A morphometric study of bone and tooth volumes in the pipid frog Xenopus laevis (Daudin), with comments on the importance of tooth resorption during normal tooth replacement.
Volumetric estimations of teeth and bone on serial sections using a semiautomatic image analyzer indicate that, in the polyphyodont dentition of the pipid anuran Xenopus laevis (Daudin), the mean volume of the dentine composing the teeth is about 23.5% of the volume of the supporting maxillae and premaxillae. During tooth replacement, osteoclasts resorb up to 98% of the dentine. Teeth may be resorbed rather than shed in order to conserve tooth constituents because, if shedding of complete teeth did occur, a quantity of calcified tissue equal to perhaps 45 times the volume of the bone of the upper jaw might be lost over an animal's projected life span of about 13-15 years.
Shaw
J P
JP
Department of Anatomy, University Medical School, Edinburgh, United Kingdom.
D000818:Animals; D003804:Dentin / Q000033:anatomy & histology* / Q000502:physiology / Q000648:ultrastructure; D005260:Female; D008437:Maxilla / Q000033:anatomy & histology*; D008854:Microscopy, Electron; D014070:Tooth / Q000033:anatomy & histology* / Q000502:physiology / Q000648:ultrastructure; D014091:Tooth Resorption / Q000503:physiopathology*; D014982:Xenopus laevis / Q000033:anatomy & histology* / Q000502:physiology