Enlargement of rat submandibular salivary gland induced by single amputation of lower incisor teeth. Histological, histometric and ultrastructural studies.

Histological, histometric and ultrastructural studies of rat submandibular salivary glands (SMG) following single amputation of lower incisor teeth were made. The SMG enlargement occurred after the tooth amputation, and its maximal increase of weight was reached 7 days later. The results of histological and histometric observations showed that the enlargement of SMG was due to both hypertrophy and hyperplasia of the acinar cells, and hypertrophic acinar cells were ultrastructurally characterized by well-developed organelles such as rough-surfaced endoplasmic reticulum and Golgi apparatus which filled the entire cytoplasm. Hydropically swollen nerve endings with disappearance of vesicles were frequently found. In later stages, degenerative or necrotic cells were scattered in the acini, and the size and the structure of the remaining acinar cells became gradually similar to those of non-treated glands. The morphological changes seen in the enlarged SMG induced by single amputation of the lower incisor teeth in rat were similar in many ways to those of sialadenosis induced experimentally by active sympathomimetic drugs.