← Children 0–12
The TMJ and the facial growth pattern. In the 0–12 age group we do not simply straighten teeth. This is the time when we guide the growth of the upper and lower jaw – and the therapeutic window is limited and does not come back.
How does mouth breathing damage the TMJ?
Mouth breathing in early childhood is associated with unfavourable craniofacial features: mandibular retrognathia, a narrow, high-arched palate, lip incompetence and an increased mandibular plane angle.
The mechanism is simple: a mouth-breathing child lowers the jaw and carries the head forward. The tongue no longer rests on the palate – it loses its natural role as “scaffolding” for the upper jaw. The facial and masticatory muscles work asymmetrically. The condyle starts to sit incorrectly in the joint socket – setting off a chain of changes that is hard to reverse once growth is complete.
Clinical research indicates that mouth breathing – particularly in early childhood – is associated with unfavourable craniofacial features such as mandibular retrognathia, a narrow palate and an increased mandibular plane angle. Am J Orthod Dentofacial Orthop, 2025
RESEARCHER PROFILE
The research of Dr Kazumi Ikeda
Dr Kazumi Ikeda DDS – Nihon University, Tokyo · Diplomate of the American Board of Orthodontics · Author of “TMJ 1st Orthodontics” · Roth Study Club International Japan
Dr Ikeda is one of the world’s leading researchers on the relationship between TMJ status and the mandibular growth pattern. His MRI studies in children of pre-orthodontic age are a fundamental source of knowledge about when and how TMJ damage occurs.
302 temporomandibular joints were examined by MRI in 151 pre-orthodontic patients aged 6–15. A high prevalence of disc displacement was demonstrated, with a statistically significant increase in severity with age – the degree was significantly higher in the 10–12 group than in the 6–9 group (p < 0.01). Journal of Prosthodontics, 2014;23(5):397–401
The cause-and-effect chain
STEP 1
Mouth breathing
STEP 2
TMJ overload
STEP 3
Disc displacement
STEP 4
Disturbed mandibular growth
RESULT
Retrognathia · malocclusion · OSA
Bilateral non-reducing disc displacement in growing individuals inhibits mandibular growth on both sides, producing retrognathia. Growth inhibition was most pronounced during growth spurts. Bryndahl F. et al., Journal of Dental Research, 2006;85(12):1118–1123
What do we assess in a child’s TMJ?
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Clinical assessment of opening symmetry
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Palpation of the mandibular condyles
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Assessment of clicking and joint sounds
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Analysis of the growth pattern on the cephalogram
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In justified cases: CBCT or MRI to assess the position of the condyle and the articular disc
Sources: Ikeda K., Kawamura A., Ikeda R., J Prosthodont. 2014;23(5):397–401 · Bryndahl F. et al., J Dent Res. 2006;85(12):1118–1123 · Am J Orthod Dentofacial Orthop. 2025.
Keep it simple, smile.
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