Apoptosis of periodontal ligament cells induced by mechanical stress during tooth movement

• Published in: Oral diseases 2001-09, Vol.7 (5), p.287-290
• Main Authors: Hatai, T, Yokozeki, M, Funato, N, Baba, Y, Moriyama, K, Ichijo, H, Kuroda, T
• Format: Article
• Language: English
• Subjects: Alveolar Bone Loss - etiology; Animals; Apoptosis; Biological and medical sciences; Compressive Strength; Dental Stress Analysis - methods; Dentistry; Ent. Stomatology; In Situ Nick-End Labeling; Investigative techniques, diagnostic techniques (general aspects); Male; mechanical stress; Medical sciences; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; periodontal ligament; Periodontal Ligament - pathology; Rats; Rats, Sprague-Dawley; Stress, Mechanical; tooth movement; Tooth Movement Techniques - adverse effects
• ISSN: 1354-523X; 1601-0825
• DOI: 10.1034/j.1601-0825.2001.00663.x

The mechanical force generated during tooth movement creates compressed and cell‐free areas in the periodontal membrane. The way in which periodontal ligament cells disappear at the compressed area during tooth movement remains unclear. In the present study we examined whether periodontal ligament cells undergo apoptosis by mechanical stress during tooth movement using the terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP‐biotin nick‐end‐labelling method (TUNEL). TUNEL‐positive stainings of periodontal ligament cells began to appear at the compressed areas 12 h after tooth movement, and the number of those cells reached maximum at 24 h after tooth movement. Thereafter TUNEL‐positive cells disappeared at 48 h, and direct and undermining bone resorption began at the same area 72 h after tooth movement. These results showed that compressed periodontal ligament cells were eliminated by apoptosis in the early phase of tooth movement.