Development of functional dentin incisors after a partial resection of the odontogenic organ of rat incisors

摘要: The resection of the labial half odontogenic organ rat incisors resulted in development teeth without enamel. Ten out 26 operated rats developed a functional dentin incisor, i.e. continuously growing and erupting tooth. These were little shorter much thinner than normal incisors. pulp presented structure. Periodontal ligament cement started to develop at lingual face gradually all tooth faces invested by these tissues. original socket space, accommodate tooth, was narrowed newly formed bone around inner socket. Eleven defective incisors; showed signs growth, however, their eruption impaired. operation failed five rats. incisor islands epithelial cells aspect dense mass mesenchyme cells. islands, densely packed, dark-staining encircling few pale-staining cells, merged gradually, forming root sheath cervical loop limiting long apical foramen. bulk bulbous part (apical bud) absent; thus, there no differentiation ameloblasts crown-analogue incisor. growth eruptive behaviour similar that indicates it has bear stem cell niche retain its regenerative capacity. As bud, this is apparently located stellate reticulum loop. putative molecular mechanisms related either maintenance or enamel are discussed. data our results, showing suggest root-analogue rodent an anatomic-physiological entity.