Craniofacial morphological characteristics of Japanese adults with various malocclusions were investigated. Cephalometric radiographs of 100 Class I, 100 Class II, and 100 Class III cases were selected and subjected to counterpart analysis as described by Enlow. Results of individuals with normal Class I occlusion revealed a mean value of 39.5° for the angle of the middle cranial fossa relative to the posterior maxillary plane alignment (MCF/PM). This value was used as the basis for intrinsic alignment comparisons for all other skull points. Class I and II malocclusions were classified as either type A or B, depending on whether point A or B was protrusive in the functional occlusal plane (FOP). We found that type B was more common for both Class I and Glass II malocclusion. Further, in both Classes, type B cases exhibited an underlying Class III character. We also noted that both B groups had different structural craniofacial patterns relative to those seen in A groups. Both dental Class IA and Class IB had a skeletal Class II tendency. The difference between Class IA and Class IIA, or between Glass IB and Class IIB was slight but quantitative. Class III and Glass IIA individuals had distinctly different and essentially opposite underlying patterns. Most compensatory effects were ineffective in both Class IIA and Class III groups. However, the composite compensatory result in Class IB case was, for the most part, effective.
Junctional epithelium (JE) originates from reduced enamel epithelium and is replaced by cells from oral gingival epithelium (OGE) shortly after tooth eruption. Although derived from OGE, cells of JE exhibit both morphologic and functional differences from precursor tissue. We sought to elucidate these differences by investigating histochemical localization of cell surface glycoconjugates in regenerated epithelial cells following gingivectomy in the rat. Distribution and reaction patterns of lectins (Ulex europaeus agglutinin-I, peanut agglutinin, soybean agglutinin, and wheat germ agglutinin) were determined using both light and electron microscopy. We found that although regenerated JE derived from OGE following gingivectomy, its morphologic features as well as histochemical lectin patterns underwent transition to those of non-treated JE. These findings indicate that freshly regenerated JE and primary JE are morphologically and histochemically similar.
We established a human tongue cancer (well-differentiated squamous cell carcinoma) xenograft line, LK-1, in nude mice. LK-1 showed logarithmic growth from 5 to 7 weeks after transplantation, and the take rate for 25 generations was 95.0%. We confirmed the expression of cytokeratins 1, 5, 7, 10, 14, 16, 17, 18 and 19, and type I, III, IV and V collagens by electrophoretical and immunohistochemical analyses. Although the amount of type I, IV and V collagens increased gradually from 5 weeks after transplantation, the distribution of type IV collagen was often discontinuous in the cancer basement membrane. From these data we concluded that LK-1 is an excellent model for the investigation of the cell biology of well-differentiated oral squamous cell carcinoma, and for examining the effects of clinical therapies for this disease.
The molecular relationships of extracellular matrix (ECM) from bovine periodontal ligaments to supporting mechanisms of the ligament were investigated. Glycosaminoglycan (GAG) and collagen components of the ECM were compared quantitatively and qualitatively for periodontal tissue adjacent to mandibular anterior (APL) and maxillary posterior (PPL) teeth. There was no significant quantitative difference GAG between the APL and PPL. GAGs in both APL and PPL consisted primarily of dermatan sulfate (DS), chondroitin sulfate (CS) and hyaluronic acid (HA). Heparan sulfate was present as a minor component. Analysis of unsaturated disaccharides obtained from the GAG revealed that ΔDi-0S from CS in the PPL was significantly higher than that in the APL, and ΔDi-4S from DS in the APL was significantly higher than within the PPL. Furthermore, there was significantly more collagen (as determined by Hyp content) in the APL than in the PPL although the chemical composition of collagen was the same for both. These results suggest that ECM molecules in the APL exhibit both quantitative and qualitative differences to those in the PPL, possibly owing to contrasting mechanisms of tooth support in response to different masticatory functions.