1
|
Lan KW, Jiang LL, Yan Y. Comparative study of surface electromyography of masticatory muscles in patients with different types of bruxism. World J Clin Cases 2022; 10:6876-6889. [PMID: 36051132 PMCID: PMC9297420 DOI: 10.12998/wjcc.v10.i20.6876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/22/2022] [Accepted: 05/22/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Bruxism is a rhythmic masticatory muscle activity that occurs involuntarily in a non-physiologically functional state. There is a lack of research classifying the functional status of masticatory muscles in patients with different mandibular movement types (centric clenching or eccentric grinding) of bruxism.
AIM To assess the differences of the masticatory muscle activity in patients with different types of bruxism.
METHODS A total of 21 subjects with centric bruxism (CB) and 21 subjects with eccentric bruxism (ECB) were screened from college students according to a questionnaire and their tooth wear features. Sixteen subjects with no bruxism were also recruited. The surface electromyography (EMG) signals of the temporalis anterior (TA) and superficial masseter muscle (MM) were measured in different mandibular positions and during the chewing task. The EMG amplitude and chewing cycle duration parameters were then analyzed.
RESULTS The CB group showed fewer muscle maximal motor units, with the MM being more pronounced, a higher proportion of muscle contractions to be recruited for the same load of chewing activity, and a longer chewing cycle. The ECB group showed more TA maximal motor units and higher MM activity on the non-working side in unilateral chewing.
CONCLUSION CB mainly affects the MM, and patients with CB show reduced masticatory muscle contraction efficiency and chewing cycle efficiency. ECB mainly affects the TA, and patients with ECB show enhanced contraction of non-functional lateral muscle bundles.
Collapse
Affiliation(s)
- Kai-Wen Lan
- Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Guangzhou 510080, Guangdong Province, China
| | - Liu-Lin Jiang
- Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Guangzhou 510080, Guangdong Province, China
| | - Ying Yan
- Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Guangzhou 510080, Guangdong Province, China
| |
Collapse
|
2
|
Walton TR, Layton DM. Mediotrusive Occlusal Contacts: Best Evidence Consensus Statement. J Prosthodont 2021; 30:43-51. [PMID: 33783093 DOI: 10.1111/jopr.13328] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Indexed: 12/01/2022] Open
Abstract
PURPOSE The impact of mediotrusive (MT) occlusal contacts has been a topic of controversy and confusion in both clinical practice and in the dental literature. The purpose of this Best Evidence Consensus Statement was to explore whether MT interferences are harmful in the natural or therapeutic occlusion directed by 4 focus questions relating to prevalence, jaw function, jaw dysfunction and biomechanical models. MATERIALS AND METHODS An electronic search in October 2020 sought evidence in MEDLINE (Ovid) using (mediotrus* OR nonworking side OR nonworking contact OR balancing side OR interfer* side OR premature contact) in the multipurpose (.mp) search field; and in Google Scholar using permutations of the above. Supplementary articles were sourced from the associated reference lists. There was no language restriction. The search yield was reviewed in duplicate. RESULTS The electronic search identified 420 articles. Following screening, 164 were selected for eligibility assessments. Of these, 47 were included in the current paper. CONCLUSIONS Non-standardized nomenclature and methodology is used to identify MT interferences in patient populations, with resultant prevalence varying from 0% to 77%, (median = 16%). MT interferences may alter the biomechanics of mandibular function. Together with the presence of repeated high loads resultant strain can manifest as pathophysiology of the temporomandibular joint and associated muscle structures. MT interferences should be avoided in any therapeutic occlusal scheme to minimize pulpal, periodontal, structural and mechanical complications or exacerbation of temporomandibular disorders (TMDs). Naturally occurring molar MT interferences should be eliminated only if signs and symptoms of TMDs are present. Literature supports there being a biomechanical basis which can explain how MT interferences may affect temporomandibular joint morphology and jaw function.
Collapse
Affiliation(s)
- Terry R Walton
- School of Dentistry, Faculty of Medical Sciences, University of Sydney, & Specialist private practice, Sydney, New South Wales, Australia
| | - Danielle M Layton
- School of Dentistry, Faculty of Health and Behavioural Sciences, University of Queensland, & Specialist private practice, St Lucia, Queensland, Australia
| |
Collapse
|
3
|
Chuhuaicura P, Lezcano MF, Dias FJ, Fuentes AD, Arias A, Fuentes R. Mandibular border movements: The two envelopes of motion. J Oral Rehabil 2020; 48:384-391. [PMID: 33151578 DOI: 10.1111/joor.13124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/26/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The envelope of motion is a diagrammatic representation of the mandibular border movements. Classically, those movements are carried out eccentrically; starting from the position of maximal intercuspation, the mandible describes an excursion movement until reaching maximal mouth opening. Reverse movements would describe a different path, but up to now concentric development of mandibular border movements has not been considered. Literature states that beyond mandibular border movements limits, no movement is possible. Therefore, it is of great interest to compare both paths-both envelopes of motion-and define the actual limits of mandibular movement. OBJECTIVE The aim of this study was to compare the geometric characteristics of mandibular border movements carried out eccentrically and concentrically by healthy subjects. METHODS Sixteen individuals aged between 18 and 27 years, molar class I and with no temporomandibular disorders, participated in the study. Eccentric and concentric mandibular movements were recorded using a 3D electromagnetic articulograph. Data were processed with computational scripts developed in MATLAB. Maximum mouth opening, trajectories, displacement ranges, polygon areas and chewing cycle area/ mandibular border movements area ratio were analysed. RESULTS The frontal plane showed significant differences in all the parameters evaluated. Higher values were registered in the concentric area of the border movement envelope (P = .008) and in the trajectories on both sides. Statistical differences were observed in polygon areas (P = .006) in the sagittal plane and right ranges (P = .046) in the horizontal plane. CONCLUSION Concentric mandibular movements revealed significant differences in three-dimensional trajectories in the frontal plane.
Collapse
Affiliation(s)
- Priscila Chuhuaicura
- Dental School, Research Centre in Dental Sciences (CICO), Universidad de La Frontera, Temuco, Chile.,Department of Integral Adults Dentistry, Dental School, Universidad de La Frontera, Temuco, Chile
| | - María Florencia Lezcano
- Dental School, Research Centre in Dental Sciences (CICO), Universidad de La Frontera, Temuco, Chile.,Department of Integral Adults Dentistry, Dental School, Universidad de La Frontera, Temuco, Chile.,Laboratorio de Cibernética, Departamento de Bioingeniería, Facultad de Ingeniería, Universidad Nacional de Entre Ríos, Entre Ríos, Argentina
| | - Fernando José Dias
- Dental School, Research Centre in Dental Sciences (CICO), Universidad de La Frontera, Temuco, Chile.,Department of Integral Adults Dentistry, Dental School, Universidad de La Frontera, Temuco, Chile
| | - Aler Daniel Fuentes
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile.,Oral Physiology Laboratory, Faculty of Medicine, Biomedical Sciences Institute, Universidad de Chile, Santiago, Chile
| | - Alain Arias
- Dental School, Research Centre in Dental Sciences (CICO), Universidad de La Frontera, Temuco, Chile.,Department of Integral Adults Dentistry, Dental School, Universidad de La Frontera, Temuco, Chile
| | - Ramón Fuentes
- Dental School, Research Centre in Dental Sciences (CICO), Universidad de La Frontera, Temuco, Chile.,Department of Integral Adults Dentistry, Dental School, Universidad de La Frontera, Temuco, Chile
| |
Collapse
|