The submental arrowhead variation of the mylohyoid and anterior belly of the digastric muscles.

PURPOSE

Submental anatomical variation is of clinical importance with regard to head and neck surgeries. One such anatomical variation is that of additional musculature joining the intermediate tendon of the digastric muscle to the midline of the mylohyoid musculature-a variation which this report refers to, accordingly, as an arrowhead variation. Though the arrowhead variation has been described in several case reports, it has not been subject to cross-sectional study. The purpose of this study is to determine the prevalence of the arrowhead variation.

METHODS

Prevalence of the arrowhead variation was assessed in 19 cadavers via gross dissection.

RESULTS

Two of the 19 cadavers (10.5%) were found to have arrowhead variations. The arrowhead variation was found in one male (1:11; 9.1%) and one female (1:8; 12.5%), respectively.

CONCLUSIONS

This report demonstrates that the submental arrowhead variation of the anterior digastric and mylohyoid musculature has been reported in isolated case reports since the nineteenth century. This report is the first cross-sectional study of the arrowhead variant, identifying it in approximately one in ten individuals and in both sexes. Therefore, the presence of an arrowhead variation should be regularly considered with regard to diagnosis of submental masses. Likewise, the arrowhead variation should be considered in the preoperative planning of the myriad operations performed in the submental region.