Tissue Changes During Tooth Eruption

An immunohistochemical study examining the role of collagen type VI in the rodent periodontal ligament

“…The apparent absence of stain for collagen type VI in the mid-zone cannot be explained by a simple lack of collagenous matrix in the region, as transmission electron microscope studies (Berkovitz et al, 1981;Berkovitz & Moxham, 1989) have demonstrated a homogeneous distribution of banded collagen fbrils across the ligament. The staining pattern may, however, be related to the architecture of the banded fibrils.…”

“…The staining pattern may, however, be related to the architecture of the banded fibrils. Although histological studies with silver-staining procedures have suggested that the collagen fibrils of the mid-zone are organized into a plexus of banded fibre bundles (Sicher, 1942), transmission electron microscope (Berkovitz & Moxham, 1989) and scanning electron microscope preparations of erupting incisor periodontal ligaments (Sloan, 1978) have suggested that the banded fibrils in the mid-zone are organized into longitudinal lamellae separated by fibroblast cytoplasmic processes. The morphological features of the ligament reported in the present study, using histological sections prepared by cryotechniques and scanning electron microscopy, are consistent with these latter observations, and no underlying bundles were evident in the mid-zone, despite the presence of coarse fibrous arrangements in the matrix of the alveolar zone.…”

“…The complex fibrous architecture of the rat incisor periodontal ligament enables the tooth and its supporting tissues to resist masticatory loads while, at the same time, allowing continuous tooth eruption to compensate for tooth attrition (Sloan, 1982;Berkovitz & Moxham, 1989). Although it is generally recognized that the collagen fibres of the periodontal ligament are arranged into a continuous plexus, which connects the cemental aspect of the tooth root and the supporting alveolar bone in fully erupted teeth of limited growth, the arrangement of the fibres in the continuously erupting incisor is less well established (Sloan, 1982).…”

“…Although it is generally recognized that the collagen fibres of the periodontal ligament are arranged into a continuous plexus, which connects the cemental aspect of the tooth root and the supporting alveolar bone in fully erupted teeth of limited growth, the arrangement of the fibres in the continuously erupting incisor is less well established (Sloan, 1982). Because autoradiographic and biochemical studies have demonstrated high rates of collagen turnover in the mid-zone of the periodontal ligament (Rippin, I976, 1978;Sodek, 1977), it has been suggested that there is a rapidly remodelling 'zone of shear' between the alveolar and cemental regions of the ligament which facilitates, or even generates, the forces necessary for incisor eruption (Beertsen & Everts, 1977;Berkovitz & Moxham, 1989). At the same time, however, to accommodate these events it was necessary to suggest that the remodelling fibrous bundles of the alveolar and cemental zones were interconnected by a complex plexi-0018-2214 9 1993 Chapman & Hall form arrangement in the mid-zone of the ligament (Sicher, 1942), though there is evidence which suggests that the collagenous matrix is organized into fine laminates in this region (Sloan, I982;Berkovitz & Moxham, 1989).…”

Estudo histomorfometrico do ligamento periodontal de incisivos de ratos em erupção impedida e desimpedida

“…Como consequência destes experimentos surgiram as teorias da erupção dental e a discussão das propriedades funcionais dos dentes e do periodonto de sustentação (BERKOVITZ, 1976); SHULMAN, 1977).…”