Alan, I have no such research, not positive research anyway. However, when discussing the memoirs of "Rebel Private: Front and Rear", an army friend mentioned the episode where the author spoke about being shot in the foot during one of the major ANV battles. Older men might recall that was sometimes a self inflicted wound in the Vietnam War era. Personaly, I am hesitant to make unfavorable judgements on combat veterans. The subject in this instance transferred from the 5th TX Infantry to the 8th TX Cavalry, both of whom were very distinguished units. He served for the duration of the War in the East.
Not trying to snub your question. No doubt, some men sustained self-inflicted wounds. I would imagine there were a few artillery soldiers who had missing front teeth.