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| Author(s): |
Paulinne Junqueira Silva Andresen Strini
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Piracicaba, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba |
| Defense date: | 2011-04-07 |
| Examining board members: |
Maria Beatriz Duarte Gavião;
Claudia Duarte Kroll;
Fausto Bérzin;
Fernanda Miori Pascon;
Paula Rezende Camargo
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| Advisor: | Maria Beatriz Duarte Gavião |
| Abstract | |
Temporomandibular disorders (TMD) are a group of changes that affect the stomatognathic system, especially the muscular component. The aim of this study was to evaluate the maximum bite force (MBF), the electromyographic activity (EMG) and the thickness of masticatory and neck muscles by means of ultrasonography (US), in addition to clinical influence of head posture, in adults with and without TMD. The sample consisted of 47 individuals of both genders, with 28 included in the control group (mean age 25.9±4.7 years old) and 19 in the TMD group (25.4±3.8 years old), classified according the Research Diagnostic Criteria (RDC / TMD). A plumb line was used as reference to verify the alignment and to define the side of head tilt. MBF was determined by a pressure transducer positioned between the dental arches to the level of first molars and the values were converted into Newtons. EMG and US were evaluated for the masseter, temporalis and sternocleidomastoid (SCM) at rest and at maximal voluntary contraction (MVC), bilaterally. Data normality was checked by Shapiro-Wilks and the comparison between the data done by parametric and nonparametric tests, with the correlation obtained by Spearman's correlation (p ? 0.05). The results showed statistically significant differences when comparing values of MBF between TMD (285.5 ±98.8 N) and controls (353.4 ±69.6 N). Significant differences were also observed for thickness of the masseter muscle between the TMD (11.2±1.9 mm, rest; 13.4±1.9 mm, MVC) and the control group (12.7±1.8 mm, rest; 14.8±2.0 mm, MVC) and between the state of rest and contraction in both groups for the masticatory muscles. In relation to gender, MBF was lower in female subjects with TMD as well the thickness of the muscles analyzed, in both groups. The values of EMG for the SCM showed significant differences between the resting state (100.6 ±28.0 %) and MVC (105.6 ±101.9 %) in the control group, with greater scores during dental clenching. In the same way, significant differences were observed between the control and TMD for SCM activity during head flexion for right (77.0±34.2 %, TMD; 115.6 ±56.8 %, control) and left SCM (80.7 ±46.1 %, DTM; 113.1±49.5 %, control) and for the thickness of the SCM during extension, to the left side (10.0±2.0 %, TMD; 10.9±1.5 %, control) and at rest to the right side (10.4±1.8 %, TMD; 11.5±1.8 %, control). Additionally, a significant correlation was found between values of the MBF, US and EMG of the masseter, temporal and SCM for TMD group and also when considered the side of head tilt for SCM. Thus, it can be concluded that patients with TMD showed smaller values of MBF and changes in muscle function that may affect the masticatory and neck muscles, especially during the mandibular movements, revealing the existence of a functional link between them (AU) | |
| FAPESP's process: | 09/00710-2 - Electromyographic and structural assessment of masseter and sternocleidomastoid muscles in patients with temporomandibular dysfunction in different bite forces |
| Grantee: | Paulinne Junqueira Silva Andresen Strini |
| Support Opportunities: | Scholarships in Brazil - Doctorate |