METHODS: Ten subjects (n = 10) who had upper and lower fixed appliances (MBT, 3 M Unitek, 0.022″ × 0.028″) were recruited for this study. Human gingival crevicular fluid (GCF) was obtained using periopaper strips at pre-treatment (T0), 1 month (T1), 3 months (T3), and 6 months (T6) of orthodontic treatment. Periapical radiographs of the upper permanent central incisors were taken at T0 and T6 to measure the amount of root resorption. Identification of changes in PA was performed using liquid chromatography-tandem mass spectrometry. Student's t-test was then performed to determine the significance of the differences in protein abundance before and after orthodontic treatment.
RESULTS: Our findings showed that all ten subjects had mild root resorption, with an average resorption length of 0.56 ± 0.30 mm. A total of 186 proteins were found to be commonly present at T0, T1, T3, and T6. There were significant changes in the abundance of 16 proteins (student's t-test, p ≤ 0.05). The increased PA of S100A9, immunoglobulin J chain, heat shock protein 1A, immunoglobulin heavy variable 4-34 and vitronectin at T1 suggested a response to stress that involved inflammation during the early phase of orthodontic treatment. On the other hand, the increased PA of thymidine phosphorylase at T3 suggested growth promotion and, angiogenic and chemotactic activities.
CONCLUSIONS: The identified proteins can be potential early markers for root resorption based on the increase in their respective PA and predicted roles during the early phase of orthodontic treatment. Non-invasive detection of root resorption using protein markers as early as possible is extremely important as it can aid orthodontists in successful orthodontic treatment.
MATERIALS/METHODS: The study was conducted on ten histologically proven cases of oral cancer undergoing radiotherapy. Stimulated whole saliva was collected at three stages of radiotherapy-0, 3, and 6 weeks. Salivary amylase was estimated using Henry-Chiamori method and comparison was made with appropriate age- and gender-matched controls.
RESULTS: Salivary amylase levels showed significant decrease in healthy subjects when compared to oral cancer patients (P < 0.001). The latter group also showed changing trend with initial decrease from 0 to 3 weeks followed by increase from 3 to 6 weeks following radiotherapy (P < 0.0528).
CONCLUSIONS: The trend in changes in the levels of salivary amylase could be used as a surrogate marker of salivary gland function in patients with oral cancer undergoing radiotherapy as primary treatment.