• Journal of Oral Medicine and Pain
• /
• v.22 no.2
• /
• pp.295-307
• /
• 1997

This study was performed to investigate the reproductibility of eccentric mandibular movements according to preferred chewing side, range of mouth opening, type of lateral guidance and involvement of temporomandibular disorders. 50 patients with temporomandibular disorders and 65 dental students without any signs and symptoms were randomly selected for this study as the patients group and the control group, respectively. For recording and observation of eccentric mandibular movement trajectory, BioEGN$^\textregistered$ of Biopak$^\textregistered$ system (Bioresearch Inc., USA) was used. Each eccentric movement to anterior, right and left side was performed three times similar to the movement pattern for Pantronic Reproducibility Index. mandibular path was analyzed by three dimensional positional change and the three paths from one direction were compared with one another. From this, reproducibility index of one-directional lateral movement could be calculated, and total reproducibility index, named BioEGN reproducibility index(BERI), was also computed from three-directional eccentric movement likewise. BioEGN reproducibility Index could have four value of score by small or large scale, and by outgoing or incoming movement. The data were analyzed by SAS/stat program and the results obtained were as follows: 1. Right side chewing subjects showed more consistent pattern In reproducibility index in comparison between patients group and control group than left chewing subjects have done, and reproducibility was low in patients group. However, there was no difference between the two stoups in bilateral chewing subjects. 2. There were no difference in reproducibility index between preferred chewing side and contralateral side in unilateral chewing subjects whereas reproducibility index in left side on outgoing movement were higher than in right side in bilateral chewing subjects. 3. Difference in total reproducibility index(BERI) between canine guidance group and non-canine guidance group were not observed though difference in reproducibility index on lateral movement were observed in part. 4. There were no difference in reproducibility index between affected side and contralateral side in unilaterally affected patients, and between unilaterally affected patients and bilaterally affected patients in patients group. 5. Highly significant positive correlationship were shown among the four 쇼pes of total reproducibility index(BERI) in total subjects, and range of clinical mouth opening was negatively correlated with BEBI on outgoing movements and with index on outgoing movement to preferred side.

• Journal of Periodontal and Implant Science
• /
• v.47 no.4
• /
• pp.211-218
• /
• 2017

Purpose: The purpose of the present study was to perform a pattern analysis in patients with temporomandibular disorder (TMD) resulting from unilateral mastication due to chronic periodontitis. Methods: Thirty participants with signs or symptoms of TMD who engaged in unilateral mastication due to periodontitis-related discomfort (test group) were selected. Another 30 subjects exhibiting signs or symptoms of TMD resulting from unilateral mastication not due to chronic periodontitis (control group) were also recruited. An interview-based questionnaire was administered, and an examination of the temporomandibular joint (TMJ) with determination of periodontal status was performed. Results: The duration of unilateral mastication was significantly longer in the control group than in the test group. There was a significant negative correlation between the duration of unilateral mastication and the Community Periodontal Index score. Using the Research Diagnostic Criteria for TMD (RDC/TMD) axis I algorithms, all the subjects were assigned to 3 main groups. The test group exhibited significantly a higher diagnostic distribution of group III (arthralgia, osteoarthritis, or osteoarthrosis), and in both the test and control groups, the number of diagnoses was larger for the non-chewing side. The control group showed a significantly higher diagnostic distribution of group I (myofacial pain), and in both the test and control groups, the number of diagnoses was larger for the chewing side. Conclusions: The results of the present study indicate that unilateral mastication due to chronic periodontitis could induce not only pain but also structural TMJ changes if adequate treatment is not administered and supported within a short time from the onset of the condition. Therefore, immediate treatment of chronic periodontitis is recommended to prevent not only the primary progress of periodontal disease, but also secondary TMJ-related problems. Furthermore, subjects who have suffered chronic long-term periodontitis without treatment should be urged to undergo a TMJ examination.

• Journal of Oral Medicine and Pain
• /
• v.38 no.2
• /
• pp.175-185
• /
• 2013

Objective : Condyle hypoplasia in temporomandibular joint(TMJ) is often observed in several radiographic views. Mandibular Condyle hypoplasia is frequently confused with osteoarthritis with bony changes in TMJ. This paper investigated clinical characteristics of mandibular condyle hypoplasia as compared with TMJ osteoarthritis. Material and method : 276 patients with TMD were taken clinical and radiological examination and were divided into study group, 189 patients diagnosed with mandibular condyle hypoplasia, and control group, 87 patients diagnosed with TMJ osteoarthritis. And clinical features(Onset, Overjet, Overbite, Noise, Locking, NAS of noise, LOM, pain, MCO, and site of diagnosis and pain)of the two groups were compared. Results : 1. Mandibular condyle hypoplasia and TMJ osteoarthritis were similar in many of the clinical features. 2. Mandibular condyle hypoplasia concordance rates of the radiographic diagnosis site and the pain site was significantly lower than TMJ osteoarthritis. 3. Bilateral mandibular condyle hypoplasia group had more occlusal discomfort, and clenching habits than unilateral mandibular condyle hypoplasia group. 4. Unilateral mandibular condyle hypoplasia group had more unilateral chewing habits and LOM than unilateral TMJ osteoarthritis group. Unilateral TMJ osteoarthritis group had more morning stiffness and higher concordance rates of the radiographic diagnosis site and the click sound site than unilateral mandibular condyle hypoplasia group. 5. Bilateral mandibular condyle hypoplasia group had more usual headaches and overjet than bilateral TMJ osteoarthritis group. Conclusion : Mandibular condyle hypoplasia has somewhat distinguishing clinical characteristics as compared with TMJ osteoarthritis.

• Journal of Yeungnam Medical Science
• /
• v.13 no.2
• /
• pp.308-323
• /
• 1996

This study tried to find the prevalence and distribution of temporo-mandibulr disorders(TMD) for workers (employee) in Seoul area to investigate the correlation between TMD and possible etiological factors such as general muscle and joint symptoms, headache, unilateral chewing and parafunction. This study was an epidemiological investigation of answers obtained from 282 persons by questionaire from Aug. 1995 to Nov. 1995. The major findings from the questionaire were as follows. (1) 43.26% of the subjects(282 persons) has TMD. (41.88% of man and 43.26% of women) (2) The more often people have general muscle and joint symptoms and headache, the more susceptible they are to TMD. Their correlation was very significant(p<0.001). (3) The more people have bad oral habits such as bruxism, clenching and biting habit, the more likely they have TMD. The more sensitive people are to stress, the more frequently they have bad oral habits such as bruxism, clenching and biting habit. (4) Unilateral chewing has higher TMD index than bilateral chewing. There is no relationship between ache areas and TMD index.

• The Journal of Korean Academy of Prosthodontics
• /
• v.25 no.1
• /
• pp.269-279
• /
• 1987

The purpose of this study was to obtain basic data needed to clinical diagnosis and treatment by investigating the occlusal wear facets and those related factors. Sixty-six subjects, ranging from 24 to 26 years of age without symptoms of stomatognatic system, were selected from dental students in Chosun University. The area of occlusal wear facets was measured and twenty subjects were selected, and divided into two groups (Group I and Group II). The Group I had small facet areas, and the Group II had large facet areas. These two groups were investigated into right and left side wear facet areas, vertical overlaps, occlusion types of working side, masticatory muscle activities, and asymmetry of right and left side masticatory muscle function. The results were as follows: 1. The average wear facet areas of all subjects was $22.84{\pm}88.95mm^2$, and Group I and Group II were $96.12{\pm}32.00mm^2$ and $372.94{\pm}65.63mm^2$ respectively. 2. The right and left wear facet areas of Group I were $46.72{\pm}14.36mm^2$ and $49.40{\pm}21.46mm^2$ respectively. The right and left wear facet areas of Group II were $175.27{\pm}45.75mm^2$ and $185.69{\pm}45.37mm^2$ repsectively. 3. The vertical overlap of Group I and Group II was $3.88{\pm}0.81mm$ and $2.88{\pm}1.14mm $ respectively. 4. Most of the Group I had Canine protection occlusion (80%), and most of the Group II had Group function occlusion (80%). 5. The masticatory muscle activities at rest position, maximum bite, habitual chewing, right and left unilateral chewing were greater in Group II than in Group I, especially in the masseter muscle of working side at right and left unilateral chewing. (P<0.01). 6. The asymmetry of right and left wear facets and masticatory muscle activities were greater in Group II than in Group I. (P<0.01).

• Journal of Oral Medicine and Pain
• /
• v.32 no.3
• /
• pp.319-328
• /
• 2007

The purpose of this study was to quantitatively assess treatment effect of physical therapy on experimentally-induced masseter muscle fatigue by two parameters of muscle stiffness and elasticity. Three physical therapeutic modalities inducing electroacupunture stimulation therapy(EAST), Microwave diathermy and low-level laser therapy(LLLT) were compared. 10 healthy volunteers with normal occlusion (mean age of $26.3{\pm}1.16$ years, M:F=1:1) were participated in this study. All subjects were asked to chew gum on the right side until they felt pain(more and VAS 5 (0 to 10)) and their masseter muscles were examined with a tactile sensor in order to evaluate changes of stiffness and elasticity according to gum chewing and three physical therapeutic modalities. Subjective discomfort or pain was self-estimated by VAS as well. Unilateral gum chewing increased stiffness and decreased elasticity only on the chewing side but VAS increased on the both sides(p<0.05). EAST or Microwave diathermy greatly decreased stiffness and VAS and increased elasticity(p<0.05) but LLLT did not exhibit significant difference. From the results of this study, it is concluded that both EAST and Microwave diathermy have favorable effect on stiffness and elasticity of muscles and pain relief while effect of LLLT is not reliable. In addition, experimental unilateral gum chewing compromises stiffness and elasticity of masseter muscles only the chewing side while subjective discomfort or pain can be felt on the both sides.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.4
• /
• pp.451-457
• /
• 2017

Bell's palsy is an acute-onset unilateral peripheral facial neuropathy. For patients with sequelae of facial paresis, the successful rehabilitation of fully edentulous arches is challenging. This case report described the treatment procedures and clinical considerations to fabricate complete dentures of a patient who showed unilateral displacement of mandible, unilateral chewing pattern and parafunctional jaw movement due to sequelae of Bell's palsy. Gothic arch tracing was used to record reproducible centric relation and lingualized occlusion was performed to provide freedom to move between centric relation and the patient's habitual functional area in fabricating satisfactory dentures in terms of function and esthetics.

• The Journal of Korean Physical Therapy
• /
• v.35 no.6
• /
• pp.185-189
• /
• 2023

Purpose: This study investigated the immediate biomechanical effects of unilateral mastication for 10 minutes on the temporomandibular joint (TMJ) with 21 healthy adult participants. Methods: The gum group chewed gum on the right side for 10 minutes, and the control group rested for 10 minutes. Biomechanical data were obtained using a three-dimensional infrared camera before and after intervention. An independent t-test assessed the variation of kinematic data to identify differences between before and after intervention. Results: Among biomechanical variables, the gum group's length of the left forehead middle region and the temporomandibular joint angle decreased compared to the control group (p<0.05). Conclusion: Caution with unilateral masticatory activity is recommended, as unilateral mastication causes biomechanical changes due to excessive load on the soft tissues of the contralateral TMJ.

• The Journal of Korean Medicine
• /
• v.43 no.2
• /
• pp.61-74
• /
• 2022

Objectives: This study aimed to explore the short-term effects of bilateral masticatory training using an intraoral device on memory and concentration, which is an advanced form of Gochi, compared to the unilateral form with gum. Methods: Thirty young healthy participants (age, 16-30 years) were screened and randomly assigned to one of two sequences in a crossover design. The participants assigned to sequence A (n=15) performed bilateral mastication using an intraoral device with a total of 300 taps, followed by unilateral mastication using gum with the same number of repetitions and frequency, separated by a 7-day washout period. A reverse order was used for sequence B. The primary and secondary outcomes were the digit span test result and the symbol digit modality test and the word list recall results, respectively, which were conducted before and after each intervention. Results: Symbol digit modality test scores increased by 12.03±8.33 with bilateral mastication, which was significantly higher than that obtained with chewing gum (5.17 points;95% confidence interval: 0.99, 9.34; p<0.05). Changes in the digit span test and word list recall scores were not significantly different between the two groups. In the digit span test forward, symbol digit modality test, and word list recall test, bilateral mastication was not inferior to unilateral mastication in improving memory and concentration. Conclusions: Bilateral masticatory exercises using an intraoral device are not inferior to unilateral mastication with gum for improving memory in healthy young individuals. Further research is needed to determine the efficacy of bilateral masticatory training on cognitive function.

• Journal of Korean society of Dental Hygiene
• /
• v.11 no.6
• /
• pp.853-862
• /
• 2011

Objectives : The aim of this study was to investigate the number of self-report symptoms for temporomandibular disorders(TMD) and related factors in the third grade students of high school. Methods : A total of 1,043 high school the 3rd students age 16 20 completed a questionnaire from 11 high schools in Andong city from April to June 2010. Student's t-test was used to analyze the difference of TMD number. Multiple regression analysis was performed to determine the effects of independent variables on TMD number. Results : 1. Students who have one TMD were 71.3%, two 41.7% and over three 25.7%, respectively. 2. The number of TMD symptom of students who have no good habits such as clenching, bite lip and cheeks, resting on hand, chewing gum, hard foods, and unilateral chewing was a statistically significant higher than those who doesn't have ones(p=0.00). 3. TMD number of students who have been under more stress was a significantly higher than those who didn't have been(p=0.00). 4. Bite lip and cheek(${\beta}$=0.03, p=0.037), chewing gum(${\beta}$=0.03, p=0.029), resting on hand(${\beta}$=0.04, p=0.006), hard foods(${\beta}$=0.07, p=0.000), and stress out(${\beta}$=-0.03, p=0.018) were significantly associated with TMD number by multiple regression analysis. Conclusions : Variables associated with TMD were bite lip and cheek, chewing gum, resting on hand, hard foods, and stress out factor. According to our findings, it is so important to teach good habits on oral health to the 3rd grade students in high school. Further prospective study should explore cause of TDM from those variables.