“…Different hypotheses for the pathogenesis of SCC have been stated: (1) residual mucosa trapped in the bone during the surgical procedure [1,3,4,6,9,15,24,[31][32][33]; (2) retention of blood or sinus tissue uid that forms a closed space without communication with the outside [1,8,31,[34][35][36]; (3) a racial predisposition to secondary mucoceles after chronic sinusitis surgery [6,32,37]; (4) implantation of sinus mucosa in a different location [2,5,8,15,25]; (5) early closure of the ostium for the natural drainage before the complete mucosalization of the sinus, with regeneration of granulation tissue [3,9,11,32,38-43]; (6) trauma, being the SCC secondary to accidental traumatisms or surgery (especially to the Caldwell-Luc procedure) [6,43]; (7) in ammation, being the SCC secondary to a continuous in ammatory process in a scarcely ventilated space, due to the occlusion of the drainage ostium [6,32]; and (8) metaplasia from irritation, changing the original strati ed epithelium of the nasal mucosa to respiratory epithelium [39,41]. (9) Pluripotentiality of odontogenic epithelium in a cystic lesion with odontogenic origin with the presence of respiratory epithelium [5,12,15,25,37,44].…”