• 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.

• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.71-79
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• 2011

Aim: Disc displacement without reduction of the temporomandibular joint (TMJ) has been managed by mandibular manipulation to reduce the displaced disc but with a low success rate. The purpose of this study was to determine whether auriculotemporal nerve block anesthesia had an effect on the reduction of the displaced disc and to analyze the factors that influenced the result. Methods: 112 patients were diagnosed with disc displacement without reduction and treated by mandibular manipulation. Disc was recaptured in 35 patients. Among the 77 patients with whom disc recapture had failed, the auriculotemporal nerve was blocked with a local anesthetic in the 49 patients (mean $age \;{\pm}\; SD\; =\; 34.4\;{\pm}\; 15.1$; male 24, female 25) and then mandibular manipulation was performed again. Factors including age, elapsed time from the onset, and opening amount were analyzed in association with disc reduction rate with the auriculotemporal nerve block. Results: Among 49 patients who did not respond to manipulation only, manual reduction with auriculotemporal nerve block anesthesia was successful in 19 patients (38.8%). Maximum unassisted opening amount significantly increased in the 19 patients with successful recapture of the disc ($mean \;{\pm}\; SD\; =\; 46.1 \;{\pm}\; 4.5\; mm$), in contrast to the limited opening amount of the 49 patients before local anesthesia of the auriculotemporal nerve ($mean \;{\pm}\; SD\; =\; 25.7 \;{\pm}\; 6.0\; mm$). Age, elapsed time after the onset, and preoperative opening amount were not associated with the reduction rate. Conclusion: The results of this study suggest that auriculotemporal nerve block anesthesia increases the reduction rate of the disc displacement without reduction of the TMJ when combined with mandibular manipulation, and such anesthesia should be applied at the first stage of manual treatment of disc displacement without reduction.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.375-381
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• 2007

Occlusal stabilization appliance is one of the most common treatment option for management of temporomandibular disorders. It acts in oral cavity for several hours per day, and usually it will take at least 6 months to 2 years of total wearing periods to take a treatment goal. In the oral cavity, occlusal stabilization appliance, unintentional manner, is able to acts as a reservoir of bacteria and protect bacteria from saliva and oxygen. This condition is so favorable to many bacteria such as S. mutans and other anaerobes, usually have been reported as causative factors of dental caries, periodontal disease and oral malodor. In this study, we investigated anaerobic bacteria and S. mutans count before and after occlusal stabilization appliance use to evaluate the possible role of occlusal stabilization appliance as protector of these bacteria. Four men(average 27.5 years) wore maxillary occlusal stabilization appliance at each night(average 9 hours) for 5 days. we swabbed saliva-plaque mixed sample at 3 different site(maxillary left 2nd molar, maxillary left central incisor, mandibular left 2nd molar) before and after occlusal stabilization appliance use. Each samples were plated in (1) anaerobic blood agar medium, (2) selective S. mutans medium(MS-MUTV) and incubated in anaerobic chamber($CO^2$ 10%, $37^{\circ}C$) for 72 hours. Each bacterial colony forming unit(CFU) were counted with naked eyes. From obtained data, we can conclude as follows: 1. There was some changes about anaerobic bacteria and S. mutans count in oral cavity after occlusal stabilization appliance use. 2. The number of anaerobic bacteria was significantly increased at maxillary 2nd molar(P=0.003), maxillary central incisor(P=0.020) after occlusal stabilization appliance use compared with before. 3. Occlusal stabilization appliance use itself had indirect effect to increase the number of anaerobic bacteria at other uncovered opponent tooth site. 4. The number of S. mutans was significantly increased at maxillary 2nd molar(P=0.043), maxillary central incisor (P=0.049) after occlusal stabilization appliance use compared with before. 5. Occlusal stabilization appliance use itself had not any effect on the number of S. mutans at other uncovered opponent tooth site.

• Journal of Oral Medicine and Pain
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• v.34 no.4
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• pp.409-420
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• 2009

The aim of this study was to investigate clinical assessment, panorama & MRI findings and cephalometric characteristics in 42 patients with condylar resorption, who visited in the Department of Oral Medicine Kyungpook National University Hospital at 2006. The results were as follows; 1. Clinical assessment 1) Female was 34 and male was 8, females were predominant. Distribution of age showed as follows; 10s was 14, 20s was 13, 30s was 7, 40s was 3, 50s was 4 and 60s was 1 patient. 10s and 20s were predominant. 2) Most of the patients had parafunctional habit. 2. Findings of panorama & MRI 1) Most of the patients had degree of Grade II condylar resorption by panorama taking. 2) Most of the patients had disc dislocation and belonged to the degree of stage IV by MRI taking. 3. Cephalometric Characteristics 1) SN, SAr and saddle angle in female patients were significantly smaller and SN in male patients showed only significantly smaller than normal group. 2) SNA showed no difference from the normal group in both patients. SNB was smaller and ANB was lager in female patients than normal group. 3) SN-GoMe and FMA increased in patients. 4) Total posterior facial height & ramus height were significantly smaller. 5) Mandibular body length did not show any significant difference.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.211-218
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• 2007

The purpose of this study was to compare the maximum bite forces between pre- and post-treatment related to specific diagnostic groups of TMD including masticatory muscle disorder (MMD), disc derangement (DD), joint inflammation (JI) and osteoarthritis (OA). Bite force between pre- and post-treatment was compared in 36 patients with unilateral TMD, successfully-managed in the Department of Oral Medicine, Dankook University Dental Hospital, for this study. The ratio of men to women was 7:29 and their mean age of $28.1{\pm}13.7$ years. The patients were categorized, through clinical and radiographic examination, into aforementioned 4 groups; MMD (N=18), DD (N=6), JI (N=5) and OA (N=7). The maximum bite force measurements were done at the antagonizing canines and 1st molars using a bite force recorder. Paired t-test, ANOVA, Multiple Comparison t-tests were used for statistical analysis. The results of this study showed that the maximum bite force before treatment increased after TMD treatment, which was noticeable at the canines (p=0.001 and p=0.000 for the affected and unaffected sides, respectively). In comparison related to the diagnostic groups of TMD, patients with osteoarthritis of TMJ exhibited the lowest strength while those with inflammatory disorder of TMJ had the highest strength on the affected sides. Increase of bite force after treatment was also found in each group. Significant difference between pre- and post-treatment was found at canines on the affected sides in MMD (p=0.045) and DD groups (p=0.009) while on the unaffected sides in OA group (p=0.003). Conclusively, the reduced bite force due to TMD could be recovered by conservative TMD treatment and that the difference of bite forces between pre- and post-treatment was noticeable at the canines.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.45-55
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• 2005

As people prefer to use right or left hand, some have preferred chewing side while others do not. Totally, 82 volunteers composed of students and staffs from Dental Hospital College of Dentistry Yonsei University participated in this study for the investigation of influence of preferred chewing habit, that has lasted for more than a year, on electromyographic(EMG) activity of masticatory muscles and bite force. Among the 82 volunteers, 46 had preferred chewing habit while the other 36 did not. Prior to the investigation, those with factors that could affect the study, such as, general disease, irregular dentition and malocclusion, were screened and excluded by questionnaire and clinical examination. The results were as follows: 1. There was no significant difference in EMG activities between chewing side and non-chewing side of preferred chewing subjects at rest as well as maximal voluntary contraction(MCV)(p>0.05). 2. Asymmetrical coefficient of temporal and masseter muscle EMG activities between preferred chewing subjects and non-preferred chewing subjects at rest was not significantly different(p>0.05). 3. Asymmetrical coefficient of masseter EMG activity was significantly higher(p<0.05) than that of non-preferred chewing subjects at MCV, whereas that of anterior temporal muscle showed no difference(p<0.05). 4. In preferred chewing subjects, there was no significant difference in average bite force and occlusal contact area between chewing side and non-chewing side(p>0.05). 5. There was no significant difference in Asymmetrical coefficients of average bite force and occlusal contact area between preferred chewing subjects and non-preferred chewing subjects (p>0.05). Consequently, preferred chewing habit can be considered as physiological asymmetry with normal function rather than to have influence on EMG muscle activity of masticatory muscles, average bite force and occlusal contact area. Objective standardization to differentiate preferred chewing subjects and non-preferred chewing subjects should be established in the further study.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.223-229
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• 2006

The objectives of this study was to investigate the amount of tooth ablation and the change of intrapulpal temperature by Er:YAG laser as it relates to pulse energy and pulse repetition rate at the identical power and, thereby, to reveal which of the two parameters strongly relates with ablation efficiency and intrapulpal temperature. Extracted healthy human molar teeth were sectioned into two pieces and each specimen was irradiated within the combination of pulse energy and pulse repetition time at the same power of 3W; $300mJy{\times}10Hz$ group, $200mJy{\times}15Hz$ group, and $150mJy{\times}20Hz$ group. Each specimen comprised ten tooth specimens. A laser beam with conjunction of a water flow rate of 1.6 ml/min was applied over enamel surfaces of the specimens during 3 seconds and the ablation amount was determined by difference in weight before and after irradiation. To investigate the temperature change in the pulp according to the above groups, another five extracted healthy human molar teeth were prepared. Each tooth was embedded into resin block and the temperature-measuring probes were kept on the irradiated and the opposite walls in the dental pulp during lasing. When the power was kept constant at 3W, ablation amount increased with pulse energy rather than pulse repetition rate (p=0.000). Although intrapulpal temperature increased with pulse repetition rate, there were no significant differences among the groups and between the irradiated and the opposite pulpal walls, except at a condition of $150y{\times}20Hz$ (p=0.033). Conclusively, it is suggested that ablation efficacy is influenced by pulse energy rather than pulse repetition rate.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.59-67
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• 2006

There exist patients complaining speech problem due to dysesthesia or anesthesia following dental surgical procedure accompanied by local anesthesia in clinical setting. However, it is not clear whether sensory problems in orofacial region may have an influence on motor speech abilities. The purpose of this study was to investigate whether transitory sensory impairment of mandibular nerve by local anesthesia may influence on the motor speech abilities and thus to evaluate possibility of distorted motor speech abilities due to dysesthesia of mandibular nerve. The subjects in this study consisted of 7 men and 3 women, whose right inferior alveolar nerve, lingual nerve and long buccal nerve was anesthetized by 1.8 mL lidocaine containing 1:100,000 epinephrine. All the subjects were instructed to self estimate degree of anesthesia on the affected region and speech discomfort with VAS before anesthesia, 30 seconds, 30, 60, 90, 120 and 150 minutes after anesthesia. In order to evaluate speech problems objectively, the words and sentences suggested to be read for testing speech speed, diadochokinetic rate, intonation, tremor and articulation were recorded according to the time and evaluated using a Computerized Speech $Lab^{(R)}$. Articulation was evaluated by a speech language clinician. The results of this study indicated that subjective discomfort of speech and depth of anesthesia was increased with time until 60 minutes after anesthesia and then decreased. Degree of subjective speech discomfort was correlated with depth of anesthesia self estimated by each subject. On the while, there was no significant difference in objective assessment item including speech speed, diadochokinetic rate, intonation and tremor. There was no change in articulation related with anesthesia. Based on the results of this study, it is not thought that sensory impairment of unilateral mandibular nerve deteriorates motor speech abilities in spite of individual's complaint of speech discomfort.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.173-189
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• 2000

The purpose of this study was to evaluate the effect of specific head positions on the mandibular rotational torque movements in maximum mouth opening, protrusion and lateral excursion. Thirty dental students without any sign or symptom of temporomandibular disorders(TMDs) were included as a control group and 90 patients with TMDs were selected and examined by routine diagnostic procedure for TMDs including radiographs and were classified into 3 subgroups : disc displacement with reduction, disc displacement without reduction, and degenerative joint disease. Mandibular rotational torque movements were observed in four head postures: upright head posture(NHP), upward head posture(UHP), downward head posture(DHP), and forward head posture(FHP). For UHP, the head was inclined 30 degrees upward: for DHP, the head was inclined 30 degrees downward: for FHP, the head was positioned 4cm forward. These positions were adjusted with the use of cervical range-of-motion instrumentation(CROM, Performance Attainment Inc., St. Paul, U.S.A.). Mandibular rotational torque movements were monitored with the Rotate program of BioPAK system (Bioresearch Inc., WI, U.S.A.). The rotational torque movements in frontal and horizontal plane during mandibular border movement were recorded with two parameters: frontal rotational torque angle and horizontal rotational torque angle. The data obtained was analyzed by the SAS/Stat program. The obtained results were as follows : 1. The control group showed significantly larger mandibular rotational angles in UHP than those in DHP and FHP during maximum mouth opening in both frontal and horizontal planes. Disc displacement with reduction group showed significantly larger mandibular rotational angles in DHP and FHP than those in NHP during lateral excursion to the affected and non-affected sides in both frontal and horizontal planes(p<0.05). 2. Disc displacement without reduction group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening as well as lateral excursion to the affected and non-affected sides in both frontal and horizontal planes. Degenerative joint disease group showed significantly larger mandibular rotational angles in FHP than those in any other head postures during maximum mouth opening, protrusion and lateral excursion in both frontal and horizontal planes(p<0.05). 3. In NHP, mandibular rotational angle of the control group was significantly larger than that of any other patient subgroups. Mandibular rotational angle of disc displacement with reduction group was significantly larger than that of disc displacement without reduction group during maximum mouth opening in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group or degenerative joint disease group during maximum mouth opening in the horizontal plane(p<0.05). 4. In NHP, mandibular rotational angles of disc displacement without reduction group were significantly larger than those of the control group or disc displacement with reduction group during lateral excursion to the affected side in both frontal and horizontal planes. Mandibular rotational angle of disc displacement without reduction group was significantly smaller than that of the control group during lateral excursion to the non-affected side in frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of disc displacement with reduction group during lateral excursion to the non-affected side in the horizontal plane(p<0.05). 5. In NHP, mandibular rotational angle of the control group was significantly smaller than that of disc displacement with reduction group or disc displacement without reduction group during protrusion in the frontal plane. Mandibular rotational angle of disc displacement without reduction group was significantly larger than that of the disc displacement with reduction group or degenerative joint disease group during protrusion in the horizontal plane. Mandibular rotational angle of the control group was significantly smaller than that of disc displacement without reduction group or degenerative joint disease group during protrusion in the horizontal plane(p<0.05). 6. In NHP, disc displacement without reduction group and degenerative joint disease group showed significantly larger mandibular rotational angles during lateral excursion to the affected side than during lateral excursion to the non-affected side in both frontal and horizontal planes(p<0.05). The findings indicate that changes in head posture can influence mandibular rotational torque movements. The more advanced state is a progressive stage of TMDs, the more influenced by FHP are mandibular rotational torque movements of the patients with TMDs.

• Journal of Oral Medicine and Pain
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• v.32 no.2
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• pp.157-175
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• 2007

This study was conducted through an interview process in which questionnaires were administered to 293 people. The questionnaires related to the behaviors of oral hygiene care, and disease history related to halitosis, and status of halitosis, halitosis measurement, oral examination, and caries activity tests such as the snyder test, Salivary flow rate test, and Salivary buffering capacity test. Our sample was taken from 293 rural residents within the period from 4th to 21st of January 2006. This was done in order to provide basic data to prepare both policies of halitosis prevention and a device to efficiently measure halitosis status and investigate the factors related therein. The major findings of this study results are as follows: 1. As for frequency of tooth brushing, twice a day occupied the greatest portion at 46.1 % Women exceeded men in frequency of tooth brushing. Tongue brushing everyday produced a 25.6 % result among subjects and The use of auxiliary oral hygiene devices occupied 9.2 %. 2. As for degree of usual self-awareness of halitosis: 62.5 %. This result also demonstrate that the severest time of self-awareness in regards to halitosis is wake up time in the morning. The time period produced the highest portion of 72.7 % in times of self-awareness. In terms of the area in which halitosis was observed, gum resulted in 23.0 %. As for types of halitosis, fetid smell was the most frequent at 37.2 %. 3. As for the result of halitosis measurement, values of OG less than 50 ppm occupied 54.3 % and $50{\sim}100ppm$ occupied 41.6 %. As for $NH_3$ values, $20{\sim}60ppm$ showed the highest value range of 52.6 %. 4. As for OG per disease history related to halitosis, values of OG were significantly high in the ranges of $50{\sim}100ppm$ within family history groups of food impaction by dental caries, diabetes mellitus and halitosis. As for values of $NH_3$, there showed a significant difference in respiratory system disease groups. 5 Value range of OG per ordinary halitosis self-awareness degree: values ranging less than 50 ppm were recorded at 55.9 % from the group realizing not aware of smell. 57.5 % from groups only realizing sometimes, while values range of $50{\sim}100ppm$ were recorded at 52.0 % from groups always aware of smell. 63.6 % from groups always strongly aware of smell. Meanwhile as for the values ranges of $NH_3$, $20{\sim}60ppm$. they occupied high portions for all groups of exams. 6. Values of OG per oral examination: the more pulp-exposed teeth and food impaction and the higher the tongue plaque index, values of OG increased within the range of $50{\sim}100ppm$. As for values of $NH_3$, the more prosthetic teeth and the higher the tongue plaque index, this value increased significantly, and the values increased up to no less than 60 ppm for groups of mandibular partial denture. 7. Within the realm of caries activity test: as for the Snyder test, high activity was highest by 43.0 % wherewith the higher the activity of acidogenic bacteria the higher the OG values. As for the salivary flow rate test, the number of cases below 8.0 ml showed the highest tendency by 62.5 %. The larger the salivary flow rate the more decreased OG values distribution. As for the salivary buffering capacity test, $6{\sim}10$ drops of 0.1N lactic acid showed the overwhelming trend by 58.7 % whereby the higher the salivary buffering capacity the greater distribution occupancy ratio of OG values below 50 ppm which is scentless to on ordinary person. 8. As for the correlation between oral environment and halitosis, OG showed the positive correlation with pulp exposed teeth, filled teeth, present teeth, tongue plaque index, and food impaction, while the negative correlation with salivary flow rate and prosthetic teeth. $NH_3$ showed a positive correlation with prosthetic teeth and frequency of tooth brushing, while decayed teeth was negative correlation. 9. As for the multiple regression analysis result, there have been selected female, pulp exposed teeth, prosthetic teeth, food impaction, salivary flow rate, tongue plaque index and severe activities in the Snyder test as factors affecting OG wherein explanatory power on it was 45.1 %. There have been selected females, pulp exposed teeth, tongue plaque index, and prosthetic teeth as factors affecting on $NH_3$ wherein explanatory power on it was 6.6 %. With the aforementioned results in mind, the status of halitosis among rural residents is considered to bare a close relation with oral environments and other factors related to halitosis such as the Snyder test from caries activity test, and salivary flow rate test. For the prevention of halitosis of residents in rural areas, we have to focus on correct tooth brushing methods and tongue brushing, with using auxiliary oral hygiene devices to remove fur of tongue plaque and food impaction. Also, when the cause and ingredients of halitosis are diverse and complex, in order to analyze exactly the factors of individual halitosis development, we need continuous and systematic study in order to provide rural residents with programs of oral hygiene education and encourage the use of dental hygienists in public health centers.