COMPARISON OF DENTAL STATUS AND ORAL FUNCTION BETWEEN THE ELDERLY WITH AND WITHOUT TEMPOROMANDIBULAR DISORDERS muscles without clenching ” ( 7.5 % and 1.8 %, p = 0.036 ) and “ Eating between meals that food requires chewing ” ( 43.2 % and 57.1 %, p = 0.026 ). The TMD group also tended to have more prevalent parafunctions of “ Press tongue forcibly against teeth ” and “ Place tongue between teeth ” ( p = 0.067 and p = 0.079 , respectively ) compared to the non-TMD group . No significant differences were found in the mean number of parafunctional items between the two groups ( p = 0.928 , Table 4 ).
4 . Discussion The current study highlighted a different dental status between the TMD elderly and non-TMD elderly groups . Our TMD elderly group lost an average of 9.6 ± 8.6 teeth and were higher than the non-TMD group ; in other words , our study was in accordance with previous findings indicating that there was association of TMD with missing teeth [ 16 – 18 ]. When individuals lose many teeth , their chewing pattern can be changed and have impact on masticatory performance . Numerous studies indicated that chronic unilateral chewing increases the risk of TMD [ 18,19 ]. In addition , tooth loss causes social limitations , psychological disorders , and reduces the quality of life , all of which have been regarded as factors contributing to TMD . The main finding of our study was that periodontal diseases have influence on TMD . PPD ≥ 4 mm indicates periodontal tissue destruction due to inflammation , while the CAL measurement estimates lifetime accumulated destruction of the periodontal attachment . These measures permit comparisons the severity of periodontal diseases between population groups . Our finding indicated that PPD and CAL were worse in the TMD group than in the non-TMD group . More than half of the TMD group had PPD ≥ 6 mm and over 70 % of those had the CAL ≥ 6 mm and excluded sextants . All these numbers were comparatively high compared to 42 % and 51.8 %, respectively , in the non-TMD group . In the elderly population , periodontal diseases are the most frequent cause of tooth loss ; therefore , TMD was significantly associated with both periodontal diseases and tooth loss in the current study . Gingival bleeding does not affect single tooth but can affect many remaining teeth in the mouth , but the TMD group had more missing teeth than the non- TMD . Therefore , the number of teeth with gingival bleeding was observed less in the TMD group in our study . Periodontal inflammation has been considered a potential risk factor for other diseases . Proinflammatory cytokines enhance the pathogenesis of periodontal diseases . Interleukin ( IL-1 ) and tumour necrosis factor alpha ( TNF-α ) represent proinflammatory cytokines that stimulate a number of events which occur during infection with periodontal pathogens . Graves et al . found a widespread presence of IL-1 and TNF in the connective tissue and loss of alveolar bone along with periodontal inflammation [ 20 ]. High levels of IL-1 and TNF-α are a response to the inflammatory process and they might penetrate into the TMJ synovial fluid and cause bone tissue resorption ; therefore , the degree of endogenous cytokine control is important for bone tissue destruction in the TMJ structure [ 21 ].
Table 4 . Comparisons of parafunctional behaviours between the TMD and non-TMD elderly .
TMD Non-TMD Parafunctional habit ( n = 146 ) ( n = 112 ) p- value a n % n %
Sleep activities
Clench or grind teeth when asleep
Sleep in a position that puts pressure on the jaw
Waking activities
Grind teeth together during waking hours
Clench teeth together during waking hours
Press , touch , or hold teeth together other than while eating
Hold , tighten , or tense muscles without clenching
Hold or put jaw forward or to the side
Press tongue forcibly against teeth
16 11.0 9 8.0 0.431
57 39.0 44 39.3 0.968
9 6.2 7 6.3 0.977
12 8.2 10 8.9 0.840
28 19.2 24 21.4 0.655
11 7.5 2 1.8 0.036 *
17 11.6 11 9.8 0.641
31 21.2 14 12.5 0.067
Place tongue between teeth 32 21.9 15 13.4 0.079
Bite , chew , or play with your tongue , cheeks or lips
Hold jaw in rigid or tense position
Hold between the teeth or bite objects
27 18.5 19 17.0 0.750
17 11.6 10 8.9 0.480
8 5.5 8 7.1 0.583
Use chewing gum 20 13.7 19 17.0 0.468
Play musical instrument that involves use of mouth or jaw
4 2.7 1 0.9 0.392
Lean with your hand on the jaw 50 34.2 36 32.1 0.722 Chew food on one side only 82 56.2 63 56.3 0.989
Eating between meals that food requires chewing
63 43.2 64 57.1 0.026 *
Sustained talking 67 45.9 49 43.8 0.732 Singing 33 22.6 34 30.4 0.159 Yawning 48 32.9 43 38.4 0.353
Hold telephone between your head and shoulders
Number of parafunctional habits
10 6.8 6 5.4 0.622
0 15 10.3 12 10.7 1 – 4 72 49.3 54 48.2 5 – 8 36 24.7 31 27.7 ≥ 9 23 15.8 15 13.4
0.921
Mean number of 4.40 ± 3.71 4.36 ± 3.23 0.928 parafunctional habits ± SD b a
Chi-square test , b Student ’ s t-test , * statistically significant . TMD : Temporomandibular disorders , SD : standard deviation .
Regarding peripheral sensitization , nociceptive afferents in the periodontal ligament could be activated when periodontal tissues under pressure become painful due to bacterial infections . Afferent nerve fibres carry the impulse to the trigeminal spinal tract nucleus and stimulate interneurons . The efferent fibres of the inhibitory interneurons synapse , which lead to the elevator muscle reaction , bring the teeth away from the noxious stimulus [ 22,23 ]. These repetitions might cause masticatory muscle dysfunction . The
Original Article
Stomatology Edu Journal
121