What Is External Resorption?

The cause is not very clear so far, and there are reports that it is related to the damage of cement. According to existing clinical reports, the occurrence of root resorption is related to the following conditions.

Zou Xiaoying	(Attending physician)	Department of Dentistry, Peking University Stomatological Hospital
Wang Xiaoyan	(Chief physician)	Department of Dentistry, Peking University Stomatological Hospital

External root absorption (External Resorption) refers to the progressive pathological absorption that occurs on the root surface. The disease has no obvious clinical symptoms, and it is often found on X-ray examination that severe external absorption can cause tooth loss.

Western Medicine Name: External root absorption
English name: External Resorption

Affiliated Department: Department of Physiology-Stomatology
Contagious: Non-contagious

Pathogenesis of external root absorption

1. After tooth trauma, occlusal trauma and periodontal tissue inflammation, external tooth root absorption often occurs in affected teeth.

2. Local pressure on the root of the tooth, such as intracranial cysts, tumors or impact of impacted, impacted teeth.

3. Some dental treatments, such as high-concentration hydrogen peroxide bleaching of unmyelinated teeth, can cause external absorption of the neck of the tooth; external absorption caused by orthodontic treatment and autologous tooth transplantation or replantation is not uncommon.

4. Systemic diseases, some systemic diseases that cause calcium metabolism disorders in the body, such as hypoparathyroidism or hyperfunction, calcium gout, Gaucher disease, Paget disease, etc.

5. Unexplained idiopathic external absorption, manifested as multiple teeth, extensive, rapidly progressing external absorption.

Pathogenesis of external root absorption

Tooth root absorption must meet two conditions:

(1) Impairment of anterior dentin (internal absorption) or anterior cementum (external absorption);

(2) There are harmful irritants and inflammatory reactions in the injury area.

Pathophysiology of external root absorption

The dentin-like layer on the surface of the root disappeared, and the cartilage appeared as a cannibalized depression, which gradually progressed to the dentin; osteoclasts were visible in the depression.

According to pathological characteristics, it can be divided into:

1. Surface absorption.

2. Inflammatory absorption.

3. Displacement absorption.

Clinical manifestations of external root absorption

1. The affected tooth can be without any symptoms for a long time. Only after a considerable amount of external absorption occurs, the worm-like defects of different depths on the surface of the root are displayed on the X-ray film.

2. In the case of inflammatory absorption, there is an X-ray transmission area around it.

3. During replacement absorption, the periodontal ligament disappears, and the alveolar bone is directly attached to the root surface, showing ankylosis.

4. Severe progressive external root absorption, full absorption of the root of the tooth causes crown loss. External resorption, such as replantation.