Evaluation of Periodontal Ligament under Orthodontic Force by using Optical Coherence Tomography

Abstract

The changes of the periodontal ligament according to orthodontic forces were evaluated by using optical coherence tomography. We have imaged periodontal ligament spaces of mandibular teeth both in a human dry skull and in postmortem beagles with applying different distraction force with different levels, 0 gm, 10 gm, and 30 gm on mandibular anterior teeth of white rats. We showed that the periodontal ligament due to external force was very sensitive to the orthodontic force, and the minute structural change could be imaged with optical biopsy technique or OCT. Although the experimental results were the pilot study, these preliminary results might be applicable for establishing the proper criteria in clinical dental treatment presenting clearly visualized proofs with OCT images. With exploiting the real-time imaging function of OCT, we could expect that the optical imaging technique can monitor dynamically the sequential changes of periodontal ligament in human teeth in vivo as well as in animal teeth.