A dilator/insert internally support the lateral nasal walls and securely stay in place without discomfort. It stays inserted by a pair of ledges (9a and 10a) and/or catches (7a and 8a), each resting behind a respective: limen nasi ridge (a somewhat vertical central protuberance on a lateral nasal wall);...http://www.google.de/patents/US6270512?utm_source=gb-gplus-sharePatent US6270512 - Internal nasal dilator
