• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.206-216
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• 2000

Predictional study for lateral change between pre- and post-orthognathic surgery has been emphasized mainly on anterior area of lateral profile; upper lip, lower lip and chin et al. So interest for lateral profile change has been less in posterior area of lateral profile and literature analyzing gonial angle change is rare. The purpose of this study is to make prediction for gonial angle change possible and to offer somewhat treatment guidance for gonial angle to be improved by investigating overall gonial angle change between pre- and post-orthognathic surgery and inquiring into factors influencing on pattern of genial angle change. For this study 35 patients were selected retrospectively. Lateral cephalometric radiographs were taken in just pre-op time, pod 1 day, pod 1 year. They were analyzed and genial angles were measured. The results were as follows : 1. Gonial angle at pod 1 day was decreased about $9.3^{\circ}$ than pre-op and gonial angle at pod 1 year was increased about $4.0^{\circ}$ than pod 1 day. So genial angle at pod 1 year was decreased about $5.3^{\circ}$ than pre-op genial angle(p<0.01). 2. Mean pre-op gonial angle was $129.4^{\circ}$, showing significantly high value than normal and mean gonial angle at pod 1 year was $124.1^{\circ}$, showing value near to normal. 3. Mean gonial angle change between pre-op and pod 1 year was decreased about $5.4^{\circ}$ in female and $5.3^{\circ}$ in male. There was no statistically significant difference between male and female(p>0.05). 4. Principal factor influencing on decreased gonial angle in gonial angle change between pre-op and pod 1 year was amount of mandibular setback. 5. Principal factor influencing on increased gonial angle in gonial angle change between pod 1 day and pod 1 year was % horizontal relapse, and it was thought that resorption and bone remodelling on posterior area in mandibular distal segment also were related to increased gonial angle. 6. It is thought that sagittal split ramus osteotomy in mandibular prognathic patients with high value of gonial angle is effective to improvement of gonial angle, and In patients who have normal range of gonial angle and are required with excessive mandibular setback, short lingual cut method, additional resection of posterior margin of distal segment, Obwegeser II method will be considerd. 7. More prudent operation and careful post-op management will be responsible for maintenance of postoperative stable gonial angle.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.359-371
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• 2010

Facial asymmetry has been found with a higher frequency (70~84%) in skeletal class III malocclusion patients. Anticipating the poor prognosis of prosthesis due to malocclusion, occlusal stability must be obtained by orthodontic treatment. Moreover, orthodontic surgery would be needed in some severe cases for better functional and esthetic results. The orthognathic surgery is performed on one jaw or two jaw depending on the results of facial diagnosis. Genioplasty may change the vertical, horizontal, sagittal position of chin by osteotomy or augmentation using implants, also. This case is about a 24 year-old male patient who visited our clinic to solve the facial asymmetry and mandibular prognathism. Skeletal class III malocclusion, maxillary canting and menton deviation to left by 13 mm were detected. Multiple ill-fitting prostheses, unesthetic maxillary anterior prostheses, and several dental caries were found. After pre-operative orthodontic treatment, Le-Fort I osteotomy, sagittal split ramus osteotomy, genioplasty, right mandibular angle augmentation were done for the correction of jaw relation and asymmetry. By diagnostic wax-up after post-operative orthodontic treatment, maxillary full mouth rehabilitation and mandibular posterior restorations were planned out. For better result, clinical crown lengthening procedure was done on #11, 12 and implant was placed on left mandibular first molar area. The patient was satisfied with the final prostheses. Because of his high caries risk, long-term prognosis will depend on the consistent maintenance of oral hygiene and periodic follow-up.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.1
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• pp.55-61
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• 2011

Conventional slinding genioplsty has the risk of mental nerve injury after operation and difficult to correct vertical asymmetry of chin. So, authors propose a new genioplasty to correct asymmetry of chin. Switching genioplasty is a modification method of conventional genioplasty. Between mandibular right and left canine, osteotomy line of triangular shape make until mandibular lower border. In large side, osteotome line of wedge shape is added to reduction. After osteotomy, segment of wedge shape was separated from chin. Distal segment was rotated to reduction side. Because of rotation of distal segment, space is made in opposite side. Seperated segement of wedge shape from large side is switched this space to fill. So, stability of distal segment is achieved. Authors applied to swiching genioplasty the patients who was remained the chin asymmetry after both sagittal split ramus osteotome was done because mandible asymmetry. After operation, patient and operator were satisfied with excellent esthetic results without any other complication. The switching genioplasty is effective surgical technique for chin asymmetry because it has more advantages than conventional sliding genioplasty. First, other donor side does not need for bone graft. Second, the switching genioplasty can reduce infection, bone resroption, dehiscence, capsular contraction after allograft. Third, have little mental nerve damage. Forth, anteroposterior correction is possible. Fifth, operation time is less than other genioplasty for chin asymmetry.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.5
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• pp.311-319
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• 2012

Purpose: The aim of this study is to evaluate the vertical changes of the lip and perioral soft tissue, following orthognathic surgery in skeletal class III patients by a cephalometric analysis of a cone beam computed tomography (CBCT). Methods: A total of 20 skeletal class III patients, who had bimaxillary surgery with Le Fort 1 osteotomy and bilateral sagittal split ramus osteotomy, were included in this study. The surgical plan for maxilla was posterosuperior impaction with the anterior nasal spine, as the rotation center. Further, the surgical plan for mandible was also posterosuperior movement. The soft tissue changes between lateral cephalogram and CBCT were compared. And the correlations between independent variables and dependent variables were evaluated. Results: There were no significant differences of the soft tissues changes between lateral cephalogram and CBCT. Upper lip philtrum length (SnLs), nasolabial angle increased and upper lip vermilion length (LsStms), lower lip length (StmiB'), lower lip vermilion length (StmiLi), lower lip philtrum length (LiB') and soft tissue lower facial height (SnMe') decreased after surgery. Change of SnLs (${\Delta}$SnLs) was influenced by vertical change of menton (${\Delta}$MeV), and change of LsStms (${\Delta}$LsStms) was influenced by upper lip thickness (ULT). Change of StmiLi' (${\Delta}$StmiLi') were influenced by preoperative overjet. Change of StmiB' (${\Delta}$StmiB') were influenced by preoperative overjet, vertical change of lower incisor (${\Delta}$L1V) and horizontal change of posterior nasal spine (${\Delta}$PNSH). Change of LiB' (${\Delta}$LiB') was influenced by ${\Delta}$L1V and ${\Delta}$PNSH. Change of SnMe' (${\Delta}$SnMe') was influenced by ${\Delta}$MeV, horizontal change of upper incisor (${\Delta}$U1H) and horizontal change of lower incisor (${\Delta}$L1H). ${\Delta}$Nasolabial angle was influenced by change of ULT (${\Delta}$ULT). Conclusion: Both soft tissues and hard tissues can be evaluated by CBCT. Posterosuperior rotation of maxillomandibular complex resulted in increase of upper lip philtrum length and nasolabial angle, while the upper lip vermilion length, lower lip philtrum length, lower lip vermilion length, and soft tissue lower facial height showed a decrease.

• The korean journal of orthodontics
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• v.50 no.5
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• pp.336-345
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• 2020

Objective: To investigate the treatment modalities (Tx-Mods) for patients with unilateral hemifacial microsomia (UHFM) according to Pruzansky-Kaban types and growth stages. Methods: The samples consisted of 82 Korean UHFM patients. Tx-Mods were defined as follows: Tx-Mod-1, growth observation due to mild facial asymmetry; Tx-Mod-2, unilateral functional appliance; Tx-Mod-3, fixed orthodontic treatment; Tx-Mod-4, growth observation due to a definite need for surgical intervention; Tx-Mod-5, unilateral mandibular or bimaxillary distraction osteogenesis (DO); Tx-Mod-6, maxillary fixation using LeFort I osteotomy and mandibular DO/sagittal split ramus osteotomy; Tx-Mod-7, orthognathic surgery; and Tx-Mod-8, costochondral grafting. The type and frequency of Tx-Mod, the number of patients who underwent surgical procedures, and the number of surgeries that each patient underwent, were investigated. Results: The degree of invasiveness and complexity of Tx-Mod increased, with an increase in treatment stage and Pruzansky-Kaban type (initial < final; [I, IIa] < [IIb, III], all p < 0.001). The percentage of patients who underwent surgical procedures increased up to 4.2 times, with an increase in the Pruzansky-Kaban type (I, 24.1%; IIa, 47.1%; IIb, 84.4%; III, 100%; p < 0.001). However, the mean number of surgical procedures that each patient underwent showed a tendency of increase according to the Pruzansky-Kaban types (I, n = 1.1; IIa, n = 1.5; IIb, n = 1.6; III, n = 2.3; p > 0.05). Conclusions: These findings might be used as basic guidelines for successful treatment planning and prognosis prediction in UHFM patients.

• Korean Journal of Cleft Lip And Palate
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• v.8 no.2
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• pp.71-79
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• 2005

Purpose: Maxillary hypoplasia is a common developmental problem of cleft lip and palate. Fair results with distraction osteogenesis have been reported especially when these patients need a large amount of maxillary advancement, instead of orthognathic surgery. The purpose of this study is to evaluate the clinical results with a relatively new distractor, $TS-MD^{(R)}$ (Trans-sinusoidal maxillary distractor, KLS Martin, Tuttlingen, Germany) which was used for the advancement of the maxilla in the cleft patients. Patients and Method: Distraction osteogenesis using $TS-MD^{(R)}$ was performed for four CLP patients (three males and one female) who had maxillary hypoplasia. All patients were over 16 years old. As three patients showed mandibular prognathism as well, bilateral sagittal split ramus osteotomy for mandibular setback was performed at the same time. After consolidation periods of 4 to 12 weeks, the distraction devices were removed and miniplates were placed for simultaneous internal fixation. Results: Three patients showed a large amount of incisal overbite but one patient did not have sufficient maxillary advancement. Le Fort I osteotomy, maxillary advancement and internal fixation should have been performed for the patient when removing the distraction devices. Different from the $clinician{\box}s$ expectation, the amount of maxillary advancement using $TS-MD^{(R)}$ was not sufficient, although the device has rigid mechanical property. Rotation of maxilla during distraction forward and downward was also observed. Conclusion: Even though the maxillary advancement with $TS-MD^{(R)}$ device could be achieved, the clinical control of some characteristics related with the device was necessary. More clinical studies on $TS-MD^{(R)}$ should be performed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.3
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• pp.152-159
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• 2017

Objectives: The aim of this study was to investigate the effects of advancement magnitude and changes in mandibular plane angle on the stability of mandibular advancement. Materials and Methods: This retrospective cohort study evaluated the postoperative stability of mandibular advancement in class II skeletal subjects who underwent bilateral sagittal split osteotomy. Radiographs taken preoperatively, immediately postoperatively and 1 year postoperatively were traced and analyzed using linear and angular measurements. To determine horizontal and vertical relapse, an X-Y coordinate system was established in which the X-axis was constructed by rotating S-N downward by $7^{\circ}$ (approximation of the Frankfort horizontal plane) and the Y-axis was defined as a line perpendicular to the X-axis and passing through the point Sella. For certain reference points including point A, point B, pogonion and menton, the perpendicular distance between each point and both axes was determined and cephalometric variables were recorded as X and Y coordinates. Results: Twenty-five subjects were studied. A significant correlation between the amount of mandibular advancement and relapse in the B point (vertical and horizontal) and the pogonion point was observed (vertical and horizontal, P<0.001). Evaluation of data demonstrated a positive correlation between the mandibular plane angle (SN/ML) change and vertical relapse in the B point (P<0.05). A simple regression model demonstrated that 74% of horizontal relapse and 42.3% of vertical relapse in the B point was related to the amount of mandibular advancement. The receiver operating characteristic test showed that 8.5 mm mandibular advancement is related to a relapse rate of 1 mm or more in the pogonion, vertically or horizontally. Conclusion: The magnitude of mandibular advancement is a stronger surgical predictor for horizontal rather than vertical relapse at the B point. Changes in mandibular plane angle (SN/ML) during surgery affect vertical, but not horizontal relapse at the B point.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.3
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• pp.217-227
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• 1992

The purpose of this paper is to investigate changes in soft tissue in 22 patients treated by vertical ramus osteotomy and sagittal split ramus osteotomy for the correction of mandibular prognathism. 22 individuals, 12 males and 10 females, were selected from the patients with mandibular prognathism at the Department of Oral and Maxillofacial Surgery, Colledge of Dentistry, Kyung Hee University. Patient were analyzed with cephalogram taken 1 week before and at least 6 weeks after surgery under the same condition. Measurements were made constructed hard tissue and sop tissue points located on each before-and-after film tracing. Comparision were made of these figures to estimate the amount that the soft tissue followed the hard tissue structures in each surgical procedure : ratio of sop and hard tissue changes were formulated. The results were as follows. 1. The horizontal changes of Pogs and Bs as a ratio of the horizontal changes of Pog and B point were 1.02 and 1.16 respectively. 2. One millimeter of posterior changes at Pog resulted in 0.86mm of posterior change at Li and 0.09mm of posterior change at Ls. The greatest amount of sop tissue change occurred at Pogs, with substantially less posterior displacement at Bs, even less at Li and at least at Ls. 3. The ratio of LI to Li was 1:0.81 and the ratio of LI to Ls was not significant.(1 : 0.17) 4. The ULA(Cm-Sn-Ls) and the relative lower lip projection (LLP) was incnease4 but the relative upper lip projection (ULP) was slightly decreased 5. The angular change of the upper lip inclined angle (Ls-Sn/ANS-PNS) and lower lip inclined angle(Li-Pogs/Me-Go) expressed as a ratio of the posterior change of Pog were 0.57 and 0.20 respectively. 6. The ratio of the lower anterior facial height change of the soft tissue(Sn-Mes) to the hard tissue(ANS-Gn) were 0.78 and and the ratio of vertical height changes of the hard tissue and sop tissue to the posterior change of the Pog were 0.18 and 0.19 respectively. 7. The sop tissue angular change of facial convexity(G-Sn-Pogs) expressed as a ratio of the angular change of the hard tissue angle of facial convexity(N-A-Pog) was 1.24.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.2
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• pp.82-87
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• 2013

Purpose: This study evaluated postoperative maxillary stabilities in patients with skeletal Class III malocclusion who were taken both maxillary advancement surgery and mandibular retrusive surgery, using Le Fort I osteotomy, through three-dimensional computed tomography. Methods: We selected 14 patients who were taken postoperative three-dimensional computerized tomography at the time before surgery, immediately after surgery, six months after surgery among the patients undergone both maxillary advancement surgery using Le Fort I osteotomy and mandibular retrusive surgery using bilateral sagittal split ramus osteotomy. We measured and compared the vertical distance of A-point and posterior nasal spine (PNS), the horizontal distance of A-point and PNS in transverse plane and coronal plane of the three-dimensional reconstructed images, respectively. Results: In transverse plane, the distance difference between immediately after surgery ($S_1$) and immediately before surgery ($S_0$) of A-point was $-0.04{\pm}1.80$ mm, $S_2$ and $S_0$ was $-0.15{\pm}1.69$ mm, and between $S_1$ and $S_2$ was $0.11{\pm}0.58$ mm. There were no significant differences between these data (P>0.05). In transverse plane, the distance between $S_1-S_0$ of PNS was $-3.87{\pm}2.37$ mm, $S_2-S_0$ of PNS was $-3.79{\pm}2.39$ mm, and $S_1-S_2$ of PNS was $-0.08{\pm}0.18$ mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between $S_1-S_0$ of A-point was $3.99{\pm}0.86$ mm, $S_2-S_0$ was $3.57{\pm}1.09$ mm, and $S_1-S_2$ was $0.42{\pm}0.42$ mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between $S_1-S_0$ of PNS was $3.82{\pm}0.96$ mm, $S_2-S_0$ was $3.43{\pm}0.91$ mm, and $S_1S_2$ was $0.39{\pm}0.49$ mm. There were significant differences between these data (P<0.05). In transverse plane, it was estimated that PNS has no statistical postoperative stability in the same direction. In coronal plane, it was estimated that both A-point and PNS had no statistical postoperative stability (P<0.05). Conclusion: Clinically, the operation plan needs to take into account of the maxillary relapse.