As ultrasonography provides objective parameters and values, it is a reliable method of examining the structure and dimensions of the masseter muscle. Although the method is well known, there is no standardization in clinical examination and data analysis yet. The study aimed to measure masseter muscle thickness in designated areas to establish the most repeatable and clinically applicable method of ultrasound examination, and to assess differences in measurements in designated areas for clinical purposes by devising the size-independent parameter. The size-independent parameter may potentially be more clinically applicable than distance records, which are affected by the size of the subject. An ultrasound examination of 124 masseter muscles was performed. Axial examination in 3 horizontal regions (lower, middle and upper) and coronal examination in 2 vertical regions (proximal and distal) was carried out. Masseter muscle thickness was measured in every designated area when relaxed (muscle at rest (RMT)) and with clenched teeth (contracted muscle (CMT)). A morphological independent functional index of thickness difference (FITD) was calculated. The study revealed very high statistical differences between RMT and CMT (p < 0.0001) in all designated areas but with location variations. Masseter muscle thickness significantly differed depending on the examined area and transducer projection. The ultrasound study showed that masseter muscle thickness significantly differs depending on the examined area. The authors emphasize the necessity to examine the masseter muscle in specified areas with both coronal and axial projections to achieve objective and repeatable examination. Notable clinical value is assigned to FITD, which is independent from the morphological dimensions of the muscle.

BACKGROUND:Numerous studies have discussed cases of concomitant temporomandibular disorders (TMD) and otologic symptoms (OS). However, attempts to determine the true origin of these symptoms combined with assessments of the condition of the organ of ...

Background . Parafunctions are involuntary habits harmful to the chewing system. Tooth contact parafunctions are developed mostly under high emotional tension associated with stress. One of them is bruxism, i.e. teeth clenching and/or grinding. Young people in the last high-school grades are a...

Background/Objectives: Chronic stress has an undeniable effect in generating emotional disorders and physiological changes. It results in excessive muscle tension throughout the body, also in the masticatory system. A situation of chronic stress was the COVID-19 pandemic. The aim of this paper was to assess the prevalence of specific masticatory pain symptoms, their severity, and the co-occurrence of associated symptoms (otological symptoms and headaches) in patients diagnosed before and during the COVID-19 pandemic. Methods: A total of 202 patients were divided into two groups: Group A (mean age of 36.46; F = 64; and M = 37) and B (mean age of 26.04; F = 70; and M = 31) included patients who presented for the study before and after the COVID-19 pandemic, respectively. The Oral Behaviours Checklist (OBC) questionnaire was used: patients with result ≥2 scores in the OBC were evaluated by DC/TMD. To evaluate the intensity of pain in masticatory structures, the elements of the RDC-TMD questionnaire were used. Otologic symptoms and headaches were assessed as coexisted complaints. Results: A significant increase in pain occurrence was observed in Group B mainly for masseter muscles (p < 0.0001), temporalis (p = 0.0044), and medial pterygoid muscles (p = 0.0153). A significantly more frequent reporting of pain/tenderness was observed among men in most of the evaluated muscles. For the lateral pterygoid muscles, changes in palpation pain did not reach statistical significance. There was a statistically significant difference in the intensity of pain in the temporomandibular joint area between both the entire groups A and B (p = 0.000152), as well as between women in Group A and B (p = 0.006453) and men in the study groups (p = 0.007990). An increase in the incidence of headaches was observed among men in Group B (Group A with 40.6% vs. Group B with 67.3%). The most commonly reported otological symptom in both groups was ear pain and/or discomfort in the preauricular region, with the frequency of otological symptoms being higher in Group B. Conclusions: (1) The COVID-19 pandemic affected the incidence and severity of masticatory muscle pain and associated complaints. (2) A decrease in the age of patients reporting complaints of masticatory mm pain was observed during the COVID-19 pandemic. (3) An increase in the frequency of headaches was observed in the male group during the pan-demic, while in women there was an increase in palpation tenderness of masticatory muscles.