Change in initial response of periodontal ligament according to tooth movement speed in periodontal ligament distraction osteogenesis

PurposeThe aims of this animal study were to (1) determine how tooth movement speed affects morphological and histological change, and (2) verify how this speed affects change in the initial response of the tension-side periodontal ligament with application of periodontal ligament distraction osteogenesis (PLDO).Materials and methodsFive mature, male, 10–15-month-old beagle dogs were used. After extraction of the mandibular second premolars and a surgical procedure, distraction devices were placed between the first and third premolars to distalize the first premolars. The animals were separated into three groups (Group 1, 0.25 mm; Group 2, 0.5 mm; Group 3, 1.0 mm per day) and retraction applied over 4 days.ResultsAmount of distal movement in the first premolars was 0.91 ± 0.03 mm, 1.75 ± 0.07 mm, and 3.41 ± 0.06 mm in Groups 1, 2, and 3, respectively. While extension of the periodontal ligament with slight bleeding was observed on the tension side in Group 1, rupture with spaces filled with blood clots was seen in the periodontal ligament in Groups 2 and 3.ConclusionThis suggests that the initial response of tension-side periodontal ligament differs according to tooth movement speed in PLDO.