Читать книгу Temporomandibular Disorders - Robin J. M. Gray - Страница 72

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).

Figure 3.11 (a) A stereo‐stethoscope used for listening to the temporomandibular joint. (b) Stereo‐stethoscope in use allowing auscultation and comparison of one TMJ with the other.

(M. Ziad Al‐Ani, Robin J.M. Gray.)

The apparatus provides a method of detecting TMJ sounds and determining whether they emanate from the right or left side or are bilateral. It should be remembered that it is sometimes extremely difficult to determine which side a click is coming from by listening with a stethoscope because of the ‘echo’ and reverberation across the bones of the skull from the contralateral side. In addition, auscultation permits the clinician to detect the frequently softer closing click that is sometimes difficult to detect on joint palpation alone.

For the diagnosis of disc displacement with reduction and to assist in determining a suitable treatment plan, it is important to determine whether the click can be eliminated by protrusion of the mandible. At the chair side, the patient is asked to protrude the mandible and then perform a series of opening and closing mouth movements, usually with the upper and lower incisors in an ‘edge‐to‐edge’ relationship. The click will be present during the first movement but, if the click is eliminated in subsequent movements in this protrusive mandibular position, the diagnosis of disc displacement with reduction is highly probable and it is likely that provision of a suitable splint design will reduce or eliminate the symptoms.