Orthodontic Force Application in Correlation with Salivary Lactate Dehydrogenase Activity

Orthodontic tooth movement generate mechanical forces to periodontal ligament and alveolar bone. The forces correlate with initial responses of periodontal tissues and involving many metabolic changes. One of the metabolic changes detected in saliva is lactate dehydrogenase (LDH) activity. Objectives: To evaluate the correlation between orthodontic interrupted force application, lactate dehydrogenase activity and the distance of tooth movement. Methods: One hundred forty samples were collected from 20 subjects, consisted of saliva at pre-extraction of first upper premolar, pre-retraction of upper canine and 1, 7, 14, 21 and 28 days post-retraction of upper canine with 100g interrupted orthodontic force. Results: ANOVA showed significant differences between LDH activities and duration of force (F=11.926; p=0.000). Significant differences between pre-retraction of upper canine group and 14 and 28 days post-retraction of canine. The region of retraction correlated with the distance of tooth movement (F=7.377; p=0.007). The duration of force correlated with the distance of tooth movement (F=66.554; p=0.000). The differences were significant between pre-retraction of upper canine group and 1, 7, 14, 21 and 28 days postretraction of canine. Conclusion: This study concluded that orthodontic interrupted force application on canine could increase the distance of tooth movement and LDH activity in saliva.