Pathological changes of oral mucosal tissues on orthodontic appliances

Objectives: The aim of this study was to develop a new approach to diagnosis of inflammation in the periodontal tissue and oral mucous membrane organization among patients due to use of fixed orthodontic appliences. Saliva sampling has the advantages of being non invasive, allowing multiple sampling, being easy and stress free. We examined the phathological changing of neutrophils, monocytes and oral mucosal cells among the saliva.

Methods: Male Wistar rats weighing 280-300 g were used.　The rats were applied expansion device bonded maxilla central incisors under thiopental sodium (50 mg/kg i.p.). Investigations were conducted on the pilocarpine-administration (8 mg/kg i.p.) saliva obtained from rat on bonded appliences. Saliva smears were done on cleaned and defectted glass slides. After fixation in 95% ethanol the smears were stained with May-Grünwalt-Gimsa and Annexin　V-FITC (A V-F). Oral epithelial cells and inflow elements under microscopes analysis with regard to shape size, the neucleus-cytoplasm ratio.

Results: In control salivary samples, epithelial cells were numerous, equal in shape and size, and their nucleus-to-cytoplasm ratio was normal and leveled. Mainly neutrophils and monocytes were observed among epithelial cells. Neutrophil is weakly stained with A V-F. In orthodontic rats, oral epithelial cells showed morphological alternations. The morphological changes in oral mucosal cells were most pronounced on day 1 and 3. In rats with 7 days of exposure to the orthodontic appliance, changes in oral epithelial cells were observed. Neutrophil destruction mediated by apoptosis was detected by attaining myeloperoxidase labeling. The apoptotic neutrophils were more rounded and less spread on day 3 and 7.

Conclusions: These results suggest that saliva samplings (salivary cells) are anevaluational index of the pathological changes in mucousal membrane organization onfixed orthodontic appliences.