• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.149-159
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• 2000

Occlusal disease is comparable to periodontitis in that it is generally not reversible. Occlusal disease, however, like periodontitis, often maintainable. It does itself to treatment and when restorative dentistry is utilized it becomes, in that sense, reversible. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. An integrated treatment plan is first developed on one set of diagnostic casts, properly mounted on a semiadjustable articulator using jaw relationship records. This is accomplished by using wax to make reconstructive modifications to the casts. These modified casts become the blueprint for planned occlusal changes and the fabrication of provisional restorations. The treatment goals are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. This report shows the treatment procedures for a patient whose mandibular position has been altered due to posterior bite collapse. Migration of the maxillary anterior teeth had occurred, and the posterior occlusal contacts showed pathologic interference. Precise diagnosis using mounted casts was executed and prosthodontic reconstruction by the aid of an unconventional orthodontic correction on maxillary flaring was planned. An unconventional orthodontic correction can be accomplished by using preexisting natural teeth, which can be modified for use in active tooth movement or splinted together for orthodontic anchorage. This technique has an advantage over conventional fixed appliance orthodontic therapy because it can accomplish tooth movement concurrently with restorative and periodontal therapy. On occasion, minor tooth movement can be necessary to achieve the optimum occlusal scheme, crown form, and tooth position for the forces of occlusion to be displaced down the long axis of the periodontally compromised teeth. Once the occlusion, periodontal health, and crown contours for the provisional splinted restoration are acceptable, the final splinted restoration can be similarly fabricated, and it becomes an excellent orthodontic retainer.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.3
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• pp.171-185
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• 2000

The treatment objectives of the complete oral rehabilitation are : (1) comfortably functioning temporomandibular joints and stomatognathic musculature, (2) adherence to the basic principle of occlusion advocated by Schuyler, (3) anterior guidance that is in harmony with the envelope of function, (4) restorations that will not violate the patient's neutral zone. There may be many roads to achieving these objectives, but they all convey varing degrees of stress and strain on the dentist and patient. There are no "easy" cases of oral rehabilitation. Time must be taken to think, time must be taken to plan, and time must be taken to perform, since time is the critical element in both success and failure. Moreover, a systematized and integrated approach will lead to a prognosis that is favorable and predictable. This approach facilitates development of optimum oral function, comfort, and esthetics, resulting in a satisfied patient. Such a systematized approach consists of four logical phase : (1) patient evaluation, (2) comprehensive analysis and treatment planning, (3) integrated and systematic reconstruction, and (4) postoperative maintenance. Firstly, we must evaluate the mandibular position. The results of a repetitive, unstrained, nondeflective, nonmanipulated mandibular closure into complete maxillomandibular intercuspation is not so much a "centric" occlusion as it is a stable occlusion. Accordingly, we ought to concern ourselves less with mandibular centricity and more with mandibular stability, which actually is the relationship we are trying to establish. The key to this stability is intercuspal precision. Once neuromuscular passivity has been achieved during an appropriate period of occlusal adjustment and provisionalization, subsequent intercuspal precision becomes the controlling factors in maintaining a stable mandibular position. Secondly, we must evaluate the planned vertical dimension of occlusion in relationship to what may now be an altered(generally diminished), and avoid the hazard of using such an abnormal position to indicate ultimate occlusal contacting points. There are no hard and fast rules to follow, no formulas, and no precise ratios between the vertical dimension of occlusion. Like centric relation, it is an area, not a point.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.273-280
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• 1994

The Magnetic Resonance Imaging has been used widely to evaluate the disk position without any interruption of the TMJ structures, and the Dynamic MRI presenting computed serial imaging or the video-recorded simulation images is thought to be very effective to evaluate the disk position under function. This is to study the correlation between the clinical diagnosis and the findings of Dynamic MRI for the diagnosis of internal derangement of the temporomandibular joints. 30 joints(15 patients) were examined clinically, and the movement of TMJ meniscus was reviewed in the dynamic MRI. The comparative results are as follows : 1. All internal derangements of TMJ disk displacement without reduction were consistent with MRI findings. 2. 5 joints (50%) of disk displacements with reduction could not be confirmed by MRI findings. 3. The disk displacements in MRI were found in 55% of painful joints, 50% of clicking joints, and 70% of the joints with restricted movement. 4. The reliability of MRI for the diagnosis of TMD was evaluated as 77% ; 24 of 30 joints who presented with clinical diagnosis of TMD. 5. MRI is very reliable to diagnose the disk displacement without reduction, but it is rather not so effective to diagnose the early derangement or muscle disorders.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.4
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• pp.565-579
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• 1993

This study was accomplished to analyse and compare the occlusal contact patterns during eccentric mandibular movements in adult with normal occlusion. 50 subjects(male 27, female 23), who had natural occlusion and no symptom of temporomandibular disorder, were selected. Teeth contact patterns during mandibular eccentric movements were recorded and the distribution of tooth contacts in maximum intercuspation analysed by T-scan system. And then, tooth contact numbers recored by T-scan and silicone bite registration at centric occlusion were analysed and compared. The results obtained were as follows : 1. Antero-posteriorly, the qualitative center of occlusal contacts in centric occlusion were in the first molar areas, but there was a slight deviation in left-right directions. Thus, distribution of occlusal contacts were not bilaterally symmetric. 2. During the mandibular movements from centric occlusal position to right lateral and left lateral directions, the frequency that maxillary canine joined in lateral guidance was relatively high, but pure canine protected occlusion or pure group function occlusion had small frequency. 3. During mandibular protrusive movement, one or more maxillary central incisors frequently joined in protrusive guidance. 4. During mandibular eccentric movements, working and balancing side premature contact was observered in relatively high frequency. 5. In centric occlusal position, the numbers of occlusal contacts recorded on T-scan were relatively smaller than on silicone bite registration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.3
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• pp.259-266
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• 2005

The function of the masseter and anterior temporal muscles was assessed by electromyography in 30 patients with mandibular prognathism (20 patients with facial asymmetry and 10 patients without facial asymmetry) before orthognathic surgery and 4weeks afterwards. Electromyogram(EMG) recordings were made during resting, clenching and swallowing. We compared with right-left difference of this recording and asymmetry index before and after orthognathic surgery. The result of this study was as follows. 1. There was no significant right-left difference in muscle activities of masticatory muscles both asymmetric groups and controls and many variable change after orthognathic surgery.(P>0.05) 2. The mean electric activity of the masticatory muscles was found to have decreased during more clenching than resting, but there was no statistically significant difference because of individual difference of measuring values.(P>0.05) 3. The asymmetry index of masticatory muscles in asymmetric groups was significantly greater during clenching compared with controls.(P<0.05) In conclusion, no right-left difference of muscle activities was found in patients with facial asymmetry before orthognathic surgery and 4weeks afterwards. Not only muscular functioning but also many other factors, such as occlusion, temporomandibular joint disorder and trauma, probably affect facial asymmetry and will be analyzed in future studies. And we will need long term follow-up after orthognathic surgery.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.275-282
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• 2001

Centric relation is defined the horizontal position between maxilla and mandible when condylar head of mandible is positioned adequately in mandibular fossa. The most recent concept of centric relation position is defined as the mandibular position in which the condyles are in their most superoanterior position in the articular fossa, resting against the posterior slope of the articular eminences, with the articular disk properly interposed. To be suitable as a reference point during occlusal management, a mandibular position of centric relation has to be functionally acceptable to the patient and clinically reproducible and achievable during everyday practice. There are numerous methods for determination of centric relation, and in this study we used three of them, Gothic arch tracing(Group I), leaf gauge(Group II), and anterior jig(Group III). The subjects were 10, 8 men and 2 women, age-ranged from 23 to 26 years old, had no prosthetics in thier mouth, and had no sign and symptom of temporomandibular disorders. We gained three occlusal records using each method, and then the degree of the reproducibility was examined with split cast technique. In this study the reproducibility of centric relation using split cast technique was greater in the order of Group I(mean 1.6), Group II(mean 1.4), and Group III(mean 1.3), but there was no significant differences among them statistically(p>0.05).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.3
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• pp.262-266
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• 2006

The silver nanocrystalline is widely used for biological field because of its biocompatibility and anti-microbial effect. The objective of this study was to evaluate the therapeutic efficacy of the silver nanocrystalline ointment on the temporomandibular joint (TMJ) capsulitis. Total 39 patients were included in this study and all patients were received single topical application of the silver nanocrystalline ointment (group A, n=30) or placebo ointment (group B, n=19). Measured variables were maximum mouth opening (MMO), visual analog scale (VAS) for pain, and VAS for function. In results, we could not assess any therapeutic efficacy of single application in the chronic TMJ capsulitis (p>0.05). However, the single application of silver nanocrystalline ointment showed significant improvement in MMO and VAS for pain compared to placebo effect in the acute TMJ capsulitis (p<0.05). We could not find any complications related to ointment application in both groups. In conclusion, the single application of silver nanocrystalline ointment was effective in improving patient's symptom in acute TMJ capsulitis without any noticing complications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.5
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• pp.544-549
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• 2000

The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and high incidence of recurrence. TMJ ankylosis has been treated by excision and total joint reconstruction with alloplastic, allogeneic, autogenous materials as interpositional materials. The temporalis myofascial flap had been considered to be a successful interpositional material, due to its anatomical, topographical, and functional properties. This study evaluated the efficacy of the temporalis myofascial flap for nine TMJs (five patients) through the preauricular approach and coronoidectomy. Radiographic and physiologic long term result was investigated in this study. The result reveals that the temporalis myofascial flap is a good autogenous tissue satisfying the criteria of an ideal interpositional material, which offers a material that fulfills the physiological function of the disc. In spite of favorable functional outcome, mild postoperative openbite tendency remains another challenge.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.1-6
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• 2017

Botulinum toxin (BoNT) injections have been used not only in the field of cosmetic surgery such as forehead and eye wrinkle treatment but also in the treatment of chronic migraine, dystonia, spasticity, temporomandibular disorders (TMD). BoNT injections are the only approved therapies to date for prophylactic treatment of chronic migraine patients. Unlike the previously known paralysis of motor neurons, the mechanism of action for migraine is to block the release of non-cholinergic neurotransmitters such as substance P, CGRP, and glutamate, which are associated with peripheral sensitization and neurogenic inflammation in the sensory nerve, it is hypothesized that the signal is blocked. This review focuses on the analgesic effects of BoNT and suggests the direction for the development of injection methods for chronic migraine patients.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.2
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• pp.171-178
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• 2007

Botulinum toxin type A (BTX-A) has a local effect at the neuromuscular junction by blocking acetylcholine release and thus causing paralysis and atrophy of the affected muscles. In dentistry, Botulinum toxin type A(BTX-A) is used for the treatment of masseteric hypertrophy, temporomandibular disorder, and severe bruxism related neurologic disorder. We hypothesized that the muscle atrophy after BTX-A injection into masseter muscle in growing rats, could affect the jaw growth. The purpose of this study was to determine the effects of the BTX-A injected into the masseter muscle on the jaw growth in rats. Rats were divided into four groups(group 1; control group, group 2; saline injection group, group 3; BTX-A injection group, group 4; baseline control group). Group 4 was sacrificed at the beginning of the experiment to provide baseline values of jaw measurements. The weight, length and width of jaw in those groups were measured every weeks. This study reported that the mandibular body length, condylar length, coronoid process length, anterior region height, coronoid process height and condylar height of the jaw in BTX-A injection group were shorter than those of the control and saline injection groups(P<0.05). In conclusion, BTX-A injected into the masseter muscle may affect the undergrowth of the jaw in rats.