Delivanis H P, Kuftinec M M
Am J Orthod. 1980 Oct;78(4):438-43. doi: 10.1016/0002-9416(80)90024-x.
Class II, Division 2 malocclusions show several common characteristics. One of the features is the presence of a deep overbite ("deckbiss"), which can be the result of an excessive eruption of the maxillary central incisors. This study tested the theory that the deep overbite, together with the apparent entrapment of the mandible, may be partly due to the bending of the maxillary central incisors or the presence of the Collum angle. In a comparison between the group of patients with Class II. Division 2 malocclusions and the control group, it was determined that the former group exhibited significantly larger Collum angles than the latter group (p < 0.005). It is suggested that in describing the maxillary incisor angulation in this type of malocclusion, the long axis of the crown, rather than the long axis of the tooth connecting the incisal edge to the apex, be used as a measure of their position.
II类2分类错牙合具有几个共同特征。其中一个特征是深覆牙合(“deckbiss”)的存在,这可能是上颌中切牙过度萌出的结果。本研究检验了这样一种理论,即深覆牙合以及明显的下颌受限,可能部分归因于上颌中切牙的弯曲或颈缘角的存在。在II类2分类错牙合患者组与对照组的比较中,确定前一组的颈缘角明显大于后一组(p < 0.005)。建议在描述这类错牙合中上颌切牙的角度时,使用牙冠的长轴,而不是连接切缘与根尖的牙齿长轴,来衡量它们的位置。