The external ear (EE) is an osseous-cartilaginous structure that extends from the auricle to the tympanic membrane. In the context of these embryological and anatomical knowledge, auricular acupuncture is described with its clinical implications. The trigeminal nerve innervates these areas on the auricle. These organs are to be found represented in the antihelix, the scapha and fossa triangularis of the auricle. The locomotor and lymphatic systems develop from the mesoderm tissue. Innervated mostly by a branch of cervical plexus. These organs are represented in the tail of the helix and the lobule. The skin, endocrine and nervous systems develop from the ectoderm. The endodermal organs are represented in the concha and this part of the ear is innervated mainly by the vagus nerve. The internal organs except for the heart and the kidneys develop from the endoderm. Of the human body which is developed from each of these three primary tissue types. The ear is one of the few anatomic structures All organs develop from the foetus’s three germ layers, the endoderm, ectoderm, and mesoderm. The embryological hypothesis of ear acupuncture was launched in the 1970’s by Bourdiol of France. 6 [Color figure can be viewed in the online issue, which is available at Auricular acupuncture/auriculotherapy is a treatment based on the detection and stimulation of acupuncture points on the auricle. 3 The second arrow represents the ventral rotation of the first pharyngeal arch as described by Wood-Jones and I-Chuan in 1934. The first arrow represents the dorsal rotation of the second pharyngeal arch as described by His in 1885. The fate of the hillocks as described by the authors are indicated by numbers 1 to 6. (D) The proposed theories of the embryological development of the human auricle as described by several authors. Numbers 1 to 3 have been described to be of the first pharyngeal arch origin and 4 to 6 as the second pharyngeal arch derivative. (C) Simplified version of the auricular hillocks. 3 Image reproduced with permission of the National Museum of Health and Medicine. (B) Close up of the auricular hillocks as described by His in 1885. (A) Lateral view of the original embryo in Carnegie stage 17 (42-44 days) specimen 6521. The proposed theories on the embryological development of the human auricle. As a consequence, we propose that preauricular sinuses should be classified as first pharyngeal arch anomalies. Consequently, this indicates that almost the entire auricle is derived from the second pharyngeal arch, with the exception of the tragus and the anterior EAM.Ĭonclusions: The 3D reconstructions show the anatomy and development of the auricle to be different from concepts presented in current textbooks. The branches of the trigeminal nerve only innervate the tragus and the anterior external auditory meatus (EAM).
Contrary to common knowledge, the auricle is almost entirely inner-vated by branches of the facial nerve. Results: The hillocks were absent in most stages. Additionally, literature research was performed. Three-dimensional (3D) reconstructions were prepared.
Methods: Histological sections of the selected embryos were examined. Study Design: 22 human embryos from the Carnegie collection between Carnegie stage 13 and 23 (28-60 days) were selected based on their histological quality. The aim of this study was to assess the validity of this theory by modern techniques and to expand the knowledge of the embryological development and morphology of the auricle. The most commonly reproduced developmental theory by His (1885) describes six hillocks three on the first and three on the second pha-ryngeal arch. However, little is known about the embryological development of the auricle. Additionally, the auricle plays an important role in the staging of human embryos. Objectives/Hypothesis: Congenital auricular anomalies are common.
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