1991 Volume 94 Issue 3 Pages 307-315
Morphological relation between the sphenoidal sinus and the petrous apex cell was studied using HRCT images obtained by 339 adults and 43 infants. The adults were classified into normal group(without chronic otitis media or its surgery)237 cases, and otitis group(chronic otitis media or its post. op.), 102 cases, The posterior extent of the sphenoidal sinus was evaluated in reference to the carotid canal, and the petrous apex cells were evaluated by their mode of distribution in the apex.
In the normal adults, no evident relation was seen between the posterior extent and the mode of distribution. Although adult normal female showed statistically significant better development of the posterior extent, sinus-cell relation was similar between both sexes. The adult. normal group and otitis group behave similarly by sinus-cell relation, i.e., no evident relation, although inhibited mode of distribution was seen by otitis group. When the adult and infant were compared, the sinus-cell relation was similar and the posterior extent suffered underdevelopment by infant.
The distance, between the posterior extension of the sphenoidal sinus and the apex cell at the medial-anterior tip of the petrous bone, is between 8…16mm and the contact of the both separated by thin bony wall(less than 0.5mm)was seen in 3 adult cases(0.9%).
Both the sphenoidal sinus and the petrous apex cells are under genetic influence of variable degree, separate genes seem to be at work, thus effecting no evident relation between the two.part from the internal or genetic influence, environmental or outer influence also affectsthe jevelopment of the two, less than the genetic. And the common factor as the inflammation might Wing about adverse effects upon the development of the two, as both the sinus and cells often suffer common underdevelopments.
The trans-sphenoidal approach to the petrous apex ls lndicated when the apex is already expanded and in contact with the sinus wall. Rare cystic lesions and primary cholesteatoma are reported as operated upon by this approach.
