• Journal of Oral Medicine and Pain
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• v.25 no.1
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• pp.117-128
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• 2000

The present study explored the influence of temporomandibular disorders(TMD) with anterior open bite on swallowing. Fifteen subjects with anterior open bite(group A), 9 subjects with anterior open bite and TMD(group B), and 24 subjects without malocclusion or TMD symptoms (group C) were included. BioPAK system(Bioresearch Inc., Milwaukee, WI, USA) was used to record the muscle activities of anterior temporal, masseter, sternocleidomastoid(SCM) and anterior digastric muscles during maximum clenching and swallowing. Positional change of the mandible during swallowing was also recorded using the same system. The obtained results were as follows: 1. Group A, B, and C did not show significant differences each other in the muscle activity of resting position in most of head and neck muscles. 2. Group B showed significantly lower muscle activity in maximum clenching than group C in anterior temporal(p<0.01), masseter(p<0.05), SCM(p<0.05) and digastric muscles(p<0.05). 3. Group A showed significantly lower muscle activity during swallowing than group C in anterior temporal and masseter muscles(p<0.01). Group B showed significantly lower muscle activity during swallowing than group C in anterior temporal(p<0.01), masseter(p<0.01), and SCM muscles(p<0.05). 4. Group A and B showed increased positional change of the mandible during swallowing measured from vertical, anteroposterior and lateral aspects, and prolonged swallowing(p<0.05). 5. After given instructions for normal swallowing pattern, group A and B showed increased muscle activity during swallowing in anterior temporal, masseter and SCM muscles(p<0.01). Positional change of the mandible and time elapsed for swallowing also decreased after the instruction(p<0.01). 6. Occlusal splint did not change the muscle activity during swallowing. However, vertical change(p<0.01) and swallowing time(p<0.05) were decreased with splint.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.91-99
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• 2000

This study was done to identify the changes of bite force and occlusal contact between before and after stabilization splint therapy. 16 female patients, accepted for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University, were selected as the sample of this investigation. For comparisons, the samples of 16 were divided into just before stabilization splint, 1 month after stabilization splint, 2 months after stabilization splint, and 3 months after stabilization splint and used the T-scan system to identify the bite force and occlusal contact changes for each group. Statistical analysis of the data was carried out ANOVA tests, and Turkey tests using $SPSS/PC^+$. The results were as follows : 1. Bite force change from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 2. Bite force changes from 1 to 3 months after stabilization splint therapy showed no statistical significance (p>0.05). 3. The changes of anterior occlusal contacts showed no statistical significance regardless of the wearing periods of stabilization splint (P>0.05). 4. The changes of posterior occlusal contacts from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 5. The changes of posterior occlusal contacts Outing 1 to 3 months after stabilization splint therapy showed no statistical significance (P>0.05). 6. Posterior teeth rather than anterior teeth were more influenced by the changes of the number of occlusal contacts. To sum up above results, we may respect to capturing and stabilizing centric relation Position just 1 month after stabilization splint therapy.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.577-585
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• 1994

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a $45^{\circ}$ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed: 1. Large overjet and deep overbite were corrected. 2. Class II molar relationship was changed into Class I. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.457-462
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• 2007

This paper reports on the research which investigates acoustic signals acquired in turning with rough and finish simultaneously. The material is aluminum thin pipe. Two acoustic sensors were set on CNC machine. One was set on the finish bite and the other the rough. Two signals were first analyzed in order to consider how much the acoustic signal from the finish bite was coupled by that from the rough. A simple data collecting system to acquire signals from the finish was then determined because two acoustic signals were little coupled. Second the fundamental experiments were accomplished to study the effects of machine vibration and material state. The signal characteristics due to surface defects were studied from the collected acoustic signal data. The signal analysis was based on real time data, root mean squared average and frequency spectrum by fast fourier transform. As a result, the acoustic signals were made effects by machine condition, material structure. The acoustic signal from the finish bite was closely correlated with surface quality. Two types surface micro defects were then evaluated by the signal characteristics.

• The korean journal of orthodontics
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• v.12 no.1
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• pp.37-43
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• 1982

The patient,20 year-old female, complained of anterior open bite. She had tongue thrusting habit and suffered from maxillary sinusitis since 12-years old. Cephalometric analysis revealed slightly forward relationship in maxilla, but normal in mandible. The anterior open bite was corrected through retraction and extrusion of anterior segment and mesial movement of posterior segment under multibanded system after extraction of 4-first premolars. After 2 years and 3 months, she gained ideal overbite, overjet and good interdigitation of buccal segment.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.4
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• pp.484-514
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• 1994

Cantilever bridge is widely used by mny clinicians, but its worst mechanical character, so called Class I lever system, makes dentists hesitate to restore the missing tooth with it. Therefore it is important to study stress of the cantilever bridge. In this study, two models of cantilever bridges that restores the missing mandibular second molar with two abutment teeth were constructed. One model was a type of cantilever bridge supported by a normal alveolar bone, the other one was supported by an alveolar bone resorbed to its 1/3 of root length. Maximum bite force(550N) and funtional maximum bite force(300N) were vertically applied to the distal end of the pontic, distal 1/3, and distal half of the pontic. And each force was also applied to centric occlusal contacts as a distributed force. Total 16 loading cases were compared and analyzed with 3-dimensional finite element method. The results were as follows: 1. The stress was concentrated on the joint of the pontic and the retainer, grooves, and distal cervical margin of the posterior retainer. 2. In case of maximum bite force(550N) at the end of the pontic, the risk of fracture at the joint of the pontic and the retainer was high. 3. In case of distributed force in centric occlusion and functional maximum bite force(300N), the stresses were less than the yield strength of the type VI gold for any loading cases. 4. In case of alveolar bone resorption, the occlusal force to the cantilever pontic caused more stress on the root apex and less stress on the alveolar crest region of the distal surface of the posterior abutment. 5. In case of alveolar bone resorption, the displacement was larger than that of normal alveolar bone in all loading cases.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.85-94
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• 1984

The purpose of this study was to investigate treatment effectiveness of TENS and bite plane for bruxism and TMJ dysfunction patients. The electromyograms were made on males aged 23 to 25 with sound stomatognathic system, 5 males bruxism aged 24 to 27, and 1 male and 4 females TMJ dysfunction patients (right TMJ pain) aged 14 to 33. The electromyographic study was limited to the middle of masseter muscle and anterior temporal muscle. The electromyographic study was carried out with 8-channel EM2 (Myotronics Research Inc.) and was taken 5 mandibular positions of clinical rest position, clench intercuspal position, clench protruded, cluch right, clench left. The 2 pairs of surface electrodes were used exactly, with the ear lobe as reference point. The recording were subjected to determine the mean voltage. The results were as follows; 1. In the clinical rest position, the muscle activities of bruxism and TMJ dysfunction patients were higher than those of normal at the before treatment, but that were lower or similar to those of normal at the TENS after and after bite plane wearing. 2. In the clench I.C.P., the muscle activities of TMJ dysfunction patients were decreased as the order of the before treatment, after TENS, after occlusal bite plane wearing, but those of bruxism were irregular. 3. In the clench right and the clench left, the muscle activities of the middle of masseter muscle of the non-working side of bruxism were higher than those of the working side at the before treatment and after TENS, but the muscle activities of after occlusal bite plane wearing were similar to those of the normal. 4. In the clench right and the clench left, the muscle activities of the middle of masseter muscle and anterior temporal muscle of the working side of TMJ dysfunction patients were higher than those of non-working side as like the normal at the before treatment, after TENS, and after occlusal bite plane wearing.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.95-104
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• 1996

This study was undertaken to investigate the correlations bite force and the electromyographic activities of masticatory muscle in deepbite, using the T-Scan system and electromyograph. The subjects of this study consisted of two groups ; one of 20 individuals with normal occlusion, the other group of 30 with deepbite. The deepbite was composed of Class I deepbite(male 9, female 7) and Clas II div. 1 deepbite(male 8, female 6). The obtained results of this study were as follows : 1. The maximum bite force was 155.93 N in normal occlusion, 165.11 N in Class I deepbite group, 111.55 N in Class II div. 1 deepbite group. 2. The greater !he number of tooth contacts, the more the bite force increased in all groups. 3. During maximum clenching, masseter and ant. temporailsmuscle activity of normal and Class I deepbite group were significantly higher than that of Class II div. 1 deepbite group, and the activity of masseter muscle was higher than that of ant. temporalis muscle in all groups. 4. The greater the maximum bite force, the more the muscle activities increased in all groups.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.475-488
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• 1988

Certain malocclusion are associated with specific "facial type," and it is important for the clinician to classify the common facial characteristic of each patient. Because the reaction to treatment mechanics and the stability of the denture is depended upon the analysis of the facial pattern. Basically, there are 3 district facial types or patterns under which almost all malocclusion can be classified. 1. mesofacial is the most average growth. 2. brachyfacial which is a horizontal growth pattern has a week muscle, with dental arch, deep bite. 3. dolichofacial which is a vertical growth pattern has a strong muscle, narrow dental arch, open bite. Brachyfacial pattern show a resistant to mandibular rotation during treatment can accept a more protrusive denture and are prominantly nonextraction, whereas dolichofacial patterns tend to open during treatment require a more retracted denture in order to assure post-treatment stability. Brachyfacial pattern would better treat to use extrusive force system, whereas dolichofacial pattern treat to use intrusive force system with head gear and intermaxillary elastics.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.6
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• pp.591-601
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• 2008

STATEMENT OF PROBLEM: The improvement in oral function and comfort from the dental implant appears to depend on the particular type of implant support used with the denture. The number and positioning of implants have an influence on the force transfer and subsequent stress distribution around implants. Nevertheless, a quantitative comparison has not been made between the types of implant prosthesis used with different materials compared to conventional complete denture. PURPOSE: The objective of this study is to assess the masticatory performance, bite force and impact of two different type of implant supported prostheses on oral health-related quality of life compared to conventional complete denture with GOHAI, validated oral-specific health status measures, the sieving method, and the Prescale Dental System. MATERIAL AND METHODS: From the years 1999 to 2006, a total of 30 completely edentulous patients in a single arch were selected from the Yonsei University Dental Hospital, Department of Prosthodontics and Implant Clinic in Seoul, S. Korea. Patients were divided into 3 groups of 10 each. Group HR was restored with fixed-detachable hybrid prostheses with resin teeth. Group FP had fixed dentures with porcelain teeth while Group CD had a complete denture. The masticatory performance was compared between 3 groups. RESULTS: The results showed a significant improvement in oral health-related quality of life with dental implants compared to a conventional denture in GOHAI comparison. Overall, implant prostheses showed a higher masticatory performance ($S_{50}$) and maximum bite force compared with conventional dentures (P < .05) but no differences between different implant supported prostheses (P > .05). CONCLUSION: Within the limitation of this study, the numbers of implant and material of implant prostheses does not appear to impact patient satisfaction, masticatory performance or bite force.