• Imaging Science in Dentistry
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• v.50 no.1
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• pp.9-14
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• 2020

Purpose: The purpose of this study was to evaluate vertical bone loss and alveolar bone thickness in the maxillary and mandibular incisors of patients with skeletal class III malocclusion. This study also aimed to evaluate the periodontal condition of class III malocclusion patients who had not undergone orthodontic treatment. Materials and Methods: The sample included cone-beam computed tomography scans of 24 Korean subjects (3 male and 21 female). Alveolar bone thickness (ABT), alveolar bone area (ABA), alveolar bone loss (ABL), and fenestration of the maxillary and mandibular incisors were measured using 3-dimensional imaging software. Results: All incisors displayed an ABT of less than 1.0 mm from the labial surface to root level 7 (70% of the root length). A statistically significant difference was observed between the mandibular labial and lingual ABAs and between the maxillary labial and mandibular labial ABAs. The lingual ABA of the mandibular lateral incisors was larger than that of the mandibular central incisors. ABL was severe on the labial surface. A statistically significant difference was observed between the maxillary and mandibular labial ABL values(21.8% and 34.4%, respectively). Mandibular lingual ABL (27.6%) was significantly more severe than maxillary lingual ABL (18.3%) (P<0.05). Eighty-two fenestrations were found on the labial surfaces of the incisors, while only 2 fenestrations were observed on the lingual surfaces. Fenestrations were most commonly observed at root level 6. Conclusion: Careful evaluation is needed before orthodontic treatment to avoid iatrogenic damage of periodontal support when treating patients with class III malocclusion.

• The korean journal of orthodontics
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• v.52 no.2
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• pp.85-101
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• 2022

Objective: To classify facial asymmetry (FA) phenotypes in adult patients with skeletal Class III (C-III) malocclusion. Methods: A total of 120 C-III patients who underwent orthognathic surgery (OGS) and whose three-dimensional computed tomography images were taken one month prior to OGS were evaluated. Thirty hard tissue landmarks were identified. After measurement of 22 variables, including cant (°, mm), shift (mm), and yaw (°) of the maxilla, maxillary dentition (Max-dent), mandibular dentition, mandible, and mandibular border (Man-border) and differences in the frontal ramus angle (FRA, °) and ramus height (RH, mm), K-means cluster analysis was conducted using three variables (cant in the Max-dent [mm] and shift [mm] and yaw [°] in the Manborder). Statistical analyses were conducted to characterize the differences in the FA variables among the clusters. Results: The FA phenotypes were classified into five types: 1) non-asymmetry type (35.8%); 2) maxillary-cant type (14.2%; severe cant of the Max-dent, mild shift of the Man-border); 3) mandibular-shift and yaw type (16.7%; moderate shift and yaw of the Man-border, mild RH-difference); 4) complex type (9.2%; severe cant of the Max-dent, moderate cant, severe shift, and severe yaw of the Man-border, moderate differences in FRA and RH); and 5) maxillary reverse-cant type (24.2%; reverse-cant of the Max-dent). Strategic decompensation by pre-surgical orthodontic treatment and considerations for OGS planning were proposed according to the FA phenotypes. Conclusions: This FA phenotype classification may be an effective tool for differential diagnosis and surgical planning for Class III patients with FA.

• The korean journal of orthodontics
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• v.43 no.5
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• pp.209-217
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• 2013

Objective: This study investigated whether temporomandibular joint (TMJ) condyle-fossa relationships are bilaterally symmetric in class III malocclusion patients with and without asymmetry and compared to those with normal occlusion. The hypothesis was a difference in condyle-fossa relationships exists in asymmetric patients. Methods: Group 1 comprised 40 Korean normal occlusion subjects. Groups 2 and 3 comprised patients diagnosed with skeletal class III malocclusion, who were grouped according to the presence of mandibular asymmetry: Group 2 included symmetric mandibles, while group 3 included asymmetric mandibles. Pretreatment three-dimensional cone-beam computed tomography (3D CBCT) images were obtained. Right- and left-sided TMJ spaces in groups 1 and 2 or deviated and non-deviated sides in group 3 were evaluated, and the axial condylar angle was compared. Results: The TMJ spaces demonstrated no significant bilateral differences in any group. Only group 3 had slightly narrower superior spaces (p < 0.001). The axial condylar angles between group 1 and 2 were not significant. However, group 3 showed a statistically significant bilateral difference (p < 0.001); toward the deviated side, the axial condylar angle was steeper. Conclusions: Even in the asymmetric group, the TMJ spaces were similar between deviated and non-deviated sides, indicating a bilateral condyle-fossa relationship in patients with asymmetry that may be as symmetrical as that in patients with symmetry. However, the axial condylar angle had bilateral differences only in asymmetric groups. The mean TMJ space value and the bilateral difference may be used for evaluating condyle-fossa relationships with CBCT.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.581-589
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• 1998

In order to correct a maxillofacial-skeletal disharmony successfully and achieve a favorable facial profile, orthodontic treatment must begin at pubertal growth spurt. Therefore predicting the pubertal growth pattern and evaluating the growth potential is very important. For an orthodontist, estimating skeletal maturity in relation to one's personal growth spurt is essential and it must be considered into the treatment. The objective of this study was to find out whether there was a difference in menacheal age among different malocclusion groups and to evaluate the skeletal maturity at menarche. The subjects were 64 Class I malocclusion patients, 51 Class II patients and 38 Class III patients. Skeletal maturity was estimated from handwrist radiographs of these patients. Handwrist radiographs were taken between 3 months before and after the menarche. The results were as follows. 1. The mean chronologic age of menarche was $12.50{\pm}1.01$ years. 2. For the Class I malocclusion group the mean age of menarche was $12.36{\pm}1.04$ years, for Class II $12.81{\pm}1.03$ years and for Class III $12.32{\pm}0.82$ years. According to these results Class II malocclusion patients started mensturation later than Class I and Class III malocclusion patients. 3. No difference was found considering the skeletal maturity at menarche among the malocclusion groups. 4. The skeletal maturity index at menarche was SMI 7 for $45.10\%$, SMI 8 for $27.25\%$, SMI 9 for $10.46\%$, SMI 6 for $7.84\%$, SMI 10 for $7.84\%$ and SMI 5 for $1.31\%$ patients. 5. Statistically there was a significant correlation between skeletal maturity estimated by handwrist radiographs and menacheal age(p<0.05, r=0.25430).

• The korean journal of orthodontics
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• v.38 no.1
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• pp.60-67
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• 2008

Treatment of adult patients with Class III malocclusion frequently requires a combined orthodontic and surgical approach. However, if for various reasons, nonsurgical orthodontic treatment is chosen, a stable outcome requires careful consideration of the patient's biologic limitation. This case presents the orthodontic treatment of an adult with a Class III malocclusion, which was treated nonsurgically using indirect skeletal anchorage.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.407-412
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• 2011

Purpose: The purpose of the present study was to evaluate the postoperative skeletal stability of two-jaw surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) via surgery first orthodontic treatment (SFOT) in class III malocclusion. Methods: Thirty-two patients who had two-jaw surgery via SFOT were included in this study. Serial lateral cephalograms were obtained before (T0), immediately after (T1), and six months after (T2) surgery. Twelve variables were measured for horizontal and vertical skeletal stability as well as for dental change. All measurements were evaluated statistically by a paired t-test ($P$ <0.05). Results: The mean skeletal changes were $0.1{\pm}2.5$ mm at point A and $-12.0{\pm}7.4$ mm at the pogonion. The mean horizontal relapse was 11.6% at the pogonion, and the mean vertical surgical changes included an upward displacement of $2.1{\pm}7.1$ mm and a forward displacement of $1.4{\pm}4.6$ mm at the pogonion. Upper incisor inclination decreased after surgery and was maintained at T2, and lower incisors were proclined from T1 to T2 by postsurgical orthodontic treatment. Conclusion: Postoperative skeletal stability of two-jaw surgery via surgery first orthodontic treatment in class III malocclusion was clinically acceptable.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.323-328
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• 2001

Anterior open bite is one in which the teeth in the anterior portion of the maxilla and mandible are vertically apart and lack the overlapping necessary for the incisive function when the mandible is in closed position. Anterior open bite is a result of the interaction of many different etiologic factors including thumb and finger sucking, lip and tongue habits, airway obstruction, skeletal growth abnormalities and its tendency may appear with any type of skeletal patterns, such as Class I, II or III malocclusion types. Though the treatment methods for anterior open bite are various, the conventional FR-4, designed by Rolf Fr$\"{a}$nkel, is known to be effective in treating open bite cases with Class I or II skeletal patterns. It is due to that an incidence of skeletal Class II is high in the Occidentals, and open bite is accompanied by these malocclusion type in many cases. However, an incidence of skeletal Class III is high in the Orientals, and open bite is sometimes accompanied by skeletal Class III in many cases. Although the use of the conventional FR-4 was effective in the treatment of open bite, skeletal Class III would be worsened. So, a modified FR-4(placing the labial bow in the lower, the labial pads in the upper) was designed for the treatment of patients showing skeletal Class III and open bite.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.349-357
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• 2010

Physical factors and intra- and extra-oral factors of a patient have to be considered in order to decide a treatment plan for the skeletal class III malocclusion patient. Most of cases, the pre-prosthodontic treatment requires the orthodontic approaches and maxillofacial surgery. However, in some cases, patients' economic or medical condition makes impracticable situation for the orthodontic or surgical intervention. For those cases, the compromised prosthetic treatment which provides more stable and persistent occlusal stabilization is recommended. In this case report, a woman patient has a skeletal class III maxillomandibular relationship and misses multiple teeth. The prosthetic treatment without orthodontic and surgical intervention is performed due to her physical problem. The functional and esthetic results are achieved by the fixed prosthesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.1
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• pp.51-55
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• 2000

Purpose : The purpose of this study is to setup a standard treatment protocol in surgical correction of skeletal malocclusion with Angle Class III patients. We asessed the soft tissue changes according to skeletal changes of patients who have undergone orthognathic surgery with bilateral split sagittal ramus osteotomy (BSSRO) and advancing genioplasty. Materials & Methods : The soft tissue change of 9 skeletal Class III patients was assessed after BSSRO and advancing genioplasty. The patient group was skeletal Class III who was surgically treated by BSSRO & advancing genioplasty. The average follow up period is 13 months with the range of 6 and 30 months. All patients have undergone preoperative and postoperative orthodontic treatment. The assessment was devided into two groups. One was antero-posterior relationship and the other was vertical relationship of dimensional changes of soft tissue after orthognathic surgery. Results : In antero-posterior dimensional changes after surgery, the percentage of soft tissue change in comparison to hard tissue was 89%. Vertical ratio after surgery, 86% soft tissue changes were assessed.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.851-860
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• 1994

Before 1970, mandibular overgrowth was known as main cause of skeletal Class III malocclusion in growing children ; however, recent study reports that many skeletal Class III malocclusion patients also show maxillary deficiency. Since 1972, when Delaire re-accommodated Protraction Head Gear (P.H.G.), many researchers have reported that skeletal Class III discrepancies could be corrected through use of P.H.G., which induces anterior movement of maxilla and change in mandibular growth pattern into infero-posterior direction ; nevertheless, it is very difficult to predict resultant changes of orofacial region. The purpose of this study was to find out what treatment effect P.H.G. has on different study samples. Author divided 51 skeletal Class III malocclusion patients with maxillary deficiency who were treated with P.H.G. into different study groups depending on sex, treatment beginning age, intraoral appliance, and facial growth pattern. By doing so, following results were obtained. 1. Treatment beginning age and Sex Four age groups (5.8 to 8 year-old, 8 to 10 year-old, 10 to 12 year-old, 12 to 14 year-old) were compared, and no significant difference was observed. (p<0.05) There was no significant difference between the sex groups, either. (p<0.05). 2. Intraoral appliance Treatment effects of study groups that used R.P.E.(mean age of 10.2) and Labio-Lingual appliance(mean age of 8.9) were compared. There was no significant difference depending on the type of intraoral appliance that was used. (p<0.05) 3. Facial growth pattern 1) Amounts of SNB and ANB corrections were smaller in clockwise growth pattern group than those in normal or counterclockwise growth pattern group. (p<0.05) 2) Amounts of increase in Wits appraisal and mandibular plane angle were greater in counterclockwise growth pattern group than those in normal or clockwise growth pattern group. (p<0.05) 3)Amounts of increase in articular angle were greater in counter lockwise growth pattern group than those in clockwise growth pattern group. (p<0.05)