• The korean journal of orthodontics
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• v.25 no.5 s.52
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• pp.577-585
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• 1995

This study has been performed to determine whether significant differences in the maxillary basal bone pattern exist between skeletal class II malocclusion and normal occlusion. Materials for the skeletal Class III sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 29 adult individuals, 15 males and 14 females. The average age was 19.75 years with a range from 16.4 to 29.1 years. A normal control sample consisted of lateral cephalometric roentgenograms and maxillary cast models of 24 adult individuals, 13 males and 11 females. The average age was 24.25 years with a range from 20.8 to 29.4 years. The results of this study can be summarized and concluded as like follows. 1. In comparing sexual difference of maxillary basal bone morphology in skeletal Class III malocclusion, the following Parameters of males were found to be significally larger than those of females : inter first premolar width, inter molar width, oblique canine height, oblique molar height and maxillary basal bone perimeter. 2. In comparing sexual difference of maxillary basal bone morphology in normal occlusion, the following parameters of males were found to be significally larger than those of females : inter canine width, inter first and second premolar width, inter molar width, oblique canine height and oblique molar height. 3. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion md normal occlusion in males, the following parameters were found to be significally larger in normal occlusion : inter canine width, inter canine height, inter molar height, oblique canine height and oblique molar height. 4. In comparing maxillary basal bone morphologic difference between skeletal Class III malocclusion and normal occlusion in females, the following parameters were found to be significally larger in normal occlusion : inter canine height, inter molar height, oblique canine height, oblique molar height and maxillary basal bone perimeter.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.141-147
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• 2007

The purpose of this study was to evaluate the effects of maxillary occlusal plane angle to postoperative skeletal stability by comparative analysis after two-jaw surgery of patients with skeletal CIII malocclusion. This study was made with lateral cephalometric radiography of 52 patients with skeletal class III malocclusion that were performed to Le Fort I osteotomy and BSSRO. And 52 patients were divided to Group A(n=30) and B(n=22). Maxillary posterior impaction was not conducted in Group A, which the pre-operative maxillary occlusal plane angle was in a normal range, and for Group B, which the pre-operative maxillary occlusal plane was low, the maxillary posterior impaction was conducted. The results were obtained as follows : 1. The relapse rate of Group A, which the pre-operative maxillary occlusal plane angle was in a normal range, was relatively stable compared to Group B, which the pre-operative maxillary occlusal plane was low. 2. The relapse rate of each measurement of Group B, which had the maxillary occlusal plane altered during the operation, was somewhat high, and of those, the post-operative relapse rate of overjet, overbite, mandibular plane angle appeared to be significantly high in the statistics. The analyzed results above, was thought to be indicating that the pre-operative maxillary occlusal plane angle was closely related to the post-operative skeletal stability, and that obtaining post-operative skeletal stability only through operative normalization of occlusal plane angle may meet limitations.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.1
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• pp.27-34
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• 2006

After orthognathic surgery in skeletal class III patients, the hyoid bone position and the upper airway dimension could be changed due to mandibular setback. There has been many studies about airway dimension of the patients with skeletal class II malocclusion or obstructive sleep apnea. but not with skeletal class III. The purpose of this study was to examine the change of position of the hyoid bone and the consequent change of airway space as the result of retrusion of mandible after orthognathic surgery in skeletal Cl III malocclusion patients. It is also to apply this results in predicting, diagnosing and treating the subsequent obstructive sleep apnea. Forty patients who were diagnosed as skeletal Cl III maloccusion, received orthoganthic surgery of both jaws including mandibular setback, and were followed up post-operatively for more than 6 months were selected. There were 10 male patients 30 female patients. The preoperative and postoperative lateral cephalograms were traced and the distances and angles were measured. The nasopharyngeal space increased postoperatively while the oropharyngeal space decreased. Except for the change of oroparyngeal space, the changes in male patients were greater than female patients. The hyoid bone moved in the posterior-inferior direction, and the change was greater in males than in females. If the postoperative mandibular setback is great, then a significant decrease of airway space and posterior and inferior movement of the hyoid bone were observed. This can result in symptoms related to obstructive sleep apnea. This result should be considered in the diagnosis and treatment planning of orthognathic surgery patients.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.303-315
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• 1999

The aim of this study was to evaluate the morphology of the mandibular symphysis and anterior alveolar and skeletal relationship under the influence of the rotational growth pattern of mandible in skeletal Class III malocclusion. A total of U untreated adult subjects were divided into two groups-forward rotational growth pattern group, backward rotational growth pattern group-according to the suggestion of Skieller et al.. The antero-posterior position, vertical relationship, mandibular symphysis and anterior alveolar and skeletal relationship were assessed on lateral cephalometric radiographs. Mandibular symphysis and anterior alveolar and skeletal relationship in each subject were studied and the following conclusions were drawn : 1. Concerning the antero-posterior position, forward rotational growth pattern group showed significantly larger SNA, SNB. Conceming the vertical relationship, all measurements showed statistically significant differences. 2. Forward rotatioal growth pattern group showed significantly larger IMPA, MnAD, backward rotational growth pattern group showed significantly larger MxABH. 3. There was no statistically significant difference in symphysis ratio to mandibular plane between forward and backward rotational growth pattern group. 4. In the correlative analysis of rotational growth pattern of mandible and mandibular symphysis, anterior alveolar and skeletal relationship, statistically significant correlations in overbite, IMPA, MnAD, symphysis width were showed.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.694-699
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• 2001

The prognosis for class III patients in growing child can be made in mixed dentition and the severity of the symptom is often amenable to early intervention. Class III malocclusion can be classified as functional class lit and skeletal origin. Skeletal Class III malocclusion is usually characterized by overdeveloped mandible, underdeveloped maxilla, but the cause of pseudo class III is most dentoalveolar or functional shift of mandible. The primary goal of early intervention of malocclusion is to supply an environment that is conducive to the development of favorable occlusal relationships and avoiding of worsening of the problems. Inverted labial bow appliance is introduced as an appliance to combine the advantage of active plate and activator. It is undemanding with this appliance to initiate not only dentoalveolar expansion of upper dentition but also to orient the functional retrusion of mandible. With simple design the compliance for patients such as mouth breathing problem can be improved. For successful use of this appliance it is utmost important to make accurate and early diagnosis between pseudo- and skeletal class III malocclusion. This article will demonstrate the use of an Inverted labial bow appliance for early treatment of a functional Class III malocclusion. After 4 month treatment, anterior crossbite was treated and the results were achieved mainly dentoalveolar change of upper and lower anterior teeth.

• The Journal of the Korean dental association
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• v.46 no.2 s.465
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• pp.88-99
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• 2008

In growing patients with Class III malocclusion and midfacial deficiency, the treatment protocol calls for orthopedic maxillary protraction and clinicians choose the facemask therapy generally. But facemask is not esthetic or comfortable to patients because it should be worn extraorally. Consequently it is difficult to obtain patients cooperation, and this often influences the treatment effects negatively. MTA (modified tandem appliance), that is a small intraoral appliance, is carried conveniently and esthetic relatively. So it seemed more patient-friendly than a facemask. While the treatment effect of this is similar to that of a facemask. This report presents skeletal Class III malocclusion two cases treated by MTA with good results.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.475-483
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• 1993

The purpose of this study was to investigate the treatment effects on anterior crossbite patients using chin cap and labiolingual arch appliance. In the present study, I statistically evaluated measurement values on a cephalogram before and after treatment form twenty anterior crossbite cases. The results were as follows: 1. In the craniofacial patterns, cranial base increased after treatment. 2. In the maxillo-mandibular relationship, ANB and Facial convexity significantly increased. 3. In the denture patterns, occlusal plane, Ul to FH and Overjet significantly increased. On the contrary overbite decreased significantly. Lower incisors inclined lingually. 4. In the soft tissue profile changes, lower lip protrusion was signifacantly improved.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.87-98
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• 2023

This report presents a case of successful treatment of skeletal Class III malocclusion with transverse discrepancy in adult by surgery-first approach. Traditionally dental decompensation is necessary prior to surgery in 2-jaw surgery to correct transverse and rotational discrepancy. However, the hyrax-type palatal expansion appliance was used to improve maxillary expansion accuracy and postoperative stability in this surgery-first approach (segmental Le Fort I osteotomy and mandibular setback surgery). It was established to be an effective means of precisely predicting postoperative occlusion and achieving stable retention after surgery of skeletal Class III malocclusion with maxillary transverse discrepancy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.18.1-18.9
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• 2016

Background: The aim of this study was to examine the relationship between improvements in lip asymmetry at rest and while smiling after orthognathic surgery in patients with skeletal class III malocclusion. Methods: This study included 21 patients with skeletal class III malocclusion and facial asymmetry. We used preoperative and postoperative CT data and photographs to measure the vertical distance of the lips when smiling. The photographs were calibrated based on these distances and the CT image. We compared preoperative and postoperative results with the t test and correlations between measurements at rest and when smiling by regression analyses. Results: There were significant correlations between the postoperative changes in canting of the mouth corners at rest, canting of the canines, canting of the first molars, the slope of the line connecting the canines, and the slope of the line connecting first molars. The magnitude of the postoperative lip line improvement while smiling was not significantly correlated with changes in the canting and slopes of the canines, molars, and lip lines at rest. Conclusions: It remains difficult to predict lip line changes while smiling compared with at rest after orthognathic surgery in patients with mandibular prognathism, accompanied by facial asymmetry.

• 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.