Abstract
An attempt was made to study the role of the cartilaginous nasal septum in the growth of the upper face, which is related to one of the most important problems in orthodontics. The cartilaginous nasal septum of 25 growing rats was resected with an electric knife at 20 days of age. The control group consisted of nine rats. Measurements were taken on the serial roentgenographic cephalograms and dry skulls of both groups were prepared. Findings were as follows: l. The nasal, frontal, premaxillary and maxillary bones of the experimental group were shorter than those of the control, especially in the anteroposterior dimension. The width at the orbital and frontomaxillary regions was broader in the experimental group. 2. In the experimental group, the growth in the anterior part of the upper face (the orbital, nasal, alveolar and incisal parts) was dominantly inhibited and the change in the growth direction was downward, showing a downward deflection of the snout. 3. The mandible shifted backward and downward, caused by the change in the maxillary growth direction. A slight mesiocclusion of the molars was observed in the experimental group.
