Experimental results do not support a gas reserve function for the mastoid.
The mastoid is an aerated extension of the middle ear gas pocket whose state of development was shown to be an indicator of past and future otitis media experience. While the function(s) of the mastoid is not known, a number of hypotheses has been advanced to explain the reported association between mastoid size and middle ear disease. These include the hypotheses that, with respect to the middle ear, the mastoid functions as a pressure buffer, a gas reserve, and/or a pressure regulator. In this paper, a physical model of the mastoid is presented that makes specific predictions against which the validity of the hypothesized gas reserve function could be tested. Data from three published clinical experiments were evaluated for consistency with the predictions of the model, and the hypothesis was rejected. Also, when reinterpreted within the context of the model, the published data do not support a pressure-regulating function for the mastoid.
Doyle
W J
WJ
Department of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, and University of Pittsburgh School of Medicine, 3705 Fifth Ave., Pittsburgh, PA 15213, USA. docdoyle@ix.netcom.com
D004432:Ear, Middle / Q000502:physiology* / Q000503:physiopathology; D005740:Gases; D006801:Humans; D008416:Mastoid / Q000502:physiology* / Q000503:physiopathology; D008954:Models, Biological; D009305:Nasopharynx / Q000502:physiology; D010033:Otitis Media / Q000503:physiopathology; D010313:Partial Pressure
D005740:Gases