is thought to indicate the presence of inflammation in the capsule. Anatomically, this area is not as well innervated as the posterior part of the joint, and more useful information can be obtained by intra‐auricular palpation.
Intra‐auricular palpation
TMJ pain and tenderness are mainly related to the area of the posterior bilaminar zone of the disc and the posterior aspect of the capsule. Examination of this area can be achieved more readily and reliably by intra‐auricular palpation. This involves placing the little finger in the external auditory meatus on one side at a time and applying gentle forward pressure, while asking the patient to open and close the mouth (Figure 3.7).
Figure 3.7 Intra‐auricular palpation of the temporomandibular joint.
(M. Ziad Al‐Ani, Robin J.M. Gray.)
Be aware that, if there is acute disc displacement, this method of examination can be very uncomfortable for the patient.
Examination by manipulation of the mandible
With the patient relaxed, the mandible is gently manipulated posteriorly by gentle pressure applied to the symphysis region. This is a method of eliciting tenderness in the posterior bilaminar zone by compressing this area of tissue between the distal part of the condyle and the fossa if there is disc displacement. Again, this can be very uncomfortable so only gentle manipulation should be used.
Mandibular (masticatory) muscle tenderness
Masseter muscle
This muscle can be palpated bimanually by placing one finger intraorally and another externally on the cheek. The origin of the masseter muscle along the anterior two‐thirds of the zygomatic arch is the area frequently found to be tender (Figure 3.8a). There is often a palpable difference between one masseter and the other in that, on the affected side, the muscle tends to be ‘bunched up’ and quite easy to palpate, whereas on the unaffected side the muscle has a soft rubbery consistency and the margin is less easy to define. The insertion of the masseter on the outer aspect of the angle of the mandible should be palpated (Figure 3.8b), but this is less frequently found to be tender.
Figure 3.8 (a) Palpation of the origin and (b) insertion of the masseter.
(M. Ziad Al‐Ani, Robin J.M. Gray.)
Temporalis muscle
This muscle can be examined by palpating its origin extraorally. Ask the patient to clench the teeth together and the outline of the muscle origin can be identified, especially the anterior fibres. Digital palpation can be preformed between the superior and inferior temporal lines extending posteriorly (Figure 3.9).
Figure 3.9 Palpation of the anterior vertical fibres of the temporalis.
(M. Ziad Al‐Ani, Robin J.M. Gray.)
The anterior, more vertical fibres comprise the main elevator muscle of the jaw and are most commonly tender on palpation. The posterior fibres are almost horizontal in orientation and less frequently tender because their main function is to retrude the mandible.
It is suggested that the insertion of the temporalis muscle into the anterior margin of the coronoid process can be palpated intraorally by placing the little finger on the anterior border of the ramus and running it upwards, but this is not a reliable test because this is an uncomfortable and inaccessible area to try to access even in those who do not have muscle tenderness.
Lateral pterygoid muscle
This muscle is inaccessible to manual palpation so palpation for tenderness lacks validity and reliability and is difficult if not impossible to perform.
A more reliable technique is to examine the response to resistance. The patient is asked to open the mouth. The examiner's hand is placed under the patient's chin and pressure is applied to try to close the mouth while the patient tries to resist (Figure 3.10a). This results in a more reliable test because the muscle is fixed. If there is tenderness in the lateral pterygoid muscle, this test will produce pain in the preauricular region. The same can be done by resisting lateral mandibular movement (Figure 3.10b).
Figure 3.10 (a) Examination of lateral pterygoid muscle against vertical resisted movement; (b) Examination of lateral pterygoid muscle against lateral resistance.
(M. Ziad Al‐Ani, Robin J.M. Gray.)
If the patient were, for instance to move the mandible to the right and this movement were resisted, left preauricular pain would arise if there was lateral pterygoid tenderness on the left.
Joint sounds
Clicking
Clicking from the TMJ is often felt by the patient but can be inaudible to the examiner. A click can occasionally be felt by palpating the TMJ in the preauricular region but is more often detected on intra‐auricular palpation.
If joint sounds are to be listened for, a reliable method is use of a stereo‐stethoscope. This consists of a standard earpiece with two outlets, rather than one, and two tubes, each of which is connected to a separate diaphragm (Figure 3.11).
