Electromyographic activity of masticatory muscles in elderly women – a pilot study

Figures & data

Table 1 Patients inclusion and exclusion criteria in the study

Inclusion criteria	Exclusion criteria
Age >65 years	Dental pathology such as active caries or periodontal disease
Female gender	Unacceptable retention of dentures
Normal occlusion (I class angle)	Orofacial pain or having evidence of temporomandibular joint pathology
Unilateral chewing pattern	Taking medications that affect muscle function such as myorelaxants (eg, Baclofen, Tizanidine, and Tolperisone) and psychotropic drugs Diabetes mellitus Musculoskeletal dysfunction Stroke Parkinson’s disease Depression

Table 2 Studied parameters in relation to dental status categories

Variable	Complete removable dentures wearers	Partial removable dentures wearers	Individuals with natural dentition
Age (years), mean ± SD	84.40±6.08	80.11±9.10	79.78±7.63
Hand grip strength (kg), mean ± SD	13.65±3.87	13.18±5.05	14.84±4.79
Body mass index (kg/m^2), mean ± SD	24.69±4.03	27.85±3.89	28.67±4.20
Body cell mass index (kg/m^2), mean ± SD	6.09±0.83	6.33±0.86	6.50±1.18
Difference of masseter muscle tension (mm), mean ± SD	3.70±1.70	3.67±2.18	3.67±1.73

Abbreviation: SD, standard deviation.

Table 3 Maximal voluntary contraction in masseters and temporalis muscles in relation to descriptive variables: multivariate models with Akaike’s criterion of variables selection

Variable	Maximal voluntary contraction
	Active masseter	Active temporalis muscle	Passive temporalis muscle
Age	−2.501, P=0.054	−4.055, P=0.001	−3.589, P=0.002
Body mass index		−3.368, P=0.120	−3.897, P=0.057

Notes: Data are presented as coefficient and P-value. Variables that have not been included in the model are omitted. The level of significance was set at 0.05. In the model variables with a P-value from Student’s t-test of >0.05 were also added, providing that their presence improve the model.

Table 4 Mean muscle activity during chewing in masseters and temporalis muscles in relation to descriptive variables: multivariate models with Akaike’s criterion of variables selection

Variable	Mean muscle activity during sequence			Mean muscle activity during cycle
	Active masseter	Active temporalis muscle	Passive temporalis muscle	Active masseter	Active temporalis muscle	Passive temporalis muscle
Age	−0.812, P=0.111	−1.600, P=0.017	−0.924, P=0.070	−1.184, P=0.045	−1.677, P=0.002	−0.986, P=0.060
Body mass index		−2.693, P=0.023	−2.064, P=0.027	−1.491, P=0.171	−2.813, P=0.021	−2.160, P=0.023
Complete removable denture		Reference	Reference		Reference	Reference
Partial removable denture		15.995, P=0.146	14.799, P=0.091		15.430, P=0.169	14.910, P=0.095
Natural dentition		25.692, P=0.044	18.386, P=0.065		25.908, P=0.047	18.204, P=0.073

Notes: Data are presented as coefficient and P-value. Variables that have not been included in the model are omitted. The level of significance was set at 0.05. In the model variables with a P-value from Student’s t-test of >0.05 were also added, providing that their presence improve the model.

Table 5 Maximal muscle activity during chewing in masseters and temporalis muscles in relation to descriptive variables: multivariate models with Akaike’s criterion of variables selection

Variable	Maximal muscles activity during sequence		Maximal muscles activity during cycle
	Active temporalis muscle	Passive temporalis muscle	Active masseter	Active temporalis muscle	Passive temporalis muscle
Age	−3.849, P=0.017	−2.305, P=0.083		−2.256, P=0.034	−1.338, P=0.084
Body mass index	−6.912, P=0.017			−4.199, P=0.027	−3.533, P=0.014
Body cell mass index		21.858, P=0.067
Complete removable denture	Reference	Reference	Reference	Reference	Reference
Partial removable denture	42.027, P=0.115		3.389, P=0.823	23.329, P=0.187	21.295, P=0.109
Natural dentition	59.177, P=0.054		26.935, P=0.086	43.839, P=0.034	30.411, P=0.047

Notes: Data are presented as coefficient and P-value. Variables that have not been included in the model are omitted. The level of significance was set at 0.05. In the model variables with a P-value from Student’s t-test of >0.05 were also added, providing that their presence improve the model.