Ultrasonic diagnosis of oral and neck malignant lymphoma.

A series of 14 patients with nodal and extranodal non-Hodgkin's lymphoma of the oral and neck region was analyzed by ultrasonogram evaluation. Eight nodal lymphomas and six extranodal lymphomas commonly exhibited almost completely similar ultrasonographic findings, specifically, clear delineation of the boundary echo and a homogeneous, weak internal echo, the so-called pseudo-liquid-like images. The results derived from our study suggest that ultrasonic diagnosis is also helpful in evaluating patients with lymphoma during the initial diagnosis and initial treatment like other diagnostic imaging modalities.     

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.     

Effects of intense chewing on some parameters of masticatory function.

This study recorded the influence of 30 minutes of intense chewing on the masticatory function in 17 healthy subjects. Functional recordings of mandibular movements and velocity, measurements of masticatory efficiency, maximal occlusal force, and occlusal force endurance time were performed before and after functional stimulation and finally in a 2- to 5-day follow-up registration. After intense chewing, a substantially decreased masticatory cycle and occlusal level phase duration were recorded. No major mandibular displacements or changes in velocity were recorded. Masticatory efficiency and maximal occlusal force in the incisal region diminished after 30 minutes of intense chewing. Occlusal force endurance time was also lowered after intense chewing. The measurements were close to their original values at the follow-up. Intense chewing had various short-term effects on masticatory function, including a significant reduction of masticatory efficiency, maximal occlusal force, occlusal force endurance, and masticatory cycle duration.     

Influence of tempering method on residual stress in dental porcelain.

The porcelain component of a porcelain-fused-to-metal restoration is strengthened by residual (tempering) stresses which are induced by cooling procedures followed in dental laboratories. The thermophysical properties of materials and cooling rate are the main factors which determine the residual stress. In this paper, the temperatures in the midplane of body-porcelain disks were measured from a heat-soak temperature (1000 degrees C) to room temperature during two different cooling procedures: slow cooling in air and forced-air cooling. Experimental results approximated exponential cooling wherein the cooling rates could be represented by a linear equation of temperature. Residual stresses, as affected by the tempering method and thickness of a porcelain disk, were calculated by computer simulation for regions away from the edges. The following temperature-dependent factors were incorporated into the simulation: elastic modulus, viscosity, and coefficient of thermal expansion. The cooling rate dependencies of the glass transition temperature and the temperature distribution during cooling were also included. The cooling rates used in this simulation were derived from the tempering data. The agreement between development of transient and residual stresses--calculated by computer simulation for various cooling methods, and the tendency toward failures of porcelain disks subjected to the tempering processes--was examined. Simulated residual stresses were also in good agreement with those measured by the indentation fracture method of Marshall and Lawn (1977) and Anusavice et al. (1989).     

Oral alimentary tract cyst

A cyst in the floor of the mouth of a 2-yr-old boy was characterized by smooth muscle tissue with an overlying epithelial lining of varying morphology including gastric mucosa. The combination of smooth muscle with a variety of epithelial linings argues against the "misplaced anlage" histogenesis.     

Sizes of dental arches and general body growth up to 6 years of age in children with isolated cleft palate.

Development of the dental arches and height and weight at the ages of 3 yr and 6 yr were studied longitudinally in 60 children with isolated cleft palate (CP) and in 50 noncleft (NONC) children. Retrospective comparisons were also made in the CP group with arch size at the age of 0.2 yr and 1.8 yr. Anterior width at 0.2 yr of age was associated with canine width at the age of 3 yr (r = 0.70) and 6 yr (r = 0.60). Change in maxillary posterior width from 3 yr to 6 yr of age was related to the extension of the cleft, so that in the group with total cleft this dimension diminished. Measured in standard deviation scores (SDS), the means of maxillary width at canines and primary second molars in CP children varied from -1.0 to -2.0 and mandibular dimensions from -0.6 to -1.4. Discrepancy in arch depth diminished with age. Body size differed less from normal than the size of the dental arches. At 3 yr of age the height was -0.4 SDS in CP boys and -0.5 SDS in CP girls, but at 6 yr of age only -0.1 SDS in both boys and girls. Correlations between body size and the size of the dental arches were generally low (r less than 0.20) both in CP and NONC children. The small size of the dental arches in CP children does not seem to be merely a reflection of the overall smaller size of CP children.     

Epithelial expression of major histocompatibility complex (MHC) antigens in normal rat salivary and lacrimal glands.

The presence and distribution of MHC class I and class II antigens within these glands of Wistar and Lewis rats was studied using monoclonal antibodies and an indirect immunoperoxidase technique. In rats of both strains and sexes, MHC class 1 antigens were expressed by ductal epithelium in addition to vascular endothelium and other connective tissue elements. Except for a small proportion of secretory cells within lacrimal glands, acini were uniformly negative for class I antigen. MHC class II immune response-associated (Ia) antigens were expressed by stromal dendritic cells in all glands. Glandular expression of Ia was limited to submandibular glands of the two strains. In Lewis rats, staining was detected in some striated and collecting ducts, whereas positive glandular reactivity in Wistar rats was predominantly within the granular-cell tubules. Quantitative histomorphometric studies of Wistar submandibular glands, taken from 2.5-60-week-old male and female animals, demonstrated a close relationship between the extent of glandular Ia reactivity and postnatal granular-cell tubule development. These results indicate that whilst constitutive expression of Ia is a feature of rat submandibular epithelium, the glandular components involved are strain dependent.     

Nifedipine-induced gingival hyperplasia.

Gingival hyperplasia is an adverse reaction of nifedipine therapy. Oral manifestations of this condition include enlarged and painful gingiva accompanied by spontaneous bleeding. Nifedipine-induced gingival hyperplasia may be reversible once a proper drug substitution is made. Two cases of gingival hyperplasia resulting from nifedipine are described and the drug's possible mode of action is discussed.     

Changes in facial skin temperature associated with chewing efforts in man: a thermographic evaluation.

Eleven healthy male adults chewed hard and soft chewing-gums for 5 min. A thermographic record of the face on the chewing side was made at the beginning of, during and after the effort. Facial temperature distributions during open/close cyclic unloaded jaw movements were recorded at a later date. The dimensions of the zones whose temperatures were 1.4 degrees C or more higher than the central temperature during the experiment were determined. There was a linear increase in the dimensions of these zones after the chewing. In contrast, the cyclic jaw movements did not result in significant increases. Chewing the hard gum produced significantly higher temperature rises than did the soft in the masseter area. After the chewing effort, the temperature fell gradually, but did not return to the initial state even after 30 min. The overall decreasing pattern of the temperature distribution for chewing the soft gum was similar to that for the hard gum. The facial temperature associated with chewing efforts rose in accordance with the resistance offered by the chewing-gums.     

Histologic comparison of regeneration in human intrabony defects when osteogenin is combined with demineralized freeze-dried bone allograft and with purified bovine collagen.

A bone-inductive protein, osteogenin, has been isolated from long bones of humans and offers promise as a grafting material. Studies, however, suggest that osteogenin must be combined with a bone-derived matrix in order to initiate bone differentiation. The purpose of this study was to determine if osteogenin combined with demineralized freeze dried bone allograft (DFDBA), a bone-derived matrix, and with a bovine tendon-derived matrix will enhanced regeneration of intrabony defects in humans. The tendon-derived matrix and DFDBA used alone served as controls. The ability of each material to form a new attachment apparatus was evaluated independently in submerged and nonsubmerged environments in 2 patient populations. Lymphocyte testing was performed to assess development of an immune reaction to osteogenin. The most apical level of calculus on the root served as the histologic reference point to measure regeneration. Biopsies were obtained at 6 months and regeneration was measured histomorphometrically by 2 blinded evaluators. Serial sections from 36 submerged defects in 8 patients and 50 nonsubmerged defects in 6 patients were submitted for statistical analysis. Mean results indicate that osteogenin combined with DFDBA significantly enhanced regeneration of a new attachment apparatus and component tissues in a submerged environment. DFDBA plus osteogenin and DFDBA alone formed significantly more new attachment apparatus and component tissues than either the tendon-derived matrix plus osteogenin or the tendon-derived matrix alone in both submerged and nonsubmerged environments. There were no significant differences between the tendon-derived matrix plus osteogenin and the tendon-derived matrix alone in either the submerged or nonsubmerged environment. Osteogenin does not impair normal lymphocyte blastogenesis at 6 months postsurgical challenge.