Four Essential Checks for Temporomandibular Joint Evaluation

The temporal mandibular joint is a prone area for inflammation, primarily due to muscle imbalance. Once inflammation occurs in this area, it is essential to promptly visit a hospital for a detailed examination. Typically, four main temporal mandibular joint examination procedures are conducted, including facial and joint mobility examination, masticatory muscle examination, mandibular movement examination, and occlusion relationship examination.

1. Facial and Joint Mobility Examination

The temporal mandibular joint has a close relationship with the jawbones, particularly the mandible. Therefore, during the examination of the temporal mandibular joint, it is crucial to observe whether the face is symmetrical on both sides, the size and length of the joint area, mandibular angle, mandibular ramus, and mandibular body are normal, and if both sides are symmetrical. Additionally, checking if the chin is centered and if the lower one-third of the face is harmonious is essential. There are two methods for condylar mobility examination: placing the index or middle fingers on both sides of the tragus in front of the ear, outside the condyle, and asking the patient to perform opening and closing movements to assess the condylar mobility; or inserting the little fingers into the external auditory canal and pressing against the anterior wall of the canal for palpation to understand the condylar mobility and sense of impact, while comparing both sides to assist in the diagnosis of joint diseases.

2. Masticatory Muscle Examination

Examination of the contractile force of the masticatory muscles, such as the temporal muscle and masseter muscle, involves palpating for pain and observing symmetry and coordination on both sides. Within the oral cavity, the anatomic locations of the masticatory muscles can be traced to palpate the anterior portion of the temporal muscle (at the anterior edge of the mandibular ramus, upward), the inferior head of the lateral pterygoid muscle (above the maxillary tuberosity), and the inferior portion of the medial pterygoid muscle (posterior and inferior to the lingual side of the mandibular molars and the medial aspect of the mandibular ramus). Comparisons between the left and right sides are made to detect any tenderness or other abnormalities.

3. Mandibular Movement Examination

Through the patient's opening and closing movements, protrusion, and lateral movements, this examination checks if the joint function is normal, presence of pain, clicking, or other noises. It also observes the timing, nature, frequency, and loudness of any clicking sounds. Consistency in joint mobility between both sides, presence of deviation, normality of the opening degree and pattern, and any abnormalities such as joint locking during opening and closing movements are also assessed.

4. Occlusion Relationship Examination

Occlusion abnormalities are one of the causes of temporal mandibular joint disorders. During the occlusion relationship examination, it is first necessary to assess if the occlusion is normal and whether there are any disorders. The overbite, overjet, longitudinal curve of occlusion, and compensatory curve should also be checked for normality. The uniformity and degree of tooth wear should be evaluated. Additionally, the presence of dental caries, periodontal disease, missing teeth, and tooth inclination should be examined to provide objective evidence for the diagnosis and treatment of joint diseases.