[Construction and evolution of the localization of the three preauricular acupoints]

Since Huangdi Mingtang Jing (Yellow Emperor's Illustrated Manual of Acupuncture Points) proposed the localization of the three preauricular acupoints, namely Ermen (TE21), Tinggong (SI19), and Tinghui (GB2), the textual descriptions of their localization in ancient literature have basically remained unchanged. However, according to the consensus of ancient literature descriptions, the localization combined with anatomy differs from the current national standard for acupoint localization. By systematically collecting and organizing the localization descriptions of the three preauricular acupoints in literature throughout different dynasties, and combining them with the anatomy of the preauricular region, this paper re-localizes the three preauricular acupoints. Based on literature records, acupuncture bronze figures, and Mingtang diagrams, the evolution process of the localization of the three preauricular acupoints is discussed, and the important evolutionary nodes and reasons for their evolution are analyzed. In addition, modern descriptions of the indications of the three preauricular acupoints are basically copied or rewritten from acupuncture literature before the Ming dynasty, and their indications are in fact practical summaries of acupoint localization in ancient literature before the Ming dynasty. In view of this, combined with the anatomical structure of the preauricular region, the localization of the three preauricular acupoints should follow the localization determined by the consensus of ancient literature, namely, Ermen (TE21) is located in the depression anterior to the supratragic notch, Tinggong (SI19) is located on the tragus, and Tinghui (GB2) is located at the pulsation of the superficial temporal artery anterior to the tragus.