The deciduous maxillary central incisor is single-rooted, and the ratio of its root length to its crown length is ().
A. 1:1
B. 1:2
C. 1:3
D. 2:1
E. 3:1
查看答案
The mixed dentition period shows at ()
A. the age of 2~6
B. the age of 2.5~6
C. the age of 6~12
D. the age of 9~12
E. the age of 6~15
The correct description about the transverse curve of occlusion is ()
A. it is located on the maxilla
B. it is located on the mandible
C. it is located on both the maxilla and the mandible
D. it is a downward convex curve that connects the cusps of canines on the both sides
E. none of the above
The function of masticatory movement can be divided into three stages: ()
A. Protruding, retruding and lateral movements.
B. Cutting, crushing, and grinding movements.
C. Front and back, opening and closing, and lateral movements.
D. Mouth opening, food locating, and chewing movements.
E. Centric occlusion, small open bite occlusion, and return to centric occlusion.
Attrition is ()
A. non-physiological
B. a physiological phenomenon of natural consumption of hard dental tissue
C. caused by tooth brushing
D. All of the above.
E. None of the above.
微信支付 
支付宝支付