“…The mastoid process and its surrounding region represent one of the most sexually dimorphic parts of the human skull, and is often included in data collection protocols and sex estimation methods (Buikstra and Ubelaker, 1994; Garvin et al, 2014; Jung and Woo, 2016; Langley et al, 2017; Lewis and Garvin, 2016; Nagaoka et al, 2008; Ramsthaler et al, 2010; Rogers, 2005; Stevenson et al, 2009; Walker, 2008; Williams and Rogers, 2006; Yilmaz et al, 2015). The mastoid process can be assessed either visually by its massiveness and voluminosity (Buikstra and Ubelaker, 1994; Walker, 2008), or metrically by its length (sometimes referred to as height), which typically is measured as the vertical projection of the mastoid process below and perpendicular to the Frankfurt horizontal (FH) plane (Moore-Jansen and RL Jantz, 1986; Buikstra and Ubelaker, 1994; Moore-Jansen, RL Jantz, Ousley SD, 1994, Howells 1973).…”