Page 87 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

increase of congestion of the vascular structures in bone and soft tissue with
focal hemorrhage/extravasation of erythrocytes in the surrounding soft tissue. Furthermore, a slight increase in osteoblastic and osteoclastic activity was
noted. The teeth showed no pathological changes except for a focal irregularity
of cement which was anatomically present on the lingual site. Group III showed
a marked loss of vascularity of the bone and soft tissue, with an increase of
fibrotic soft tissue. The bone tissue was vital, although marked osteoblastic
activation and an increase of osteoclastic bone resorption was observed [Fig.
3A]. The teeth had an avascular pulp with irregular deposits of cement at the
interface between the teeth and the adjacent soft tissue on the lingual side.
Group IV showed further general depletion of vascular structures and an
increase of fibrosis in bone and soft tissue when compared to group III. The
fibroblasts showed radiation-induced changes (i.e. enlarged, vesicular nuclei)
[Fig. 3B]. The bone tissue showed small necrotic fields, although the majority of 4 the bone tissue was vital. Some of the vital bone was devoid of an osteoblastic
lining (periosteum), whilst multifocally, an increase in resorptive activity by multinucleated osteoclasts was observed. The teeth had an avascular pulp and showed partially resorbed cement on the lingual side of the teeth.
None of the groups showed thrombosis, vasculitis or reactive changes of the endothelium. Finally, no evident difference in observations between the irradiated site and the contralateral site was observed.
Figure 3. Micrographs of the bone histology samples stained with H&E. Panel A shows plump and enlarged osteoblasts (small arrows) and an increased number of multinucleated osteoclasts (large arrows) signaling increased bone turnover. Panel B shows enlarged atypical nuclei of the fibroblasts in the fibrous tissue, commonly associated with radiation induced changes.
Onset of late irradiation effects
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