• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.175-182
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• 1990

This study was performed to investigate the influence of occlusal change on the masticatory muscle activity. 8 students without any symptom of T.M.J. dysfunction, any history of prosthodontic or orthodontic treatment on dental college of WonKwang Univ. were participated in this study. The activity of masseter and anterior temporal muscles were measured by bioelectric processor(EM2, Myotronics, Inc., U.S.A.) during voluntary maximal clenching on natural teeth, by splint with bilateral posterior surface contact, by splint with unilateral posterior surface contact, and by splint without unilateral posterior teeth contact. The obtained results were as follows ; 1. The loss of posterior contact on noe side resulted in change of the activity of anterior temporal and masseter muscle during clenching on ipsilateral side, but there was no change of muscle activity on contralateral side. 2. The activity of anterior temporal and masseter muscle during clenching were not affected by the pattern of occlusal contact. 3. There were no difference between the activity of anterior temporal and masseter miuscle during clenching by natural teeth and by occlusal splint.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.105-111
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• 2007

Correlation between occlusal contact pattern and TMD have been hypothesized and partially investigated but results are controversial and not conclusive. The purposes of this study were to compare right-to-left difference of occlusal contact pattern, through contact points, contact force and occlusal balance, in the patients with unilateral TMD and also to evaluate its change related with TMD treatment. 36 patients with unilateral TMD from Department of Oral Medicine in Dankook University Dental Hospital were selected in this study (M:F=7:29, mean age of $29.2{\pm}14.8$ years). A computerized T-Scan II system (Tekscan, INC., USA) was employed for occlusal analysis and the simultaneity and occlusal balance through the number of tooth contact and magnitude of contact force were determined before and after TMD treatment. The number of contact points and contact force was more on the unaffected side than the affected side before treatment (p=0.056 and p=0.060, respectively) while significant difference between both sides was not found after treatment. The number of contact points and contact force on the affected sides significantly increased after treatment (p=0.038 and p=0.052), but the unaffected sides exhibited no significant difference between before and after treatment. In addition, sides difference in relative contact force decreased from about 27% to about 12% after TMD treatment (p=0.001). According to the results of this study, it is likely that unilateral TMD impairs right-to-left occlusal balance and that conservative TMD treatment alleviates the imbalance, subsequently leading to more symmetrical occlusal condition with increased contact points and force.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.160-178
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• 2023

Diagnosis and analysis of occlusal relationships are important factors in prosthetic treatment. A thorough occlusion analysis and evaluation should be performed before treatment to restore a stable interocclusal relationship. Analysis and evaluation are essential during the treatment process and at regular follow-ups. Recently, with the development of dental equipment and digital processing methods, new quantitative analysis methods that can record the patient's occlusal relationship have been introduced. Among them, the T-Scan Novus (Tekscan Inc., S. Boston, MA, USA) displays the strength of the initial contact point and the occlusal contact point of the teeth using a pressure sensor. With this, occlusal contact time of the teeth, anteroposterior and left-right balance of occlusal force can be compared. The Dental prescale II (GC Co., Tokyo, Japan) scans the occlusal contact point using a pressure-sensing film and analyzes the density of the contact point. It can measure the distribution and strength of the occlusal force of the teeth in the most natural occlusion state. Based on this, appropriate prosthetic treatment (four-unit fixed partial denture, removable partial denture, complete denture, and complete oral restoration cases) was performed according to the area and extent of the patient's tooth loss. The patient's occlusion at the first visit, treatment stage, right after treatment, and regular follow-up were compared and evaluated using a quantitative method for appropriate occlusion analysis using T-Scan Novus and Dental prescale II. This report enhances the understanding of occlusion analysis during prosthetic restoration. The results satisfied both the clinician and patients in terms of function and aesthetics.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.489-496
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• 1995

The purpose of this study was to evaluate an effect of change on head posture initial occlusal contacts with measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture in TMDs patient. For this study, 24 patients from age 13 to 36 were selected, they were examined health history taken, patients who have sign and symptoms of TMDs were examine before the study. For the normal group, 21 adults from age 23 to 25 were selected. They have normal or class I molar relationship, and have no other prosthetic restorations. Difference on distance between initial occlusal contact and maximum intercuspal position with mandibular kinesiograph$(MKG^R)$(K6 diagnostic system, Myo-tronic Inc, USA) in upright, supine, 45$^{\circ}$ extension, 30$^{\circ}$ flexion position of the head were measured. The Frankfort horizontal plane was used as a reference plane. The results were as follows : 1. There were significant differences between initial occlusal contacts of the normal and patient group on upright position and 30$^{\circ}$ flexion of the head(p<0.05, p<0.01) 2. The position of the initial occlusal contacts have a tendency to place anterior and inferior to maximal intercuspal position in upright position and 30( flexion of the head as well as posterior and inferior in supine position and 45$^{\circ}$ extension of the head in the normal and patient groups. 3. There were significant differences among the initial occlusal contacts between uptight and supine position; upright and 45$^{\circ}$ extension of the head(p<0.05); supine position and 30$^{\circ}$ flexion of the head, .and 30(flexion and 45$^{\circ}$ extension of the head in the patient group(p<0.01) The result have shown that after treatment on the supine position, it may be necessary to check occlusal contact on the upright position as well ass flexion of the head. It may need careful adjustment in occlusal condition on upright position of TMDs patient.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.1
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• pp.11-19
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• 2007

There are have been reports that the distribution of electromyographical(EMG) activity is determined in a predictable manner by both the location and number of occlusal contacts. However, these reports placed an emphasis on whole dentition. Inclined plane contacts in the frontal plane are classified as A-, B- or C-types. Objectives: The aim of this study was to evaluate the relation between occlusal tooth contact patterns and EMG activity of masseter muscle during maximum voluntary clenching. Methods: Fifteen healthy human subjects(Mean age; 25.3 years) volunteered to participate in this study. Acrylic resin overlays were fabricated for upper 2nd premolars and 1st molars bilaterally, and offered 3 types(A-, B- and AB- type contact). EMG activity of the masseter muscles was recorded bilaterally during maximum voluntary clenching. Statistical analysis was performed using the one-way ANOVA. Results: The group with a A-type contact showed a statistically lower EMG activity of masseter muscle than that of natural group(p<0.05) and that of B- and AB- type groups(p<0.01) on both upper 2nd premolars and upper 1st molars. Conclusions: These results suggest that occlusal tooth contact patterns have an influence on EMG activity of masseter muscle during maximum voluntary clenching.

• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.37-49
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• 1992

80 patients who presented at Wonkwang University Dental Hospital with craniomandibular disorders were collected for this study. To observe the occlusal contact pattern such as contact numbers, contact force and presence or absence of anterior occlusal contact, the author used T-Scan system (Tekscan, Inc, U.S.A.) with are computerized occlusal analysing system. And to study the correlation between craniofacial profile and occlusal contact pattern, cephalogram were also taken, The cephalometric items related to growth pattern, jaw bone relation and denture pattern were measured and analysed according to routine method by computerized program. The obtained data were statistically processed with SPSS/PC+ package about anterior contact pattern and its craniofacial relationship. The obtained results were as follows : 1. In terms of growth pattern, patients without anterior tooth contacts showed a tendency to downward growth of craniofacial profile. The value in this subjects were significantly different from the value of patients with anterior tooth contacts in items of low gonial angle, Jarabak ratio, SN to GoMe angle, FMA, occlusal plane to mandibular plane angle and ramus height. 2. In terms of jaw bone relationship, patients without anterior tooth contacts showed a tendency to backward growth of craniofacial profile. The value of this patients were significantly different from the value of patients with anterior tooth contacts in items of SNB, ANB, mandibular plane to anterior cranial base ratio, SNPo, NAPo and APDI items. 3. But in denture pattern, no statistically significant difference by the presence or absence of anterior tooth contacts were showed between this patients groups. 4. From this study, it could be proposed that anterior open bite in the patients with craniomandibular disorders would be originated from not dental discrepancy but skeletal discrepancy.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.151-157
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• 2017

Objective: The objective of this study was to investigate the differences in masticatory efficiency among patients with different Angle's classes of malocclusion and to assess the correlation between masticatory efficiency and the occlusal contact area. Methods: The mixing ability index (MAI) was calculated for measuring masticatory efficiency of 61 adult patients according to Angle's classifications of malocclusion. The study included 25, 15, and 21 patients with Angle's Class I, II, and III malocclusions, respectively. Silicone interocclusal recording material was used to measure the occlusal contact area. Results: Both the MAI and occlusal contact area showed the highest average values in the Class I malocclusion group, followed by the Class II and Class III malocclusion groups. No significant difference was observed in the MAI values between the Class I and Class II malocclusion groups (p > 0.05), whereas a significant difference was observed between the Class I and Class III malocclusion groups (p < 0.01) and between the Class II and Class III malocclusion groups (p < 0.05). A weak positive correlation was also observed between the MAI and occlusal contact area (p < 0.01, $r^2=0.13$). Conclusions: The results of this study indicated that masticatory efficiency was the highest in patients with Angle's Class I malocclusion, followed by those with Angle's Class II and Angle's Class III malocclusions. Moreover, a weak positive correlation was observed between masticatory efficiency and the occlusal contact area.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.81-88
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• 1989

저자는 정상 치열을 가지며 두개하악장애의 증상 및 병력이 없는 성인 21명을 대상으로 computerized occlusal analysis system인 T-Scan system을 이용하여 교합력에 따른 치아접촉수와 총치아접촉시간을 측정한 후 정량적인 분석을 시도하여 다음과 같은 결론을 얻었다. 1. 최대 측두근 전부 근활성도의 약 20%, 50%, 80% 수준의 교합력에서 치아접촉수의 평균은 각각 1.6개, 8.8개, 16.7개로 교합력이 증가할수록 유의하게 증가하였다. 2. 최대 측두근 전부 근활성도의 약 20%, 50%, 80% 수준의 교합력에서 치아당 치아접촉수이 평균은 대구치에서는 0.2, 1.4, 2.2 개였으며 소구치에서는 0.1, 0.5, 1.1개였고, 전치에서는 0.1, 0.2, 0.6개로 교합력이 증가함에 따라 유의하게 증가하였다. 3. 치아접촉분포로 구분된 대칭군과 비대칭군간의 총치아접촉시간에는 유의한 차이가 없었다.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.271-277
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• 1989

The purpose of this preliminary report was to describe the operating procedure of T-scan system and to identify the location, timing and force of occlusal contact in patient with normal occlusion using computerized T-scan system. From the preliminary observation , the author obtained the following results. 1. T-scan system displayed 2 dimensional and 3 dimensional description of occlusion: contact locations, timing (sequence) and forces of occlusal contacts. 2. The T-scan sensor was the most important part of the T-scan system. 3. The data of T-scan system cannot be stored in computer diskett. 4. The T-scan system is thought to be the most effective system to detect occlusal contacts and can be applied to the followings : occlusal diagnosis, occlusal equilibration, crown and bridge restorative procedures, denture adjustment, implant procedures, splint adjustment, laboratory procedures, periodontal treatment, orthodontics, TMJ treatment and patient education etc.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.377-391
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• 2015

Inter-dental arch discrepancy between maxilla and mandible could cause three dimensional occlusal problems, and collapse of occlusal plane, multiple teeth loss and decrease of masticatory efficiency could be observed in patient having unstable occlusal contact. Patient showing posterior bite collapse, unstable occlusal contact and improper anterior guidance should be treated to recover stable centric occlusion, occlusal contact, and anterior guidance in conjunction between prosthodontics and orthodontic treatment. This clinical report describes the favorable results of orthodontic and prosthodontics rehabilitation of patient with above mentioned problems.