Design and Development of an Instrument for Measurement of Biting Force in Human Beings

The gnathodynamometer is a device meant for the measurement of biting force and the assessment of masticator performance. The devices reported in the literature have not been very convenient to use, and have often undergone modifications. In this paper, a systematic mechatronic approach has been followed in the design and development of a gnathodynamometer, to overcome reported inadequacies. The design problem imposes several constraints of size, access, loading, safety, hygiene, and so on. The gnathodynamometer developed in this work is designed for a maximum biting force of 600 N, and a maximum deflection of 1 mm. Design of the main component, which is the fork, has been elaborately explained. Strain gauges located at the root of the inner surface of each prong have been used to sense the strains arising due to the application of biting force. The complete electronic circuit has been designed. Readings of biting force are displayed on a digital readout. The circuit includes selection of strain gauges, design of Wheatstone bridge, preamplifier. The device is then calibrated and a relationship between applied biting force and output voltage is obtained.