Longitudinal Multilevel Modeling of Facial Pain, Muscle Tension, and Stress

Abstract

The role of masticatory muscle activation on pain in temporomandibular muscle and joint disorders (TMJD) is controversial. This single-group, prospective panel study examined the relationships among masticatory muscle tension, emotional distress, and TMJD pain in a sample of 7,023 observations obtained from 171 individuals using longitudinal multilevel modeling. Three main hypotheses were tested. The first posited that emotional distress and muscle tension directly influenced pain (hypothesis 1a: Distress → TMJD Pain; hypothesis 1b: Muscle Tension → TMJD Pain). The second posited that emotional distress directly influenced muscle tension (Distress → Muscle Tension), and the third posited that the effect of emotional distress on pain was mediated by muscle tension (Distress → Muscle Tension → TMJD pain). We also examined the fit of the data to possible alternative models. All the data used in this study were collected via an experience sampling methodology. The fit of the preferred models was better than that of the alternative models, with the preferred models explaining large proportions of the data, especially for level 2 variance (hypothesis 1a = 41% variance; hypothesis 1b = 69% variance; hypothesis 2 = 48% variance). In the mediation model, the addition of muscle tension to the model reduced the impact of emotional distress. The findings support a causal role for masticatory muscle tension in TMJD pain. Clinically, the results suggest that addressing tension and other oral parafunctions in those diagnosed with TMJDs should be an important part of the conservative, noninvasive care of individuals diagnosed with the myofascial pain or arthralgia of TMJD.

International consensus on the assessment of bruxism: Report of a work in progress

“…Indeed, a variety of conditions may interact with bruxism (and with each other) in the clinical setting, thus influencing the particular degree of bruxism that leads to a negative health outcome. For instance, whilst prolonged clenching can be a very plausible overload mechanism for the masticatory muscles and temporomandibular joints, 40 once masticatory muscle fatigue or pain sets in, adaptation may lead to a reduction of masticatory mus-cle activity, 41,42 thus making it impossible to establish a clear cut-off for the presence of fatigue or pain.…”

Frequency of awake bruxism behaviours in the natural environment. A 7‐day, multiple‐point observation of real‐time report in healthy young adults

“…Ecological momentary assessment has been already proven reliable in the research setting to assess a variety of oral behaviours, even including the role of jaw muscle tension as a predictor for facial pain . Nonetheless, EMA‐based data on AB are fragmental and limited to a few investigations on selected behaviours, such as teeth clenching and teeth contacting habits .…”

Management of temporomandibular joint disorders: A surgeon's perspective

“…Myofascial pain and dysfunction is by far the most prevalent . It is primarily a muscle disorder resulting from oral parafunctional habits such as clenching or bruxism that is sometimes related to psychogenic disorders such as headache, fibromyalgia, chronic back pain and irritable bowel syndrome with stress, anxiety and depression being the key features . Internal derangement is used to describe a temporomandibular disorder where there is an abnormal position of the articular disc resulting in mechanical interference (i.e., clicking) and restriction of the normal range of mandibular activity (i.e, limited mouth opening) or even hypermobility that may result in jaw dislocation .…”

“…The aetiology of the most common types of temporomandibular disorders is complex and remains largely unresolved . Psychogenic factors have been implicated but, like trauma and malocclusion, these are often considered as exacerbating factors rather than the primary cause of temporomandibular disorders . Hence, there is speculation that only certain patients who are vulnerable to temporomandibular disorders will develop pain and dysfunction following an exacerbating event such as acute physical or psychological trauma, which suggests perhaps an underlying genetic predisposition to TMD which remains an enigma …”

“…Restricted jaw function encompasses a limited range of mandibular movements in all directions. Like pain, restricted jaw function causes a great deal of anxiety for the patient who faces difficulties in everyday activities such as eating and speaking . Patients may describe their limited jaw opening as caused by either a generalised tight feeling (that is most likely a muscular disorder) or the sensation that the jaw suddenly “catches” or “gets stuck” which is usually related to the joint, in particular, internal disc derangement …”