Histology of the Periodontium Following Tooth Movement

¹ Department of Oral Anatomy, Indiana University School of Dentistry, Indianapolis, Indiana

The application of force to the crowns of multirooted teeth of young experimental animals produced a tipping movement accompanied by evidence of tissue changes within hours. When the periodontal ligament was hyalinized, bone resorption on the pressure side started on the medullary space surface of the alveolar bone and was designated as an undermining resorption. When the periodontal ligament was not deprived of its normal level of vitality, resorption started on the periodontal ligament surface of the alveolar bone. Mesenchymal cells with capillary proliferation were the predominating feature associated with bone and root surfaces undergoing resorption. Tissue changes accompanying experimental tooth movement, whether on the tension or pressure sides, were devoid of any signs of inflammation. Blood vessels on the tension side were of larger size and were situated mostly in the middle of the periodontal space. On the pressure side the vessels were small and closely related to the bone surface undergoing resorption.