Individual variations of root morphology in the post-canine teeth of squirrel monkeys

松鼠猴后犬齿牙根形态的个体差异

• 批准号: 11640711
• 负责人: KONDO Shintaro
• 金额: $ 1.66万
• 依托单位: Showa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640711/
• 关键词: primate; new world monley; Saimiri; post-canine teeth; tooth root; interradicular dentine process; molar reduction; deciduous premolars; 小臼歯; 歯槽; 大臼歯

The morphological characteristics of the roots of the post-canine teeth of squirrel monkeys (Saimin) were investigated. Materials used were 98 skulls and their extracted teeth.Maxillary molars had three roots, two buccal and one lingual, which arose from a common root.trunk. The roots were often fused in the distal molars, with the buccal roots most often fused to each other. When the maxillary molars had three roots, the interradicular dentine process running between them was Y- or T-shaped ; when they had two roots, it was a straight line. The root structure of M3 had a more reduced pattern than those of M1 and M2.The mandibular molars had mesial and distal roots. These two roots sometimes fused completely in M3. When the fusion of the two roots was slight, it occurred on the lingual side, but not on the buccal side, and it was gutter-shaped. The gutter-shaped root was most frequently found in M2.When the mandibular molars had two separated roots, the interradicular dentine process was a straight line. Maxillary permanent premolars had the most commonly two roots, one buccal and one lingual, while in more than half of the cases P2 had a single root. Of the maxillary deciduous teeth, dp2 had a single root, but dp3 and dp4 had three roots, two buccal and one lingual. The dp4 teeth resembled M1 in both crown and root structures, but dp4 had more flared and slenderroots than Ml. Most of the mandibular permanent premolars had a single root. Of the P4 teeth, 31.6% had bifurcated roots situated mesiodistally and had a well-developed talonid. The mesial mandibular deciduous premolars had only dne root, as did their successors. The dp4 teeth had both mesial and distal roots, a pattern identical to M1.

对松鼠猴（Saimin）后犬牙根部的形态特征进行了研究。所用材料为98颗头骨及其拔出的牙齿。上颌磨牙有3个牙根，2个颊牙根和1个舌牙根，由共同的牙根和树干产生。牙根通常在远中磨牙中融合，其中颊根最常彼此融合。当上颌磨牙有三根时，其间的根间牙本质突呈Y形或T形；当它们有两个根时，它是一条直线。 M3的牙根结构比M1和M2的牙根结构更加缩小。下颌磨牙有近中牙根和远中牙根。这两个根有时在 M3 中完全融合。当两牙根融合较轻微时，发生在舌侧，而颊侧则不发生，呈沟状。沟状牙根最常见于M2。当下颌磨牙有两个分离的牙根时，根间牙本质突起是一条直线。上颌恒前磨牙最常见有两个牙根，一个颊牙根，一个舌牙根，而在一半以上的病例中，P2 具有单牙根。上颌乳牙中，dp2 为单牙根，而 dp3 和 dp4 则为 3 根，2 颗颊牙，1 颗舌牙。 dp4牙齿的牙冠和牙根结构与M1相似，但dp4比Ml有更多的喇叭形和细长的牙根。大多数下颌永久前磨牙具有单根。在 P4 牙齿中，31.6% 的牙根分叉，位于近中远侧，并且具有发育良好的爪骨。下颌内侧乳牙前磨牙只有根，它们的后继牙也是如此。 dp4 牙齿具有近中牙根和远中牙根，其模式与 M1 相同。

项目成果

Kondo S., Natori M., Hanamura H, Amino S.: "An odontometrical study of the molariform teeth in squirrel monkeys(Saimiri)"J Growth. 40(in print). (2001)

Kondo S.、Natori M.、Hanamura H、Amino S.：“松鼠猴（Saimiri）磨牙状牙齿的牙测量研究”J Growth。

Kondo S., Natori M., and Hanamura H: "Morphological characteristics of the roots of the molars of squirrel monkeys (Saimiri). In'- Brook, A.(ed.), "Dental Morphology 2001""Sheffield Academic Press Ltd. 87 (2001)

Kondo S.、Natori M. 和 Hanamura H：“松鼠猴 (Saimiri) 臼齿根部的形态特征。In- Brook, A.(ed.)，“牙科形态学 2001””谢菲尔德学术出版社有限公司

Kondo S., Natori M., Hanamura H: "Morphological characteristics of the roots of the molars of squirrel monkeys (Saimiri).In : Brook, A.(ed.),"Dental Morphology 2001"pp.87-100"Sheffield Academic Press Ltd.. 350 (2001)

Kondo S.、Natori M.、Hanamura H：“松鼠猴磨牙根部的形态特征（Saimiri）。见：Brook, A.（编辑），“Dental Morphology 2001”pp.87-100“Sheffield