De l'interprétation embryologique de la «fistula praeauricularis congenita«

[Pathogenesis of the preauricular appendages, melotia, and poliotia (author's transl)]

Preauricular appendages are usually considered deriving from excessively growing or supernumerary auricular hillocks at the border of the first cleft. However, the hypothesis being presented here deduces their origin from hyoidal ectodermal cells which differ from their mandibular host-tissue by a specific genetic potency, effecting the formation of extodermal proliferations. The separation of these germs from the hyoidal ectoderm and their fastening to the mandibular ectoderm happen during the closure of the first cleft, when the hyo-mandibular connecting lamina is regressing during the first half of the 6th week of pregnancy. Their transfer away from the hyo-mandibular boundary, which is situated right in front of the auricle, happens during the developmental movement of the mandibular ectoderm of the embryonal face. Thus the preauricular appendages are characterized as a new kind of choristomas: their germs derive from ectodermal cells and also develop in ectodermal tissue. There is also the embryological evidence, that melotia and poliotia are likewise representing extraordinary big preauricular appendages.

Surgical treatment of the infected preauricular sinus

Preauricular sinus is a frequent occurring congenital abnormality (circa 0.25% in the white race), but gives mostly no symptoms. In a certain amount of cases symptoms can arise as recurring purulent secretion or a preauricular abscess. If the disease is recognized an adequate therapy can be accomplished. Sometimes the disease is not recognized and diagnosed as a sebaceous cyst or a furunculus. Also, if the sinus is recognized, it is necessary not to underestimate the disease. In several clinical studies a recurrencerate of 15--33% is quoted. Singer published in 1966 a technique of extirpation of the infected preauricular sinus with excellent results. This technique was adopted with addition of the use of the operating microscope. In nine patients with an infected preauricular sinus extirpation in toto was accomplished in a silent period. Under these nine patients were two recurrences after previous inadequate surgery. After a minimal follow-up of 2 years the patients were symptom-free. The quoted technique of extirpation of the infected preauricular sinus in toto seems to be an improvement for the therapeutic armamentarium.

Congenital aural and pre-auricular sinuses in the South African Bantu

The incidence of ear pits was studied in the South African Bantu population. A short account of the anatomy, occurrence, inheritance, developmental origin, complications and treatment of this anomaly was given. Mention has been made of the clinical significance and the possible association between ear pits and other systemic and ear abnormalities, including deafness. There seems to be a higher incidence of other abnormalities in children born with sinuses. The blanket term 'pre-auricular fistula' should possibly be discarded in favour of auricular sinuses or ear pits.