Seiji Iida

Ossifying fibroma vs fibrous dysplasia of the jaw: molecular and immunological characterization

Ossifying fibroma and fibrous dysplasia of the jaw are maxillofacial fibro-osseous lesions that should be distinguished each other by a pathologist because they show distinct patterns of disease progression. However, both lesions often show similar histological and radiological features, making distinction between the two a diagnostic dilemma. In this study, we performed immunological and molecular analyses of five ossifying fibromas, four cases of extragnathic fibrous dysplasia, and five cases of gnathic fibrous dysplasia with typical histological and radiographic features. First, we examined the difference between fibrous dysplasia and ossifying fibroma in the expression of Runx2 (which determined osteogenic differentiation from mesenchymal stem cells) and other osteogenic markers. Fibroblastic cells in fibrous dysplasia and ossifying fibroma showed strong Runx2 expression in the nucleus. The bone matrices of both lesions showed similar expression patterns for all markers tested except for osteocalcin. Immunoreactivity for osteocalcin was strong throughout calcified regions in fibrous dysplasia, but weak in ossifying fibroma lesions. Second, we performed PCR analysis with peptide nucleic acid (PNA) for mutations at the Arg201 codon of the alpha subunit of the stimulatory G protein gene (GNAS), which has reported to be a marker for extragnathic fibrous dysplasia. All nine cases of extragnathic or gnathic fibrous dysplasia were positive for this mutation. On the other hand, none of the five cases of ossifying fibroma showed the mutation. These findings indicate that although fibrous dysplasia and ossifying fibroma are similar disease entities, especially in the demonstration of the osteogenic lineage in stromal fibroblast-like cells, they show distinct differences that can be revealed by immunohistochemical detection of osteocalcin expression. Furthermore, PCR analysis with PNA for GNAS mutations at the Arg201 codon is a useful method to differentiate between fibrous dysplasia and ossifying fibroma.

Migration of a dental implant into the maxillary sinus. A case report.

This article reports a rare case of a displaced dental implant that migrated into the maxillary sinus.

Decision analysis and treatment threshold in a management for the N0 neck of the oral cavity carcinoma

The optimal method of management of clinical N0 neck in squamous cell carcinoma of the oral cavity remains controversial. We used decision analysis to determine the current optimal strategy in comparison with observation of the neck and elective neck dissection. A total of 165 previously untreated patients with N0 classification were investigated. Probabilities of each recurrence were calculated and probabilities of being cured in each event were substituted with the 5-year overall survival calculation with Kaplan-Meier method. A sensitivity analysis was performed to determine the optimal threshold for treatment of the N0 neck. The threshold of N0 neck was calculated using the formula with putting the three probabilities of being cured. In this study the threshold was estimated at 44.4%. N0 neck of squamous cell carcinoma of the oral cavity should be observed if the probability of occult metastasis is less than 44.4%. Proper calculation of three probabilities of being cured in each institution will make a decision of the optimal method of clinical N0 neck by using the threshold formula.

Investigation of CXCR4 in squamous cell carcinoma of the tongue

Cancer metastasis is not a random process and different cancer types have favorite metastatic sites. Recent studies on metastasis have focused on chemoattraction, particularly on the role of chemokines. Therefore, in this study we investigated whether CXCR4 (receptor for stromal cell-derived factor-1) is expressed in squamous cell carcinoma of the tongue. For this purpose, immunohistochemical staining was performed on 26 sections obtained from 23 patients (15 patients having tongue tumor without lymph node metastasis and eight patients having lymph node metastasis). All tumor cells expressed CXCR4, whereas normal mucosa of the tongue had no or faint expression CXCR4. Metastatic tumor cells in lymph nodes had stronger expression than primary tongue tumor cells. Our data raises the possibility that CXCR4 could be involved in lymph node metastasis of oral squamous cell carcinoma.

Influence of the incompletely erupted lower third molar on mandibular angle and condylar fractures.

BACKGROUND Several studies have shown an increased risk of mandibular angle fractures by the presence of the lower third molar (M3), especially the incompletely erupted M3. The presence of M3s might influence condylar fractures, which is one of the most common fracture sites, as well as the angle fracture. METHODS Six hundred ninety-two mandibular sides among 346 patients with mandibular fracture were analyzed. They were classified into two groups according to the presence of incompletely erupted M3s and were analyzed according to fracture site, age, and cause of injury. RESULTS Among these patients with mandibular fractures, the frequency of occurrence of the mandibular angle fracture was higher in the group with incompletely erupted M3s (p < 0.0001) and that of the condylar fracture was higher in the group without it (p < 0.001). CONCLUSION The result of this retrospective investigation shows that an incompletely erupted M3 decreases the risk of condylar fractures and increases the risk of mandibular angle fractures.

Tumor Thickness and Paralingual Distance of Coronal MR Imaging Predicts Cervical Node Metastases in Oral Tongue Carcinoma

BACKGROUND AND PURPOSE: The presence of cervical lymph node metastases is an important prognostic factor for oral tongue cancer. The accurate preoperative assessment is essential for treatment. Several studies have suggested that histologic tumor thickness is related to the metastases. The aim of this study was to determine whether MR images of oral tongue tumor have the potential to predict cervical lymph node metastases. MATERIALS AND METHODS: A total of 43 patients with squamous cell carcinoma of the oral tongue were investigated. Tumor thickness, sublingual distance between tumor and sublingual space, and paralingual distance between tumor and paralingual space, as determined from coronal MR imaging, were preoperatively estimated. Logistic regression analysis was used to identify independent predictors of lymph node metastases. RESULTS: Univariate logistic regression analysis showed that T classification, N classification, and 3 measured MR imaging distances (millimeters) were significantly associated with lymph node metastases. Multivariate logistic regression analysis showed that tumor thickness (odds ratio, 1.34; 95% confidence interval [CI], 1.11–1.63; P < .005) and paralingual distance (odds ratio, 0.53; 95% CI, 0.35–0.82; P < .005) were significant predictors for lymph node metastases. The probability of metastases was estimated with these models. The preoperative decision (20% probability) as to whether to perform neck dissection could be based on tumor thickness of >9.7 mm and paralingual distance of <5.2 mm. CONCLUSION: MR images provide satisfactory accuracy for the preoperative estimation of the tumor thickness and the paralingual distance, which are valuable for predicting cervical lymph node metastases.

Breast feeding for cleft lip and palate patients, using the Hotz-type plate.

OBJECTIVE Oral-cavity feeding movements were analyzed during sucking and used to modify a Hotz-type plate to facilitate sucking in infants with cleft lip and palate. DESIGN Sucking movements were analyzed using lateral view cine radiography as three adults fed from a bottle. A Hotz-type plate was then modified to better isolate the oral cavity and to occlude the oral airway. The plate was then utilized in direct breast feeding by 10 babies. OUTCOME MEASURES Sucking rate, amount of milk taken, and duration of use of the plate were assessed. RESULTS Wearing this plate, four babies with cleft lip and palate could suck their mothers breast, drinking about 22 g/trial. CONCLUSIONS Although supplemental bottle feeding was required to provide enough nourishment, this is the first step to reaching ideal breast feeding situation for these patients.

Basic fibroblast growth factor supports expansion of mouse compact bone-derived mesenchymal stem cells (MSCs) and regeneration of bone from MSC in vivo

Some progress has been made in development of methods to regenerate bone from cultured cells, however no method is put to practical use. Here, we developed methods to isolate, purify, and expand mesenchymal stem cells (MSCs) from mouse compact bone that may be used to regenerate bone in vivo. These cells were maintained in long-term culture and were capable of differentiating along multiple lineages, including chondrocyte, osteocyte, and adipocyte trajectories. We used standard cell isolation and culture methods to establish cell cultures from mouse compact bone and bone marrow. Cultures were grown in four distinct media to determine the optimal composition of culture medium for bone-derived MSCs. Putative MSCs were subjected to flow cytometry, alkaline phosphatase assays, immunohistochemical staining, and several differentiation assays to assess cell identity, protein expression, and developmental potential. Finally, we used an in vivo bone formation assay to determine whether putative MSCs were capable of regenerating bone. We found that compact bone of mice was a better source of MCSs than the bone marrow, that growth in plastic flasks served to purify MSCs from hematopoietic cells, and that MSCs grown in basic fibroblast growth factor (bFGF)-conditioned medium were, based on multiple criteria, superior to those grown in leukemia inhibitory factor-conditioned medium. Moreover, we found that the MSCs isolated from compact bone and grown in bFGF-conditioned medium were capable of supporting bone formation in vivo. The methods and results described here have implications for understanding MSC biology and for clinical purpose.

Extensive nasopalatine duct cyst causing nasolabial protrusion.

In this report, we show a case of the extensive nasopalatine duct cyst showing remarkable nasolabial protrusion. CT and MR examinations showed remarkable expansion of the extraosseous part of the lesion toward anterior and lateral sides, and this finding is considered to show the rather aggressive nature of this common cystic lesion after penetration of the maxillary cortex.

Novel effects of CCN3 that may direct the differentiation of chondrocytes.

Identification and characterization of local molecules directing the differentiation of chondrocytes to either transient or permanent cartilage are major issues in cartilage biology. Here, we found CCN family protein 3 (CCN3) was abundantly produced in rat developing epiphyseal cartilage. Evaluations in vitro showed that CCN3 repressed epiphyseal chondrocyte proliferation, while promoting matrix production in multiple assays performed. Furthermore, CCN3 enhanced the articular chondrocytic phenotype; whereas it repressed the one representing endochondral ossification. Additionally, the phenotype of growth plate chondrocytes and chondrogenic progenitors also appeared to be affected by CCN3 in a similar manner. These findings suggest a significant role of CCN3 in inducing chondrocytes to articular ones during joint formation.