including neurovascular damage and abnormal bleeding. The authors present here a patient of aspiration pneumonia after mandibular osteotomy.An 18-year-old female patient underwent sagittal split ramus osteotomy and genioplasty for mandibular prognathism. She began choking and coughing immediately after surgery. She was diagnosed with aspiration pneumonia based on chest radiography and computed tomography findings. Her hyoid bone was shifted 23 mm inferiorly after surgery, and this movement may have caused swallowing dysfunction. She was treated with intravenous antibiotics and discharged on the 18th postoperative day.Although the hyoid bone is transiently shifted inferiorly by mandibular setback with or without genioplasty, this shift does not usually affect swallowing function. Damage to the suprahyoid muscles during genioplasty may cause both an inferior shift and dysmobility of the hyoid bone. Therefore, surgeons must be careful not to damage the suprahyoid muscles at the lingual site osteotomy in genioplasty to avoid this complication.

Is It Safe and Effective to Lengthen a Chin With Interpositional Allogenic (Iliac) Graft?

PURPOSE: This is a retrospective review of a consecutive series of patients undergoing chin lengthening at the time of orthognathic surgery over a 3-year timeframe. MATERIALS AND METHODS: The genioplasty procedures studied included lengthening to the extent that an interpositional graft was deemed necessary (n = 19). Allogenic (iliac) corticocancellous bone was used in all cases. Each patient underwent lateral cephalometric radiography within 2 months before and 5 weeks after surgery. From the radiographs, quantitative measurements (millimeters) were made to document the vertical lengthening and horizontal advancement achieved. Chin region wound healing parameters were reviewed to document evidence of infection, sequestra, need for reoperation, and evidence of fibrous union. Inpatient hospital and outpatient office records were reviewed for any evidence of sepsis or viral transmission. RESULTS: The patients' mean age at operation was 35 years (range, 15 to 58 yr). Analysis of preoperative and 5-week postoperative radiographs documented a mean vertical lengthening of 7 mm (range, 4 to 10 mm). The mean horizontal advancement at the pogonion was confirmed to be 2 mm (range, 1 to 3 mm). None of the study patients sustained chin region infection graft sequestra, fibrous union, or need for reoperation. There were no cases of postoperative sepsis or viral illness to indicate systemic infectious sequelae. CONCLUSION: The study confirms the safety of allogenic (iliac) corticocancellous grafting to fill interpositional defects associated with a transverse symphyseal lengthening osteotomy.

Stellate Ganglion Block, Compared With Xenon Light Irradiation, Is a More Effective Treatment of Neurosensory Deficits Resulting From Orthognathic Surgery, as Measured by Current Perception Threshold.

PURPOSE: The aim of this study was to evaluate the relative effectiveness of stellate ganglion blockade (SGB) versus xenon light irradiation (XLI) for the treatment of neurosensory deficits resulting from orthognathic surgery as determined by a comparison of prospective measurements of electrical current perception thresholds (CPTs) and ranged CPTs (R-CPTs). MATERIALS AND METHODS: CPT and R-CPT in the mental foramen area were measured during electrical stimulation at 98 different sites on the body in patients who had undergone orthognathic surgery. After surgery, patients were assigned to the SGB group or the XLI group. CPT and R-CPT of the 2 groups were measured at stimulation frequencies of 2,000, 250, and 5 Hz before surgery, 1 week after surgery, and after 10 treatment sessions. Furthermore, the influence of surgical factors, such as genioplasty and a surgically exposed inferior alveolar nerve (IAN), was examined in the 2 groups. RESULTS: Patients' CPT and R-CPT values indicated a considerable amount of sensory disturbance in most cases after surgery. The change in magnitude of all CPT and R-CPT values for the SGB group decreased considerably compared with that for the XLI group after treatment. There was no correlation between CPT or R-CPT values and surgical factors (eg, genioplasty and exposure of the IAN). CONCLUSION: SGB of the IAN could be an effective method for treating neurosensory deficits after orthognathic surgery on the IAN.

Severe bone resorption in expanded polytetrafluoroethylene chin augmentation.

Expanded polytetrafluoroethylene implant is usually considered as a wonderful implant for chin cosmetic augmentation with no or less bone resorption compared with solid silicone implant. However, one severe bony erosion in expanded polytetrafluoroethylene chin augmentation was found in our clinical work. We consider that the possible reason about severe bone resorption in such situation is most relative to the mentalis muscle hyperactivity, rather than the kinds of materials. We also strongly advise that genioplasty is suitable for the cases with mentalis muscle hyperactivity caused by a dentofacial deformity.