Public Perceptions of Normal and Ideal Head Shape: A Crowdsourced Survey Analysis

Background: Cephalic index (CI) is an objective measure of head shape used by craniofacial surgeons to support a diagnosis of head shape abnormality. However, the consensus on what values correspond to a normal head shape are changing following the Back to Sleep campaign. Recent work has shown an increase in mean CI from 74 to 84. Following this shift, no study has been undertaken to evaluate whether the perception of normal head shape has changed as well. Methods: About 1020 subjects, 18 or older, were recruited through Amazon Turk crowdsourcing platform. Subjects were asked to select the head shapes they considered most normal in a series of questions identifying ideal head shape in children 6 months or younger. Demographic information was recorded for study participants to identify differing ethnic perceptions of head shape. Results: The mean cephalic index preferred by a crowdsourced population was 81.84 (SD 2.48). There was a difference in mean preferred CI between people who identified as black (CI = 82.875) and people who identified as white (CI = 81.500; P = .00062). There was no difference in mean preferred CI between males and females. Education level, age healthcare occupation status, medical literacy, and work involving children did not affect preference. Conclusions: The typical head shape has changed following the Back to Sleep campaign and the current perception of head shape aligns with the newly described norm as opposed to the historic population data. Criteria for intervention and outcome goals should be adjusted accordingly.