Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site aecom.UUCP Path: utzoo!linus!philabs!aecom!werner From: werner@aecom.UUCP (Craig Werner) Newsgroups: net.med Subject: The tooth -- the truth. Message-ID: <2044@aecom.UUCP> Date: Sat, 9-Nov-85 00:56:35 EST Article-I.D.: aecom.2044 Posted: Sat Nov 9 00:56:35 1985 Date-Received: Sun, 10-Nov-85 16:06:08 EST Distribution: na Organization: Albert Einstein Coll. of Med., NY Lines: 39 [Maybe I'm harping on this a little too much, but I don't believe in letting incorrect information go unchallenged.] From Wheater, et al. _Functional_Histology_ 1982 edition, p, 175. Fully formed enamel contains less than one percent organic material and is the hardest and most dense tissue in the body. The structure of mature enamel is not fully understood, but it appears that the process of mineralization is not uniform and, as a result, mature enamel consists of highly calcified prisms separated so so-called interprismatic material, which may differ only in the orientation of its crystals. Each prism extends from the dentino-enamel junction to the enamel surface and may represent the enamel from a single ameloblast [enamel-forming cell]. Overlying the ameloblast layer are several layers of cells, also of epithelial origin, which constitute the enamel organ. As enamel formation progresses, the Enamel Organ becomes reduced in thickness compared with the earlier stages of its [embryonic] development. At tooth eruption, the enamel organ, including the ameloblasts, degenerate leaving the enamel exposed to the hostile oral environments, completely incapable of regeneration. [Let me repeat the last line: completely incapable of regeneration.] [Let me translate the first: Microtubules are organic matter (made up of protein). If < 1% of the matrix is organic, that rules out the presence of microtubules, even if you don't beleive me that they only occur within cells - which they do.] [Incidentally, the text was accompanied by the Micrographs, so that one could look and account for all the layers with one's own eyes.] Hence we're back to Stoll's claim that microtubular "flow" regenerates Enamel being incompatible with the available evidence. I don't think he's being malicious in this respect - he's just repeated someone else's claim. -- Craig Werner !philabs!aecom!werner "I never knew there was anything wrong with me till I met Dr. Hackenbush."