• The korean journal of orthodontics
• /
• v.45 no.3
• /
• pp.121-129
• /
• 2015

Objective: This study aimed to assess three-dimensional changes in the temporomandibular joint positions and mandibular dimensions after correction of dental factors restricting mandibular growth in patients with Class II division 1 or division 2 malocclusion in the pubertal growth period. Methods: This prospective clinical study included 14 patients each with Class II division 1 (group I) and Class II division 2 (group II) malocclusions. The quad-helix was used for maxillary expansion, while utility arches were used for intrusion (group I) or protrusion and intrusion (group II) of the maxillary incisors. After approximately 2 months of treatment, an adequate maxillary arch width and acceptable maxillary incisor inclination were obtained. The patients were followed for an average of 6 months. Intraoral and extraoral photographs, plaster models, and cone-beam computed tomography (CBCT) images were obtained before and after treatment. Lateral cephalometric and temporomandibular joint measurements were made from the CBCT images. Results: The mandibular dimensions increased in both groups, although mandibular positional changes were also found in group II. There were no differences in the condylar position within the mandibular fossa or the condylar dimensions. The mandibular fossa depth and condylar positions were symmetrical at treatment initiation and completion. Conclusions: Class II malocclusion can be partially corrected by achieving an ideal maxillary arch form, particularly in patients with Class II division 2 malocclusion. Restrictions of the mandible in the transverse or sagittal plane do not affect the temporomandibular joint positions in these patients because of the high adaptability of this joint.

• The korean journal of orthodontics
• /
• v.38 no.5
• /
• pp.358-370
• /
• 2008

Objective: The purpose of this study was to investigate the horizontal skeletal pattern and dental arch differences between Class III malocclusion patients and normal occlusion patients. Methods: Twenty skeletal Class III malocclusion patients and ten normal occlusion patients were selected and 3D facial CT were taken to analyze the horizontal skeletal differences between the two groups. Results: In the horizontal comparison of the maxilla, skeletal width and perimeter were significantly smaller in skeletal Class III patients on ANS and A point reference planes. The difference between maxillary width of ANS and A point reference planes showed that there was greater constriction of the first and second premolar in skeletal Class III patients. In the horizontal comparison of the mandible, the widths of the canine and premolar area were significantly larger in skeletal Class III patients on B point reference plane. The differences between width of the upper and lower jaws (comparison of A and B reference planes) were significantly large in the canine and premolar area. Conclusions: From this study, the characteristics of Class III malocclusion patients were shown through horizontal constriction of the maxilla. But to make clear further detailed characteristics of Class III malocclusion patients, additional studies are necessary.

• The korean journal of orthodontics
• /
• v.43 no.6
• /
• pp.288-293
• /
• 2013

Objective: This study was aimed at comparing the mandibular arch forms of Korean and Vietnamese patients by using facial axis (FA) points on three-dimensional (3D) models. Methods: Mandibular casts of 68 Korean (Class I malocclusion, 30; Class II malocclusion, 38) and 78 Vietnamese (Class I malocclusion, 41; Class II malocclusion, 37) patients were scanned in their occluded positions and grouped according to arch form (tapered, ovoid, and square). The FA point of each tooth was digitized on the 3D mandibular models. The measurements and frequency distributions of the arch forms were compared between the ethnic groups. Results: The Vietnamese patients had significantly greater intercanine depth and intercanine and intermolar width-to-depth ratios than the Korean patients (p < 0.05). The frequency distributions of the arch forms were also significantly different (p = 0.038), but no sexual dimorphism was found. Conclusions: Vietnamese people tend to have deeper and wider arches than Korean people. The three arch forms are evenly distributed in Korean people, but Vietnamese people frequently have square arches. Clinicians should identify the correct arch form of an ethnic group before initiating orthodontic treatment.

• The korean journal of orthodontics
• /
• v.37 no.1 s.120
• /
• pp.29-43
• /
• 2007

Objective: To establish proper diagnosis and treatment plan for skeletal Class II malocclusions, some important factors to consider are the patient's skeletal morphology, prognosis as well as the treatment effects. Therefore, the present study analyzed the effects of activator treatment on different skeletal patterns in growing Class II malocclusion patients. Methods: A total of 116 patients (53 boys & 63 girls) in the experimental group were treated with the activator appliance. The experimental group was classified into either hyperdivergent or hypodivergent groups according to articular and genial angles. Results: Patients with hypodivergent growth patterns showed good effects of activator treatment. Conclusion: It seems conceivable that through classifying adolescent Class II malocclusion patients into different skeletal patterns, activator treatment effects may be predicted during the diagnosis and treatment planning stage.

• The korean journal of orthodontics
• /
• v.48 no.6
• /
• pp.357-366
• /
• 2018

Objective: The purpose of this study was to analyze the transverse dental compensation in reference to the maxillary and mandibular basal bones using cone-beam computed tomography (CBCT) and evaluate the correlations between transverse dental compensation and skeletal asymmetry variables in patients with skeletal Class III malocclusion and facial asymmetry. Methods: Thirty patients with skeletal Class I (control group; 15 men, 15 women) and 30 patients with skeletal Class III with menton deviation (asymmetry group; 16 men, 14 women) were included. Skeletal and dental measurements were acquired from reconstructed CBCT images using OnDemand3D 1.0 software. All measurements were compared between groups and between the deviated and nondeviated sides of the asymmetry group. Correlation coefficients for the association between skeletal and dental measurements were calculated. Results: Differences in the ramus inclination (p < 0.001), maxillary canine and first molar inclinations (p < 0.001), and distances from the canine and first molar cusp tips to the midmaxillary or midmandibular planes (p < 0.01) between the right and left sides were significantly greater in the asymmetry group than in the control group. In the asymmetry group, the ramus inclination difference (p < 0.05) and mandibular canting (p < 0.05) were correlated with the amount of menton deviation. In addition, dental measurements were positively correlated with the amount of menton deviation (p < 0.05). Conclusions: Transverse dental compensation was correlated with the maxillary and mandibular asymmetry patterns. These results would be helpful in understanding the pattern of transverse dental compensation and planning surgical procedure for patients with skeletal Class III malocclusion and facial asymmetry.

• Journal of Oral Medicine and Pain
• /
• v.32 no.1
• /
• pp.121-128
• /
• 2007

If patients complain about sudden ill-fitting occlusal sensation(acute malocclusion), a dentist has to consider many possible causes about that. Acute malocclusion is characterized its sudden onset and mainly can be caused by teeth and its related structure problem. But we always keep on mind that acute malocclusion also can be caused by temporomandibular disorders In this 3 cases of acute malocclusion, evaluating by patient history, clinical and radiographic findings, we diagnosed them as 1. Lateral pterygoid muscle spasm, 2.. Retrodiscitis, 3. Osteoarthritis. Through this non-odontogenic acute malocclusion cases, we emphasize the key of diagnosis is on comprehensive and careful patient history taking and clinical examination.

• Proceedings of the Korea Contents Association Conference
• /
• 2019.05a
• /
• pp.275-276
• /
• 2019

The purpose of this study was to assess condylar size in volumetric 3D imaging in patients with class I, class II, class III malocclusions. To evaluate the differences among the three experimental groups, the condylar values of men were analyzed. There was a significant difference in the measured values of height. Among the three experimental groups, the condylar measurements in women showed significant differences in height and width. This study is expected to be used for determining the connection between malocclusion and condyle as a base line data.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.5
• /
• pp.397-403
• /
• 2001

Purpose: The purpose of this study was to evaluate the postoperative stability of LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion and to help the establishment of treatment planning in patients with a skeletal class III malocclusion in the future. Materials and Methods: The lateral cephalograms of 14 patients who had been underwent two-jaw surgery via one-piece LeFort I osteotomy were traced and the landmarks were identified. Repeated tracings and construction of reference planes were done. Comparisons were made from the immediate postoperative to late postoperative results of each landmarks on the horizontal and vertical directions. Conclusions: 1. The horizontal changes of landmark ANS, point A, PNS and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 2. The vertical changes of landmark ANS, point A, PNS, Mx6Cr and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 3. The horizontal change of landmark Mx6Cr between immediate postoperative to late postoperative data was statistically significant(p<0.05). 4. Results showed that it was stable that one-piece LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion.

• Journal of dental hygiene science
• /
• v.23 no.2
• /
• pp.112-122
• /
• 2023

Background: This study aimed to evaluate the effect of a prefabricated functional appliance (Myobrace^®) on skeletal, dental, and soft tissue components in children with Class II, division 1 malocclusion. Methods: Thirteen patients with Class II, division 1 malocclusion (9 girls and 4 boys; mean age, 8.2±0.9 years at the start and 9.3±1.0 years at the end of the treatment) were treated with Myobrace^® for a mean period of 12.9±4.0 months. Patients were instructed to use the appliance daily for 1 hour and overnight while sleeping. A control group of 10 patients with untreated Class II, division 1 malocclusion (3 girls and 7 boys; mean age, 9.0±1.6 years at the start and 10.4±2.1 years at the end of the observation) was included to eliminate possible growth effects. The mean observation period for this group was 17.7±11.2 months. Lateral cephalograms were taken at the start and end of the treatment, and findings from 41 measurements were analyzed using the V-Ceph^TM program. The mean and standard deviation of cephalometric measurements were analyzed using paired and independent sample t-tests. Results: The treatment group showed significant changes in SNB, ANB, maxillary protrusion, ramus height, proclination of upper anterior teeth, interincisal angle, overjet, and upper lip protrusion compared with the control group. However, only decrease in ANB, maxillary protrusion, overjet, upper lip protrusion, and increase in interincisal angle were significantly higher in the treatment group than in the control group. Conclusion: The prefabricated functional appliance induced skeletal, dentoalveolar, and soft tissue changes, resulting in a significant reduction in anteroposterior discrepancy.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.40
• /
• pp.27.1-27.8
• /
• 2018

Purpose: Various complications occur when a maxillofacial fracture is malunionized or improperly resolved. Malocclusion is the most common complication, followed by facial deformity, temporomandibular joint disorder (TMD), and neurological symptoms. The purpose of this study was to evaluate the dental treatment of postoperative complications after maxillofacial fracture. Materials and methods: In this study, nine patients with a postoperative complication after maxillofacial fracture who had been performed the initial operation from other units and were referred to the authors' department had been included. Of the nine patients, six had mandibular fractures, one had maxillary fractures, one had maxillary and mandibular complex fractures, and one had multiple facial fractures. All the patients had tooth fractures, dislocations, displacements, and alveolar bone fractures at the time of trauma, but complications occurred because none of the patients underwent preoperative and postoperative dental treatment. Malocclusion and TMD are the most common complications, followed by dental problems (pulp necrosis, tooth extrusion, osteomyelitis, etc.) due to improper treatment of teeth and alveolar bone injuries. The patients were referred to the department of dentistry to undergo treatment for the complications. One of the nine patients underwent orthognathic surgery for a severe open bite. Another patient underwent bone reconstruction using an iliac bone graft and vestibuloplasty with extensive bone loss. The other patients, who complained of moderate occlusal abnormalities and TMDs such as mouth-opening limitation, underwent occlusal treatment by prosthodontic repair and temporomandibular joint treatment instead of surgery. Results: One patient who underwent orthognathic surgery had complete loss of open bite and TMD after surgery. One patient who underwent reconstruction using an iliac bone graft had a good healing process. Other patients were treated with splint, injection, and physical therapy for mouth-opening limitation and temporomandibular joint pain. After treatment, the TMDs were resolved, but the remaining occlusal abnormalities were resolved with prosthetic restoration. Conclusions: Considering the severity of malocclusion and TMJ symptom and the feasibillity of reoperation, nonsurgical methods such as orthodontic and prosthodontic treatments and splint therapy can be used to manage the dental and TMD complication after the trauma surgery. However, reoperation needs to be strongly considered for severe malocclusion and TMD problem.