【摘要】 将198个颅骨及243个下颌骨(性别未作鉴定)分为不同年龄的四组:2～5岁者(仅有5对乳牙槽);6～12岁者(已出现第一恒磨牙槽);12～17岁者(已出现第二恒磨牙槽)及18岁以上者(已出现第三磨牙槽,除去老年)。对上、下颌牙槽弓进行了测量、分析,得出以下初步结果: 1.国人牙槽弓的指数在成人分别为:上颌:118.2,下颌:77.6。 2.两内侧门牙间正中点至犬牙前外侧缘最突出点间之距离,分别为左:19.6毫米,右:19.8毫米(上颌);左:13.8毫米,右:14.0毫米(下颌)。 3.犬齿前外侧缘最突出点至第二恒磨牙槽外缘最突出点间之距离分别为:左:32.7毫米,右:32.7毫米(上颌);犬牙牙槽前外缘最突出点至第三磨牙牙槽外缘最突出点之距离:左:43.7毫米,右:44.5毫米(下颌)。 4.成人牙槽弓的辐辏距离(Convergence distance)和辐辏角(Convergence angle)分别为42.9毫米,43.1度(上颌);26.4毫米,51.1度(下颌)。 5.上、下颌牙槽弓在不同年龄组均呈现大多数不对称性;尤以上颌为甚,占82.2％《成人);下颌者为67.0％(成人)。更多还原

【Abstract】 Measurements were made from different landmarks of the superior and inferior alveolar arches in 197 skulls and in 243 mandibles. The data were divided into four groups: 2-5 years old(only deciduous teeth in occlusion); 6-12 years old(first permanent molars in occlusion, but not second molars); 12-17 years old (second permanent molars in occlusion, but not third molars); adults (third molars in occlusion, not including the aged). The results from the observation of the adult specimens are as follows:The indices of alveolar arches are about 118.2 in maxilla; 77.6 in mandible.The average distances from Prosthion (incision in mandible) to Canine point are 19.6mm (left side), 19.8mm (right side) in maxilla; 13.8mm (left side), 14.0mm (right side) in mandible.The distances from canine point to ectomolare (the lateral most margin of the al veolar cavities of second molars in maxilla; of third molars in mandible) are about 33.7mm (left and right sides) in maxilla; 43.7mm (left side), 44.5mm (right side). in mandible.The convergence distance of alveolar arches is 42.9mm in maxilla; 26.4mm in mandible and the convergence angle is 51.5° in mandible; 43.1° in maxilla.It was found that most of the superior and inferior alveolar arches were asymmetrical, the percentages of asymmetry being 82.2 in maxilla and 67.0 in mandible of adults.更多还原