Corticotomy and compression osteogenesis in the posterior maxilla for treating severe anterior open bite.

A new technique is described for outpatient treatment of anterior open bite. The compression osteogenesis method with a two-stage corticotomy was used in the posterior maxilla to treat a woman with severe anterior open bite. Three-week post-surgical compression using anchor plates and elastics repositioned the posterior maxillary bone/teeth segments by 7 mm to the ideal superior position. The patient had a stable skeletal position of the maxilla at 14-month follow-up with satisfactory results and no complications after orthodontic treatment. This technique appears to be an efficient option for treating patients with anterior open bite.

Infiltrating lipoma of the mental region: report of a case.

Lipoma is an uncommon tumour in the oral cavity. Infiltrating lipoma is extremely rare. An infiltrating lipoma of the mental region in a 48-year old woman is reported. Wide myectomy was performed, and follow-up showed excellent healing without recurrence.

Distribution of substance P and calcitonin gene-related peptide-like immunoreactive nerve fibers in the rat temporomandibular joint.

The density and distribution of substance P-like immunoreactive (SP-LI) and calcitonin gene-related peptide-like immunoreactive (CGRP-LI) nerve fibers in rat temporomandibular joint (TMJ) were investigated in whole-mount preparations and frozen sections by immunohistochemistry with the avidin-biotin-peroxidase complex method. Both types of immunoreactive nerves were observed primarily in the joint capsule, the peripheral articular disc, the synovial membrane, and the periosteum. The distribution of CGRP-LI nerves was similar to that of SP-LI nerves. The anterior portion of the joint capsule and disc was most densely innervated, followed by the posterior, lateral, and medial portions. In addition, CGRP-LI nerves were more numerous and more dense in immuno-intensity than SP-LI nerves. In the synovial membrane, many SP- and CGRP-LI nerves terminated in the subsynovial layer, but some branches extended into the superficial synovial lining layer close to the joint cavity. Immunolabeled nerves were prominently located in the disc attachment and peripheral portion of the disc, and occasional nerves were located in the dense collagenous disc band as an actual disc. However, no fibers were detected in the central disc band. Thus, most of the disc was not innervated by any nerves. The present study provides a morphological basis for the possible roles of neuropeptides in endocytosis by synoviocytes, regulation of blood flow in the synovial membrane, nociception mechanisms of the TMJ, and modulation of the inflammatory response in the TMJ.

Immunocytochemical localization of cathepsin D in rat junctional epithelium.

Localization of cathepsin D was studied in the junctional epithelium (JE) of healthy rat gingivae by immuno-light and -electron microscopy, by means of both the avidin-biotin-peroxidase complex method and a colloidal gold IgG method. At the light-microscopic level, cathepsin D was demonstrated in the JE and oral sulcular epithelium (OSE). Cathepsin D immunoreactivity was remarkable in the coronal portion of the JE and decreased toward its apical portion. However, cathepsin D immunoreactivity in the basal cell layer of the JE was negligible or negative. In the OSE, the granular layer was positive for cathepsin D. In the adjacent connective tissue, many macrophage-like cells (not clear at this level) close to the basal cell layer showed strong immunoreactivity. At the electron microscopic level, cathepsin D was found in the primary lysosomes and trans-cisternae of Golgi apparatus in the JE cells. These lysosomes were often fused together or were fused with cathepsin D-negative intracytoplasmic vacuoles to form secondary lysosomes, which indicated that intracellular digestion may have been in progress. However, neutrophils contained few gold particles based on cathepsin D. It is likely that the amounts of cathepsin D contained in the JE cells and macrophages are larger than those of cathepsin D contained in the neutrophils. These findings provided morphological evidence that JE cells have the same endocytotic capacity as macrophages and neutrophils, and that JE cells participate in the intracellular digestion that is carried out by lysosomal enzymes such as cathepsin D. It is suggested, in addition, that maximum intracellular digestion occurs in the coronal portion of the JE.

Immunohistochemical study of nerve fibres with substance P- or calcitonin gene-related peptide-like immunoreactivity in the junctional epithelium of developing rats.

The beginning of innervation in the junctional epithelium of maxillary first molars was examined in gingival tissues from 19 to 32-day-old rats. Substance P- or calcitonin gene-related peptide (CGRP)-like immunoreactivity was demonstrated by the avidin-biotin peroxidase complex method. In 19-day-old rats, nerve fibres with substance P- or CGRP-like immunoreactivity were seen in the connective tissue and oral epithelium, but not in the reduced enamel epithelium, which would be transformed into the junctional epithelium. In 21-day-old rats, the fibres with substance P- or CGRP-like immunoreactivity formed a plexus in the oral sulcular epithelium and thin varicose fibres were seen for the first time entering the adjacent reduced enamel epithelium. These fibres also penetrated the middle portion of the reduced enamel epithelium, but did not reach the cuboidal reduced ameloblasts. More nerve fibres had CGRP-like immunoreactivity than substance P-like immunoreactivity. In 23-day-old rats, many fibres with both immunoreactivities were seen in the basal layers of the junctional epithelium, but only a few were seen in its superficial layers. In 28-32-day-old rats, numerous fibres with both immunoreactivities were distributed in the whole junctional epithelium and showed a similar pattern of innervation. For all immunoreactive fibres, the density in the middle portion in the junctional epithelium was the highest. The nerve plexus was formed in the basal layers and some fibres with a varicose appearance were found in the superficial layers.

Differences in the transport systems between cementocytes and osteocytes in rats using microperoxidase as a tracer.

Microperoxidase (MP) tracer was injected intravenously into rats to investigate any differences in transport pathways of tissue fluids in the lacunae and canaliculi of cementum and bone. Light microscopically, in deep cementum lacunae, pericellular spaces contained a large amount of MP, while close to the cementum surface, the spaces contained scarcely any. In bone, MP was detected throughout all pericellular spaces. MP was detected intracellularly as granular reaction products in most cementocytes and osteocytes. Electron microscopically, MP was found in the pericellular spaces of cementum and bone lacunae, particularly on collagen fibrils and amorphous material. MP deposits were also intense along the plasma membrane of cementocytes in the deep cementum and along the innermost edge of the deep cementum matrix and bone matrix. In uptake of MP by cementocytes, although extracellular tracer was deposited extensively along the plasma membrane of the deeply positioned cementocytes, uptake by these deep cementocytes was less than that of those close to the surface. However, in bone, most osteocytes showed uniform uptake. These results suggest that the transport pathways for tissue fluids in cementum are in the pericellular spaces, but that cementum has an uneven circulation of tissue fluid. In cementum, although there seems to be a well-developed canalicular system to transport tissue fluid into the deep regions, the deep cementocytes had less endocytotic ability than those close to the surface.

Immunocytochemical localization of cathepsin D in the rat osteoclast.

We performed immunocytochemical localization of cathepsin D in osteoclasts of the proximal growth plate of the rat femurs using both the avidin-biotin-peroxidase complex method for cryo-semi-thin (1 micron) sections and the colloidal gold-labeled IgG method for K4M ultra-thin sections. At the light microscopic level, cathepsin D immunoreactivity in the osteoclasts appeared at the vesicles, granules, and/or small vacuoles. They were distributed throughout the cytoplasm of each cell and were relatively numerous close to the bone surface. This antigen could not be detected at the eroded bone surface. As for other cells, immunoreactivity was seen only in the lysosomes of osteoblast-like cells. Immunoreactivity in the osteoclasts was stronger and greater in the density and number than in osteoblast-like cells. At the electron microscopic level, osteoclasts with well-developed ruffled border possessed numerous cathepsin D-containing lysosomes, vacuoles, and coated vesicle-like structures. Cathepsin D-containing lysosomes fused with cathepsin-negative vacuoles and formed large secondary lysosomes. Osteoclasts with poorly developed ruffled border possessed fewer cathepsin D-containing lysosomes than those with well-developed ruffled border. No immunogold particles were seen in vacuole-like channel expansions of the ruffled borders, between the channels of the ruffled borders, or on the eroded bone surface. These findings demonstrate that osteoclasts contain a large amount of cathepsin D. They suggest that cathepsin D is necessary for osteoclastic bone resorption, that it plays an indirect rather than direct role.

A light and electron microscopic anterograde WGA-HRP tracing study on the sensory innervation of junctional and sulcular epithelium in the rat molar.

The sensory innervation of junctional and oral sulcular epithelium was investigated by use of anterograde transport of wheat-germ agglutinin-horseradish peroxidase from the trigeminal ganglion. By light microscopy, labeled intra-epithelial nerve fibers were observed forming a dense plexus in the apical two-thirds of the junctional epithelium, with some fibers located near the enamel space. Occasional fibers extended coronally to the sulcus bottom. By electron microscopy, labeled intra-epithelial axon terminals or varicosities were demonstrated to be in close contact with both junctional epithelial cells and neutrophils. These varicosities, which were occasionally surrounded by the cytoplasmic processes of epithelial cells or neutrophils, frequently contained large granular and small clear vesicles. In contrast to the junctional epithelium, the oral sulcular epithelium was sparsely innervated, except for the transition region between the oral sulcular epithelium and the junctional epithelium, where a dense innervation by labeled intraepithelial fibers was found. These fibers extended as far as the stratum spinosum. Electron microscopy revealed mitochondria-filled profiles of varicosities between epithelial cells. This study shows differences in the distribution and ultrastructure of sensory nerves between the junctional and oral sulcular epithelia, and further provides morphological evidence that sensory nerves in the junctional epithelium come into contact not only with epithelial cells but also with neutrophils.

The peripheral distribution of trigeminal nerve fibres in the rat temporomandibular joint studied by an anterograde axonal transport method with wheat germ agglutinin-horseradish peroxidase.

Wheat germ agglutinin-horseradish peroxidase was injected into the trigeminal ganglion to trace the peripheral distribution of the nerve fibres in the temporomandibular joint. It was transported anterogradely along trigeminal nerve fibres. Horseradish-peroxidase-labelled nerve fibres were found in the anterior and posterior bands of the articular disc, and terminated as nerve endings near the intermediate zone of the disc. However, the intermediate zone itself did not contain any nerve endings. Other nerve fibres penetrated from the subsynovial layer into the synovial membrane and also terminated as nerve endings close to the articular cavity. Thus, this method is suitable for tracing peripheral nerve fibres and nerve endings originating in the trigeminal ganglion.

Endocytosis in odontoclasts and osteoclasts using microperoxidase as a tracer.

Microperoxidase (MP, a peptide tracer) was intravenously injected into rats after six days of tooth movement by the Waldo method. Bone resorption was seen along the distal bone surface of the inter-radicular septum of the upper first molar, and tooth root resorption occurred along the mesial and distal surfaces of the distal root of the same molar. Odontoclasts were smaller in size and numbers than osteoclasts, but had the same organelles [multiple nuclei, ruffled borders (RB), clear zones, vacuoles, mitochondria, and specific granules] as osteoclasts. MP was deposited on the resorbed area through the clear zone and was transported into the vacuoles along the channels of the RB. The uptake of MP by odontoclasts was small, compared with that by osteoclasts. Collagen fibrils were found in the channels of the RB but were not detected in the vacuoles. Instead, filament-like structures were seen in the vacuoles and were located very near the collagen fibrils in the channels. Fibroblasts outside the resorbed lacunae had endocytosed collagen. In contrast, some cells close to odontoclasts (osteoclasts) in the dentin (bone)-resorbed lacunae had not endocytosed any collagen fibrils. These findings suggest (1) that odontoclasts resorb the dentin or cementum just as osteoclasts do in bone resorption, (2) that the resorbed area connects with the extracellular spaces of the odontoclasts or osteoclasts, and (3) that the organic components (e.g., collagen fibrils) of dentin or cementum are endocytosed through the channels of the RB in the same manner as that for MP. However, the endocytotic ability of odontoclasts appears inferior to that of osteoclasts.

[A cytochemical study of lysosomal system in rat junctional epithelium after intravenous horseradish peroxidase injection].

Lysosome formation was studied in rat junctional epithelium (JE) by detection of acid phosphatase (ACPase) using the cerium reaction method after intravenous injection of horseradish peroxidase (HRP). Intravenously injected HRP was endocytosed by the whole JE, especially at the coronal portion. ACPase activity was also observed in numerous organellae (vacuoles, dense bodies, multivesicular bodies and Golgi cisternae) in the junctional epithelial cells. These ACPase positive organellae often fused with each other, and their contents were mixed in the fused structures. The numbers of the ACPase-positive organellae in the HRP-exposed JE were more numerous than those in the JE without HRP, especially at the coronal portion. Thus, the distribution of the ACPase-positive products in the JE was closely related to that of HRP-positive products. These findings indicated that the whole JE has not only endocytotic ability but also intracellular digestion ability by the lysosomal enzymes.

A cytochemical study of horseradish peroxidase uptake in rat junctional epithelium.

The uptake of horseradish peroxidase (HRP) was studied in rat junctional epithelium (JE). Intravenous HRP (12.5 mg, 25 mg, or 50 mg) was only endocytosed by the entire JE (particularly by the coronal portion of the JE). Although HRP uptake was negligible at a concentration of 12.5 mg, marked uptake was observed at concentrations of 25 mg and 50 mg. However, there was no difference in the HRP uptake by the JE between the concentrations of 25 mg and 50 mg. By electron microscopy, HRP was detected in the organellae (micropinocytotic vesicles, intracytoplasmic vacuoles, dense bodies, and multivesicular bodies) in the junctional epithelial cells (JE cells). HRP-positive micropinocytotic vesicles were detected in all JE cells. However, intracytoplasmic vacuoles, which are characteristically observed in JE cells, were not always positive for HRP. Numerous HRP-negative vacuoles were detected in the JE cells. The number of HRP-positive organellae in the coronal portion of the JE was pronounced, compared with those in other portions. These findings provided evidence that the entire JE, especially its coronal portion, has endocytotic ability by micropinocytotic vesicles, rather than intracytoplasmic vacuoles, for foreign substances.

[Difference in uptake of junctional epithelium using microperoxidase and horseradish peroxidase as tracers in healthy rat gingiva].

A microperoxidase (MP, molecular weight 1,900; molecular diameter 20 A) or a horseradish peroxidase (HRP, molecular weight 40,000; molecular diameter 40 A) was intravenously injected into healthy rat junctional epithelium (JE) to investigate the endocytosis of foreign substances. By light microscopy, intravenous HRP was taken up throughout the JE, and the uptake was marked at the coronal portion of the JE. On the other hand, MP was taken up by only the coronal portion of the JE. At the electron microscopic level, the tracers were taken up by endocytotic organellae (phagosomes and micropinocytotic vesicles) of junctional epithelial cells (JE cells). HRP-positive endocytotic organellae in the JE cells were more numerous than MP-positive organellae. Thus, JE, especially its coronal portion, exhibited strong endocytotic activity for HRP compared with that for MP. These findings suggest that the JE has selective endocytotic ability for foreign substances, and plays an important role in protecting periodontal tissue.