Contracture of the jaw-closing muscles is one of the causes of limitation of jaw opening. This study examined whether there is any difference between the EMG activities of jaw-closing muscles during jaw opening in healthy people and in patients with masseter muscle contracture (MMC), who do not have a history of trauma or infection. The patient group consisted of eleven females, 18 to 62 years old with no history of trauma or infections, with limited mouth opening due to MMC. The control group included eleven healthy females, 23 to 50 years old. The EMG activity was recorded bilaterally in the central portion of masseter muscles (Mm), the anterior portion of temporal muscles (Tm), and the anterior belly of digastric muscles (Dm). Nine out of the patient group showed obvious EMG activity in Mm during jaw opening which was different from typical EMG patterns during jaw opening of up to 40 mm in the control group. Among the nine patients, eight showed antagonistic contraction in Tm as well as Mm. The mean integral value of Mm and Tm during jaw opening in the patient group was significantly higher than in the control group (P<0.01). These results suggest that EMG activity during jaw opening in MMC patients with no history of trauma or infections is different from that in healthy people.
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http://dx.doi.org/10.1080/08869634.2002.11746190 | DOI Listing |
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
January 2025
Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Bengbu Medical University, Bengbu Anhui, 233004, P. R. China.
Objective: To investigate the effectiveness of posterior lateral perforator flap in lower limb combined with free fibula for maxillary tissue defect repair.
Methods: Between December 2018 and December 2023, 16 patients with the maxillary malignant tumors were admitted. There were 10 males and 6 females, with an average age of 64.
Orthod Fr
January 2025
Service de Chirurgie maxillo-faciale, CHU de Caen Normandie, avenue de la Côte de Nacre, 14033 Caen, France
Introduction: Temporomandibular joint ankylosis is defined as permanent jaw constriction with an interincisal mouth opening of less than 30 mm, due to bony, fibro-osseous or fibrous fusion. Ankylosis may be uni- or bilateral. The complications of this ankylosis affect the functions of mastication, swallowing and phonation, sometimes facial morphology, and disturb dental hygiene.
View Article and Find Full Text PDFNatl J Maxillofac Surg
November 2024
Department of Oral and Maxillofacial Surgery, Lucknow, Uttar Pradesh, India.
Introduction: Restricted mouth opening has major health implications, such as malnutrition, difficulty in speech, and poor oral hygiene resulting in a functional shortage of the masticatory system. Reduced mouth opening can occur due to trismus, as in the oral submucous fibrosis (OSMF) condition. Excision of fibrous bands in OSMF leads to reestablishment of the mouth opening.
View Article and Find Full Text PDFOrphanet J Rare Dis
January 2025
Department of Voice, Speech and Hearing Disorders, University Dysphagia Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Background: Bulbar function is frequently impaired in patients with spinal muscular atrophy (SMA). Although extremely important for the patient's quality of life, it is difficult to address therapeutically. Due to bulbar dysfunction, maximum mouth opening (MMO) is suspected to be reduced in children with SMA.
View Article and Find Full Text PDFAnat Rec (Hoboken)
January 2025
Instituto de Plasmas e Fusão Nuclear & Centro de Recursos Naturais e Ambiente (CERENA), Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.
Hypercanines, or hypertrophied canines, are observed in a wide range of both extinct and extant synapsids. In non-mammaliaform cynodonts, the Permo-Triassic forerunners of mammals, long canines are not uncommon, appearing in several unrelated taxa within the clade. Among them is Trucidocynodon riograndensis, a carnivorous ecteniniid cynodont from the Late Triassic of Brazil, which exhibits a specialized dentition, including spear-shaped incisors, very long and narrow canines, and sectorial postcanines with distally oriented cusps, all of which have finely serrated margins.
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