Temporomandibular Disorder (TMD) Assessment Made Simple

Jaw pain and/or functional restriction can significantly affect patients’ daily lives. As physiotherapists, we play a leading role in assessing and managing temporomandibular disorders (TMD), yet many physios lack the confidence in managing these conditions, often referring to specialised TMD physios.

While it’s important to know our scope, the management of TMD doesn’t have to be left to specialised physios—particularly when there are evidence-based classification systems available to help guide our clinical reasoning and treatment planning. With key insights drawn from expert TMD physio Lucy Butler’s excellent Masterclass, this blog outlines the TMD classification system that every physio should be using in practice:

If you want to learn exactly how an expert assesses and manages TMDs, watch Lucy Butler’s full Masterclass HERE.

Overview

TMD is a collective term used to describe painful or non-painful conditions affecting the temporomandibular joint (TMJ), masticatory muscles, and associated structures. It includes a wide range of muscular and articular pathologies that can present as jaw pain, facial pain, clicking, locking, headaches, ear symptoms, or functional restriction.

Prevalence data shows that TMD affects approximately 4% of the population annually, with 65% of those cases being recurrent. Women are disproportionately affected, with a 4:1 female-to-male ratio (1).

Causes are often multifactorial. Macrotrauma (e.g., dental surgery, intubation, or acute jaw injury) may trigger initial symptoms, while microtraumas, such as bruxism, clenching, nail biting, or gum chewing, serve as common perpetuating factors. Importantly, research also points to a strong biopsychosocial influence, with co-existing anxiety, depression, and chronic pain syndromes playing a significant role in chronic TMD presentation.

To bring clarity and structure to the assessment of TMD, the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were developed (2). This framework allows physios and other healthcare professionals to categorise TMD conditions into meaningful subtypes which help to tailor their intervention approach. The framework consists of two axes:

Axis I – Physical diagnoses

This focuses on the clinical and physical aspects of TMD, offering a standardised diagnostic system for identifying specific myogenous and arthrogenous subtypes. Each diagnosis has clear inclusion criteria based on patient history and physical examination findings, including pain location, provocation testing, and functional limitations.

Axis II – Psychosocial assessment

This recognises the psychological and behavioural influences on TMD. It includes validated tools that assess pain-related disability, anxiety, depression, somatisation, coping behaviours, and social functioning. This axis is particularly important in cases where symptoms are chronic, widespread, or unresponsive to mechanical treatment alone.

The focus of this blog is to outline the myogenous and arthrogenous subtypes. However, it’s important to keep in mind that understanding both axes is essential for building a complete clinical picture and avoiding a narrow, purely biomechanical approach.

Myogenous subtypes

Myogenous TMD refers to disorders involving the masticatory muscles, and it is one of the most common TMD subtypes. The DC/TMD further classifies myogenous disorders into:

1 – Myalgia

Key criteria to assess for are:

• Subjective history: pain in the jaw, temple, in the ear or front of ear AND pain modified with jaw movement.
• Clinical examination: confirmation of pain location at temporalis or masseter AND patient reports familiar pain in the temporalis or masseter muscles with at least one of palpation of the muscles OR maximum unassisted or assisted jaw opening movements.

2 – Myofascial pain

This subtype includes the same clinical features as local myalgia the key difference in criteria is the patient also reports pain at a site beyond the boundary of the muscle being palpated, for example, temporalis may refer to the teeth or the eye, while masseter pain might radiate to the ear or lower jaw.

Sensitivity and specificity for these diagnoses are high, making them clinically reliable – as long as you complete an accurate assessment, of course! See Lucy explain how she palpates important structures during her objective examination in this clip from her Masterclass:

Arthrogenous subtypes

Arthrogenous TMD includes disorders related to the articular structures of the jaw. These are divided into:

1 – Arthralgia

• Subjective history: pain in the jaw, temple, ear or front of ear AND pain modified with jaw movement, function or parafunction.
• Clinical exam: familiar pain in the TMJ with palpation of lateral pole, or around the lateral pole OR pain with maximum unassisted or assisted opening, right or left lateral or protrusive movements.

2 – Subluxation

This is a hypermobility issue where the condyle translates excessively beyond the articular eminence, leading to temporary inability to close the jaw. Patients may report “locking open” and needing to self-manipulate to restore function.

• Subjective history: in the past 30 days feeling like the jaw is locking or catching in wide opening position (even for a moment) AND inability to close the mouth from wide open position without self-manoeuvre.
• Clinical exam: inability to return to normal closed mouth position without performing self-manoeuvre (however this is not required for diagnosis).

3 – Disc displacement (with or without reduction)

This condition is marked by anterior misalignment of the articular disc. See Lucy explain these subtypes in this snippet from her Masterclass:

1. Disc displacement with reduction: Audible clicking during opening/closing, often without functional limitation. Intermittent locking may also occur with disc displacement with reduction. Imaging (e.g. MRI) remains the gold standard for confirmation, though clinical diagnosis is often sufficient. Keep an eye out for:
   • Subjective history: in the past 30 days TMJ noises present with jaw movement or function OR patient reports any noise present during clinical exam.
   • Clinical examination: clicking, popping and/or snapping noise during both opening and closing movement detected with palpation during at least ⅓ repetitions of jaw opening and closing movements OR clicking, popping and/or snapping noise detected with palpation during at least ⅓ opening or closing movements AND at least ⅓ repetitions of right or left lateral or protrusive movements.
2. Without reduction: this can include limited opening subtype (usually <40mm) and without limited opening subtype (opening ≥40mm):
   • Subjective history: Jaw locked so mouth would not open all the way AND limitation in jaw opening severe enough to interfere with ability to eat.
   • Clinical examination: maximum assisted opening (passive stretch) movement including vertical incisal overlap <40mm (limited opening).

4 – Degenerative joint disease

This is a disorder involving the TMJ characterised by deterioration of the articular tissue with osseous changes in the condyle and/or articular eminence. The sensitivity/specificity of clinical tests are not as high for this condition, but keep a look out for:

• Subjective history: 30 days of any TMJ noises present with jaw movement or function OR patient report of any noise present during clinical examination.
• Clinical examination: crepitus detected with palpation during at least one of: opening, closing, right or left lateral or protrusive movements.

There you have it, a structured approach to assessment using the DC/TMD. Recognition of subtype is essential to prioritise intervention, and recognition hinges on accurate assessment. Watch Lucy explain how she assesses jaw movements in this video from her Masterclass:

Wrapping up

For physiotherapists working with orofacial pain (and those who are lacking confidence in the area… you’re not alone!), the DC/TMD system offers a clear, structured approach to classifying and diagnosing TMD. Understanding the myogenous and arthrogenous subtypes, along with their associated criteria, allows us to match treatment to pathology and enhance clinical outcomes. Most importantly, incorporating both physical and psychosocial components ensures we’re not just treating the jaw, but the whole person. If you’re not already applying DC/TMD in your assessments, this is your invitation to start.

If you want to know how Lucy Butler assesses and manages TMD, watch her full Masterclass HERE.