The treatment of closed jaw locking due to temporomandibular joint (TMJ) arthrosis is described. Conventional mandibular manipulation of the lower and/or upper joint compartments was performed using hydraulic pressure from an imaging X-ray medium. The procedure was used in 40 patients with closed locking (5 acute and 35 chronic). The results of the treatment are evaluated and factors affecting the results are examined. In four of the five patients with acute closed locking, the lock was successfully released after use of the pumping technique on the lower joint compartment. In patients with chronic locking, an average improvement of 6.6 mm in the degree of interincisal opening was observed within 3-4 days of treatment with the pumping technique. In 13 of these patients, satisfactory opening (at least 40 mm) was achieved immediately. All the patients underwent further forward and contralateral manipulation to assist mouth opening, and after a period of 2-3 months 16 patients showed a further average improvement of 5.4 mm in interincisal opening.
In this study the authors set out to investigate the stress distribution around the chin due to articulation, and to discuss whether the calculated stresses can cause bone remodeling. A finite element model of facial soft tissue was constructed and movements related to the articulation of the five basic Japanese vowel sounds were reproduced individually on the model. The stress distribution of each vowel depended on the shapes formed by the lips and the degree of mandibular opening. Stresses increased with the strain on the soft tissue of the lips. It seemed unlikely that the calculated stress alone was sufficient to produce a hypertrophic increase in modeling. However, it seemed that muscle forces might produce an effective strain load with a range sufficient to cause bone remodeling by accumulation of stresses around the chin.
Hydroxyproline (Hyp) and total protein levels were studied in gingiva from patients treated with phenytoin (PHT) and cyclosporine-A (CSA). The study included 5 groups of subjects : PHT and CSA groups with and without gingival overgrowth (PHT-GO+), (PHT-GO-), (CSA-GO+), (CSA-GO-), and periodontally healthy controls (C). After taking clinical measurements, gingival samples were harvested by gingivectomy or excising one or two papillae from the posterior areas. The samples were analyzed biochemically. In the PHT groups, both Hyp and total protein levels were significantly higher than in the C group. The differences between the PHT-GO+ and PHT-GO-groups were not statistically significant. In the CSA groups, total protein levels were significantly higher than in controls while no significant difference was found in Hyp levels. The differences between the CSA-GO+ and CSA-GO-groups were not statistically significant. When the PHT and CSA groups were compared, Hyp levels were significantly higher in the PHT-GO+ group than in the CSA-GO+ group. Total protein level differences between the PHT and CSA groups were not statistically significant. Correlations between age, plaque index, gingival overgrowth index, Hyp and total protein levels were analyzed and most were found not to be statistically significant. PHT appears to stimulate both collagen and total protein synthesis in gingiva while CSA seems to have a stronger effect on total protein synthesis. This suggests that the mechanisms underlying PHT-and CSA-induced gingival overgrowth are different and further comparative studies are needed.
A valuable characteristic of the “IPS Empress” used for producing all ceramic dental restorations is that it is a prefired ceramic ingot. The ingot is heated, softened and press-injected into the cavity, and ceramic restorations are fabricated by the lost wax casting method. The leucite crystals present in the ingot are scattered and distributed into the glassy phase in a more homogeneous manner through this pressing procedure, and the resulting ceramics are of higher flexural strength than conventional ones. The present study was carried out to clarify the microstructure of Empress ceramics by etching, and to observe the etched surface by scanning electron microscopy, in comparison with several other conventional ceramics. It was shown that the form and distribution of the leucite crystals in Empress ceramics are quite different before and after pressing, and that the staining and layering ceramics are also different from conventional ceramics. The method of surface treatment of ceramics prior to etching, such as fracturing or grinding, the kind of etching material used, the concentration and the etching time are important factors for revealing, observing and evaluating the microstructure of ceramics containing leucite crystals.
The early replicative phase of Epstein-Barr virus (EBV) was detected by immunohistochemistry, in addition to routine histology with hematoxylin eosin staining, in formalin fixed, paraffin-embedded archive specimens of 97 hyperkerato tic lesions including oral hairy leukoplakia (HL) in order to assess whether EBV is specific to HL, or if it occurs in other hyperkeratotic lesions of the oral mucosa. Monoclonal antibody (MAb) BZ-1 directed against the BZLF-1 gene product of EBV was used for immunostaining by the avidin-biotin peroxidase technique. The reaction was visualized with DAB/ H2O2 solution and counterstained with PAS stain to detect any coexisting of hyphae of Candida. Eight lesions were reactive with BZ-1, confirming a diagnosis of HL, although the total number of lesions with koilocytoid features was 33. Seventy percent of the patients with confirmed HL lesions were HIV-seropositive, and 50% of the HL lesions were associated with Candida hyphae. One third of the lesions with koilocytoid features were associated with hyphae of Candida. Only one renal transplant patient had HL, confirmed by a positive BZ-1 reaction, although 60% of the hyperkeratotic lesions showed koilocytoid features in a subgroup of 15 patients with renal transplants.
The term “choristoma” is used to describe a mass of histologically normal tissue presenting in an aberrant site. A rare case of osseous choristoma of the tongue is presented and the literature is briefly reviewed.
Two cases of either peripheral odontogenic fibroma (POF) (WHO type) or peripheral ameloblastoma are reported. Their immunohistochemical characteristics were investigated in an attempt to clarify their histogenesis. The results showed that the epithelial component of this neoplasm tended to retain its distinct odontogenic character and expressed a keratin profile different from that of the overlying oral epithelium from which both cases most probably originated. The connective tissue element of these tumors was vimentin-positive and S-100 protein negative, confirming their mesodermal nature but precluding the possibility of ectomesenchymal derivation. No reactivity for desmin was noted.