By studing the growth and replacement sts tus of teeth in the 41 specimen,we have found that all deciduous teeth,which are I_1,I_2,I_3,C,PM_1,PM-3,grew out in about two weeks after birth,and the replacement time of permanent teeth were as follows :I_1,2～3 years old;

The total rates of renewing were 265. 03%～429.13%on the inner line and 127. 33%～193. 95%on the outer line. From this, it might be infered that the teeth of inner and outer line renewing 3～4and 2 times, respectively in a year. Grass carp superseded its teeth one by one and alternately from either side.

Others, like the site of the replacement tooth bud, suggest that initiation may take place in already committed epithelium from the first initiation event in the larval stage.

The adult dentition is characterized by the presence of replacement tooth series with the lamnoid tooth pattern.

Current replacement tooth methods use synthetic materials that can elicit an immune induced host rejection response.

The dentist needs to dye the replacement tooth structure to match the patient's teeth.

By studing the growth and replacement sts tus of teeth in the 41 specimen,we have found that all deciduous teeth,which are I_1,I_2,I_3,C,PM_1,PM-3,grew out in about two weeks after birth,and the replacement time of permanent teeth were as follows :I_1,2～3 years old;I_2,3～4 years old;I_3,4～5 years old;C,5～6 years old;M_1,1～2 years old;M_2,2～3 years old;M_3,3～4 years old.The oldest one was 27 years old with identification of the teeth.Ac- cording to the degrees of the teeth wear and tear,and the growth status...

By studing the growth and replacement sts tus of teeth in the 41 specimen,we have found that all deciduous teeth,which are I_1,I_2,I_3,C,PM_1,PM-3,grew out in about two weeks after birth,and the replacement time of permanent teeth were as follows :I_1,2～3 years old;I_2,3～4 years old;I_3,4～5 years old;C,5～6 years old;M_1,1～2 years old;M_2,2～3 years old;M_3,3～4 years old.The oldest one was 27 years old with identification of the teeth.Ac- cording to the degrees of the teeth wear and tear,and the growth status of the horns,these takins were divided into six age-classes.

This paper presents the results of a apreliminary study on the teethrenewing regularity of yearling Grass carp[Ctenophyaryngodon idella(Cuvier et Valenciennes)] cultured in pond. Materials were collected from march 1990 to Ferbruary 1991, and 505 samples were measured.The fish had 9 different dental formulas,of which the common were 2,5/4,2 and 2,4/5,2, accounting for 95.64%, 67.72%fish replaced their teeth and each of them changed 1.64 teeth in average. The rates of renewing were higher in spring and summer...

This paper presents the results of a apreliminary study on the teethrenewing regularity of yearling Grass carp[Ctenophyaryngodon idella(Cuvier et Valenciennes)] cultured in pond. Materials were collected from march 1990 to Ferbruary 1991, and 505 samples were measured.The fish had 9 different dental formulas,of which the common were 2,5/4,2 and 2,4/5,2, accounting for 95.64%, 67.72%fish replaced their teeth and each of them changed 1.64 teeth in average. The rates of renewing were higher in spring and summer than in autumn and winter.2～3peaks of teeth renewing rates occured in a survey year.and the first one mostly appeared in the period of April to August. The total rates of renewing were 265. 03%～429.13%on the inner line and 127. 33%～193. 95%on the outer line. From this, it might be infered that the teeth of inner and outer line renewing 3～4and 2 times, respectively in a year. Grass carp superseded its teeth one by one and alternately from either side.In addition, the biological significance of the teeth-renewing regularity and its significance in preventing and treating the fish enteritis was discussed.