Prediction of the permanent dentition in deciduous anterior crossbite.

Early prospective evaluation for self-correction of deciduous anterior crossbite can enable identification of patients who require early treatment as well as those who do not. The purpose of the present study was to generate an algorithm that can be used to predict self-correction in the transitional dentition in 3-year-old subjects. The subjects were divided into 2 groups. One group comprised 22 subjects whose anterior crossbite self-corrected during the transitional stage (hereafter referred to as group N). The other group was comprised of 22 subjects whose anterior crossbite persisted during the transitional dentition (hereafter referred to as group R). All subjects were examined using lateral cephalometric radiography in order to evaluate differences in occlusion. Fifteen measurements were used for the evaluation. For each measurement, the variance ratio and the difference in the population mean between groups N and R were tested and t-values were derived. Based on the Student's t-test results, only measurements that had statistically significant differences (P < .05) were extracted. Predictor variables that had a partial F value of 5 or greater were selected for stepwise discriminant analysis, and the following equation was obtained: deciduous indicator (DI) = -0.58(cranial length anterior) + 1.31(posterior facial height) - 0.76(porion location) - 2.02(Wits appraisal) - 70.28. The lower the DI value (negative), the higher the probability that the crossbite will self-correct at the transitional dentition. On the other hand, a high (positive) discriminant score strongly suggests that the subject requires treatment in the primary dentition. The result of this analysis showed that the apparent error rate was 95.46% and the Maharanobis' generalized distance was 8.99.

Cephalometric changes during self-correction of primary anterior crossbite.

Longitudinal growth changes were investigated cephalometrically for sixty-one Japanese girls who had anterior crossbite at the initial visit (ages 3 years and 11 months on an average). Cephalograms were taken annually from the initial visit to the end of the observation period (ages 7 years 6 months on an average). Eleven of them (Group N1) showed self-correction of anterior crossbite during the primary dentition; ten (Group N2) showed self-correction when the permanent incisors erupted and forty (Group R) did not show self-correction. There was no statistical skeletal difference between Groups N1 and N2 during the observation period. Groups N1 and N2 were larger, however, than Group R in A'-Ptm'/Pog'-Go (p < 0.05) and Group N1 was smaller than Group R in Pog'-Go/N-S (p < 0.01) at the end of the observation period. In summary, favorable growth of the maxilla relative to the mandible leads to self-correction of primary crossbite and when mandible size relative to the cranial base is large, primary crossbite does not show self-correction.

Displacement and stress distribution in the temporomandibular joint during clenching.

The aim of this study was to analyze biomechanical reactions in the mandible and TMJ during clenching under various restraint conditions. A three-dimensional finite element model of the mandible, including the TMJ, was created for test purposes. The results were as follows: (1) Under any restraint conditions, displacement was greatest on the surface of the condyle and less on the articular disc and the surface of the glenoid fossa, in that order. Resultant stresses followed the same trend. (2) Displacement and stress were greatest when the lower central incisor was restrained and attenuated as the posterior teeth were restrained. Because the biomechanical reaction of the TMJ during clenching was greatest when the lower central incisor was restrained, premature contact of these teeth may be one of the factors involved in the initiation of temporomandibular arthrosis.

Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions.

PURPOSE: To compare the long-term clinical results of two small incision cataract surgery procedures. SETTING: Seven centers in Japan. METHODS: Two hundred eyes were randomly assigned to receive a silicone intraocular lens (IOL) through a 3.2 mm incision or a poly(methyl methacrylate) (PMMA) IOL through a 5.5 mm incision. Except for incision size and implantation technique, the surgical methods were identical. Uncorrected and corrected visual acuity, keratometry, flare-cell intensity, specular microscopy, and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate were analyzed up to 3 years after surgery. RESULTS: Eyes in the 3.2 mm incision group had significantly better uncorrected and corrected visual acuity in the early postoperative period and lower aqueous flare intensity immediately after surgery, but these differences disappeared after the first postoperative month. However, surgically induced astigmatism was significantly less in the 3.2 mm incision group than in the 5.5 incision group throughout the study. The Nd:YAG laser capsulotomy rate was higher in the silicone IOL group (23.5% at 3 years postoperatively) than in the PMMA IOL group (18.4%) but the difference was not statistically significant. CONCLUSION: Smaller incision cataract surgery led to early recovery of visual function in the short term and less induced astigmatism in the long term.

Three-dimensional computed tomography evaluation of postsurgical condylar displacement after mandibular osteotomy.

OBJECTIVE: The purpose of this study was to examine both condylar displacement of the temporomandibular joint after sagittal split ramus osteotomy with rigid osteosynthesis and intraoral vertical ramus osteotomy without osteosynthesis in patients with mandibular prognathism by means of three-dimensional computed tomography. STUDY DESIGN: In this pilot study, five patients treated with sagittal split ramus osteotomy and 5 patients treated with intraoral vertical ramus osteotomy were evaluated. A technique to superimpose a postoperative three-dimensional computed tomography image on its corresponding preoperative image was designed. Postoperative condylar displacement, rotation, and tilting were measured in three-dimensional computed tomography images. RESULTS: Within 3 to 6 months after surgery, changes in the inclination of the condylar axes were distinctly seen, although changes in the position of the condyles within the joints were minimal. In particular, outward rotation of the condylar long axes after intraoral vertical ramus osteotomy was a frequent finding. CONCLUSIONS: The three-dimensional computed tomography superimposition technique was a practical method of evaluating postsurgical condylar displacement after mandibular osteotomy.

Longitudinal changes in the skeletal pattern of deciduous anterior crossbite.

Some patients who have an anterior crossbite in the deciduous dentition lose the crossbite during the transitional stage to permanent anterior teeth without orthodontic and/or orthopedic treatment. We observed 220 anterior crossbite patients at regular intervals and identified three groups of patients: in group N (n = 16) the crossbite corrected when the central incisors erupted; in group R1 (n = 16) the crossbite was within [formula: see text] and remained unchanged following the eruption of the permanent central incisors; in group R2 (n = 12) the crossbite extended over [formula: see text] and remained following the eruption of the permanent central incisors. The purpose of this study was to determine whether any differences existed among the above three groups at the initial examination, or if differences arose during eruption of the teeth. The findings indicate that the mandibular position in group N was more posterior than in groups R1 and R2, and the lengths of Pog'-Go and Gn-Cd in group N were smaller. Tooth axis of the lower incisors in groups R1 and R2 showed lingual tipping, and the maxilla in group R2 was underdeveloped. The findings of the longitudinal changes indicated that the maxillary length in group N increased and mandibular forward growth was suppressed. The initial maxillary position in groups R1 and R2 remained much the same until the permanent central incisors erupted.

Orthodontic treatment of an open bite patient with oral-facial-digital syndrome.

A case of oral-facial-digital syndrome was treated orthodontically. Characteristics of this case were mandibular protrusion with open bite. Occlusal stability after correction of this malocclusion was achieved with the uprighting of the posterior teeth, surgical reduction of the enlarged tonsils and highly attached tongue frenum, and oral functional training.

Tenascin: growth and adhesion modulation--extracellular matrix degrading function: an in vitro study.

Tenascin (TN), a recently characterised extracellular matrix protein, largely confined to the process with the development of embryo in areas of epithelial-mesenchymal interactions and in areas where there are morphogenetic movements and tissue patterning, has a highly restricted expression in adult tissues. The expression of TN is enhanced in a variety of human neoplastic lesions. However, function(s) and molecular mechanisms of enhanced expression in neoplastic lesions remain unclear. We employed human tongue carcinoma cells (SCCKN), human salivary gland adenocarcinoma cells (SGT-1), normal mouse embryonic fibroblasts (NIH3T3-3) and K-ras-2 transformed fibroblasts (Cle-H3) in an in vitro study to elucidate the biological roles of TN. In in vitro studies, all the cell lines examined had enhanced secretion of TN in the presence of transforming growth factor-beta in a dose-dependent manner and TN itself was found to possess a growth-enhancing activity. Moreover, studies on adhesion of the cell lines on coated substrates of fibronectin (FN), laminin (LN), tenascin (TN), TN/FN and TN/LN showed that all the cells adhere and spread well on FN and LN. However, on TN they attach poorly and remain rounded. The relative concentrations of TN and FN affected the cellular adhesion and morphology. In SCCKN and SGT-1, but not in NIH3T3 and Cle-He3 fibroblasts, a higher concentration of TN inhibited cellular adhesion on fibronectin, suggesting that cells attach poorly on TN, it may interfere with the action of fibronectin, and the relative concentrations of TN, FN or LN may affect cellular adhesion and morphology which may differ in different cell types. When TN was added in the growth medium of exponentially growing cells, the cells lost their cell to cell contact and were seen to be separating. The presence of these extracellular matrix proteins were further tested to determine whether they could modulate the secretion of proteolytic enzymes responsible for extracellular matrix degradation by tumour cells, when the neoplastic cells but not the non-neoplastic cells grown on FN/TN substrate showed positive immunofluorescence for collagenase. FN, LN or TN alone did not induce collagenase in the tumour cells. If the same is true in vivo, although a number of factors and interactions may implicate the ultimate outcome, the enhanced expression of TN in neoplastic lesions may have potential implications for tumour growth, differentiation, cellular adhesion, invasion and metastasis.

Posterior bite raising effects on a primary anterior crossbite case.

Stainless steel crowns were cemented on the mandibular primary molars to make bite raising for an anterior reversed bite case. Chewing force and MKG were recorded before and after bite raising. Data from MKG revealed that co-ordination pattern of muscle activities after bite raising became higher in masseter muscles than those before anterior reversed bite was corrected easily without any incisal interferences by using this treatment method.

Stimulation of in vivo calcification using collagen membranes cultured with osteoblastic cells in vitro: a preliminary report.

Guided tissue regeneration (GTR) is a useful modality in the management of periodontal disease and for bone augmentation around osseointegrated implants. This study evaluated the in vivo use of atelocollagen membrane (AC) on which osteoblastic cells (OBCs) were cultured in vitro, for application as a GTR membranous material. Osteoblastic cells isolated in our laboratory from mouse calvaria formed a thin film on the AC in vitro which was easily manipulated after 21 days in culture. The AC and OBCs complex material (ACOB) was subjected to freezing and thawing and implanted in mouse subcutaneous tissue for the study of histologic events surrounding the implanted ACOB. Histologic findings in the subcutaneous tissue showed calcification on the ACOB at 28 days postimplantation, while no such finding was evident at the control site, where only AC without OBCs were grafted. The present study suggests the possibility of membrane calcification for GTR through ACOB produced by OBCs on an AC in vitro.

Allotransplantation of cryopreserved menisci in monkey: histological change.

The purpose of this study was to carry out a histological evaluation of cryopreserved menisci used as allografts in monkeys. Menisci were evaluated histologically at one, three, six and at twelve months after transplantation. In the deep layer of the allografts, the number of cells and the amount of the extracellular matrix had decreased at three to six months after transplantation. After twelve months, the evaluation revealed that both the cell counts and the extracellular matrix had increased returning to nearly normal levels. However, the colour of the matrix stained with Masson's trichrome had changed to red. This change may correspond with the occurrence that of young newly-formed collagen. Since the articular cartilage showed minimal degenerative change, it is concluded that meniscal transplantation is useful and should be considered for meniscal injuries.

Comparative study of intraocular lens implantation through 3.2- and 5.5-mm incisions.

PURPOSE: To prospectively and comprehensively compare the clinical results of two small-incision cataract surgery procedures, silicone intraocular lens (refractive index of 1.46) implantation through a 3.2-mm incision and polymethylmethacrylate intraocular lens implantation through a 5.5-mm incision. METHODS: Two hundred eyes with cataract randomly were assigned to either procedure. Except for incision size, identical surgical methods were used in every case. Data on uncorrected and corrected visual acuity, keratometry, corneal topography, flare-cell measurement, fluorophotometry, specular microscopy, glare disability measurement, and photographic examination of intraocular lens decentration were analyzed up to 6 months after surgery. RESULTS: Eyes in the 3.2-mm incision group displayed significantly better uncorrected and corrected visual acuity in the early postoperative period, lower aqueous flare intensity and cell counts immediately after surgery, less operatively induced astigmatism throughout the study period, and less corneal topographic changes taken 3 months after surgery. No significant between-group differences were noted for other parameters. Complications in the two groups were few and comparable. CONCLUSION: Both procedures of small-incision cataract surgery offered satisfactory clinical results, but 3.2-mm incision cataract surgery allowed significantly earlier recovery of visual function and better preservation of corneal shape.

Multiple symmetrical lipomatosis: no longer just a Mediterranean disease?

Multiple symmetrical lipomatosis is a rare condition, of which the etiology remains unclear. Most reported cases have been from the Mediterranean countries, and it is generally thought of as a disorder characteristic of that region. However, there have been 11 cases reported in Japan since 1978, suggesting that this condition is no longer confined to Mediterranean countries.

Bone formation under the influence of bone morphogenetic protein/self-setting apatite cement composite as a delivery system.

Self-setting apatite cement (apatite cement) with a phase of hydroxyapatite (HAP) was employed as a delivery system for bone morphogenetic protein (BMP). A composite of BMP and apatite cement (BMP/HAP composite) was implanted both in thigh muscle and surgically created defect of a critical size of 5 mm, which is a size that does not heal spontaneously in the femur of mice, to evaluate its osteogenetic potential as an augmentation and reconstructive material for clinical usage. The histological and immunohistochemical assessment of proteoglycans reiterated osteogenesis in the muscle tissue. On day 14 postimplantation of BMP/HAP composite, chondroid tissue was formed in the muscle, and HAP particles were seen in newly formed chondroid tissue. On the 21st day, endo-chondral ossification had occurred, however, small HAP particles remained in the newly formed bone, i.e., HAP particles and newly formed osseous tissues coexisted in a central area. BMP/HAP composite was incorporated by newly formed osseous tissue in the experimented animals. HAP particle found in BMP/HAP composite implanted into the bone defect was resorbed and replaced by osseous tissue. The apatite cement was proved to have advantages for its shaping as well as collapsing properties, and thus, apatite cement containing BMP is suggested as a favorable augmentation material in clinical usage for delivery system of BMP.

An in vivo evaluation of an osteoinductive implantable material produced by osteoblastic cells in vitro.

Osteoinductive implantable materials have been a subject of basic science research in clinical implantology. This study examined the osteoinductive effect of an implantable material produced by osteoblastic cells that were isolated in the laboratory from mouse calvaria. After 21 days in culture, osteoblastic cells formed a thin film that could be easily manipulated. This thin film was subjected to freezing and thawing and was implanted in mouse muscle tissue. Osteoblastic cells were strongly positive for alkaline phosphatase reactivity and Von Kossa stain in vitro. Collagen type I, osteocalcin (BGP), and alkaline phosphatase were identified at the immunohistochemical electron microscopic level. Histologic findings showed an osteoinductive effect of the implanted material. The results strongly suggest the possibility of producing an osteoinductive implantable material by culturing osteoblastic cells in vitro.

A case of paraneoplastic retinopathy.

A 62-year-old male had undergone lung lobectomy for adenocarcinoma which was discovered after visual loss from paraneoplastic retinopathy. He had photopsia, decreased visual acuity, ring scotoma, extremely reduced electroretinogram and narrowing of retinal artery. Fluorescein angiography revealed progressive diminution of peripheral retinal blood flow, slow perfusion and staining of venules. The surgical removal of the tumor resulted in slight recovery of visual acuity and decrease of photopsia and photophobia, which recurred after 8 months. He has been under steroid therapy to prevent the progression of the disease for 10 months.

Effects of OK-432 on in vitro secondary responses of the non-adherent cells to IL-2 and OK-432 in cancer patients without tumor burden.

We examined the effect of OK-432 intracutaneous injection on the in vitro responses of non-adherent cells to IL-2 and OK-432, along with changes in lymphocyte subpopulations, in early cancer patients who underwent surgery. We found that 1) repeated injections of OK-432 resulted in an enhancement of LAK activity, the peak of which was seen between 7 and 10 days after the first administration, 2) this augmentation of LAK activity was not associated with changes in lymphocyte subpopulations CD8+ CD11- and CD8+ CD11+ phenotypes, and 3) the cytotoxic activity of lymphocytes stimulated in vitro with OK-432 did not show a definite change in specific pattern after in vitro OK-432 treatment. These findings indicate that repeated injections of OK-432 over a period of a week effectively enhanced LAK activity.

Effect of OK-432 on cytotoxic activity in cancer patients without tumor burden.

The present study was designed to determine the optimal therapeutic protocol for OK-432, a streptococcal preparation, and to clarify the kinetics of various immunological parameters following intracutaneous administration of OK-432 in 39 disease-free postoperative patients with early cancer. These patients were randomly divided into 4 groups according to the dose (1KE or 5KE) and the frequency of administration (one or 3 times every other day) of OK-432. NK activity 3-4 days after the first injection increased significantly in patients whose pretreatment baseline activity was below the lower level of normal values (60 LU) in all study groups (P < 0.05). The elevation of post-therapeutic NK activity lasted for 2 weeks in the group of patients given repeated injections. The serum content of cytotoxic activity against L-M cells increased significantly after the injection of OK-432 at doses of more than 5 KE doses (p < 0.05). These findings suggest that repeated injections of OK-432 over a period of a week have important immunotherapeutic results.