Lymphatic networks in the periodontal tissue and dental pulp as revealed by histochemical study

Abstract

The structural organization and fine distribution of the lymphatic networks in the periodontal tissues (gingiva, periodontal membrane, and alveolar process) and dental pulp of animals and humans were reviewed with special reference to histochemical examination by light and electron microscopy. The distinction between lymphatics and blood vessels was made on cryostat sections of undecalcified and calcified teeth treated with EDTA solution and whole mount preparations of periodontal membranes using 5'-nucleotidase (5'-Nase)-alkaline phosphatase (ALPase) double staining. This staining procedure allowed lymphatic vessels in the periodontal tissue and dental pulp to be differentiated from blood vessels. The specificity and localization of the enzyme reactions were confirmed by comparative histochemical studies of the same specimen with light microscopy and scanning or transmission electron microscopy. Well-developed 5'-Nase-positive lymphatic networks were observed on the tissue sections and whole mount preparations of the gingiva, periodontium, and dental pulp. More lymphatic vessels were seen in the root area of the periodontium than in the cervical area. In the dental pulp, lymphatic vessels were more numerous in the central part than in the peripheral odontoblastic layer. These distributions of the lymphatic capillary networks are discussed in relation to their ability to supply lymph to the teeth.

Lymph drainage in the human dental pulp

“…Taking into account the histological criteria for lymph vessels and the morphological findings described by us, proof of a specialized lymph vessel architecture in the dental pulp has been established. This result confirms the enzyme-histochemical and immunohistochemical findings of lymphatic vessels in the dental pulp (Matsumoto et al, 1997(Matsumoto et al, , 2002Sawa et al, 1998, respectively). …”

“…For the maintainance of interstitial fluid equilibrium in the pulpal tissue, the existence of an effective lymph drainage has been postulated (Bernick, 1977;Marchetti et al, 1992;Matsumoto et al, 2002). The need for a sufficient clearance of tissue fluid and cell components of healthy and inflamed pulpal tissue is due to the surrounding dentin that imposes narrow limits on the compliance of the pulpal tissue (Heyeraas and Berggreen, 1999).…”

Lymphatic architecture of human periodontal tissue beneath the oral epithelium of the free gingiva

“…sels have mainly been limited to experimental animals [8][9][10][11][12][13][14][15][16][17][18][19][20][21]34) . Recent advances in staining methods for identification of lymphatic vessels include the use of 5'-Nase in enzyme histochemical staining [23][24][25][26]35) , and vascular endothelial growth factor receptor-3 (VEGFR-3), podoplanin, D2-40, prox-1, lymphatic vessel hyaluronan receptor-1 (LYVE-1) and angiopoietin-2 in immunohistochemical staining [35][36][37][38] .…”

“…In addition, clinical lymphography can be used for diagnostic purposes 39,40) . However, to date, only animal studies have focused on the local architecture of capillary lymphatic vessels [8][9][10][11][12][13][14][15][16][17][18][19][20][21] . In an attempt to develop drug delivery routes for anticancer agents using lymphatic vessels in the head and neck region, especially beneath the oral mucosa 5-7) , Fujimura et al conducted an investigation of the lymphatic architecture in the head and neck region of experimental animals, and reported the existence of lymphatic vessels in the gingival epithelium 14) .…”

“…Previous studies have described the lymphatic architecture in periodontal tissue, including gingiva, using laboratory animals [8][9][10][11][12][13][14][15][16][17][18][19][20][21] ; however, none of the studies has investigated human gingiva. In the present study, we observed the morphological characteristics and architecture of clinically healthy gingival tissue obtained by excision during periodontal surgery with the aim of investigating the development of a drug delivery route through the lymphatic vessels for clinical application.…”