[Possibilities for the use of zonography in orthodontics].

The "Zonarc" is a panoramic device in maxillofacial radiology that is programmed to cover different image layers. In this study human skulls of various sizes and various stages of development were examined with the aid of this equipment. The following projections were used: DENT program, JLA (special) program (TMJ side view, mouth open and closed), JSA program (TMJ sagittal, mouth open and closed). The positioning of the skulls as well as the correct adjustment of the equipment have been described on the basis of this investigation. The quality of reproduction of the skeletal tissue is discussed. The results indicate that the projections JLA and JSA can be used to advantage in orthodontic diagnosis. However one has to take the cost factor into consideration.