TMJ Overview/anatomy

Question 1

What is the difference between TMJ, TMD, and orofacial pain?

Answer 1

TMJ: the temporomandibular joint itself

TMD: temporomandibular dysfunction (10-15% have b/w 20-40 yrs and women 4x more common)

Orofacial pain: pain in the face and jaw/mouth region

Question 2

What are the 4 proposed classifications for those with orofacial pain?

Answer 2

• primary headache/non-cervicogenic headache
• TM joint dysfunction
• Masticatory Muscle Disorder
• Cervicogenic headache

Question 3

What are some contributing factors to TMD?

Answer 3

• microtrauma
• malocclusion
• cervical spine (regional interdependence)
• hypermobility
• bad habits (bruxism, mouth breathing, nail biting)
• psychosocial factors

Question 4

Where does the articular disc sit in the TMJ and which muscle attaches to it?

Answer 4

• sits b/w the condyle of the mandible and the mandibular fossa
• the superior head of the lateral pterygoid

Question 5

What motions occur with opening of the TMJ?

Answer 5

• rotation then translation
• rolls posterior, slides anterior

Question 6

What muscles produce lateral excursion?

Answer 6

• ipsilateral temporalis and masseter
• contralateral medial/lateral pterygoids

Question 7

What are ROM norms for the TMJ?

Answer 7

Opening: 43mm
Lateral excursion: 9mm
Protrusion: 7mm