Terminology of facial morphology in the vertical dimension

Consideration of facial type plays an important role in the formulation of an orthodontic treatment plan and prognosis of treatment. Of particular importance is the vertical relationship, that is, whether an individual is long-faced (dolichofacial), or short-faced (brachyfacial). The vertical facial type provides a clue regarding the growth direction of the facial complex, and should be used with an anteroposterior classification to describe a patient's face. The potential for confusion in communicating vertical facial types exists due to the nature of the terminology in use. For example, the term dolichoprosopic as used in the Bimler analysis has an opposite meaning to the term dolichofacial. It would seem prudent that if such terminology is to be employed there should be some attempt at standardization, and at least an appreciation of the derivations of the terms, and their differences.     

Immunohistological localization of cell adhesion proteins and integrins in the periodontium.

The distribution of the cell adhesion proteins vitronectin, fibronectin, tenascin, and laminin as well as several integrin subunits, alpha 2, alpha 5, and alpha v, was studied in primate periodontal tissues. Full baboon mandibular sections were analyzed by immunohistochemical methods in order to localize the molecules studied in both soft and hard tissues. Vitronectin was associated with the connective tissue of the marginal gingiva, the periodontal ligament, as well as the endosteum and periosteum. A notable finding was the particularly high staining intensity of vitronectin in the periodontal ligament. Fibronectin was widely distributed in the periodontal connective tissue and was also localized to the pericellular matrix of osteocytes and blood vascular elements. Epithelial basement membranes stained positively for both fibronectin and tenascin. These proteins were also expressed in the periosteal and endosteal connective tissues and the periodontal ligament. The staining intensity for tenascin was higher in zones along the cementum and bone surfaces. Laminin was, characteristically, limited to basement membranes of epithelium and endothelium. The distribution of fibronectin, tenascin, and laminin is related to previous findings in other species. The localization of the several integrin alpha-subunits is also described in full baboon mandibular sections. The vitronectin receptor (alpha v) had a uniquely strong expression in osteoclasts of the alveolar bone and was found, at lesser intensity, on periodontal ligament fibroblasts. The fibronectin receptor alpha subunit, alpha 5, was also observed on osteoclasts, and, in addition, was widely distributed on fibroblasts, cementoblasts, and osteoblasts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Adenomatosis of minor salivary glands. Report of a case.

An account is given of a patient who had multiple canalicular adenomas in the upper lip and adjacent oral mucosa. A few months after these had been excised, several more tumors of the same type developed. Microscopic examination also revealed numerous tiny foci of adenomatous proliferation within otherwise normal salivary gland lobules. We suggest that this phenomenon represents a field neoplastic change although it appears to be benign.     

KVP meter errors induced by plastic wrap

The purpose of this study was to determine whether erroneous kVp meter readings, induced by plastic wrap, affected the actual kVp (output) of a dental X-ray machine. To evaluate the effect of plastic wrap on dental X-ray machine kVp meters, a radiation output device was used to measure output in mR/ma.s. An intraoral dental X-ray unit (S.S. White Model #90W) was used to make the exposures. First, the kVp meter was not covered with plastic wrap and output readings were recorded at various kVp settings with the milliamperage and time held constant. Secondly, the same kVp settings were selected before the plastic wrap was placed. Milliamperage and time were again held to the same constant. The X-ray console was then covered with plastic wrap prior to measuring the output for each kVp. The wrap possessed a static charge. This charge induced erroneous kVp meter readings. Out-put readings at the various induced kVp settings were then recorded. A kVp of 50 with no wrap present resulted in the same output as a kVp of 50 induced to read 40 or 60 kVp by the presence of wrap. Similar results were obtained at other kVp settings. This indicates that the plastic wrap influences only the kVp meter needle and not the actual kilovoltage of the X-ray machine. Dental X-ray machine operators should select kVp meter readings prior to placing plastic wrap and should not adjust initial settings if the meter is deflected later by the presence of wrap. The use of such a procedure will result in proper exposures, fewer retakes, and less patient radiation. If plastic wrap leads to consistent exposure errors, clinicians may wish to use a 0.5% sodium hypochlorite disinfectant as an alternative to the barrier technique.     

Subtotal vital pulp extirpation using different medical preparations (experimental morphological research)

Pulp stump and periapical tissue reaction to root canal filling with material containing calcium hydroxide and potassium nitrate after subtotal vital extirpation of the pulp was studied in 12 teeth of 6 green monkeys. Use of the material containing potassium nitrate was found to result on the 90th day of the experiment in the formation of a biologic barrier of secondary cement at the dental root apex. Such result was not achieved with calcium hydroxide-containing material. Other advantages of potassium nitrate-containing material were detected, consisting in a more rapid recovery of structural shifts in the pulp stump and periapical tissues.     

Longevity of posterior restorations

The efficacy of restorative dentistry is dependent on a number of factors, including material quality, operator proficiency and the oral hygiene of the patient. The sum effect of all factors can be measured by recording the longevity of the restorations. Many studies focus on the age of restorations at the time of failure, others include the longevity of restorations which remain in situ. The surveys may be either longitudinal, prospective or retrospective, or cross-sectional retrospective studies of dental records. They are all hampered by the lack of uniform criteria defining when to place and replace restorations and by variations in decision-making between clinicians. The present review paper shows that the longevity of amalgam restorations has been studied most frequently. About 50 per cent of all amalgam restorations exceed 8-10 years in age, cast gold restorations may last longer and multisurfaced composite restorations have a shorter life-span. Glass ionomer cements lack the physical properties needed for large posterior restorations. The results of detailed longevity studies should be the basis for selection of materials and techniques in operative/conservative treatment. The cost of dental treatment should be related to the expected lifetime of the tooth rather than to the immediate cost of a simple restoration.     

Immunoprofile of benign and malignant fibrohistiocytic tumors

Formalin-fixed, paraffin-embedded tissue sections from 26 malignant fibrous histiocytomas (MFH) and 61 benign fibrohistiocytic proliferations (BFHP) were evaluated immunohistochemically. An avidinbiotin-peroxidase technique was used to determine immunoreactivity for alpha-1 antichymotrypsin, muramidase, HLA-DR, leucocyte common antigen, S-100 protein, vimentin, desmin, and keratin. MFHs were consistently positive for ACT and vimentin and inconsistently reactive for the other antigens. MFHs were negative for LCA suggesting a mesenchymal origin for these lesions. In the MFH histologic subtypes, antigen expression was not significantly different to be useful in their classification. Also no distinctive pattern emerged relative to immunoreactivity and tumor location. The benign lesions, giant cell tumor of tendon sheath, dermatofibroma, and oral benign fibrous histiocytoma differed from the MFHs in that they were often LCA positive, suggesting origin from hematopoetic mononuclear-macrophages. The immunoprofiles of peripheral fibromas and "giant cell" fibromas were felt to be consistent with origin from mesenchymal cells. Several of the antigens studied could be used to differentiate the benign lesions studied from other benign neoplasms. The antigens were, however, of little value in separation of benign and malignant lesions.     

Microcomputer use in an oral biopsy service

The need for rapid and accurate retrieval of the data generated by an oral biopsy service and the adjacent medical center was met with the purchase and programming of a microcomputer and hard disk drive. The planning phase involved an assessment of the needs of the department, creation of an ideal form to be displayed on the video screen that can be easily used to enter the information, selection of coding systems, and selection of compatible hardware and software. Customized in-house programming using a commercially available database management system has created an entry form and menu-driven information retrieval system tailored to the needs of the department.