Oregon has joined those jurisdictions holding that teeth are not "dangerous weapons" for purposes of a statute that enhances punishment for crimes in which they are employed. The defendant had employed said teeth Mike-Tyson-style to detach part of his neighbor's earlobe during a 2008 fight. (In a surprise twist, alcohol was involved.) The Oregon Court of Appeals upheld his conviction for second-degree assault, but held the use of teeth did not make this a first-degree assault. Oregon v. Kuperus, No. A139824 (Or. App. Mar. 23, 2011).
Under state law, a "dangerous weapon" is "[a]ny weapon, device, instrument, material or substance which under the circumstances in which it is used, attempted to be used or threatened to be used, is readily capable of causing death or serious physical injury." Or. Rev. Stat. § 161.015. You could argue that teeth are "instruments," maybe, but as the court held, the better interpretation is that the list is meant to refer to items that are "external to the human body." Without that restriction, there would be no reason to have multiple degrees of assault because almost anything could be considered a "dangerous weapon." See also People v. Owusu, 712 N.E.2d 1228 (N.Y. 1999) (holding under a similar statute that teeth were not "dangerous implements," noting that "Mr. Owusu's teeth came with him").
For similar reasons, the Oregon court noted, it had held in 1975 that bare hands were not "dangerous weapons." State v. Weir, 540 P.2d 394 (1975). Pretty much every assault involves the use of a hand in one way or another, the court held then, so there would not have been much point in creating (for example) third-degree assault because that law would never be used. The only thing really remarkable about this is that the state insisted on arguing that bare hands are "weapons." Unless the defendant is Chuck Norris, this is a pretty ridiculous argument.
And since it's ridiculous, California also tried it. See "Ninth Circuit Grapples With Whether Bare Hands Are Weapons," Lowering the Bar (Mar. 23, 2010). I found it remarkable that it took that court nine pages to find that assaulting someone with no weapon couldn't be considered assault with a dangerous weapon, but I guess what's more remarkable is that he was convicted of that in the first place. As in the Oregon case, though, the Ninth Circuit held that there has to be some distinction between simple assault and assault with a dangerous weapon. "We find it difficult to see how someone could be accused of assault without [having used] a body part in some way," the court noted, and it does seem hard to argue with that.