Brain stem degeneration patterns following tooth extractions: visualization of dental and periodontal afferents

The terminal central nervous system distribution of those primary afferent neurons from the teeth and periodontium in cats was studied by degeneration methods. Lesions were created by combinations of tooth extractions and the brain stem was examined at 14, 30 and 60 days survival for degeneration patterns, with 30 days being the optimal survival time. Degenerating axons and terminals are seen bilaterally, but somewhat less on the side contralateral to the lesions and are concentrated in the ventral half of pars interpolaris and pars caudalis near obex. The results are discussed with regard to the current controversies concerning the primary central termination of these trigeminal neurons.