• Imaging Science in Dentistry
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• 제53권4호
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• pp.355-363
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• 2023

Purpose: Sonographic elastography can be used to evaluate the hardness of muscle tissue through the application of compression. Strain elastography gauges hardness through the comparison of echo sets before and after compression. This study utilized ultrasonography to measure the thickness and hardness of the masseter muscle in individuals with temporomandibular joint(TMJ) osteoarthritis. Materials and Methods: This study included 40 patients who presented with joint pain and were diagnosed with TMJ osteoarthritis via diagnostic cone-beam computed tomography, along with 40 healthy individuals. The thickness and hardness of each individual's masseter muscle were evaluated both at rest and at maximum bite using ultrasonography. The Mann-Whitney U test and the chi-square test were employed for statistical analysis, with the significance level set at P<0.05. Results: The mean thickness of the resting masseter muscle was 0.91 cm in patients with osteoarthritis, versus 1.00 cm in healthy individuals. The mean thickness of the masseter muscle at maximum bite was 1.28 cm in osteoarthritis patients and 1.36 cm in healthy individuals. The mean masseter elasticity index ratio at maximum bite was 4.51 in patients with osteoarthritis and 3.16 in healthy controls. Significant differences were observed between patients with osteoarthritis and healthy controls in both the masseter muscle thickness and the masseter elasticity index ratio, at rest and at maximum bite (P<0.05). Conclusion: The thickness of the masseter muscle in patients with TMJ osteoarthritis was less than that in healthy controls. Additionally, the hardness of the masseter muscle was greater in patients with TMJ osteoarthritis.

• Anatomy and Cell Biology
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• 제56권3호
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• pp.293-298
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• 2023

The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle. An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제42권3호
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• pp.133-138
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• 2016

Objectives: To assess the association between muscle invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis on the basis of preoperative magnetic resonance imaging (MRI). Materials and Methods: Twenty-six patients with oral squamous cell carcinoma of the posterior mandibular alveolar ridge were evaluated by MRI. The associations between cervical lymph node metastasis and independent factors evaluated by MRI were analyzed. Overall survival was also analyzed in this manner. Representative biopsy specimens were stained with anti-podoplanin and anti-CD34 antibodies. Results: Mylohyoid muscle invasion was associated with cervical lymph node metastasis. A combinational factor of mylohyoid and/or buccinator muscle invasion was also associated with cervical lymph node metastasis. Cervical lymph node metastasis and masticator space invasion had a negative effect on overall survival. No lymphatic vessels were identified near the tumor invasion front within the mandible. In contrast, lymphatic vessels were identified near the front of tumor invasion in the muscles. Conclusion: This study demonstrates an association between muscular invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.358-361
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• 2001

We had experienced a case of traumatic myositis ossificans arising in right masseter muscle, inferior to zygomatic arch occurred on 25 year old male. He had some trauma on the site one year ago and visited with complaint of mouth opening limitation and swelling. Palpable mass with facial disfigurement was noted. and several ovoid radiopaque masses were revealed on C.T. examination. On histopathologic examination, multiple bone trabeculae with osteoblasts in its periphery was noted in connective tissues and invaded to neighbouring muscles, but any chondroid components were not revealed.

• Journal of Oral Medicine and Pain
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• 제38권2호
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• pp.143-147
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• 2013

측두하악장애 중 개구제한은 일반적으로 저작근, 측두하악관절의 통증, 비정복성 관절원판변위, 측두하악관절의 유착이나 강직, 저작근의 근경축 등에 의해 발생한다. 하지만 이비인후과적인 질환, 신경 및 혈관질환, 종양, 염증, 감염 등에 의해 측두하악장애와 유사한 통증 및 개구제한이 유발 될 수 있다. 따라서 병력 조사 및 임상 검사 시 이러한 이차적 질환에 대한 고려가 필요하다. 특히 초진 시 전형적인 측두하악장애의 소견을 보인다고 할지라도 적절한 치료 및 환자의 자기 관리에도 불구하고 증상의 호전이 없거나 지속적인 악화 소견을 보이는 경우에는 염증, 감염, 종양 등의 가능성에 관한 포괄적인 재평가가 필수적이다. 본 증례에서는 제 3 대구치의 치근단 농양이 익돌하악간극(pterygomandibular space)으로 확산되어 발생한 내익돌근(medial pterygoid muscle)의 통증 및 개구제한에 관하여 경험하였기에 이를 보고하고자 한다.

• Imaging Science in Dentistry
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• 제53권3호
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• pp.257-263
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• 2023

Fibrodysplasia ossificans progressiva is a rare hereditary disorder characterized by progressive heterotopic ossification in muscle and connective tissue, with few reported cases affecting the head and neck region. Although plain radiographic findings and computed tomography features have been well documented, limited reports exist on magnetic resonance findings. This report presents 2 cases of fibrodysplasia ossificans progressiva, one with limited mouth opening due to heterotopic ossification of the lateral pterygoid muscle and the other with restricted neck movement due to heterotopic ossification of the platysma muscle. Clinical findings of restricted mouth opening or limited neck movement, along with radiological findings of associated heterotopic ossification, should prompt consideration of fibrodysplasia ossificans progressiva in the differential diagnosis. Dentists should be particularly vigilant with patients diagnosed with fibrodysplasia ossificans progressiva to avoid exposure to diagnostic biopsy and invasive dental procedures.

• 대한한의학회지
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• 제26권4호
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• pp.39-45
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• 2005

Objectives: The study investigated the efficacy of oral Korean red-ginseng (RG) on sCRP response mediated by eccentric contraction-induced muscle damage and discussed its mechanism. Methods: Nineteen healthy young subjects (aged 24.4$\pm$2.07 yr) volunteered for this double blind test. They were classified into either the RG group (N=10) or placebo (P) group (N=9) during the 10-d experimental protocol. Blood samples were collected on T1 (baseline), T1 (1h), T2 (1d), T3 (2d) and T4 (3d) after eccentric contraction-induced injury on the seventh day. Statistical analyses were conducted using nonparametric methods (p<0.05). Results: The RG group increased sCRP more than P group and didn't increase soreness peak at T2, not significant. There were no correlations between soreness intensity and sCRP. Oral RG had little efficacy for reducing sCRP at the muscle damage-mediated acute phase; rather, it increased because of its proinflammatory cytokine production. Conclusions: Oral RG could stimulate proinflammatory cytokine production, and occasionally bal-pyo-beob could be helpful for the efficient recovery of muscle injury.

• Anatomy and Cell Biology
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• 제56권3호
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• pp.322-327
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• 2023

The aim of this study was to elucidate the intramuscular arborization of the teres minor muslce for effective botulinum neurotoxin injection. Twelve specimens from 6 adult Korean cadavers (3 males and 3 females, age ranging from 66 to 78 years) were used in the study. The reference line between the 2/3 point of the axillary border of the scapula (0/5), where the muscle originates ant the insertion point of the greater tubercle of the humerus (5/5). The most intramuscular neural distribution was located on 1/5-3/5 of the muscle. The tendinous portion was observed in the 3/5-5/5. The result suggests the botulinum neurotoxin should be delivered in the 1/5-3/5 area of the teres minor muscle.

• 대한구순구개열학회:학술대회논문집
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• 대한구순구개열학회 1998년도 종합학술대회
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• pp.23-23
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• 1998

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.229-237
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• 2000

According to the functional matrix theory, Delaire proposes that individual occlusal plane was determined by variable effects of teeth, maxilla, mandible, cranium, cranial base and soft tissue matrix including the orofacial musculature. and that there is the ideal occlusal plane determined by the most proper spatial position of maxilla and mandible, functionally and esthetically. This study was designed to find out the relation between Delaire's ideal occlusal plane and muscle activity of masticatory muscles in individuals who have normal maxillo-mandibular relationships. Lateral cephalometric radiographs were taken and his/her individual occlusal plane and ideal occlusal plane were analyzed with Delaire's architectural and structural craniofacial analytic method. For evaluation of muscle activities of masticatory muscles, electromyography of anterior temporal muscle, superficial masseter muscle, and anterior belly of digastric muscle was recorded in fifty Korean normal Angle class I occlusion individuals. According to the average value of ideal occlusal plane, fifty normal Angle class I occlusion individuals were classified into three groups: Ideal occlusal plane group(I group), hyperrotation group(I+ group) and hyporotation group(I- group). The result of this study was as follows: 1. The results of Delaire's architectural and structural craniofacial analysis of lateral cephalography of the fifty Korean normal Angle class I occlusion individuals are that twelve persons(24%) have consistent or parallel with ideal occlusal plane and the average of angular difference was $1.22^{\circ}{\pm}3.69^{\circ}$. 2. There is no significant difference in muscle activities of masticatory muscles during resting(p<0.05), but significant increases of muscle activity of ipsilateral anterior temporal and masseter muscle, contralateral anterior belly of digastric muscle during unilateral chewing and of anterior temporal and masseter muscle during bilateral clenching(p<0.05). 3. To find out the effect of the angular difference between Delaire's ideal occlusal plane and real occlusal plane to muscle activity, muscle activities of masticatory muscles were compared with three groups in each other; I group, I+ group and I- group. The results were no significant differences during resting, unilateral chewing and bilateral clenching.(p>0.05) 4. Although there is no significant differences of masticatory muscle activities among the three groups, the fact that increasing tendency of masseter muscle activity of ideal occlusal plane group(I+) than those of any other groups(I+ and I-) during bilateral clenching was noted. There is only the implication that occlusal plane makes some effects on masticatory muscle activities, espacially that of masseter muscle during bilateral clenching. In conclusion, the hypothesis that occlusal plane is one of the factors which affect the muscle activities of masticatory muscles and that anyone whose occlusal plane consistent with Delaire's ideal occlusal plane has an extraordinary functional advantage in masticatory muscle function cannot be proven with electromyography methods.