• Journal of dental hygiene science
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• v.19 no.2
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• pp.96-106
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• 2019

Background: Factors affecting oral function include tooth number, oral muscle strength, and oral diseases. This study aimed to investigate the relationship among oral environment, muscle, and microbiology. Methods: Fifty-six elderly individuals in a day care center were included in the study. The survey regarding tongue and lip muscle strength and oral microorganisms was conducted from November to December 2018. Results: Tongue and lip muscle strength were greater in men than women (p>0.05). Tongue muscle strength was greater in the ${\leq}80-year-old$ group ($34.94{\pm}9.85$) than the ${\geq}90-year-old$ group ($25.57{\pm}7.54$) (p<0.05). Tongue muscle strength and lip muscle strength were greater in the ${\geq}15$ functional teeth group ($34.08{\pm}9.31$ and $9.25{\pm}1.63$, respectively) than in the <15 functional teeth group ($28.08{\pm}7.53$ and $7.76{\pm}1.51$, respectively) (p<0.05). Age was significantly correlated with functional tooth number, denture use, and tongue muscle strength. The number of functional teeth was positively correlated with tongue muscle strength, lip muscle strength, and oral microorganisms. Denture use was negatively correlated with tongue and lip muscle strength. Tongue muscle strength was significantly correlated with lip muscle strength. The number of Eubacterium nodatum was higher in men than women. The number of Parvimonas micra and Enterococcus faecalis was higher in the groups with ${\geq}15$ functional teeth, denture use, and greater tongue and lip muscle strength. The number of Lactobacillus casei was higher in the group that uses dentures and with greater tongue strength. Conclusion: Oral microbiology is more important in oral environment and management than oral muscle function. The correlation between oral muscle and oral microorganism requires further study. Therefore, oral care training should be conducted to improve the oral care practice of elderly individuals, maintain oral health through oral care, and prevent the decrease in saliva secretion by aging.

• Journal of Oral Medicine and Pain
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• v.48 no.4
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• pp.159-168
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• 2023

Purpose: Coordinated activity between the jaw and neck muscles is important in oral motor tasks such as chewing. This study examined coherence between the jaw and neck muscles during chewing in healthy adults. Methods: A total of 12 healthy adults underwent electromyography (EMG) of the jaw and neck muscles during right-sided chewing at a frequency of 1 Hz. Surface electrodes were placed over the temporalis (TA), masseter (MS), anterior digastric (DA), and sternocleidomastoid (SM) muscles on the right side. EMG signals were processed for coherence and phase analysis using advanced signal processing techniques. Results: The MS and TA muscle pair exhibited high synchronization when chewing (median coherence=0.992). Contrarily, the coherence values between the MS and DA, as well as the MS and SM muscle pairs, were relatively low (median coherence=0.848 and 0.957, respectively). Phase analysis revealed minimal temporal differences between the MS and TA muscle pair and the MS and SM muscle pair, whereas substantial phase shifts were observed between the MS and DA muscle pair. Conclusions: During chewing in healthy adults, the TA muscle works synergistically whereas the DA muscle antagonistically with the MS muscle, and the SM muscle supports the activity of the MS muscle. The observed synchrony and coordination provide insights into the intricate interplay among these muscles during oral motor tasks.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.171-183
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• 1995

This study was carried out to investigate the relationship between tensed mandibular positions, muscle tenderness and EMG activity, respectively, and between range of motion of the neck and sternocleidomastoid muscle tenderness. Under stressful conditions, most of people take several types of behavioral patterns. Two of them observed frequently are clenching of teeth and grasping of fist. Prolonged clenching or grasping should increase electromyographic activity of associated muscle, especially muscles of mastication and neck muscles and will cause hyperfunction, dysfunction and muscle pain. So it is necessary to relate EMG activity with muscle pain. The author performed routine clinical examination in 47 patients with Temporomandibular Disorders, especially for presence or absence of muscle tenderness. Mandibular rest position was used as a baseline reference position and two more position in which EMG activity was taken were rest postion with grasping of fist and teeth clenching position. BioEMG of Biopak system (Bioresearch Inc, USA) was used for measuring of integrated EMG in masseter, anterior temporalis, anterior belly of digastic muscle and sternocleidomastoid muscle. To measure of the range of neck motion. CROM(Cervical-Range-of Motion, USA) was used. The obtained results were as follows : 1. EMG activity of all muscles except in masseter was higher in grasping of fist than those in rest position and there were significant correlation in EMG activity between the two position except in anterior belly of digastric muscle. 2. When comparing EMG activity between tender and non-tender muscle, all examined muscles did not show any significant difference. From this data, we could conclude that EMG activity was generally not changed with tenderness, of couse, it might be dependent with degree of muscle tenderness. 3. Number of tender points in examined muscles was also not significantly different between in patients with masticatory muscle disorders and in patients with internal derangement. 4. Cervical posture and range of motion of the neck was not differed significantly between in patients with and in patients without tenderness of sternocleidomastoid muscle.

• Journal of Oral Medicine and Pain
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• v.17 no.1
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• pp.41-50
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• 1992

The authors performed a experimental study to evaluate the effects of masticatory muscle fatigue on tooth contact and masticatory muscle activity in 26 normal healthy women. The experimental masticatory muscle fatigue was induced by unilateral biting of 5kg force on mandibular first molar. The results were as follows : 1. The initial symptom related to muscle fatigue pain appeared in 85.19 seconds of isometric contraction and the endurance time of isometric contraction was 203.15 seconds. 2. The pain occurred more frequently in masseter region than in temporal region. In masseter pain the incidence was almost equal between both sides, whereas the temporal pain was more in contralateral side. 3. The spontaneity and the symmetry of tooth contact during maximum clenching were reduced after isometric unilateral biting. 4. After induction of experimental muscle fatigue, the EMG activities of masseter muscles of both sides and ipsilateral temporal muscle showed the tendency of decreasing activities. 5. The asymmetry indicies of masseter and temporal muscles were reduced after isometric bilateral biting.

• Journal of Oral Medicine and Pain
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• v.39 no.2
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• pp.55-62
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• 2014

Purpose: This study aims to evaluate the changes in soft tissue thickness of the masseteric region after injection of botulinum toxin type A (BTX-A). Methods: Twenty-four data acquired from medical records were classified into 4 groups: bruxer group that received masseter muscle injection only (M-B), bruxer group that received both masseter and temporalis muscle injections (MT-B), non-bruxer group that received masseter muscle injection only (M-NB) and non-bruxer group that received both masseter and temporalis muscle injections (MT-NB). Injection dose of BTX-A was 30 units for each masseter muscle and 20 units for each temporalis muscle. We measured the reduced thickness of the masseteric region before and after 12 weeks after injection using cone-beam computed tomography. Results: Among the patients that received both masseter and temporalis muscle injections, bruxer group showed a tendency to have more reduction in masseter muscle thickness than non-bruxer group. The difference in reduced thickness between M-B and MT-B tended to show greater than the difference between M-NB and MT-NB. Conclusions: In case of masseter hypertrothy patients with bruxism there was a tendency to show a difference in reduced thickness of soft tissue between the group that received both masseter and temporalis muscles injection and the group that received masseter muscle injection only hence a thorough inspection before the injection of BTX-A is condisered to be needed.

• Journal of Korean society of Dental Hygiene
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• v.19 no.2
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• pp.161-172
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• 2019

Objectives: This study aimed to analyze the correlation between oral function, oral environment, and brain cognitive function in the elderly. Methods: The subjects were 60 users of senior community center and elderly day care center. The survey was conducted from November to December 2018. Subjects were assessed by oral examination and myofunction test. Oral myofunction was measured using $IOPI^R$ and Lip de $Cum^R$. Survey data were analyzed using the statistical programs of PASW Statistics ver. 18.0. Results: Tongue muscle strength and lips muscle strength was higher in males than in females. The tongue and lip strengths were higher in the <81 years old group than the ${\geq}81$ years old group. Functional tooth analysis showed that there was a ${\geq}15$ teeth group ($40.91{\pm}7.36$) and a <15 teeth group ($32.52{\pm}7.14$). Lip muscle strength analysis showed that the ${\geq}15$ teeth group ($10.54{\pm}3.40$) was higher than the <15 teeth group ($8.20{\pm}2.41$, p<0.05). Tongue muscle strength, lumbar muscle strength, and functional tooth number were lower in the elderly subjects with mild cognitive impairment. Cognitive function was significantly correlated with functional tooth number (r=0.386, p<0.001), tongue strength (r=0.478, p<0.001), and lip strength (r=0.281, p<0.05). Tongue strength was significantly correlated with lip strength (r=0.360, p<0.001) and functional tooth number (r=0.633, p<0.001). Lip strength was significantly correlated with functional tooth number (r=0.376, p<0.001). Conclusions: These results showed that age and functional tooth number influenced oral muscle strength and that the number of functional teeth and oral muscle strength were low in the elderly with mild cognitive impairment. Oral myofunction training and oral care program are suggested to improve the quality of life of the elderly.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.1
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• pp.69-73
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• 2002

Temporal muscle flap is usefull for the reconstruction of tissue defect at the oral and maxillofacial area. This article reports 3 cases of temporal muscle flap for the soft tissue reconstruction of infraorbital, palatal and mandibular retromolar area after tumor ablation. The advantages and disadvantage, postoperative complications and technical variations were reviewed and our 3 cases were evaluated in this aspects.

• International Journal of Oral Biology
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• v.44 no.1
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• pp.20-26
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• 2019

Periodontal diseases have been associated with the development of cardiovascular diseases. Accumulating evidences have indicated that Porphyromonas gingivalis, a major periodontopathic pathogen, plays a critical role in the pathogenesis of atherosclerosis. In the present study, we demonstrated that P. gingivalis lipopolysaccharide (LPS) increases the mRNA and protein expression of matrix metalloproteinase-9 (MMP-9) in rat vascular smooth muscle cells. We showed that the MMP-9 expression induced by P. gingivalis LPS is mediated by the activation of signal transducer and activator of transcription 3 (STAT3) in vascular smooth muscle cells. Furthermore, the inhibition of STAT3 activity reduced P. gingivalis LPS-induced migration of vascular smooth muscle cells. Overall, our findings indicate that P. gingivalis LPS stimulates the migration of vascular smooth muscle cells via STAT3-mediated MMP-9 expression.

• Journal of Oral Medicine and Pain
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• v.47 no.4
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• pp.206-211
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• 2022

Purpose: The purpose of this study is to develop a reproducible and reliable method for evaluating the masseter's functional state by measuring the masseter muscle with ultrasonography (US). Methods: Nineteen healthy adults (9 males, 10 females) were the subjects of this study. During US scanning, the image was taken from the thickest part of the masseter muscle in the image. To evaluate changes in thickness during masseter function, US images were taken of the participant's masseter muscle at rest and during clenching. In this study, US scanning was conducted using two approaches to compare the difference in masseter muscle thickness determined when inducing maximum bite force (MBF). Results: All 19 subjects completed US scanning of the masseter muscle at rest and during clenching under the conventional method and the articulation paper method. There was no difference in masseter muscle thickness measured at rest. However, the thickness of the masseter muscles determined by the articulation paper during jaw clenching was greater than that measured by the conventional method. Conclusions: In conclusion, using the US for masseter muscle evaluation can offer objective and functional information on the masseter muscle. A standardized US scanning method needs to be developed to obtain reproducible and reliable information on the masseter muscle at rest and during clenching. In particular, generating MBF using an articulation paper can be a reproducible and reliable method of measuring the functional state of the masseter muscle.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.55.1-55.7
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• 2019

Background: Transverse facial clefts are Tessier's number 7 facial cleft among numbers 1-15 in Tessier's classification of craniofacial malformations, which varies from a simple widening oral commissure to a complete fissure extending towards the external ear. Case presentation: In a patient with a transverse facial cleft, to functionally arrange the orbicularis oris muscle and form the oral commissure naturally, we performed a surgical procedure including orbicularis oris muscle reconstruction and cheiloplasty with Z-plasty. Conclusion: We achieved good results functionally and esthetically by orbicularis oris muscle reconstruction and cheiloplasty with Z-plasty. The surgical modality of our anatomical repair and 3 months follow-up results are presented.