Incidence and type of exaggerated external occipital protuberances in a wide-age population

Abstract

Objective

Exaggerated external occipital protuberances, also known as occipital spurs or chignon hooks, are a commonly found anatomical variant in large field-of-view cone beam computed tomography (CBCT) images and have been shown to correlate with clinical neck pain. Occipital spurs present in 3 types: type I, smooth; type II, sharp; type III, hooked (curved). A recent study by Shahar et al. characterizes the incidence of this finding in the 18-86 age group, but limited data exist to describe the type of spur found based on sex in wide-age populations. This study aims to provide data on the incidence of occipital spurs in a wide-age population (9-54 years) characterized by sex and type of spur present.

Study Design

In total, 100 large field-of-view CBCT scans taken between February 2021 and January 2023 were assessed by an oral radiology resident and a calibrated dental student. The image was properly oriented and the presence of an occipital spur, spur type, patient age, and sex were recorded. From this, incidence based on sex and type of spur present was obtained.

Results

The data revealed that 76% of male patients and 67% of female patients in the sample had occipital spurs present. Type I spurs were present in 38.5% of females and 21.9% of males. Type II spurs were present in 46% of females and 62.5% of males. Type III spurs were found in 15.3% of females and 15.6% of males.

Conclusions

Occipital spurs present similarly between sexes, with males showing a predilection for type II spurs. Females display a similar predilection for both type I and type II spurs, and both sexes display similar incidence of type III spurs. Occipital spurs are a frequent variant that can be observed in CBCT studies taken for orthodontic planning, which is important to note, as it may have clinical implications.