On Growth of the Canine Mandible

Abstract

An investigation is described into mandibular growth in the Dog (Canis familiaris). The growth Patterns were identified by the use of the fluorescent intra-vital bone marking dye Di-Carboxymethyl Amino-methyl Fluorescein. The outlines of structures found in serial sections cut from the jaws were recorded in a numerical form on punched paper tape by tracing on an electronic X-Y co-ordinate plotting table. A series of computer programmes were developed to use the data on the paper tapes to assemble three dimensional reconstructions of the original jaws in the memory store of a computer. The reconstructions were stored on magnetic tape and used for subsequent analysis and measurement. Mandibular growth was studied in three Ways. First by computer drawn plots of the original sections. Secondly by computer derived longitudinal plots of jaw structure. Finally by measurement of the volumes of the jaws, the structures within the jaws, and of the bone laid down during the experimental period.