The unusual feature of an intramandibular chondroma in association with an odontogenic keratocyst in a 59-year-old man is described. The keratocyst recurred and required two reoperations. The coexistence of an odontogenic keratocyst and a chondroma of the jaw was probably a coincidence of two simultaneous but otherwise unrelated lesions. The possibility that the keratocyst and the chondroma were due to a single developmental disturbance of the region cannot be excluded. No signs of a recurrence were seen at the last follow-up examination four years after the operation.

In 58 embedded teeth and 126 follicles it was found that the enamel-forming epithelium could be heavily disturbed especially in narrow fissures and at the cemento-enamel junction by premature reduction preventing the enamel from being fully mineralized. The congestion of capillaries in the connective tissue of the follicle caused hemorrhage which imbibed the epithelium and the enamel stroma. In the follicles two types of hyaline bodies could be discerned. One type consisted of hyalinized islands of odontogenic epithelium. They could calcify and constituted a fluent transition to odontogenic tumors, e.g. odontoma and dentinoma. They were PAS positive and elastin negative. The other type (the Rushton type) consisted of white thrombi in congested capillaries in inflamed areas. They were PAS negative and elastin positive. The described mechanism might explain the caries susceptibility in molars and premolars with narrow fissural pits and grooves. The same is valid for the cervical areas when the enamel epithelium is prematurely reduced and the enamel stroma imbibed with hematic material.Key Words: Toothimpactedtooth germodontogenesishyaline substance

By means of a new tissue-transport technique, the sampling of clinically diagnosed oral and skin lichen planus lesions has been facilitated for routine histopathologic work, including standardized chemical-constituent and enzyme histochemical techniques. Intrasection comparisons between affected and clinically healthy areas have disclosed data concerning, for example, keratinization, lipid changes, mast-cell distribution, enzyme activity variations, and certain nonenzymic staining reactions, which may be utilized as criteria for the lichen planus lesions. Disturbed metabolism in the basal epithelial cells and uneven oxidative enzyme activities in more superficial cell layers in areas with the disease were recordings of special interest. Intraindividual comparisons between oral and skin lesions have indicated that the two manifestations of the same disease have the same pathogenesis.

52 totally or partially embedded teeth were studied in ground sections by soft microradiography to assess the quality of the enamel and the dentine. In 79 % the dentine was more or less globularly mineralized. In 50 % the dentine-enamel junction (D.E.J.) was more scalloped than normally and in three cases the border-forming globules were vacuolated. All kinds of hypoplasia were found, gross, minor, and tube. The enamel-cementum junction was irregular in 63 %, hypoplastic in 60 %, hypomineralized in 42 %, and provided with loose enamel globules in 27 %. Cementum or bonelike tissue covered the enamel lingually in two front teeth and occlusally in a third lower molar. The fissures could be extremely narrow and penetrate the enamel till near the dentine border. The distance between the fundus of the fissure and the D.E.J, was measured to 0.15-0.5 mm, is one case only 0.06 mm. In their basal parts the fissures could be invaginated or ampullar. T-hypoplasia could be found in the walls or the fundus of the fissure and the lingual aspect of the front teeth. The mineralization of the dental hard tissues in embedded teeth thus displays heavy disturbances especially in the fissures and the D.E.J.Key Words: Dental enameldentintoothimpactedmicroradiographytoothcalcification

International AbstractsThe Microscopic Appearance of the Periapical Tissue in Cases Classified as “Uncertain” or “Unsuccessful” after ApicectomyT. Arwill, G. Persson and H. ThilanderT. ArwillSearch for more papers by this author, G. PerssonSearch for more papers by this author and H. ThilanderSearch for more papers by this authorPublished Online:23 Jan 2015https://doi.org/10.1259/dmfr.1975.0013SectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail About"The Microscopic Appearance of the Periapical Tissue in Cases Classified as “Uncertain” or “Unsuccessful” after Apicectomy." Dentomaxillofacial Radiology, 4(1), p. 58 Previous article Next article FiguresReferencesRelatedDetails Volume 4, Issue 1January 1975Pages: 2-71 © 1975 The Authors. Published by the British Institute of Radiology History Published onlineJanuary 23,2015 Metrics Download PDF

Journal Article A NEW ROUTINE IN HISTOPATHOLOGY Get access Guy Heyden, Guy Heyden Department of Oral Histopathology, Faculty of Odontology, University of Göteborg, Fack, S‐400 33 Göteborg 33, Sweden Search for other works by this author on: Oxford Academic Google Scholar Tore Arwill, Tore Arwill Department of Oral Histopathology, Faculty of Odontology, University of Göteborg, Fack, S‐400 33 Göteborg 33, Sweden Search for other works by this author on: Oxford Academic Google Scholar Maria Högberg Maria Högberg Department of Oral Histopathology, Faculty of Odontology, University of Göteborg, Fack, S‐400 33 Göteborg 33, Sweden Search for other works by this author on: Oxford Academic Google Scholar British Journal of Dermatology, Volume 90, Issue 5, 1 May 1974, Pages 579–582, https://doi.org/10.1111/j.1365-2133.1974.tb06457.x Published: 01 May 1974

Activity of alkaline phosphatases in unfixed cold microtome setions from the lower first molar area of newborn mice was recorded by histochemical methods. A substrate specificity test included the following phosphate compounds: ATP, CTP, GTP, UTP, ADP, AMP, GP, PPi, MDP and naphthol AS-TR phosphate. Intense staining was obtained in osteoblasts, stratum intermedium of the enamel organ and odontoblasts with all the substrates, except PPi and MDP. Staining of skeletal muscle fibres was obtained only with triphosphates as substrates. Addition of-SH groups decreased the hydrolysis of triphosphate compounds in cells involved in mineralization while the hydrolysis of monophosphate was inhibited. In contrast triphosphatase activity in striated muscle was enhanced when-SH compounds were added. Demineralization with EDTA diminished the cytoplasmic staining but induced a nuclear staining in hard tissue forming cells when triphosphates were used as substrates. No cytoplasmic and only slight nuclear staining was seen with GP or AMP as substrates. The triphosphate hydrolyzing capacity of tongue muscle fibres was, however, increased after the decalcification treatment. Addition of Mg2+ ions to the incubation media distinctly lowered the hydrolysis of triphosphates in the investigated tissues whereas the hydrolysis of ADP, AMP, GP and naphthol AS-TR phosphate remained unchanged. In view of the findings the triphosphatase activities at alkaline pH of muscle fibres and of cells related to hard tissue formation are considered to be due to activity of separate enzymes. The orthophosphate liberating enzyme activities at alkaline pH in osteoblasts, stratum intermedium and odontoblasts may be expressions of the catalytic functions of one common enzyme. Furthermore, the results indicate that CaATP might be the substrate used by the alkaline ATPase in mineralizing areas.

The present study concerns the application of a new tissue transport medium, Histocon, in lipid histochemical analysis of biopsies. It was generally found that this medium visibly retained more lipids quantitatively than did a fixation of the tissues. The lipid “preserving” capacity of Histocon seemed to be superior even to the use of fresh frozen specimens. These beneficial effects may be due to membrane stabilizing factors in the transport medium.

Oral giant cell granulomas (8 peripheral and 4 central) have been studied histochemically for NADH2‐diaphorase, NADPH2‐diaphorase, glucose‐6‐phosphate dehydrogenase, glutamate dehydrogenase, adenosine triphosphatase, leucine aminopeptidase, and acid phosphatase activity. No differences in cellular enzyme activity are found between the peripheral and the central variety. The giant cells are positive for all the enzymes studied, except adenosine triphosphatase, whereas the pericytes of the vascular granulation tissue are positive for all the enzymes tested. 8 peripheral and 2 central oral giant cell granulomas have been studied electron microscopically. The ultrastructure of the two varieties is similar, both showing two different types of giant cells. Clusters of stromal cells, probably pericytes, are often found, lying in intimate relation with a distance of 150–140 Å between their cell membranes. Though no membrane fusions have been clearly demonstrated the histochemical activities of the giant cells and the pericytes lend support to the assumption, that the pericytes are precursors to the giant cells.

In a 9-year-old girl a tumorlike nodular projection lingual to the lower permanent incisors contained sebaceous cells, hair follicles with hairs, a small keratocyst, melanocytes, and lymphocytes and plasmocytes, and, associated with disintegrated sebaceous cells, a foreign-body giant-cell reaction. The “tumor” is termed a follicular choristoma .

A case of partial glossectomy is reported. This surgical procedure has been advocated and performed successfully on patients undergoing surgical and nonsurgical orthodontic treatment and on patients with apertognathia, lisping, and tongue-thrusting habits. In this case, the surgical intervention was indicated in a preprosthetic evaluation.

— A histologic and histochemical study was made of 45 odontogenic periapical cysts and granulomas with cholesterol formation. The specimens were transported in Histocon® solution and sectioned by cold microtome. This technique permits the preservation of the lipids and rertains the enzyme activities in the cells. Cholesterol crystals seemed to be formed in disintegrating clots of red blood corpuscles in congested capillaries of the inflammatory areas. The pericytes of the vessel walls changed their enzyme activities, indicating increased lysosomal functions, and eventually formed giant cells with tissue degrading properties.

In order to investigate the origin of intradentinal nerve-like structures, unilateral transection of the sensory (inferior alveolar nerve) and/or the autonomic (cranial cervical sympathetic ganglion) supply was performed in 6 cats. After 2—4 weeks, when degenerative change was expected in the cut nerves, electrophysiological recordings from the dentin showed total absence of impulse activity in teeth subjected to sensory denervation regardless of whether or not the autonomic innervation was intact. Control teeth, on the other hand, responded to different local pain stimuli. Electron microscopic study of predentin and inner dentin in control teeth showed intratubular nerve-like structures similar to «associate cells» earlier described in human teeth. In teeth subjected to sensory nerve resection, however, the intradentinal «associate cells» showed advanced degenerative change or were absent. Resection of the sympathetic nerve supply did not influence the appearance of these intratubular structures.The present results indicate that intratubular nerves are present in predentin and the inner dentin in the cat and that these nerves are of sensory origin. It is further suggested that the intradentinal «associate cells» earlier described in human teeth are sensory neurons.Key Words: Microscopyelectronneurophysiologydental pulpdentinnerve endingsnerve degeneration

A simple and sensitive histochemical staining method was employed to demonstrate the accumulation of heavy metal in the gingiva of a patient with anamnestic data of lead intoxication. The Mallory hematoxylin technique showed negative results. The positive reactions with the ammonium sulfide solution employed were confirmed by x-ray recordings.

This chapter discusses the ultrastructural localization of cholinesterase activity in the dental pulp. Cholinesterases are divided into specific—those that degrade acetylcholine—and nonspecific, such as butyrylcholinesterases (BuChE). Provided that specific inhibitors are used as controls, the thiocholine method is one of the most specific histochemical methods for localizing acetylcholinesterase (AChE) and BuChE. The content of cholinesterase in sympathetic ganglia and neurons varies between different species. A high cholinesterase activity in ganglia also corresponds to a high activity in the involved axons. The occurrence of an AChE activity that do not vanish on inhibition with BW284C51 may possibly depend on an incomplete inhibition. Incubation with butyrylthiocholine (BuThCh), with and without the different inhibitors, do not show any enzyme activity in the axonal membranes of the myelinated nerves.

– Frozen sections of molar tissue areas obtained from 50 newborn mice were stained with rhodamine B. A yellow brilliant fluorescence of rhodamine B was demonstrated in tissue areas which showed accumulation of histochemically discernible phospholipids as demonstrated with the OTAN method. The results suggest that the fluorochrome reacts with lipid substances – possibly in the simultaneous presence of SH groups. The method used in the present investigation was found to be valuable in studies on developmental variations in keratinizing tissues and in enamel matrix.

Abstract. Chlorhexidine solutions have been tested to determine their usefulness as media for the transport of biopsy specimens for diagnosis in order to facilitate the use of cold microtome sectioning and enzyme histochemical techniques in routine histopathological diagnostic practice. The drug was chosen for its antibacterial and protein “preserving” capacities. Tissue morphology, chemical components and enzyme activities were found to be retained well in specimens from human gingiva when stored in a cold solution, pH 7.2, containing 2.2 mM chlorhexidine gluconate, 0.19 M cacodylate buffer and 7.5% polyvinylpyrrolidone. The procedure allowed reliable enzyme activity evaluations to be performed under the light microscope within 48 hours after excision of the tissues. Fresh frozen tissues served as controls. In an additional electron microscopic study, morphology of the cells was found to be reasonably well preserved after transport in the solution.