James M. Lieberman

A comparison of clinical examination, history, and magnetic resonance imaging for identifying orthodontic patients with temporomandibular joint disorders

The temporomandibular joint (TMJ) status of 51 juvenile orthodontic patients was assessed with magnetic resonance imaging (MRI), clinical examination, and questionnaire data. The results of this study demonstrated that the prevalence of anterior displacement of the meniscus was 11.8% (6 of 51) as assessed by MRI. Clicking or pain in the TMJ area was found in 9.8% (5 of 51) of the subjects by clinical exam, and 19.8% (10 of 51) of the subjects had a history of pain or clicking of the TMJ. Three subjects had a positive MRI and a negative history and clinical examination. However, all subjects with positive MRI findings had a history of other risk factors known to be associated with TMJ internal derangement (TMJ-ID). Therefore practitioners should use a history form and a clinical examination technique that includes a broad range of signs and symptoms of temporomandibular disorders (TMD) to identify patients who may have abnormal condyle disk relationships and be at risk for TMD. Clicking and pain in the TMJ helped identify only one half of the patients with abnormal condyle-disk relationships in this study population. Future cephalometric studies will monitor the effects of abnormal condyle disk relationships on facial growth during orthodontic treatment.

Computed tomography of diverticulitis

Computed tomography (CT) is capable of imaging diverticulitis of the colon. Localized wall thickening, soft tissue density in the pericolic fat, and large soft tissue masses that may or may not contain gas have been observed in diverticulitis. Because of its noninvasive nature, CT may have an advantage in the acute phase of diverticulitis when there may be reluctance to do a barium enema. More experience will be needed to see if CT will be predictive of a need for surgery.

Measurement standards for the prevertebral region in the lateral soft-tissue radiograph of the neck

One hundred thirty-one lateral soft-tissue radiographs of the neck, taken over a 6-month period, were reviewed. Eighty-six radiographs were normal. The mean prevertebral soft-tissue thickness in the posterior-anterior dimension for each normal radiograph was measured. The mean thickness in the retropharyngeal region ranged from 6.2 mm in the infant to 3.7 mm in the adult, while the mean thickness in the retrotracheal region ranged from 9.2 mm in the preschool group to 12.1 mm in the adult.

Use of three-dimensional computerized tomography in the diagnosis of an obstructed coronoid process

The principles of three-dimensional computerized tomography are discussed. An unusual case of an iatrogenically induced coronoid obstruction is presented with the three-dimensional computerized tomograph as an integral tool in its diagnosis.