• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.174-183
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• 2000

This study was performed to investigate the characteristics of soft tissue profile of the class III malocclusion and to test the yardstick far differential diagnosis between surgical and orthodontic patients. Initial lateral cephalograms of orthodontic group(30 patients) that have acceptable occlusion and profile by orthodontic treatment alone and surgical group(30 patients) that have favorable occlusion and profile by combined surgical-orthodontic treatment were selected in Ajou university hospital. Powell and Burstone II analysis were made on the tracing. Descriptive, comparative, factor, cluster, and discriminant analysis were carried out with computer program. The results were as followings : 1. Patients who received surgery had a more concave profile and a longer lower facial height than patients who received orthodontic treatment alone. 2. Nasolabial angle, ratio of vertical height, and mentolabial sulcus were significantly different at the 5% level. And facial protuberance, upper lip protuberance, mentocervical angle, nasofrontal angle, nasomental angle, mandibular vertical height, angle between cervix and lower face, ratio of mandibular vertical height divided by cervical depth, ratio of vertical height between upper and lower lip, and maxillary protuberance were significantly different at the 1% level. 3. 8 factors were extracted and factor 2, 3, and 8 showed significant differences by factor analysis. 4. Orthodontic group (25) and surgical group (35) were classified by cluster analysis. 5. Discriminant function was D = 0.079Nasomental angle + 0.081Sn-Gn + 3.343Sn-Gn/C-Gn + 1.734Sn-St/St-Me' -26.460, and cutting score was 0, so we can discriminate that orthodontic group has the score above 0, and surgery group below 0. And 91.7% of original grouped cases were correctly classified.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.643-648
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• 2001

Class III malocclusion usually becomes manifested at a very early age, most typically evidenced clinically by the appearance of either an edge-to-edge incisor relationship or an anterior crossbite. Anterior crossbite, by it-self, retards growth of maxilla, and accelerates growth of mandible. So, treatment should be started as early as the patient cooperates, removing any factors or forces that inhibit growth and development in the same physiologic maxillary displacement direction. The facial mask is effective in most developing Class III patients, because the appliance system affects virtually all areas contributing to a Class III malocclusion. Thus, the facial mask can be applied to most developing Class If cases regardless of the specific etiology. In these cases, the results were followed. Anterior crossbite was corrected by anterior movement of maxilla and downward backward rotation of mandible and simultaneously, lower facial height was increased. So, it can be concluded that the facial mask is effective in treating growing patients with a deficient maxilla.

• The korean journal of orthodontics
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• v.44 no.6
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• pp.330-341
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• 2014

A 19-year-old woman presented to our dental clinic with anterior crossbite and mandibular prognathism. She had a concave profile, long face, and Angle Class III molar relationship. She showed disharmony in the crowding of the maxillomandibular dentition and midline deviation. The diagnosis and treatment plan were established by a three-dimensional (3D) virtual setup and 3D surgical simulation, and a surgical wafer was produced using the stereolithography technique. No presurgical orthodontic treatment was performed. Using the surgery-first approach, Le Fort I maxillary osteotomy and mandibular bilateral intraoral vertical ramus osteotomy setback were carried out. Treatment was completed with postorthodontic treatment. Thus, symmetrical and balanced facial soft tissue and facial form as well as stabilized and well-balanced occlusion were achieved.

• The korean journal of orthodontics
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• v.32 no.5 s.94
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• pp.361-373
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• 2002

The purpose of this study was to evaluate the morphological changes of olveolar bone and mandibular symphysis of lower incisor by presurgical orthodontic treatment and orthognathic surgery in skeletal class III malocclusion. The sample consisted of 30 adult class III malocclusion patients who have received bilateral sagittal split mandibular osteotomy. Lateral cephalograms were taken before treatment, after presurgical orthodontic treatment and 3 months after orthognathic surgery. Skeletal and symphyseal measurements were compared and the relationships between them were analysed. The results were as follow : 1. The labial and lingual alveolar bone height in presurgical and postsurgical group were decreased than that of pretreatment group. 2. The vertical measurements of the craniofacial skeleton showed reverse correlationship with anteroposterior width of basal alveolar bone, but IMPA showed correlatiionship (p<0.01) 3. The craniofacial skeleton and the change of symphyseal measurements(symphyseal length, symphyseal width) showed no correlationship. 4. The labial alveolar bone height showed correlationship with lingual alveolar bone height(p<0.001), and negative correlationship with lingual alveolar crestal width(p<0.01). Labial and lingual alveolar crestal width has negative correlationship (p<0.05). Mandibular symphyseal length and width has positive correlationship(p<0.01). 5. IMPA, LISA showed negative correlationship with labiolingual alveolar bone height and lingual alveolar width and positive correlationship with labial alveolar base bone width.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.4
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• pp.416-426
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• 2020

The purpose of this study was to calculate uncertainty of orthodontic measurement in skeletal class III malocclusion children using lateral cephalometry analysis software which obtained traceability in previous study. Using this data, standard reference of measurement value for skeletal class III malocclusion was obtained. Lateral cephalometric data was collected from 144 children who visited Pediatric Dentistry from 2017 to 2020 for orthodontic treatment. Orthodontic measurement was analyzed with software which obtained traceability. Type A evaluation of uncertainty and type B evaluation of uncertainty was calculated to obtain combined standard uncertainty and expanded uncertainty. Standard reference of skeletal class III children was compared to standard reference of skeletal class I children. Distribution range for skeletal class III malocclusion children aged 6 to 10 with 95% confidence interval was provided using calculated uncertainty of orthodontic measurement value.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.83-94
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• 2008

Purpose: The first objective of this study was to compare the upper midface morpholgy, focusing on the soft tissues, between skeletal Class III maloccusion patients with midfacial depression and the norm. The second objective was to estimate and analyze the change in the upper midface soft tissues following surgical correction with maxillary advancement by Lefort I osteotomy and mandibular setback by bilateral sagittal split osteotomy (BSSRO). Methods: The samples consisted of 34 adult patients (15 males and 12 females) with an average age of 21 years, who had severe anteroposterior discrepancy with midfacial depression. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Lefort I osteotomy and BSSRO. Results: The correlation coefficient between changes in maxillary advancement and changes in Or' (soft tissue orbitale) was 0.599 (p < 0.05). Change in maxillary plane angle and vertical change of the maxilla were not correlated with the change in Or' (p < 0.05). The ratio of soft tissue change in Or' to maxillary advancement was 43.57 %, and 81.54 % in Sn. Regression equations between maxillary movement and Or' were devised. The $r^2$ value was 0.476. Conclusions: The majority of measurements in the upper midface in skeletal Class III maloccusions when compared to the norm, showed significant differences. In Class III malocclusion with midfacial depression, maxillary advancement produces soft tissue change in the upper midface.

• The korean journal of orthodontics
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• v.34 no.2 s.103
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• pp.109-119
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• 2004

This study aimed at investigating the skeletal, dentoalveolar, and soft tissue changes of Class III malocclusion cases treated by second molar extraction. The lateral cephalograms of 15 subjects with moderate Class III malocclusion by average ANB $-1.4^{\circ}\;and\;IMPA\;85^{\circ}$ were traced and the computerized superimposition of average craniofacial change was made. The data was gathered and statistically analyzed. The results were as follows: 1 Lower anterior facial height/anterior facial height increased by 0.6%(P<0.01), mandibular plane increased by $1.5^{\circ}$(P<0.05). 2. There was a slightly downward & backward rotation of the mandible. 3. Lower first molar tipped distally by 4.nm(P<0.001), lower anterior teeth lingually tipped by $3.2^{\circ}$(P<0.05). 4. Retracted lower lip improved facial profile. This study may suggest that second molar extraction could be effective for a moderate Class III malocclusion to make distalization of the lower first molar easier and avoid severe lingual tipping of the lower incisor, if the lower third molar has a normal shape, good direction of eruption and adequate time for lower second molar extraction

• The korean journal of orthodontics
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• v.46 no.1
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• pp.42-54
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• 2016

The aim of this clinical report is to describe the complex treatment of an adult Class III malocclusion patient who was disappointed with the outcome of a previous oral rehabilitation. Interdisciplinary treatment planning was performed with a primary indication for implant removal because of marginal bone loss and gingival recession, followed by orthodontic and surgical procedures to correct the esthetics and skeletal malocclusion. The comprehensive treatment approach included: (1) implant removal in the area of the central incisors; (2) combined orthodontic decompensation with mesial displacement and forced extrusion of the lateral incisors; (3) extraction of the lateral incisors and placement of new implants corresponding to the central incisors, which received provisional crowns; (4) orthognathic surgery for maxillary advancement to improve occlusal and facial relationships; and finally, (5) orthodontic refinement followed by definitive prosthetic rehabilitation of the maxillary central incisors and reshaping of the adjacent teeth. At the three-year follow-up, clinical and radiographic examinations showed successful replacement of the central incisors and improved skeletal and esthetic appearances. Moreover, a Class II molar relationship was obtained with an ideal overbite, overjet, and intercuspation. In conclusion, we report the successful esthetic anterior rehabilitation of a complex case in which interdisciplinary treatment planning improved facial harmony, provided gingival architecture with sufficient width and thickness, and improved smile esthetics, resulting in enhanced patient comfort and satisfaction. This clinical case report might be useful to improve facial esthetics and occlusion in patients with dentoalveolar and skeletal defects.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.375-401
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• 1995

Cause of skeletal Class III malocclusion in growing patients can be classified into maxillary deficiency, mandibular overgrowth, and combination of the two. Use of Protraction Head Gear(P.H.G.) has been recommended for treatment of growing Class III malocclusion patients, for it results in forward & downward movement of maxilla and backward & downward rotation of mandible. Numerous animal experiments were performed and clinical study data have been reported ; nevertheless, studies on soft tissue profile change and comparison of treatment effects among the patients who had undergone treatment are considered to be somewhat insufficient. The author selected 93 patients, who had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with P.H.G. ; the sample group was divided according to sex, treatment beginning age, palatal suture opening(intraoral appliance), and facial growth pattern. For each group, changing patterns of hard and soft tissue profile observed, and comparision with 20 normal group(Angle's Class I) patients of statistical significance in amount of growth and treatment of hard and soft tissue was done. The following results were obtained. 1. Skeletal, dental, and soft tissue measurements indicated that more growth changes was induced in the sample group that used P.H.G. compared to the growth amount of normal group. 2. No statistical significance was observed in the amounts of maxillary forward movement and mandibular backward & downward rotation depending on treatment beginning age in both sex group. 3. R.P.E. showed more significant maxillary forward movement and less protrusion of upper incisor than La-Li. 4. There was no statistical significance in the amount of maxillary forward movement depending on facial growth pattern. On the other hand, measurements indicating mandibular downward & backward rotation indicated greater change in counterclockwise growth pattern group than the clockwise. 5. Changes in upper and lower lip thicknesses showed a close relationship with positional changes in underlying bone tissue and upper and lower teeth, and upper lip height and nasolabial angle increased and mentolabial angle decreased.

• The korean journal of orthodontics
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• v.39 no.1
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• pp.36-42
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• 2009

Objective: The purposes of this study were to provide an epidemiologic data base related to the orthodontic treatment need and to know the changing trends about treatment modality of private orthodontic clinics. Methods: Distribution, trends and orthodontic treatment plan of malocclusion patients were investigated in 1,620 consecutive patients who had been visited and examined in 4 private orthodontic clinics located in Seoul from 2003-2006. Results: Percentage of male and female patients was 26.9% and 73.1% respectively Age distribution had shown that percentage of the patients above 13 years was 78.9%, and above 19 years was 59.0%. Average age of whole patients was 20.5 years. With regard to Angle classification, each percentage of Class I, Class II division 1, Class II division 2 and Class III malocclusion was 38.9%, 34.8%, 2.3% and 24.0%. The percentage of extraction cases(00.9%) outnumbered nonextraction cases(39.1%) and 46% of extraction cases were upper and lower 1st premolar extraction cases. Patients who had chose treatment with fixed appliance and orthognathic surgery was 10.2%. Conclusions: Because the high percentage of adult, Class II malocclusion and orthognathic surgery cases in patients of private orthodontic clinics were shown in this study, orthodontic education program and national health policy in Korea need reformation.