Central Sensitization-Based Classification for Temporomandibular Disorders: A Pathogenetic Hypothesis

Abstract

Dysregulation of Autonomic Nervous System (ANS) and central pain pathways in temporomandibular disorders (TMD) is a growing evidence. Authors include some forms of TMD among central sensitization syndromes (CSS), a group of pathologies characterized by central morphofunctional alterations. Central Sensitization Inventory (CSI) is useful for clinical diagnosis. Clinical examination and CSI cannot identify the central site(s) affected in these diseases. Ultralow frequency transcutaneous electrical nerve stimulation (ULFTENS) is extensively used in TMD and in dental clinical practice, because of its effects on descending pain modulation pathways. The Diagnostic Criteria for TMD (DC/TMD) are the most accurate tool for diagnosis and classification of TMD. However, it includes CSI to investigate central aspects of TMD. Preliminary data on sensory ULFTENS show it is a reliable tool for the study of central and autonomic pathways in TMD. An alternative classification based on the presence of Central Sensitization and on individual response to sensory ULFTENS is proposed. TMD may be classified into 4 groups: (a) TMD with Central Sensitization ULFTENS Responders; (b) TMD with Central Sensitization ULFTENS Nonresponders; (c) TMD without Central Sensitization ULFTENS Responders; (d) TMD without Central Sensitization ULFTENS Nonresponders. This pathogenic classification of TMD may help to differentiate therapy and aetiology.

Standard Correction of Vision Worsens EMG Activity of Pericranial Muscles in Chronic TMD Subjects

“…ese results are consistent with accumulating evidence that indicates that subjects suffering from TMD exhibit dysregulation of the systems that control the response of the autonomous and somatomotor systems to sensory stimuli [36]. Furthermore, it has been hypothesized that this dysregulation in TMD patients represents a form of CS [37][38][39][40][41]. In fact, our CSI data indicate that TMD subjects receive high scores, and this is consistent with a role for central involvement that is not observed in control subjects.…”

“…In fact, our CSI data indicate that TMD subjects receive high scores, and this is consistent with a role for central involvement that is not observed in control subjects. In previous studies of central dysregulation in TMD, a notable observation is that the pupil system of TMD subjects responds in a dysregulated manner to teeth clenching in response to administration of ultra-low-frequency transcutaneous electrical nervous stimulation (ULF-TENS) with sensory amplitude, which represents a central action mechanism [27,37,[42][43][44]. In the present study, opening of the eyes was found to have a significant effect on EMG values only when TMD subjects opened their eyes while wearing glasses that provided standard eye correction.…”

The central sensitization inventory: A user’s manual

“…A separate study with the French CSI found even better sensitivity (95%) and specificity (90%) with distinguishing between fibromyalgia subjects and acute ankle pain and control subjects. This 40‐point cut‐off score has been recommended as one component of an algorithm for helping to identify CS‐related pain (vs. neuropathic and nociceptive pain) in generalized chronic pain (Nijs, Malfliet, Ickmans, Baert, & Meeus, ; Nijs, Torres‐Cueco et al., ) and low back pain subjects (Nijs, Apeldoorn et al., ), and for classifying of temporomandibular joint disorder subtypes (Monaco, Cattaneo, Marci, Pietropaoli, & Ortu, ). Most recently, five severity levels have been developed to help aid in the clinical interpretation of the CSI (subclinical = 0–29; mild = 30–39; moderate = 40–49; severe = 50–59; and extreme = 60–100) (Neblett, Hartzell, Mayer, Cohen, & Gatchel, ).…”

Intimate partner violence and temporomandibular joint disorder

“…The aetiology of TMD is multifactorial in nature, with risk factors thought to range from; individual genetic and sex-based (more common in females) factors, dental related causes including occlusion issues and bruxism, to stress, depression and anxiety related states [5]. There has been evidence to suggest that patients who have experienced TMD, may also present with functional and structural changes in the thalamus, somatosensory cortex and some have dysfunction in the pain inhibition systems [6]. Of those patients who present with chronic pain initiated by TMD, some have an increase in generalised pain sensitivity, which can be characteristic of central sensitisation of the nervous system [7].…”