• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.115-122
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• 1993

This study was undertaken to compare the activity of masticatory muscle between normal occlusion and anterior openbite. 33 subjects without the experience of orthodontic treatment, missing teeth and the symptom of T. M. disorders were selected for this study : 25 subjects were normal occlusion and 8 subjects were anterior openbite. The ten items were measured from the cephalometric headplates, and EMG recordings of the anterior temporal and masseter muscle were taken at rest position and during maximum clenching at centric occlusion. All data were analyzed and processed with the computer statistical method. The following results were obtained : 1. At rest position, the muscle activities of both temporal and masseter muscle were higher in anterior openbite than in normal occlusion. 2. During maximum clenching, the muscle activities of both temporal and masseter muscle were prominently lower in anterior openbite than in normal occlusion. 3. At rest position, the temporal muscle of anterior openbite showed the highest muscle activity, but showed the lowest muscle activity during maximum clenching. 4. Anterior openbite showed closer interrelationship between facial morphology and the muscle activity, and the muscle activity was more influenced by the form of mandible than that of maxilla.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.501-511
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• 1991

This study was performed to verify the craniofacial skeletal characteristics in anterior openbite group, in contrast to normal occlusion group, and also to find out, vertical factors which shows, correlate to the amount of anterior openbite. 21 individuals, including 10 males and 11 females, without orthodontic treatment history and anterior - posterior skeletal malrelationships, were selected and analyzed basic morphology and vertical factors, using standard lateral cephalogram. The obtained results as follows: 1. Comparison of anterior open-bite group with normal occlusion group using Moyers analysis. a) In basis morphologic analysis, Ba-SE-Me was lesser and Ba-SE-Mn. P. and Mn.P/A-B were greater in both sexes of anterior openbite group than in normal occlusion group. b) In angle measurements of vertical analysis, PMV/Pal. P. was lesser in male anterior openbite group and PMV/Occ. P. and PMV/Mn. P. were greater in both sexes of anterior openbite group than in normal occlusion group. c) In height ratio of vertical analysis, ATFH/PTFH and ALFH/ATFH were greater in both sexes of anterior openbite group than in normal occlusion group. 2. The amount of anterior openbite was correlated with PMV/Occ. P. and PMV/Mn. P.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.624-630
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• 1996

Anterior openbite is defined as the lack of contacts between the functional occluding teeth on vertical line at centric occlusion and classified into functional and skeletal anterior openbite based on its causes and characteristics. Anterior openbite causes masticatory, speech, and esthetic problems in the growing children and difficulties in diagnosis, treatment, and the prediction of its prognosis. We are reporting on the treatment of anterior openbite in the growing children and the results follow as : 1. In the growing children with anterior openbite, the overbite could be increased by the treatment according to its causes and characteristics. 2. The prognosis is not determined by the presence or severity of oral habit but the skeletal tendency of the patient.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.487-495
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• 1995

This study was undertaken to compare each maximum biting force and to investigate its relationship with the facial skeketal form, number and position of tooth contact between anterior openbite and normal occlusion adults, using the T-scan system and the lateral cephalogram. The subjects of this study consisted of a group of 25 individuals with normal occlusion and another group of 14 with anterior openbite. The obtained results of this study were as follows : 1. The maximum biting force of anterior openbite adults was less than that of normal occlusion adults. 2. In anterior openbite adults, there were negative correlations between the maximum, biting force and SN/MP, FMA, PP/MP mesurement of lateral cephalogram. 3. In anterior openbite adults, as the mesial angulation of lower first molar against the occlusal plane increased, the more the biting force decreased. 4. In both groups, the greater the number of tooth contact, the more the biting force increased. 5. In both groups, the center of effort for anteroposterior occlusal contact was located on the first molar region.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.252-259
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• 2012

Purpose: This study evaluated the postoperative stability of counter clockwise rotation of the mandibular plane in anterior openbite patients, who have had one jaw surgery performed. Methods: This study includes patients with skeletal class III malocclusion accompanied by anterior openbite among the patients who have had BSSRO performed, resulting in counter clockwise rotation of the mandibule. We excluded the patients with genioplasty and segmental surgery, and included 23 patients who underwent BSSRO. Results: We found no statistical significance between the amount of counter clockwise rotation in the mandible in the Pearson correlation test. Also, there was no significant difference between Group 1 (< $3^{\circ}$) and Group 2 (> $3^{\circ}$). Conclusion: This study evaluated the amount of horizontal relapse, and the degree of relapse. Stable results were obtained. Although there was no statistical significance between the degree of openbite and the amount of horizontal relapse, the group with a greater amount of openbite had a greater amount of relapse.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.565-606
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• 1993

The purpose of this study was to evaluate the change of before and after treatment of anterior openbite malocclusions treated by Multiloop Edgewise Archwire technique. The openbite sample consisted of 4 male and 12 female adults, treated with nonextraction or third molar extraction. The normal sample consisted of 58 subjects, which have pleasing facial profile and normal occlusion and no experience of orthodontic or prosthodontic treatment. The 58 subjects of normal sample were subdivided by cephalemetric vertical relationship of face. The 40 subjects, cephalometric vertical relationship of face was in normal range, classified as Normal Sample group 1. The 18 subjects, increased cephalometric vertical relationship of face, classified as Normal Sample group 2. The computerized cephalometric analysis was accomplished with 50 reference points for 22 skeletal measurements, 46 dentoalveolar measurements, 8 soft tissue measurements. Statistical analysis of the data was carried out with paired t-test, Student's t-test, and DUNCAN test using SAS(PC version), The results were as follows : 1. There were no statistically significant differences in skeletal measurement between before and after treatment. The major changes were in dentoalveolar region. 2. After treatment, the long axis of maxillary and mandibular posterior teeth were distally tipped-back, and uprighted to bisected occlusal plane. The interincisal angle was increased. 3. There were no statistically significant increase in the upper posterior dental height and statistically significant decrease in the lower posterior dental height. The upper anterior dental height was increased, but there was no statistically significant increase in the absolute upper anterior dental hight. The lower anterior dental height was increased. 4. After treatment, the maxillary occlusal plane to palatal plane angle and the mandibular occlusal plane to mandibular plane angle were statistically significant increased. Then, there were no statistically significant difference between after treatment group and normal sample group 2. 5. After treatment, the percentage of upper lip length to upper anterior dental height was decreased. Then, There were no statistically significant difference between after treatment group and normal sample group 2.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.281-295
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• 1994

It is very important for the ideal restorations of anterior openbite patients to record the mandibular movement and to harmonize mandibular movement with other organs in stomatognathic systems. This study was designed to compare the mandibular movement of anterior openbite patients with that of normal bite(Angle Class I) patients, to ascertain which components of mandibular movement have differences between two groups, and to use for occlusal treatment of mandibular movement. Saphon Visi-trainer Model 3(Tokyo Shizaisha Co. Japan) and Denar Pantronic(Denar Corp.,U.S.A.) were used to record mandibular movement. Pantronic survey was peformed by using an arbitrary hinge axis according to manufacturer's direction. Twenty-eight adult who have physiologically normal occlusion(Angle Class I) and are free of TM dysfunction were selected as a control group(Group 1). Fifteen adult who are anterior openbite patient and have not anterior guidance function and have posterior interference at protrusion were selected as a experimental group(Group 2). The results are as follows : 1. There was no statistically significant difference between the average immediate and progressive side shift of anterior openbite patients(0.54mm, $7.57^{\circ}$) and those of normal group(0.49mm, $5.96^{\circ}$). 2. The average protrusive and orbiting condylar inclination of anterior openbite patient$(30.87^{\circ},\;32.27^{\circ})$ were significantly lower than those of normal group$(36.11^{\circ},\;39.04^{\circ})$ (P<0.05). 3. In the results of Visi-trainer recordings, the mean for the maximum protrusion, the maximum laterotrusion, the angle of laterotrusion and the angle of protrusion in the horizontal trajectory between group 1 and 2 did not differ significantly. 4. The mean for the angle of protrusion, the maximum opening in the frontal trajectory, the ICP-RCP(A-P) distance and the angle of protrusion in the sagittal trajectory differ significantly(P<0.05). 5. The significant correlation was found between orbiting condylar inclination and protrusive condylar inclination.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.236-243
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• 2005

Anterior openbite is defined as the lack of contacts between the functional occluding teeth on vertical line at centric occlusion and classified into functional and skeletal anterior openbite based on its causes and characteristics. In mixed dentition, habit control and the elimination of abnormal perioral muscle function and moving the vertical direction development to the sagittal direction of the mandible by the functional appliance is a goal of treatment. This study presents the effective interception of oral habit by the tongue crib and functional-fixed treatment and treatment response of openbite related to tongue thrust habit.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.3
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• pp.191-194
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• 2003

Macroglossia can cause dentomusculoskeletal deformities, instability of orthodontic and orthognathic surgical treatment, and create masticatory, speech and airway management problems. To determine whether a reduction glossectomy is necessary, it will important to identify the signs and symptoms of macroglossia. Development of dentoskeletal changes directly related with tongue size, such as an anterior open bite or a Angle Class III malocclusion tendency, would indicate that reduction glossectomy may be beneficial. For reduction glossectomy, several techniques have been reported. However, in most techniques the tip of tongue is removed. So its excision causes the loss of most mobile and sensitive portion of the tongue, and creates ankylosed, globular tongue. To avoid such problems, central tongue reduction technique have been proposed. This article will introduce central tongue reduction for anterior openbite case associated with macroglossia.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.893-904
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• 1998

There are varieties of severe malocclusions, which can be treated orthodontically, but with a great deal of effort. Anterior openbite, in particular, is one malocclusion thought to be more difficult to treat, and therefore, most of them have to be corrected by means of surgical intervention. To solve these problems, numerous studies pertinent to treatment modalities have been introduced with controversies on the effectiveness of treatment. Suggested treatment modalities for anterior openbite are based directly or indirectly on the neuromuscular and morphological features and on the etiologic and/or the environmental factors. Even though the vertical relationship of the face is increased due to the growth variation, the normal occlusal relationship can be achieved by the adequate dentoalveolar compensatory mechanism, but in the case of inadequate or negative dentoalveolar compensation, openbite is likely to be present. If the skeletal dysplasia is too severe to be solved by orthodontic treatment alone, combined treatment with surgery should be done to restore the function and the esthetics of the orofacial complex. In many cases, however, orthodontic alteration of the dentition pertinent to the given skeletal pattern with the proper diagnosis and treatment planning can bring satisfactory results. The treatment changes with the Multiloop Edgewise Archwire(MEAW) therapy occurred mainly in the dentoalveolar region and showed a considerable similarity to the natural dentoalveolar compensatory mechanism. In other words, the MEAW technique allows orthodontists to produce the natural dentoalveolar compensation orthodontically. Even if an openbite is corrected by the orthodontic dentoalveolar compensation suitable for the skeletal pattern, relapse may still occur by the persisting etiologic factors which originally prohibited the natural dentoalveolar compensation. The etiologic factors should be determined at the time of initial diagnosis and should be controlled during treatment and retention.