Morphometry of lymphoid organs in health and disease

Morphometric study of the apical anatomy of C-shaped root canal systems in mandibular second molars

AIM

To investigate the apical anatomy of C-shaped canal systems in mandibular second molars by micro-computerized tomography (microCT) and stereomicroscopy.

METHODOLOGY

Forty-four permanent mandibular second molars with a C-shaped root canal systems from a native Chinese population were scanned at 100 microm intervals by microCT at a resolution of 30 x 30 microm. The apical 5 mm of each tooth was reconstructed three-dimensionally for visualization and classification of the canal configuration using Vertucci's criteria. The main and auxiliary (accessory) foramina were examined under a stereomicroscope.

RESULTS

Type IV and VIII canal configurations were most often found in the apical 5 mm of these canal systems. The prevalence of accessory canals, lateral canals, inter-canal communications and apical delta were 41%, 25%, 27% and 11%, respectively. Approximately 80% of C-shaped canals had 1-3 apical foramina; the prevalence of accessory foramina was about 48%. The mean distance between the main foramen and the anatomic root apex was 0.84 mm, and that between the accessory foramen and the apex was 1.61 mm. The mean (shortest and longest) diameters of major and accessory foramina were 0.19 - 0.32 mm and 0.07 - 0.10 mm, with a mean form factor of 0.73 and 0.82, respectively.

CONCLUSION

The apical anatomy of C-shaped root canal systems in mandibular second molars is extremely complex with many anatomical variations.

A morphometric method to discriminate normal from dysplastic/carcinoma in situ squamous epithelium in the human esophagus

The possibility to differentiate normal squamous epithelium from dysplastic/cis in the human esophagus by means of quantitative morphometry was investigated in surgical specimens from 31 consecutive patients. The epithelium was divided into three equal zones, and a total of 186 areas was investigated. Of all variables employed, the interzonal variation between the three epithelial layers was the one showing the highest degree of efficiency (95%) in discriminating normal esophageal epithelium from dysplastic/cis lesions. Nuclear density, nuclear area, nuclear irregularity, nuclear parallelity and nuclear ovality were the most efficient discriminatory individual morphological variables. A 100% sensitivity in discriminating normal squamous epithelium from dysplastic/cis through morphometric evaluation was achieved by considering nuclear area in the superficial zone, nuclear perpendiculairty in the intermediate zone, nuclear density in the total epithelial thickness and interzonal variation of these variables. On the other hand, the specificity in discriminating dysplasia/cis lesions from normal squamous epithelium was only 96.8%. This was due to the fact that one case, by visual impression considered as dysplasia, was morphometrically recorded as normal. The view of that case showed that our initial visual impression of a dysplastic lesion proved to be erroneous, and today that case would be recorded as a reactive lesion due to chronic inflammation.