KEEP IT CRISP (272 pp.)S. J. PerelmanRandom House ($2.50).
The dentist strapped Sidney Joseph Perelman into the chair with six towels and forced his jaws apart with a blunt instrument. "Now then, where are his X rays?" he asked the nurse. "We haven't any," she said. "This is the first time he's been here." "Well, bring me any X rays," barked the dentist; "when you've seen one tooth you've seen them all."
Firing a burst of compressed air down Perelman's gullet, the dentist chortled:"Well, friend, you may as well know the worst. These are the teeth of an 80-year-old man. . ....