裂齿症候群（Cracked tooth syndrome，缩写 CTS），是一种牙科症状，患者牙齿上的裂缝延伸到根部，有时候会延伸至牙髓，甚至穿越它。裂齿的种类相当多，医师往往不易正确诊断。

Cracked tooth syndrome (abbreviated to CTS, and also termed cracked cusp syndrome, split tooth syndrome, or incomplete fracture of posterior teeth), is where a tooth has incompletely cracked but no part of the tooth has yet broken off. Sometimes it is described as a greenstick fracture. The symptoms are very variable, making it a notoriously difficult condition to diagnose.