Polyps of the maxillary sinus were obtained from six patients who had repor
ted upper tooth extraction with oroantral perforation prior to the developm
ent of symptoms, from 11 patients with chronic sinusitis, and from 12 patie
nts with allergy. Histopathological features, scanning electron microscopy
of the polyp epithelium and clinical data were compared in those groups of
patients. The post-traumatic polyps differed from those of other aetiologie
s by showing the presence of granulomas, less numerous inflammatory cells w
ith very few eosinophils, nearly normal surface epithelium (smaller surface
area occupied by nonciliated epithelium, absence of epithelial squamous ce
lls, normal frequence of goblet cells), rapid appearance of symptoms, and s
horter duration of the disease. It seems that the specific characteristics
of the injury-induced polyps results from a different mechanism of their fo
rmation, involving primarily abnormal mucosal repair and to a lesser extent
an inflammatory process.