Few topics in orthodontics have sparked as much debate, or confusion, as the relationship between occlusion and temporomandibular disorders (TMD).
For decades, clinicians were taught that malocclusion was a key risk factor, that orthodontic treatment could precipitate or correct TMD, and that achieving “ideal occlusion” was central to patient comfort.
But what if this long-held belief was never truly supported by strong scientific evidence?That’s the central message of the 2025 Sheldon Friel Memorial Lecture, delivered by Prof. Ambra Michelotti and published in the European Journal of Orthodontics. The paper offers one of the clearest overviews to date of the evolving understanding of TMD, replacing outdated assumptions with evidence-based clarity.
A Historical Misunderstanding
TMD has been linked to occlusion for nearly a century. The idea began with Costen’s syndrome in the 1930s, which attributed pain and dysfunction in the temporomandibular joint to malocclusion and loss of vertical dimension.
Through the following decades, orthodontic gnathology expanded that concept, asserting that “occlusal harmony” was essential to joint health. When a high-profile legal case accused an orthodontist of causing TMD through treatment, the controversy intensified, fuelling public anxiety and altering how practitioners discussed orthodontics with patients.
However, Michelotti’s review reminds us that belief does not equal evidence. Decades of research have since shown that the supposed cause-and-effect link between occlusion, orthodontics, and TMD is weak, inconsistent, and often clinically irrelevant.
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The Modern View: A Biopsychosocial Framework
Rather than viewing TMD as a purely mechanical, tooth-driven problem, current evidence supports a biopsychosocial and neurophysiological perspective. This framework recognises that pain and dysfunction are influenced not only by occlusal factors, but also by:
- Pain perception and neuroplasticity
- Parafunctional habits
- Psychological stress and anxiety
- Hypervigilance and learned pain behaviour
In other words, the way a patient’s nervous system processes pain and adapts to changes may matter far more than the occlusal scheme itself.
Michelotti argues that most patients are remarkably capable of adapting to minor occlusal changes, whether from orthodontic treatment or natural dentoalveolar development. Problems arise mainly in individuals whose pain modulation or stress response is impaired — a small subset of patients who require a more nuanced approach.
Implications for Orthodontic Practice
For orthodontists, this shift in understanding has major clinical implications.
First, with up to 40% of patients with malocclusion showing some signs of TMD, screening should be a standard part of pre-treatment assessment. Michelotti recommends the 3Q/TMD questionnaire, a validated three-question screening tool that is both quick and reliable in identifying potential TMD symptoms.
Second, the paper urges clinicians to adopt conservative, reversible, and patient-centred management strategies. That means avoiding irreversible occlusal adjustments or pursuing the idea of “perfect occlusion” as a cure for TMD symptoms that may originate elsewhere.
Finally, effective communication is crucial. Explaining to patients that orthodontic treatment does not cause, prevent, or cure TMD helps manage expectations and reduce anxiety — both of which can improve outcomes.
A Modern Clinical Message
Michelotti’s message is both liberating and reassuring. Orthodontics cannot cause, cure, or prevent TMD, but it can and should be practised safely in patients with or without pre-existing TMD symptoms. The focus should shift from occlusal perfection to patient adaptability, psychosocial context, and overall functional wellbeing.
By embracing a biopsychosocial understanding of TMD, orthodontists can deliver safer, more individualised care, and move away from outdated mechanical theories that no longer stand up to scientific scrutiny.
Limitation
As a narrative lecture-based review, this paper synthesises existing evidence rather than presenting new trial data. However, Michelotti’s interpretation of decades of research provides one of the most balanced and clinically applicable frameworks available today.
What This Means for Clinical Practice
- Orthodontics neither causes nor cures TMD.
- Always screen for symptoms before starting treatment using validated tools such as 3Q/TMD.
- Focus on reversible, conservative management when symptoms arise.
- Avoid irreversible occlusal alterations without clear diagnosis.
Prioritise patient education and communication — understanding the why behind symptoms is key to long-term success.
About Dr. Jamal
Dr. Jamal Giri is an orthodontist and associate professor at B.P. Koirala Institute of Health Sciences in Nepal. He obtained his orthodontic training from the Institute of Medicine, Tribhuvan University, Nepal, in 2014.
Currently pursuing a PhD at the University of Adelaide, Dr. Jamal’s research focuses on the genetic and environmental factors influencing malocclusion development. He also holds a postgraduate certificate in clinical education from the University of Edinburgh and a master’s in medical education from the University of Nottingham.
Dr. Jamal teaches on the Diploma in Orthodontics and Dentofacial Orthopaedics at the London Dental Institute.
Read More
Michelotti A. Sheldon Friel Memorial Lecture 2025—Orthodontics and Temporomandibular Disorders: evolving views on risk factors, diagnosis, and management. European Journal of Orthodontics. 2025;47(6):cjaf092.
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