journal of the mechanical behavior of biomedical materials 109 (2020) 103846 Available online 12 May 2020 1751-6161/© 2020 Elsevier Ltd. All rights reserved. Development of a bite force transducer for measuring maximum voluntary bite forces between individual opposing tooth surfaces L. Jansen van Vuuren a, * , W.A. Jansen van Vuuren a , J.M. Broadbent b , W.J. Duncan b , J. N. Waddell a a Department of Oral Rehabilitation, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand b Department of Oral Sciences, Faculty of Dentistry, Sir John Walsh Research Institute, Otago University, New Zealand A R T I C L E INFO Keywords: Strain gauge Bite force transducer Bite forces ABSTRACT Bite forces are studied in order to understand a wide range of factors pertaining to the mastication system. Various strain gauge transducers have been employed to measure bite forces, with several descriptions of these available in the literature; unfortunately, many reports provide insuffcient detail to enable accurate reproduc- tion. The aim of this project was to develop a bite force transducer with the capability of measuring maximum voluntary bite forces between individual opposing tooth surfaces. Furthermore, in an attempt to address the issue of vague device descriptions in the available literature, a detailed account of the transducer development has been included. A novel strain gauge transducer was designed and built. Bite forces of forty individuals were measured to verify the capabilities and clinical application of the device. 1. Introduction In dentistry, maximum bite forces are studied in order to understand the functional state and mechanics of the mastication system (Bakke et al., 1989, 1990; Hattori et al., 2009; Bakke, 2006). In research, bite forces can provide information on how the masticatory system changes during growth, development (Braun et al., 1996; Mountain et al., 2011; Castelo et al., 2010), aging, and pathology (Palinkas et al., 2019; Morita et al., 2003). In clinical settings, bite force information can aid in diagnosis and treatment planning for temporomandibular joint disor- ders (Ahlberg et al., 2003; Brawley and Sedwick, 1938). An under- standing of the maximum bite forces is important in the feld of dental prosthetics, as bite force measurements can provide reference values for evaluating the biomechanics and effciency of prosthetic treatment (Haraldson et al., 1979; Lundquist et al., 1986; Elsyad and Khairallah, 2017; Pereira-Cenci et al., 2007). Furthermore, maximum bite forces should be considered when selecting the appropriate material from which to build a prosthetic restoration to ensure that the material load strength falls within commonly encountered bite forces (Leevailoj et al., 1998; Johansson et al., 2014; Zhang et al., 2016). The range of maximum bite forces reported on in literature, is very wide, from ~300 to ~1600 N. The wide range may be attributed to numerous infuential factors such as age, gender, ethnicity and the condition of the dentition (Shinogaya et al., 2001; Ikebe et al., 2005, 2012; Miyaura et al., 1999) or the use of different recording devices and recording locations in the mouth. Bite force measurements are normally taken by placing a force transducer between opposing teeth. Various strain gauge transducers, pressure sensors and thin flms have been employed for this purpose, with strain gauge transducers the most widely accepted device in use (Koc et al., 2010). Thin flm transducers are successfully employed in various studies concerned with bite forces on full arches, but lack the ability to measure exclusively between two teeth (Hattori et al., 2009; Bakke, 2006; Flanagan et al., 2012). There are several descriptions of strain gauge transducers available in the litera- ture; unfortunately, many lack of suffcient detail to enable accurate reproduction of the device (Rold � AN et al., 2009; Isaza et al., 2009; Lappin and Jones, 2014; Fernandes et al., 2003). For the purpose of measuring the load between two opposing teeth directly, the transducer must be narrow enough to ft between two opposing tooth surfaces, and commonly-used strain gauge transducers are typically too wide (Isaza et al., 2009; Lappin and Jones, 2014; Fas- tier-Wooller et al., 2016). These wide designs ensure that the material of construction will have enough rigidity to withstand the range of ex- pected loads. Likewise, thickness has an infuence on the recorded forces, as some studies indicated that the degree of jaw separation has an infuence on bite force and mastication (Bakke et al., 1989, 1990; * Corresponding author. Department of Oral Rehabilitation Faculty of Dentistry, PO Box 56, Dunedin, 9054, New Zealand. E-mail address: ludwig.jvv@otago.ac.nz (L. Jansen van Vuuren). Contents lists available at ScienceDirect Journal of the Mechanical Behavior of Biomedical Materials journal homepage: http://www.elsevier.com/locate/jmbbm https://doi.org/10.1016/j.jmbbm.2020.103846 Received 15 March 2020; Received in revised form 3 May 2020; Accepted 4 May 2020