• The korean journal of orthodontics
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• v.54 no.2
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• pp.128-135
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• 2024

Objective: The number of three-piece maxillary osteotomies has increased over the years; however, the literature remains controversial. The objective of this study was to evaluate the skeletal stability of this surgical modality compared with that of one-piece maxillary osteotomy. Methods: This retrospective cohort study included 39 individuals who underwent Le Fort I maxillary osteotomies and were divided into two groups: group 1 (three pieces, n = 22) and group 2 (one piece, n = 17). Three cone-beam computed tomography scans from each patient (T1, pre-surgical; T2, post-surgical; and T3, follow-up) were used to evaluate the three-dimensional skeletal changes. Results: The differences within groups were statistically significant only for group 1 in terms of surgical changes (T2-T1) with a mean difference in the canine region of 3.09 mm and the posterior region of 3.08 mm. No significant differences in surgical stability were identified between or within the groups. The mean values of the differences between groups were 0.05 mm (posterior region) and -0.39 mm (canine region). Conclusions: Our findings suggest that one- and three-piece maxillary osteotomies result in similar post-surgical skeletal stability.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.447-453
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• 2010

The hemifacial microsomia is characterized by variable underdevelopment of the craniofacial skeleton, external ear, and facial soft tissues. So, patients with hemifacial microsomia have an occlusal plane canting and malocclusion with facial asymmetry. Distraction osteogenesis (DO) with an intraoral or extraoral device is a technique using tension to generate new bone with gradual bone movement and remodeling. DO has especially been used to correct craniofacial deformities such as a hemifacial microsomia, facial asymmetry, and mandible defect that could not adequately be treated by conventional reconstruction with osteotomies. It has a significant advantage to lengthen soft and hard tissue of underdeveloped site without bone graft and a few complication such as nerve injury or muscle contracture. A 13-years old girl visited our clinic for the chief complaint of facial asymmetry. She had a left hypoplastic maxilla and mandible, occlusal plane canting and malocclusion. We diagnosed hemifacial microsomia and lanned DO to lengthen the affected side. Le Fort I osteotomy, left mandibular ramus and symphysis osteotomy were performed. The internal distraction devices fixed with screw on maxillary and mandibular ramus osteotomy sites. External devices were adapted to lower jaw for DO on symphysis osteotomy site and to upper jaw for rapid maxillary expansion (RME). At 7days after surgery, distraction was started at the rate of 1mm per day for 13days, and after 4months consolidation periods, distraction devices were removed. Simultaneous multiple maxillo-mandibular distraction osteogenesis with RME resulted in a satisfactory success in correcting facial asymmetry as well as occlusal plane canting for our hemifacial microsomia.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.121-132
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• 2008

Objective: The purpose of this study was to evaluate the upper airway dimensional change according to maxillary superior movement after orthognathic surgery and to identify the relationship between the amount of maxillary movement and upper airway dimensional changes. Methods: The samples consisted of 24 adult patients (9 males and 15 females) who had a skeletal discrepancy and had received presurgical orthodontic treatment. They underwent Le Fort I superior impaction osteotomy and mandibular setback surgery. Cephalometric x-rays were taken at 3 stages - T0 (before orthognathic surgery), T1 (just or within 2 weeks after orthognathic surgery), T2 (6 months after surgery) Results: 1, Pharyngeal airway space (PAS (R)-nasopharynx) was decreased after surgery (T1) but recovered at 6 months after surgery; 2, Pharyngeal airway space (PAS (NL)-palatal plane) was increased after surgery and at 6 months after surgery; 3, Pharyngeal airway space (PAS (OL)-occlusal plane) was increased at T1 and was decreased at T2; 4, Soft palate thickness was increased at T1 but it became the same or thinner at T2; 5, There is no statistically significant relation between the amount of maxillary superior movement and pharyngeal airway space. Conclusions: These findings suggested that the maxillary superior movement of about an average of $4.40{\pm}1.14 mm$ did not affect upper pharyngeal airway space changes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.44-52
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• 1991

Internal measurement technique has been commonly and classically used to guide down-fractured maxilla by Le Fort I osteotomy into its new position during intraoperative procedure for correlating preoperative model works with surgery. However, It has been challenged now by several authors due to some problems as its inaccuracy in three-dimensional changes at surgery, difficulty to measure during surgery and impossibility of rechecking at the end of surgery etc. The purpose of this study was to evaluate the accuracy of maxillary movement by external measuring technique and to determine its accuracy between the prediction tracing and a new maxillary position. The results indicate that the external measuring technique was predictable in the vertical, horizontal and transverse change of the maxilla as its prediction, however, it has a tendency to shift the maxilla more anterior and inferior in overall direction than prediction. Post-operative canting difference were mimic, however Ehange of the maxillary dental midline was large and had a right-shifting tendency.1 The precise methods to keep maxillary dental midline as same as prediction and the avoidance of uneven force applied to the mandible for autorotation should be necessary during surgery in use of external measurement technique.

• 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.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.657-668
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• 2000

The purpose of this study was to evaluate the amount and interrelationship of the soft tissue of nose and maxillary changes and to identify the nasal morphologic features that indicate susceptibility to nasal deflection in such a manner that they would be useful in presurgical prediction of nasal changes after maxillary advancement surgery in skeletal Class III malocclusion. The sample consisted of 25 adult patients (13 males and 12 females) who had severe anteroposterior skeletal discrepancy. The patients had received presurgical orthodontic treatment. They underwent a Le Fort I advancement osteotomy, rigid internal fixation, alar cinch suture and V-Y advancement lip closure. The presurgical and postsurgical lateral cephalograms and lateral and frontal facial photographs were evaluated. The computerized statistical analysis was carried out. Soft tissue of nose change to h point change ratios were calculated by regression equations. The results were as follows 1. The correlation of maxillary hard tissue horizontal changes and nasal soft tissue vortical changes were high and the ${\beta}_0$ for soft tissue to ADV were 0.228 at ANt, 0.257 at SNt. 2. The correlation of maxillary hard tissue and nasal soft tissue horizontal changes were high and the ${\beta}_0$ for soft tissue to ADV were 0.484 at ANt, 0.431 at SNt, 0.806 at Sn. 3. The correlation of maxillary hard tissue horizontal changes and width changes of ala of nose were high and the ${\beta}_0$ lot alar base width ratio to ADV were 0.002. 4. The DRI, Prominence of nose, Pre-Op CA is not a quantitative measure that can be used clinically to improve the predictability of vertical and horizontal nasal tip deflection. In this study, increases in nasal tip projection and anterosuperior rotation occur when there is an anterior vector of maxillary movement. These nasal changes were Quantitatively correlated to magnitude of maxillary(A point) movement.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.211-220
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• 2013

Purpose: The purpose of this study was to compare the changes in the pharyngeal airway space, tongue and hyoid bone positions according to the orthognathic surgical methods of mandibular prognathism. Methods: The subjects included 30 patients (16 males, 14 females) with the skeletal class III malocclusion. Group 1 (10 patients) underwent bilateral sagittal split ramus osteotomy (BSSRO) only; group 2 (10 patients) underwent BSSRO with genioplasty; and group 3 (10 patients) underwent BSSRO, Le Fort I osteotomy. We measured the lines between the selected upper air way, hyoid bone and tongue landmarks on the lateral cephalometric x-ray films of skeletal class III. The measurements were made preoperation, within 1 week after the operation, 3~6 months after the operation and 1 year after the operation. We compared and analyzed the measurements with matched paired t-test and independent samples t-test. Results: There were no postoperative changes in the nasopharyngeal airway space in group 3. The measurements of group 3 also increased during the follow-up period as compared to the preoperative measurements. In group 1, 2 and 3, the immediate postoperative oropharyngeal and hypopharyngeal airway spaces were decreased. In the following period, the hypopharyngeal airway space returned to the preoperative positions, but the oropharyngeal airway space was not significantly changed. The upper and lower tongue was posteriorly repositioned immediately after the surgery. During the follow-up period, the lower tongue position returned to the preoperative position, and the upper tongue position was not significantly changed. Immediately after the surgery, the B point was moved to the posterior position, and a slight anterior advancement was found in the follow-up period. Conclusion: Patients who received the mandibular setback surgery showed a decrease in the posterior airway space, and those who underwent maxillary advancement showed a significant increase of the nasopharyngeal airway space, which remained stable during the evaluation period. The change of the airway space, position of the hyoid bone and tongue did not differ according to the presence or absence of genioplasty.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.6
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• pp.628-634
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• 2008

The purpose of this study is to examine reproducibility of operation plan and 3-dimentional jaw movement patterns by comparing jaw position of STO with post-operative jaw position. Twenty patients with class III dental and skeletal malocclusion who were treated with Le-Fort I osteotomy and B-SSRO were reviewed. Lateral cephalometric radiographs were taken within two weeks before operation and two days after operation. Cephalometric radiographs were compared and analyzed with orthognathic computer program '$V-Ceph^{TM}$'. Post-operative maxillary advancement was insufficient compared to maxillary advancement through STO. Post-operative setback movement was over compared to mandibular setback movement through STO. But statistically this is not significant. Maxillary vertical location is insignificant on the whole. Especially post-operative maxillary clockwise rotation is significant compared to maxillary rotation through STO. Post-operative maxillary clockwise rotation tendency is generally observed in all patients. So surgeons and staffs must consider this tendency when operation plan is established ans operation is being performed. Using intra or extra oral marking points, face bow, and bite plate will make exact surgery possible.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.1
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• pp.92-99
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• 2008

The purpose of this study was to evaluate maxillay distraction for the cleft and other patients who were treated with RED $system^{(R)}$(Martin, Tuttlingen Germany). Eleven patients with severe maxillary hypoplasia who were treated between 2002 and 2007 in the Department of Oral and Maxillofacial surgery, Pusan National University Hospital, are reviewed for this study. Their age at the time of surgery ranged from 7 to 22 years(mean age=15.36 years). Distraction was started at 5 days after Le Fort I or III osteotomy at a rate of 1mm per day for 10 to 20days. All patients used the Rigid External Distraction II system. After distraction was completed, a 2 to 3 months period of consolidation was undertaken. The follow-up period ranged from 1 to 6 years. The mean amount of advancement of the maxilla was 14.2mm(A-point). Relapse, VPI, and local infection around the halo pin were the most common complications. In adult patients, the relapse of maxilla ranged from 21% to 35%. In the growing child, postoperative stability of the maxilla was unstable and unpredictable.