[The peculiarities of petrotympanic fissure topography in Costen syndrome and possible causes of its development].

A complex study of morphometric characteristics of the articular surfaces of the temporomandibular joint and the examination of the peculiarities of the petrotympanic fissure topography were performed on 138 samples of skulls of adult individuals with intact occlusion, complete anodontia and different forms of cranial skull (dolicho-, meso- and brachicranial). No distinct differences in studied parameters were found between the studied groups. However, in the hypsicranial group the petrotympanic fissure was found to pass more often through the medial third of the mandibular fossa, which may be a predisposing anatomical factor for Costen syndrome. Due to the fact that in anodontia the parameters characterizing the articular surfaces of the temporomandibular joint, are significantly changed, the immediate cause of the Costen syndrome are the changes of the articular surfaces of the temporomandibular joint, primarily the reduction in the size of mandibular condyle, which is accompanied by its pathological displacement and compression of the chorda tympani.

[Possibilities of a computer tomography and 3D-reconstruction in estimation of temporomandibulare joint in patients with the secondary lowered bite].

In considerable decrease of bite height the interposition of firm and soft tissues of temporomandibulare joint (TMJ) varied, its function was broken. By means of a computer tomography we estimated width of departments of the articulate crack. The increase in back articulate space was regarded at bite correction as optimum result of treatment. Measurements were made at use of multiplanar 2D-reconstruction in sagittal projections. At performance of volume (3D) reconstruction it was noticed that in patients with atypical change of interposition of TMJ elements prospective rotation of position of a head at performance of functional tests (research performance in position of the closed mouth and at bite restoration on silicone forms) was not caught. However, in these patients clinical improvement was noted in all cases. Use of 3D-reconstruction facilitate understanding of an arrangement of heads of lower jaw in cavities of joints, including with the use of functional tests. However, to estimate the minimum degrees of rotation of position of heads of articulate shoots was not obviously possible. Also measurements of width of an articulate crack weew not absolutely representative in comparison with interpretation of multiplanar 2D-reconstruction.