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The juxtaoral organ in humans is a small longish structure (10–14  mm in length, 1–2  mm in diameter), situated medially to the
medial pterygoid muscle The medial pterygoid muscle (or internal pterygoid muscle), is a thick, quadrilateral muscle of the face. It is supplied by the mandibular branch of the trigeminal nerve (V). It is important in mastication (chewing). Structure The medial ptery ...
. The
organ Organ may refer to: Biology * Organ (biology), a part of an organism Musical instruments * Organ (music), a family of keyboard musical instruments characterized by sustained tone ** Electronic organ, an electronic keyboard instrument ** Hammond ...
consists of a central ramified cord of epithelial parenchyma, embedded in connective tissue particularly rich in nerve fibers and sensory receptors. Close relations exist between epithelial cells and nerve endings. Histochemically, the parenchyma displays a characteristic pattern of various enzymes. Sporadically, epithelial follicles containing colloidal material can be found. The organ is surrounded by a dense, perineurium-like connective tissue. Originally, the formation was known to embryologists only ("Chievitz Organ") and was considered to be a transient rudimentary structure, disappearing before birth. In 1953, Wolfgang Zenker proved that the formation shows further development and can be found in adult humans with regularity. Since then, several studies have been performed on its comparative anatomy, histology, cytochemistry, and ultrastructural level. As soon as this structure had been shown to occur not only at all stages of human life but also in many other mammals and reptiles and since no signs of involution could be detected in any of the species investigated, it was renamed – from a topographical point of view – as "Juxtaoral organ" by Zenker and Salzer 1962. The results of the studies of Zenker and his group on this organ as well as the history of research are summarised in the monograph ''Juxtaoral Organ: Morphology and Clinical aspects'', Urban and Schwarzenberg, 1982. It can very rarely be the site of a
tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
. It was first noted in embryos by Johan Henrik Chievitz in 1885.


References

{{DEFAULTSORT:Juxtaoral Organ Of Chievitz Human head and neck