The collum angle is an angular measurement of the difference between the longitudinal axis of the crown and the longitudinal axis of the root. This is unusual case of the acute collum angle. Anterior cross bite is relatively a common presentation. In most cases, single or multiple tooth are involved. This article describes the rare case of 15 year old boy with the acute collum angle. The steps require for thorough diagnosis is elaborated. Attention must be given to root proximity to the cortical plate. Extrusive, intrusive and torquing forces must be carefully examined in teeth with large collum angles.