Work

Development of preauricular grooves after childbirth in present-day females

Year: 2026

Type: article

Abstract: Development of the preauricular groove has long been used as an osteological indicator of pregnancy and childbirth despite inconsistent evidence. To retrospectively evaluate the development of preauricular groove, we measured the preauricular groove volume based on pelvic computed tomography (CT) images before and after childbirth and examined its relationship to obstetric history including gravidity, parity, and the number of miscarriages. Longitudinal CT data were obtained from three females before and after childbirth, and cross-sectional CT data were collected from 98 females (47 nulliparous and 51 parous). One case of forceps delivery showed marked enlargement of the groove after childbirth in both sides, whereas no notable changes were observed in a case of cesarean section. Another case of vaginal delivery exhibited enlargement on one side and no change on the other. Cross-sectional comparisons showed that the volumes of preauricular groove were significantly larger in parous than in nulliparous females although there was a substantial overlap. No significant correlation was found with parity or gravidity, although a weak negative correlation was suggested with the number of miscarriages. The volume showed no significant association with age, height, or weight. These findings indicate that the preauricular groove may develop after first parturition but does not reliably reflect parity or gravidity. It was also suggested that factors contributing to recurrent miscarriage may negatively affect preauricular groove development.

Source: Anthropological Science

DOI: 10.1537/ase.260418