牙周病是侵犯牙龈和牙周组织的慢性炎症性破坏性疾病 ,重症牙周病是指牙槽骨吸收超过根长 1/ 2 ,牙齿松动度≥2度的严重牙周病。由于这类疾病的牙槽骨吸收严重 ,使牙齿的支持组织丧失 ,牙齿逐渐松动 ,最终脱落或拔除。当牙齿松动度大于 2度时 ,在轻微外力作用下牙齿便很容易脱 Periodontal disease is a chronic inflammatory devastating disease that affects the gums and periodontal tissues. Severe periodontal disease means severe periodontal disease with alveolar bone resorption that exceeds 1/2 of the root length and 2 degrees of freedom of tooth movement. Due to the serious absorption of alveolar bone in these diseases, the supporting tissues of the tooth are lost, the teeth are gradually loosened, and finally fall off or removed. When the degree of tooth loosening is more than 2 degrees, the tooth is easily detached with slight external force