Reflective optical fiber displacement sensor has the advantage of low requirement to the measurement environment. It can meet various special situations which cannot be finished with normal methods

and is also characterized by large measurement range and high measurement resolution. The working principle of the sensor is discussed briefly

and a kind of sensor and a small reflective face have been designed for the special requirement of the teeth chewing movement measurement. A system for teeth chewing status measurement was set up and specific calibration was made for this system. The real-time measurement result during teeth chewing is obtained

which is the first time that the teeth chewing dynamic measurement in the dental measurement area has been realized. The paper discusses the factors which effect the measurement precision and the special measurement environment in oral cavity

and some methods for reducing errors and error analyses are also given.