Regeneration of nerve fibres in the maxillary sinus mucosa after experimental surgery - An immunocytochemical double-labelling study in the rabbit

Nerve fibre regeneration in the maxillary sinus mucosa after surgery was st udied in 10 New Zealand White rabbits. Four and 8 weeks following unilatera l removal of the mucose, the animals were fixed by perfusion, and the nose- sinus complexes were frozen and cut on a cryostat equipped with a tungsten- hardened knife. A double-labelling immunocytochemical procedure was develop ed with commercially available antibodies to protein gene product (PGP) 9.5 and tyrosine hydroxylase (TH) or neuropeptide Y (NPY). The study revealed that the maxillary sinus mucosa in rabbit is reinnervated at 4 and 8 weeks postoperatively. Furthermore, the regenerated lamina propria showed increas ed TH immunoreactivity (TH-IR) and NPY-IR, compared with the contralateral, non-operated side. Many of the fibres were seen in close proximity to newl y formed vessels. These findings add further to the explanation of the alte red vasoreactivity found earlier in regenerated sinus mucosa 1 month after surgery. This study also showed that demineralization of the nose-sinus com plexes is not necessary if a hardened metal knife is used.