[Selective tomography in the study of the temporo-mandibular joint. (author's transl)]

The majority of temporo-mandibular pains and dysfunction can be related directly or indirectly to the occlusal relationship of the teeth. The first manifestation is a slight reduction of the interarticular space, that must be early diagnosed, to prevent organic changes. Tomography is the one technique able to give a exact information of temporo-mandibular joint. But if we ask to that examination to detect very slight change of the interarticular space, the technique must be accurate and established in function of morphology of the patient; we have observed great variations in direction of the axis of condyles from one person to the other, and even from one side to the other for the same subject. So that, the first stage of the roentgen examination will be a radiograph taken in submentovertical (Hirtz) position. We measure the angle formed by the axis of each condyle and the sagittal median plane. The maim beam wil be directed in the axis of the condyle for sagittal tomography and perpendicularly for frontal tomography. It is important to state precisely that for tomography "closed mouth", the patient must be in terminal occlusion during the whole examination. For tomography "open mouth" we place a wedge between dental arches.