NO. 6 EAR EXOSTOSES HRDLICKA "]"] 



It may be said that each more important racial or geographical unit 

 of people will present its own characteristic picture of ear exostoses, 

 though the fundamentals remain much the same. The differences may 

 be of but little import, but now and then are rather striking. All char- 

 acteristic group differences in these respects must necessarily be con- 

 nected, on one hand, with the neuro-vascular background of the 

 growths, and on the other hand, with the status of the normal bony 

 structures involved. 



NATURE OF THE PROCESS 



The syndrome of ear exostosis cannot be regarded as a " disease ". 

 Although secondarily it may become pathological and incidentally 

 even fatal, yet in general the outgrowths are quite innocuous, and 

 mostly not even known of, until they grow so large as to become an 

 obstruction or lead to the development of inflammatory conditions. 

 There seems to be no possibility that any bacterial agency is involved 

 in their production, and they are in no sense malignant. 



If we exclude all microorganisms and all malignancy, then there 

 remain, it would seem, but two classes of possible causes, the first 

 comprising such " poisons '" in the lymph and blood as would be capa- 

 ble of arousing bone tissue to localized bone overgrowths and out- 

 growths, and the other consisting of derangements of the trophic 

 nerve control of the parts concerned. 



" Poisonous ". i. e., harmful, substances circulating in the body 

 liquids are certainly present in many individuals, particularly in the 

 later years of life, when the liver, kidneys, and other organs no 

 longer suffice for their neutralization and elimination, and particularly 

 in various pathological conditions and diseases during which poisonous 

 products come into the blood and lymph from pathogenic bacteria. 



Granted a " predisposition " to outgrowths in the tympanic bone 

 and the squamous part of the bony meatus, some such poisons as 

 those just mentioned could readily be conceived as the initiators of 

 the exostoses. What many otologists suspected in connection with 

 syphilis, gout, and other constitutional troubles as causes of ear ex- 

 ostoses, was not really these conditions themselves as much as their 

 poisonous products. Mineral as w'ell as organic poisons, such as lead, 

 mercury, alcohol, etc., may also enter the system in other ways. That 

 some such substances may be capable of inciting abnormal osteogene- 

 sis where the ground for this is favorable may provisionally be ad- 

 mitted. That any special one or ones can excite the bony growths in 

 the ears, would need an unequivocal demonstration through experi- 

 ment. That any and all are generally powerless to produce such bony 

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