title: Changes in the periodontal ligament after experimental tooth movement using high and low continuous forces in beagle dogs.
abstract: The aim of this study was to evaluate histological changes in the periodontal structures of beagle dogs after using high and low continuous forces during experimental tooth movement. An orthodontic appliance was placed on the second premolar and the first molar by exerting a continuous and constant reciprocal force of 25 cN on one side and 300 cN on the other side of the mandible. Tooth movement was recorded weekly. Dogs were sacrificed after one, four, 20, 40, and 80 days for histological evaluation. Hematoxylin and eosin (HE) staining was used for tissue survey, staining for alkaline phosphatase as a marker was used for active osteoblasts, and tartrate-resistant acid phosphatase staining was used for osteoclasts. After 24 hours, the remodeling process had already started at the pressure and tension side, and in some samples hyalinization was found. In contrast to earlier studies, hyalinization was found throughout the entire experimental period, both in molars and in premolars. In the periodontal ligament of some teeth, small patches of hyalinization were found at the pressure side, mostly located buccally or lingually of the mesiodistal plane, whereas others showed large areas of necrotic tissue. It is concluded that hyalinization limits tooth movement, but there is no relationship with the force level.
authors.affiliation: Department of Orthodontics and Oral Biology, College of Dental Science, University Medical Center, Nijmegen, The Netherlands.
authors.forename: Martina
authors.initials: M
authors.lastname: Von Böhl
authors.forename: Jaap
authors.initials: J
authors.lastname: Maltha
authors.forename: Hans
authors.initials: H
authors.lastname: Von den Hoff
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000222:Adaptation, Physiological / Q000502:physiology; D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D001641:Bicuspid / Q000473:pathology; D015415:Biomarkers / Q000032:analysis; D003094:Collagen / Q000648:ultrastructure; D004396:Coloring Agents; D004285:Dogs; D006818:Hyalin / Q000648:ultrastructure; D007527:Isoenzymes / Q000032:analysis; D008963:Molar / Q000473:pathology; D009336:Necrosis; D009967:Orthodontic Appliances; D010006:Osteoblasts / Q000473:pathology; D010010:Osteoclasts / Q000473:pathology; D010513:Periodontal Ligament / Q000473:pathology*; D011312:Pressure; D013314:Stress, Mechanical; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation
chemical_list: D015415:Biomarkers; D004396:Coloring Agents; D007527:Isoenzymes; D003094:Collagen; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase