Dental Surveyor: Types and Parts
The most widely used surveyors are the Ney (Figure -1) and the Jelenko (Figure -2). Both of these are precision-made instruments. They differ principally in that the Jelenko arm swivels, whereas the Ney arm is fixed. The technique for surveying and trimming blockout is therefore somewhat different.
Other surveyors also differ in this respect, and the dentist may prefer one over another for this reason.
The principal parts of the Ney surveyor follow:
1. Platform on which the base is moved
2. Vertical arm that supports superstructure
3. Horizontal arm from which surveying tool suspends
4. Table to which the cast is attached
5. Base on which the table swivels
6. Paralleling tool or guideline marker (this tool contacts the convex surface to be studied in a tangential manner; the relative parallelism of one surface to another may thus be determined; by substituting a carbon marker, the height of contour then may be delineated on the surfaces of the abutment teeth and also on areas of interference requiring reduction on blockout)
7. Mandrel for holding special tools
The principal parts of the Jelenko surveyor are essentially the same as those for the Ney surveyor except that by loosening the nut at the top of the vertical arm, the horizontal arm may be made to swivel.