DEVELOPMENT OF THE SPHENOIDAL SINUSES AND ETHMOIDAL CELLS IN AXIAL COMPUTED-TOMOGRAPHY

Exact knowledge of age- and sex-related development of the paranasal s inuses is essential to assess their role in infantile diseases in the midface region. Moreover it helps to minimize the risk in case of ther apeutic intervention. Methods/Patients: On the basis of more than 5600 axial computed tomographic images (CT images) we evaluated the sex-re lated size (width and length) and evidence of the different sinuses fr om birth to age 25 focussing on the central part of the paranasal sinu ses, the ethmoidal cells, and the sphenoidal sinuses. Results/Conclusi ons: The sphenoethmoidal complex is of special interest in early ages since it is already completely developed in newborns (ethmoidal cells: 94% for both sexes) or at least shows a rapid development during the first decade. After age 8, both sinuses are almost regularly represent ed on CT with identical percentages as an indication of common origin. This is confirmed by only slight differences in size between the two sexes (ethmoidal cells: 5,7-10,1%; sphenoid sinuses: 5,4-9,7%) after t ermination of expansion and by similar periods of expansion (ethmoid c ells: until age 10, female, to 14, male and female in length; sphenoid al sinuses: until age 14, female, to 15, male and female) which partly differ from the other sinuses. However, the difference between male a nd female sinuses is statistically significant primarily at later ages (age 25: length of sphenoidal sinuses: p<0,0001/width of ethmoidal ce lls: p = 0,0117/length of ethmoidal cells: p = 0,0072). The definitive size of the ethmoidal cells (male: width 16.4 mm x length 40.7 mm; fe male: 14.9 mm x 38.5 mm) agrees with the results obtained from anatomi c and radiologic studies. In contrast, we found substantial variabilit y in both directions (up to 214%) for the sphenoidal sinuses. Since on almost 60-70% of the CT images the intersphenoidal septum was not rep resented, we can provide more detailed data about the whole sphenoidal complex (male: width 31.0 mm x length 24.5 mm; female: 29.4 mm x 26.9 mm). In conclusion, our findings agree with the data from other studi es using different methods. Moreover we can determine size of the diff erent sinuses at any time between birth and age 25 for both sexes. The ethmoidal cells and the sphenoidal sinuses are highly significant in early infantile paranasal sinus diseases.