Background. Histologic sectioning of extracted teeth has been conventionally used as the gold standard to which new diagnostic modalities are compared. Sectioning is destructive, with demands on both time and personnel. In cariology research there is an increased demand for a nondestructive technique which will not only simplify the investigative procedure but also allow for the preservation of sample for longitudinal use. Micro-computerized tomography (micro-CT) provides 3-dimensional information of the sample which can also be visualized in discrete sections.

Microgenomics implies the precise molecular analysis of a very small pure cell population that has been microdissected from biopsies. Gene expression profile analysis using microarrays provides information to elucidate the signaling pathways that drive tumorigenesis and behavior of tumors. RNA was isolated and amplified from 5 samples of formalin-fixed paraffin-embedded, (FFPE) decalcified ameloblastoma tissue using the laser capture microdissection technique. To assess the quality and quantity of the RNA, samples were analyzed using the NanoDrop spectrophotometer, as well as the 2100 ribosomal RNA Bioanalyzer. The aminoallyl antisense RNA was hybridized to 40000-oligonucleotide expression microarray using human universal reference RNA. GeneSpring software was used to analyze the microarray data and the PathArt database was utilized to perform gene-signaling pathway enquiries. The results showed 38 upregulated genes, twofold, in 5 of the 5 samples, and 988 overexpressed genes, twofold, in 2 of 5 samples. Among the 38 genes, WNT and LGR4, part of the breast cancer pathway, were overexpressed, as well as tenascin from the melanoma pathway.