Scaling properties of the frontal sinus in the African great apes--a clue to the role of the human paranasal sinuses.
The biology of scaling (allometry) can prove a useful tool in comparative anatomical studies. Amongst primates only the African Great Apes and Man possess a frontal sinus. The aim of this study was to identify the allometric properties of the frontal sinus in order to gain clues as to the role of the human paranasal sinuses. A measure of frontal sinus volume was calculated for fifty-seven Great Apes and then scaled against indicators of body size and nasal cavity volume. The results suggest that there are racial variations in frontal sinus size in the African Great Ape populations. This phenomenon mirrors the human condition. The scaling relationships identified in the study lend support to the hypothesis that the frontal sinus has a "structural" rather than a "functional" role.