Several studies have described the lymphatic architecture of periodontal tissues, including gingival tissues, using laboratory animals; however, no study has investigated human samples. In the present study, morphological characteristics and architecture of human gingival lymphatic vessels were investigated using clinically healthy gingival tissue with the aim of developing a drug delivery route through lymphatic vessels for clinical application. We collected free gingival tissue excised for therapeutic purposes during periodontal surgery from six patients, and produced frozen serial sections using the film-transfer method. The sections were then stained with 5'-nucleotidase to expose the lymphatic vessels, and threedimensional images of lymphatic vessels were reconstructed using 3D visualization software. Lymphatic vessels formed networks in the lamina propria on the oral epithelial side in free gingiva, presenting as a layer of rough irregular hexagonal meshes. Blind-ended vessels were observed entering connective tissue papillae through these meshes. The blind-ended vessels did not branch between the base of connective tissue papilla and rod-like structure at the tip, and were positioned at the center of each papilla. The lymphatic architecture of human free gingiva showed a similar distribution to that of blood vessels, although the lymphatic vessels were fewer in number than blood vessels. Activation of drainage through lymphatic vessels in gingiva is considered to be an important therapeutic measure in terms of improvement in edema. [MVRC 3(1): 17-24, 2009]

Introduction: Remodeling of tissues frequently occurs in the periodontal ligament during orthodontic tooth movement, including various changes in the vascular system. Although studies have investigated lymphatic vessels in the periodontal tissues, only a few studies have observed lymphatic vessels in the periodontal ligament, leaving many unclear aspects.Materials and Methods : Using mice (PN-0, 7 and 14 days old) with unerupted mandibular first molars, lymphatic distribution and the existence of lymphatic vessels in the periodontal tissues including the periodontal ligament were immunohistochemically (LYVE-1) observed.Results: Lymphatic vessels were observed beneath the oral epithelium, beneath the epithelium of the attached gingiva and inside the mandibular canal. Some lymphatic vessels beneath the epithelium of the attached gingiva were present along the alveolus. Although LYVE-1 positive structures distributed irregularly at each age in the areas of periodontal ligament at the future sites of crown formation, root formation and root apical region of root formation, no lymphatic vessels were identified.Discussion: In the periodontal ligament of adult mice, it was supposed that lymphatic vessels in the periodontal ligament except the apex of root were not distributed from initial stage, and lymphatic vessels were observed near the apex in adult mice was distributed during the apex of root completion stage. This might be connected to the presence of the Hertwig's epithelial sheath. [MVRC 4(1): 18-25, 2011]

We examined the normal intraneural vascularisation of the infraorbital nerve from the infraorbital foramen to the peripheral vibrissae to know a normal intraneural vascularisation in a peripheral pure sensory nerve. Indian ink was injected into the heart of the mouse for observation of vascular architecture in the infraorbital nerve. Three-dimensional images of blood vessels in the infraorbital nerve were then reconstructed using 3D visualization software.Optical microscopic observation of the peripheral section of the normal mouse infraorbital nerve (near mouse vibrissae) revealed fascicles of nerve fibers (10-60 μm in diameter) covered with perineurium, with one blood vessel normally present within the fascicle. Optical microscopic observation of the cross-section of normal mouse infraorbital nerve near the infraorbital foramen revealed nerve fiber fascicles (about 150 μm in diameter) covered with epineurium extending from proximal to peripheral areas, increasing in number as they branched. In the nerve fascicle surrounded by the perineurium near the infraorbital foramen, a few blood vessels were distributed. As the nerve fascicle branched and extended, the blood vessels also branched, providing one blood vessel in each nerve fascicle. There were multiple blood vessels in between the epineurium and perineurium. The blood vessels in nerve fascicles consisted of thin branches communicating with blood vessels outside of the perineurium. Nerve fascicles were surrounded by networks of blood vessels communicating with capillaries, arteriolae and venulae. Some blood vessels showed chain-like distribution in nerve fascicles. In the peripheral part of the infraorbital nerve, the blood vessel in the nerve fascicle exited before the nerve entered a vibrissa. The blood vessel goes out of the nerve to this point that enters the vibrissa.

No abstract