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- Ikawa, Takahiro, et al.
(author)
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Ridge reconstruction in damaged extraction sockets using tunnel beta-tricalcium phosphate blocks : A 6-month histological study in beagle dogs
- 2020
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In: Journal of Periodontal Research. - : John Wiley & Sons. - 0022-3484 .- 1600-0765. ; 55:4, s. 496-502
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Journal article (peer-reviewed)abstract
- Objective The present study aimed to evaluate the histological outcome of tunnel beta-TCP blocks grafting in extraction sockets missing the buccal bone wall, after 6 months of healing. Background Tunnel beta-tricalcium phosphate (beta-TCP) blocks made of randomly organized tunnel-shaped beta-TCP ceramics appeared promising for alveolar ridge preservation in tooth extraction sockets missing the buccal bone, in a previous study in dogs, with a 2-month healing time. Methods In six beagle dogs, the maxillary first premolars were extracted and the buccal bone was surgically removed to create bone defects of 4 mm (mesio-distal) x 5 mm (apico-coronal) x 4 mm (bucco-palatal). Thus, extraction sockets missing the buccal bone plate were grated with tunnel beta-TCP blocks (test) or left empty for spontaneous healing (control). Histology/histomorphometry was performed after 6 months of healing. Results The horizontal bucco-palatal width of the alveolar ridge was significantly greater at test sites than at control sites. The amount of mineralized tissue was greater at test sites (57.8% +/- 11.1%) than at control sites (28.9% +/- 8.5%), while the amount of connective tissue was significantly greater at control sites (41.7% +/- 6.4%) than at test sites (19.6% +/- 9.2%). No significant difference was found between sites in terms of basic multicellular units and bone marrow. Residual beta-TCP at test sites was 5.8% +/- 3.2%. Conclusion Grafting with tunnel beta-TCP block significantly limited the resorption of the alveolar ridge at extraction sockets missing the buccal bone compared with sites left to heal spontaneously, even after 6-month follow-up.
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| 2. |
- Yanagisawa, Akihiro, et al.
(author)
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Amyloid deposits derived from transthyretin in the ligamentum flavum as related to lumbar spinal canal stenosis.
- 2015
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In: Modern Pathology. - : Elsevier BV. - 0893-3952 .- 1530-0285. ; 28:2, s. 201-207
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Journal article (peer-reviewed)abstract
- Amyloidosis is a protein conformational disorder with the distinctive feature of extracellular accumulation of amyloid fibrils that come from different proteins. In the ligamentum flavum of the lumbar spine, amyloid deposits were frequently found in elderly patients with lumbar spinal canal stenosis and were at least partially formed by wild-type transthyretin. However, how amyloid deposits in the ligamentum flavum affect lumbar spinal canal stenosis has remained unclear. In this study, we analyzed clinical, pathologic, and radiologic findings of patients with lumbar spinal canal stenosis who had amyloid deposits in the ligamentum flavum. We studied 95 ligamentum flavum specimens obtained from 56 patients with lumbar spinal canal stenosis and 21 ligamentum flavum specimens obtained from 19 patients with lumbar disk herniation. We evaluated histopathologic findings and clinicoradiologic manifestations, such as thickness of the ligamentum flavum and lumbar spinal segmental instability. We found that all 95 ligamentum flavum specimens resected from patients with lumbar spinal canal stenosis had amyloid deposits, which we classified into two types, transthyretin-positive and transthyretin-negative, and that transthyretin amyloid formation in the ligamentum flavum of patients with lumbar spinal canal stenosis was an age-associated phenomenon. The amount of amyloid in the ligamentum flavum was related to clinical manifestations of lumbar spinal canal stenosis, such as thickness of the ligamentum flavum and lumbar spinal segmental instability, in the patients with lumbar spinal canal stenosis with transthyretin-positive amyloid deposits. To our knowledge, this report is the first to show clinicopathologic correlations in transthyretin amyloid deposits of the ligamentum flavum. In conclusion, transthyretin amyloid deposits in the ligamentum flavum may be related to the pathogenesis of lumbar spinal canal stenosis in elderly patients.Modern Pathology advance online publication, 5 September 2014; doi:10.1038/modpathol.2014.102.
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