• 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.

• The Journal of the Korean dental association
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• v.50 no.2
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• pp.64-71
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• 2012

Recently, the presurgical orthodontic duration tends to be shortened by virtue of the advancement of surgical and orthodontic techniques in class III orthognathic surgery cases. But the predictability of the surgical results should be secured by removing several uncertain factors in presurgical orthodontic treatment. The purpose of this study is to investigate the influence of immediate postsurgical occlusal stability on postsurgical mandibular change. The study includes 40 patients who underwent orthognathic surgery to correct skeletal class III malocclusion. The patients were divided into two groups based on the numbers of occlusal contact in surgical setup occlusion: group 1 (stable surgical occlusion, n=24) and group 2(unstable surgical occlusion, n=16). Changes of horizontal and vertical mandibular measurements during postsurgical follow up period(from 1 week postsurgery to 12month after debonding) were compared to examine the differences between two groups. The stability of surgical occlusion is one of the factors influencing postsurgical mandibular changes in class III malocclusion. The various class III malocclusion cases have specific prerequisites for the orthognathic surgery according to the skeletal patterns. The prerequisites should be obtained by minimum presurgical orthodontics to increase the predictability of the surgical results.

• The Journal of the Korean dental association
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• v.50 no.1
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• pp.13-21
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• 2012

In an edentulous situation, the dentist must make several determinations when constructing artificial teeth. These include vertical and horizontal relationships of mandible with respect to the maxilla, occlusal form and position, vertical dimension, occlusal relationships during both centric closure and eccentric excursive movements. Artificial teeth are attached to a movable base resting on movable and displaceable living tissue subject to damage. They act as a unit; therefore, they must be arranged to function as a unit. Bilateral balanced occlusion is that stability of the denture is attained when bilateral contacts ex ist throughout all dynamic and static states of the denture during function. Lateral excursion in a balanced scheme implies simultaneous working side and nonworking side contact, while occlusal contacts are maintained on both anterior and posterior teeth as the mandible moves anteriorly into protrusion.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.237-253
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• 1998

Surgical-orthodontic treatment is performed for the skeletal Class III patients with no remaining growth and too big a skeletal discrepancy (or camouflage treatment, and two jaw surgery is needed in order to have maximum effect in such patients. In two jaw surgery cases, surgical alteration of the occlusal plane is necessary to establish optimal function, esthetics and postoperative sability, therefore the establishment of the occlusal plane is essential in diagnosis and treatment. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane bsaed on the architectural and structural craniofacial analysis of Delaires. Thus, the subjects of this study were 48 patients who underwent two jaw surgery, and divided in two groups. Each group were composed of 24patients, A group were operated with ideal occlusal plane and B group were not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. There was no significance in occlusal plane angulation between $T_2\;and\;T_3$. Average long term follow-up changes of occlusal Plane angle were $0.24^{\circ}{\pm}2.43$, with FH plane and $0.15{\circ}{\pm}2.16{\circ}$ with SN plane in all 48 patients. These results demonstrated that the occlusal plane after two jaw surgery in skeletal Class III malocclusion was stable. 2. There was no significance in postoperative stability of occlusal plane between A and B group. 3. There was no significance in postoperative stability of occlusal plane depending on surgeon and operative method within each group. 4. The postoperative changes of occlusal plane were correlated to the postoperative changes of jaw rather than tooth position. 5. There was no correlation between the postoperative changes of occlusal plane and maxillary impaction and mandibular setback with surgery.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.273-280
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• 2013

This study aims to examine the influences of wearing an occlusal biteplane splint on balance of the body. 10 subjects were selected who had neither impaired occlusion and masticating systems nor difficulty in walking along with no medical history in temporomandibular joint. Measurements were conducted with the Fukuda stepping test, the limits of stability test. The level of significance, ${\alpha}$ to determine the statistical significance was .05. Fukuda stepping test and the limits of stability test were put to the Wilcoxon signed test. As a result of this study, there was a significant difference in the moving distance in the Fukuda stepping test (p<.05). In addition, there were significant differences in the results of the limits of stability test (p<.05). In conclusion, the results of this study suggest that wearing the occlusal biteplane splint has an positive influence on the balance of the boby.

• Journal of Oral Medicine and Pain
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• v.15 no.1
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• pp.105-115
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• 1991

The purpose of the study was to evaluate the occlusal stability at the moment of dynamic occlusal tooth contact and to investigate the correlation between the occlusal stability and the masticatory muscle activities. It also evaluated the effect of short-term use of occlusal splints on the occlusal stability and the masticatory muscle activities in patients with temporomandibular disorders during maximum voluntary clenching by synchondronized with temporomandibular disorders during maximum voluntary clenching by synchronized use of the T-Scan system(Tekscan, Inc, USA) and K6-Diagnostic system(Myo-tronics Research, Inc, USA) The author measured its distance from retruded contact position(RCP) to intercuspal position(IP), average of contact intervals(ACI), total left-right statistics(TLR), average muscle activities of masseter and anterior temporal muscles during maximum voluntary clenching in 20 patients with temporomandibular disorders and 22 dental students as a control group. The data were compared between two groups and investigated for any correlations between the parameters. The results were as follows : 1. Both of the mean average of contact intervals and the mean absolute value of total left-right statistics during maximum voluntary clenching were increased in the patient group when compared with the control group. 2. Muscular disharmony of anterior temporal muscles of patient group is significantly greater than that of control group. However, muscular disharmony of masseter muscles of patient group is not significantly greater than that of control group. 3. There were significant correlations between muscular disharmony of anterior temporal muscles and average of contact intervals as well as total left-right statistics, and also between muscular disharmony of masseter muscles and total left-right statistics. 4. There were not any significant correlations between distance from RCP to IP and any other parameters. 5. There were a significant decrease in total left-right statistics and muscular disharmony of anterior temporal muscles during maximum voluntary clenching after a 1week use of occlusal splint in the patient group.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.137-143
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• 2011

Purpose: Orthognathic surgery is required in patients with severe skeletal disharmony and facial asymmetry, which results in functional and esthetic improvement. Recently, bimaxillary surgery has become generalized. Establishment of the occlusal plane among several other factors included in the surgery plan is a major consideration for the diagnosis and treatment plan and it is also an important factor for postoperative stability. Methods: In this study, we assessed postoperative stability of occlusal plane, B-point, and pogonion point on 20 patients who underwent two-jaw surgery in the Chosun Dental Hospital from 2000 to 2007. Preoperative and postoperative states and at least a one year postoperative follow-up were compared. Results: The postsurgical relapse volume of the occlusal plane to the SN plane and the FH plane was $-0.26{\pm}2.8^{\circ}$ and $-0.44{\pm}3.29^{\circ}$, respectively and after two-jaw surgery, the stability of occlusal plane was maintained. The horizontal relapse degree was $0.85{\pm}0.46$ mm and $0.76{\pm}0.48$ mm, respectively, and the vertical relapse degree was $1.16{\pm}0.36$ mm and $1.13{\pm}0.71$ mm of the B point and the Pogonion point at the time after minimal 1 year. Conclusion: The vertical relapse amount was shown to be slightly larger than the horizontal relapse amount.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.325-340
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• 1991

There are evidences that occlusal splint therapy is critical to diagnose hidden akeleto-occlusal disharmonies in malocclusion patients and capable of enhancing stability after orthodontic treatment. In addition, evidences have implicated occlusal splint therapy in condylar positional changes during TMJ disorder treatment. In view of these evidences, this study was performed to investigate the effect of occlusal splint therapy on condylar positional changes in malocclusion patients and the possible clinical application of the occlusal splint as an additional orthodontic tool. For this study, 8 Angle's Class I malocclusion patients, who had centric occlusion-centric relation discrepancy within 1.0 mm and had no clinical symptoms of TMJ disorder, were selected as control group. And 22 malocclusion patients who had centric occlusion-centric relation discrepancy over 1.0 mm were selected and subdivided as Class I Malocclusion group, Class II div. 1 malocclusion group, Class II div. 2 malocclusion group, Open bite group, and Mandibular asymmetry group. For each subject the occlusal splint with mutually protected type of occlusal scheme was applied for 3 months. Condylar positions in centric relation and centric occlusion were measured using Panadent articulators and Panadent condylar position indicator (CPI) before and after occlusal splint therapy. On the basis of this study, the following conclusions might be drawn: 1, In control group, Class II div. 2 malocclusion group, and mandibular assymetry group, there were no significant differences in condylar positions before and after occlusal splint therapy. 2. In Class I malocclusion group, condyles were moved $0.27{\pm}0.45mm$ forward (p < 0.05) and $0.98{\pm}0.25mm$ upward (p < 0.01) after occlusal splint therapy. 3. In Class I malocclusion group, condyles were moved $0.24{\pm}0.21mm$ backward (p < 0.05) and $1.01{\pm}0.33mm$ upward (p < 0.01) after occlusal splint therapy. 4. In open bite group, condyles were moved $1.24{\pm}0.30mm$ upward (p < 0.01) after occlusal splint therapy. 5. In both control and experimental groups, there were no significant differences in lateral condylar positions before and after occlusal splint therapy.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.109-120
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• 1989

We tend to consider only static occlusion such as molar relationship, canine key, and interdigitation at finishing stage. Of course, this static occlusion is important for post-orthodontic stability. But we should remember that mandible is always on the move during its various functions. If no pressure or too much pressure is put on during its functions, untoward tooth movement could occur. And tooth mobility, periodontitis, wear facet, bruxism, and far worse temporomandibular disorder could occur. After many studies have been done on what is a desirable occlusal scheme to strengthen post-orthodontic stability, today, "mutually protective occlusion" is recommended. If an orthodontist does not have understanding about this occlusal scheme during orthodontic treatment, the following conditions will be resulted after orthodontic treatment. I. Centric discrepancy 1. centric prematurity 2. sunday bite 3. molar fulcrum II. Eccentric discrepancy 1. posterior interference 2. anterior interference If we have deep understanding about these discrepancies that can happen after orthodontic treatment and their causes, corrections, and especially preventions against them, post-orthodontic stability could be strengthened and further temporomandibular disorder could be prevented.

• The Journal of the Korean dental association
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• v.37 no.4 s.359
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• pp.287-293
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• 1999

Long-term posttreatment stability is great concern to all orthodontist. So, this article was disussed that etiology of relapse, classificatioan of retention, duration of retention and treat after relapse. The most important thing about stability was considered that growth pattern, periodontal remodeling, neuromuscular factors and applied the appropriate mechanotherapy. Retenton was considered during the treatment planning and required considerable analytic thought.