Objective: This study was to evaluate the activity of Lactate Dehydrogenase enzyme
in different tooth malpositions in gingival crevicular fluid (GCF). Patients, materials
and methods: A sample of 18 patients with an age range from 13 to 19years, requiring
orthodontic treatment. The study groups were designed into two groups. Group
I: well aligned teeth (control group). Group II: malposed teeth. Group II was subsequently
divided into 3 sub-groups; Rotation, Spacing and Vertical malposition. Samples
were collected for assessment of lactate dehydrogenase level in GCF at baseline, one
week, two and four weeks after treatment. Lactate dehydrogenase was measured in
GCF using Enzyme Linked Immunosorbent Assay (ELISA) technique. Results: In both
groups (group I and group II subgroups) the gingival crevicular fluid lactate dehydrogenase
enzyme had a steady increase during orthodontic tooth movement with a statistically
significant increase at one week and two weeks compared with the base line
(P≤0.05). No statistical significant difference was found between each two subgroups
of group II (P≤ 0.05). Conclusions: The level of lactate dehydrogenase enzyme in gingival
crevicular fluid could be used as a biomarker for periodontal metabolism related
to orthodontic tooth movement. The level of lactate dehydrogenase enzyme (LDH) did
not show significant difference among different tooth malpositions during correction
by orthodontic treatment.