Roentgen-craniometric and roentgen-cephalometric analysis of points on the German shepherd dog breed

Abstract

Viscerocranium condition and development teleroentgen analyses have been avoided for quite a long time, mostly due to the technical impossibility of proper fixation of animals during recording and numerous differences in defining reference proints for linear and angular measurements. Since the available literature offeredus such field data only from research on monkeys, and since there is no ideal standard for the German shepherd dog breed but only numerous variations, we have attemated to standardize elements (points) which relate the skeleton structure and teeth to other cranium bone elements. A total of 15 German shepherd dogs, 12 months old and of body mass 25-30 kilograma, was examined and the results of teleroentgen analyses were checked on skull preparations after killing the animals. The most important radiocraniommetric points on the profile x-ray of a 12 months old German shepherd dog which could be used as reference parameters in the teleroentgenogram analyses are Nasion - N, Spina nasalis anterior - SnA, point A, Prosthion - Pr, Infradentale - Id, Pogonion - Pg, Gnathion - Gn, Menton - Mn, point Sella - S, Basion - Ba, Spina nasalis posterior - SnP, Porion -Po, Orbitale - Or, Gonion - Go, Articulare - Ar and Condylion - Co. Dog head point H and point Iv were taken as typical points for the mesocephal type of dog without analogy with human medicine. Studying the x-rays in sagittal or frontal dog head projection, we determined the most important radiocraniometric points of impor-tance for the formulation of regular interrelationships of certain regions of the neuroviscerocranium: Zygion - Zy, Eurion - Eu, Ectomaxillare - Em, Ectomalare - ecm, points Elm, Ein, and the points Ecm, Ecp, Ecl and En were characteristic only for veterinary radiocraniometry. The following soft tissue points were detemined after analysis of the dog head skin profile by the radiocephalometric method. Glabela -G, Nasion - Na', Pronasale - Pm', Labrale superior - Ls', Labrale inferior - Li', Supramentale - Sm', Pogonion - Pg', Gnathion - Gn', and the following points were derived for the first time without any analogy with human radiocephalometry: Dorsum -D', Prosthion - Pr', Menthon - M' and the point in the Iv' vasorum incisure. The derived radiocephalometric points on the dog head frontal x-ray were: Zygion - Zy', Eurion - Eu', ectomalare - ecm', point en' and Rostrum - R'.