The HKT1 Na+ transporter protects plant fertility by decreasing Na+ content in stamen filaments.

Salinity stress can greatly reduce seed production because plants are especially sensitive to salt during their reproductive stage. Here, we show that the sodium ion transporter AtHKT1;1 is specifically expressed around the phloem and xylem of the stamen in Arabidopsis thaliana to prevent a marked decrease in seed production caused by salt stress. The stamens of AtHKT1;1 mutant under salt stress overaccumulate Na+, limiting their elongation and resulting in male sterility. Specifically restricting AtHKT1;1 expression to the phloem leads to a 1.5-fold increase in the seed yield upon sodium ion stress. Expanding phloem expression of AtHKT1;1 throughout the entire plant is a promising strategy for increasing plant productivity under salinity stress.

Potassium transporter KUP9 participates in K+ distribution in roots and leaves under low K+ stress.

Potassium (K) is a major essential element in plant cells, and KUP/HAK/KT-type K+ transporters participate in the absorption of K+ into roots and in the long-distance transport to above-ground parts. In Arabidopsis thaliana, KUP9 is involved in the transport of K+ and Cs+ in roots. In this study, we investigated KUP9 function in relation to the K+ status of the plant. The expression of KUP9 was upregulated in older leaves on K+-depleted medium, compared to the expression of the other 12 KUP genes in the KUP/HAK/KT family in Arabidopsis. When grown on low K+ medium, the kup9 mutant had reduced chlorophyll content in seedlings and chlorosis in older rosette leaves. Tissue-specific expression of KUP9 determined by KUP9 promoter:GUS assay depended on the K+ status of the plants: In K+ sufficient medium, KUP9 was expressed in the leaf blade towards the leaf tip, whereas in K+ depleted medium expression was mainly found in the petioles. In accordance with this, K+ accumulated in the roots of kup9 plants. The short-term 43K+ tracer measurement showed that 43K was transferred at a lower rate in roots and shoots of kup9, compared to the wild type. These data show that KUP9 participates in the distribution of K+ in leaves and K+ absorption in roots under low K+ conditions.

Interdental Distraction Osteogenesis in Unilateral Cleft Lip and Palate Patient with Wide Alveolar Cleft.

Alveolar bone grafting is routinely performed in repair of alveolar clefts. When the alveolar cleft is wider than 11 mm, however, the survival rate of the bone graft and prognosis are poor. Here, we describe successful orthodontic treatment using interdental distraction osteogenesis (IDO) with a tooth-tooth type distractor to reduce the width of the alveolar cleft in a patient with unilateral cleft lip and palate. The patient was a 12-year-old girl with unilateral cleft lip and palate, maxillary dentition midline deviation, congenitally missing maxillary lateral incisors, a palatally-displaced right upper first premolar, a wide alveolar cleft (20 mm), and mandibular prognathism due to maxillary hypoplasia. Treatment comprised a combination of orthodontic treatment and IDO. After treatment, appropriate occlusion, space closure in the maxillary arch, coincidence of the maxillary and facial midlines, and incorporation of the right maxillary first premolar into the arch were obtained. These results suggest that IDO is effective in treating cleft lip and palate patients with a wide alveolar cleft.

Growth of Palate in Unilateral Cleft Lip and Palate Patients Undergoing Two-stage Palatoplasty and Orthodontic Treatment.

The purpose of this study was to investigate the long-term effects of two-stage palatoplasty on the morphology of the maxillary alveolar arch and occlusion using plaster models of the maxilla and mandible obtained from patients with unilateral complete cleft lip and palate who also underwent orthodontic treatment. A total of 20 patients undergoing two-stage palatoplasty by Perko's method (Group T) were enrolled. Plaster models of the maxilla and mandible were obtained from each patient at Time 1, on commencement of orthodontic treatment in the mixed dentition period; at Time 2, on that of orthodontic treatment in the permanent dentition period; and at Time 3, on completion of active orthodontic treatment. Analysis of occlusion and morphological analysis were performed using a 3-dimensional measuring system. The results were compared with 15 patients who underwent one-stage palatoplasty by the push-back method using a mucoperiosteal flap (Group P). Alveolar morphology and the relationship between the maxilla and mandible were satisfactory in Group T. The palates in Group T were deeper and larger than those in Group P. Alveolar collapse in Group T was milder, and impairment of the alveolar morphology less notable than in Group P, as surgical invasion to the anterior alveolar region was avoided during the palatal growth period. These results suggest that two-stage palatoplasty is advantageous for jaw development.

Quantification of negative aesthetic ratings in primary unrepaired unilateral cleft lip infants by modified paired comparison method.

OBJECTIVE: To quantify negative aesthetic ratings in primary unrepaired cleft lip infants by further refining our previously reported paired comparison method. DESIGN: The Thurstone paired comparison method was used to quantify negative aesthetic ratings of plaster facial models selected and ordered according to a table of paired random numbers. PATIENTS, PARTICIPANTS: A total of 30 facial models of unrepaired incomplete unilateral cleft lip infants were used in this study. Raters comprised 20 oral surgeons and anesthesiologists. RESULTS: Quantification of aesthetic ratings for the 30 face models of unrepaired incomplete unilateral cleft lip infants was obtained. The ratings ranged from 0 to 5.08. CONCLUSION: Quantification of the aesthetic ratings for the 30 face models will be used as objective variables in a multivariate analysis in the third stage of this ongoing study.

Bisphosphonate-related osteonecrosis of jaw (BRONJ) in Japanese population: a case series of 13 patients at our clinic.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) affects quality of life and is an important problem for dentists. A Japanese position paper on BRONJ was published in 2010. The purpose of this study was to review clinical data on the treatment of BRONJ obtained at the Clinic of Oral and Maxillofacial Surgery, Tokyo Dental College, Chiba Hospital to further our understanding of this disease. A total of 13 patients (6 men and 7 women) were included. All the patients included in this study had received Bisphosphonate (BP) therapy and had BRONJ. Five of them (38.5%) had received oral BP therapy for osteoporosis, while the remaining 8 (61.5%) had received parenteral BP therapy for bone metastases from breast or prostate cancer. Osteoporosis patients were treated with risedronate or alendronate. Breast or prostate cancer patients were treated with zoledronate. Two patients with rheumatoid arthritis were treated with corticosteroid. Three patients had diabetes mellitus. Eleven patients were treated with antibiotics, while 5 underwent surgical treatment. Discontinuation of BP was recorded in 7 patients during dental treatment. Sequestration was observed in 6 patients during an 11-month follow-up. Eventually, healing and improvement of the oral mucosa were observed in 3 patients. The current standard treatment for BRONJ does not always provide good results. It is necessary to accumulate further clinical data to establish more effective treatment strategies for BRONJ.

Intraosseous schwannoma originating in inferior alveolar nerve: a case report.

Schwannomas (neurilemmomas) are benign neoplasms derived from Schwann cells of the neurilemma and appear most frequently on the auditory nerve or peripheral nerves of the skin. They arise in the oral and maxillofacial region infrequently, and very rarely in the center of the jaw. We herein present a case of a rare mandibular intraosseous schwannoma derived from the main trunk of the inferior alveolar nerve in a 33-year-old man. Fusiform expansion in the mandibular canal was observed and a mass showing the target sign in the mandibular canal was confirmed on T2-weighted and Gd contrastenhanced T1-weighted MRI. Based on these findings, an inferior alveolar nerve-derived schwannoma or other benign nervous system neoplasm was diagnosed. A buccal side cortical bone flap in the mandibular molar region was removed to expose the mass, which was then peeled away from the nerve fibers and completely removed. Some inferior alveolar nerve fibers that were connected to the mass were removed at the same time, but the remaining nerve fiber bundle was preserved. Histopathology confirmed the diagnosis of a schwannoma with Antoni type A and Antoni type B regions. Although the patient experienced extremely mild paresthesia in the skin over the mental region and mental foramen at immediately after surgery, this had almost entirely disappeared at 7 years and 4 months later, and there has been no tumor recurrence.

Postoperative evaluation of grafted bone in alveolar cleft using three-dimensional computed tomography data.

Objective : Postoperative evaluation of bone formation in the alveolar cleft by computed tomography imaging has been reported. We quantitatively evaluated bone grafts in the alveolar cleft preoperatively and postoperatively using three-dimensional data and superimposition of images. Subjects : A total of 12 patients with complete unilateral cleft lip and palate (six left-sided and six right-sided) were studied. Methods : Helical computed tomography scans were taken immediately before surgery and at 6 months after surgery and the DICOM files obtained were processed using Mimics and 3-matic software for three-dimensional data analysis. The preoperative and postoperative computed tomography data were superimposed, and the position and length of the unerupted canines and width of the alveolar cleft measured. Results : Strong and significant correlations were observed between bone formation in the alveolar cleft bone graft region and preoperative canine position (r  =  -.766, p < .01) and canine length (r  =  .681, p < .05). Stepwise multiple regression analysis demonstrated that only the preoperative canine position was independently and significantly correlated with bone formation in the alveolar cleft. Conclusion : These results indicate that the optimal timing for surgery is when the canine cusp is close to the alveolar plane.

No evidence of association between 8q24 and susceptibility to nonsyndromic cleft lip with or without palate in Japanese population.

OBJECTIVE: Recent genome-wide association studies identified susceptibility loci for nonsyndromic cleft lip with or without cleft palate (NSCL±P) on 8q24.21, 10q25.3, 13q31.1, 15q13.3, 17q22, and 18q22 in populations of European origin. The purpose of this study was to determine, using DNA samples, whether 8q24.21 was a susceptibility locus for the development of NSCL±P in Japanese patients. METHODS: We used DNA from 167 Japanese NSCL±P patients (45 cleft lip without cleft palate and 122 cleft lip with cleft palate patients) and 190 Japanese unaffected control individuals. We performed an association study using 13 single nucleotide polymorphisms (SNPs) selected on the 8q24.21 locus. Genotyping of each SNP was carried out by direct sequencing of genomic DNA. Additionally, a haplotype block was constructed using the selected SNPs. RESULTS: The 13 selected SNPs were successfully genotyped in 357 individuals. The p values obtained were not low enough to indicate a significant association between the haplotypes and the development of NSCL±P in this population. CONCLUSIONS: Our results suggest that the 8q24.21 locus is not associated with susceptibility to NSCL±P in Japanese patients and provide further evidence that ethnicity is a strong factor in determining susceptibility loci, albeit using a limited number of samples. Further studies are needed to identify regions involved in the development of NSCL±P in the Japanese population.

Primary treatment for cleft lip and/or cleft palate in children in Japan.

OBJECTIVE: To investigate current trends in primary treatment for children with cleft lip and/or cleft palate in Japan. DESIGN: Nationwide, retrospective study under the direction of the Academic Survey Committee of the Japanese Cleft Palate Association based on analysis of data obtained via a booklet-style questionnaire completed by institutions providing primary treatment for cleft lip and/or palate patients. PARTICIPANTS, PATIENTS: Patients were 4349 children undergoing primary repair for cleft lip and/or palate at 107 participating institutions between 1996 and 2000. MAIN OUTCOME MEASURE(S): Cleft type, laterality; use of infant palatal plate; and timing and technique of primary repair for cleft lip and/or palate were evaluated by cleft surgeons at 107 participating institutions. RESULTS: Of a total of 2874 patients with cleft lip and palate or cleft palate only, infant palatal plates were used with 1087 (37.8%) and were not used with 1787 (62.2%). Primary unilateral lip repair was performed at the age of 2 to 6 months in more than 90% of patients. Bilateral cleft lip was treated by one-stage repair in 285 patients (44.5%) and by two-stage repair in 258 (40.2%). Primary one-stage palatal repair was performed in 2212 (76.9%) and two-stage palatal repair in 262 (9.1%) cleft palate patients. Information on treatment of the remaining 400 (14%) patients was unavailable. CONCLUSION: This investigation clarified current trends in primary treatment for cleft lip and/or palate in Japan. The results suggest the need for an increase in regional core hospitals and greater variation in treatment options.

Application of interdental distraction osteogenesis to unilateral cleft lip and palate patients.

Distraction osteogenesis is widely used for the treatment of craniofacial deformities. In patients with cleft lip and palate, distraction osteogenesis can be employed to repair the alveolar cleft. In this report, we describe the management of three cases of unilateral cleft lip and palate by interdental distraction osteogenesis. Interdental distraction osteogenesis of the maxillary bone was performed to reduce the width of the alveolar cleft in these patients in conjunction with orthodontic treatment. Tooth-tooth type distraction devices were fabricated and delivered at the same time as osteotomy. Distraction was continued until the midline of the dentition coincided with the facial midline, and until the width of the alveolar cleft was reduced to the width of lateral incisor or had closed. One month after distraction was complete, orthodontic treatment with an edgewise appliance was initiated, and neighboring teeth were moved into the newly created bone. A favorable treatment outcome was achieved in all three cases.

Morphological observation of process of mouse temporomandibular joint formation.

The aim of this study was to clarify the developmental mechanism of the temporomandibular joint (TMJ) cavity, using the relationship between Meckel's cartilage and the mandible to morphologically observe the process of TMJ formation in mouse fetuses. We investigated the involvement of apoptosis in the development of the mouse TMJ cavity. We attempted to 3-dimensionally clarify the developmental process of the mandible and Meckel's cartilage by observing the developmental process optically and reconstructing 3-dimensional images to observe 3-dimensional locations of the mandible and Meckel's cartilage. Formation of the upper joint cavity began on embryonal day 16, and a complete joint cavity was formed on embryonal day 18. Formation of the lower joint cavity began on embryonal day 18, and formation was almost completed on embryonal day 19. Meckel's cartilage adjacent to the mandible decreased with development of the mandible but was vestigial on embryonal day 19. The posterior region of Meckel's cartilage developed toward the posterior direction, and it was 3-dimensionally confirmed that the mandible and Meckel's cartilage were separated. Histological observation by the TUNEL method revealed the presence of solitary and diffuse apoptotic cells not only in the joint cavity, but also around the condyle.

Congenital epidermoid cyst arising in soft palate near uvula: a case report.

Aberrant ectodermal tissues during the fetal period or acquired aberrant epithelial tissue due to trauma or surgery are thought to cause dermoid and epidermoid cysts. Their incidence is 7.0% in the head and neck region and only 1.6% in the oral cavity, where they mostly present in the floor of the mouth. On the other hand, they are extremely rare in the soft palate and uvula, and only six cases have been reported. Epidermoid cysts grow slowly and asymptomatically, and thus rarely cause oral dysfunction. However, cysts arising in the floor of the mouth can lead to developmental disorders due to impaired suckling and swallowing. This report describes a 4-week-old boy in whom an epidermoid cyst developed in the midline region of the soft palate close to the uvula. Decreased suckling ability led to a poor in body weight, so resection was performed at an early age. The histopathological diagnosis was epidermoid cyst.

A case of congenital midline fistula of the upper lip.

Congenital fistulas of the lip are commonly found in the lower lip and accompany cleft lip. They are seen as a symptom of Van der Woude syndrome, which is predominantly hereditary. In contrast, congenital fistulas of the upper lip are rare. A number of hypotheses have been proposed to explain the pathogenesis of fistulas of the upper lip, including fusion failure of facial prominences and absence of mesoblasts, suggesting a relationship between this condition and the development of cleft lip. The pathogenesis of this disorder has been attracting attention. We report the case of a 5-year-old girl with congenital fistula of the upper lip.

Vertical fracture of mandibular condyle treated with intra-articular pumping therapy: a case report.

We report a patient with vertical fracture of the mandibular condyle visualized by computed tomography (CT). A 43-year-old woman visited our department the day after the injury occurred. At the initial examination, she experienced pain in the left temporomandibular joint (TMJ) when opening her mouth. Maximum mouth opening distance was 15 mm. Routine radiography showed normal findings, but CT revealed vertical fracture of the left mandibular condyle. Based on clinical findings, conservative therapy consisting of intra-articular pumping therapy and training for mouth opening was initiated. After 10 days, mouth opening distance increased to 36 mm, and pain in the left TMJ disappeared.

Resistance to cytotoxic chemotherapy-induced apoptosis in side population cells of human oral squamous cell carcinoma cell line Ho-1-N-1.

Side population (SP) cells are isolated from various tissues and cell lines based on the exclusion of DNA-binding dye Hoechst 33,342 and exhibit potent stem cell characteristics. There have been few previous reports of SP cells in head and neck cancer cell lines. Thus, we isolated SP cells from oral squamous cell carcinoma cell line, Ho-1-N-1. Ho-1-N-1 contained 3.0% SP cells. Ho-1-N-1 SP cells showed self-renewal capacity, generating both SP and non-SP cells. Next, we analyzed differentially expressed genes between Ho-1-N-1 SP and non-SP cells using GeneChip microarray and quantitative real-time RT-PCR. SP cells expressed high levels of ATP-binding cassette transporters with related multidrug resistance (MDR) genes. The expression of ABCB1 and ABCG2 were significantly up-regulated in Ho-1-N-1 SP cells. In addition, the expression of CFLAR, BCL2 and BCL2A1 which are associated with anti-apoptosis, were also significantly increased in the SP cells. Chemoresistance to anticancer agents, including 5-fluorouracil and carboplatin, were compared between Ho1-N-1 SP and non-SP cells using flow cytometry and tetrazolium salt microtiter plate assay. Ho-1-N-1 SP cells survived significantly longer and SP ratio remarkably increased after anticancer agent treatment compared to non-SP cells. Immunocytochemical staining and apoptosis assay validated these results, and suggested an anti-apoptotic potential for Ho-1-N-1 SP cells. Ho-1-N-1 SP cells survived with various agents which were not only probably due to high level expression of ABC transporters, but also anti-apoptotic proteins. These observations indicated that Ho-1-N-1 SP cells were MDR phenotype and should be the main target for effective cancer therapy.

Spleen tyrosine kinase as a novel candidate tumor suppressor gene for human oral squamous cell carcinoma.

We analyzed the mutational and methylation status of the spleen tyrosine kinase (Syk) gene and both mRNA and protein levels in primary oral squamous cell carcinoma (OSCC) and OSCC-derived cell lines and examined the function of the Syk gene in OSCC-derived cell lines in vitro. Using quantitative real-time reverse transcription polymerase chain reaction, Western blotting and immunofluorescence on 7 OSCC-derived cell lines and normal oral keratinocytes (NOKs), Syk mRNA and protein expression were commonly downregulated in all cell lines compared to the NOKs. Although no sequence variation in the coding region of the Syk gene was identified in these cell lines, we found frequent hypermethylation in the CpG island region. Syk expression was restored by experimental demethylation. In addition, using a wound healing assay and in vitro invasion assay, we performed functional analysis using Syk transfected into the OSCC-derived cell lines, and they showed significant inhibition of motility and invasiveness. In clinical samples, high frequencies of Syk downregulation were detected by immunohistochemistry (33 of 53 [62%]). Furthermore, the Syk expression status was correlated significantly (p = 0.047) with tumor metastasis to cervical lymph nodes. These results suggest that the Syk gene is frequently inactivated during oral carcinogenesis and that an epigenetic mechanism may regulate loss of expression possibly leading to metastasis.

Osteoma of mandibular condyle as cause of acute pain and limited-mouth-opening: case report.

In benign tumors in the mandibular condyle such as osteoma and osteochondroma, symptoms such as pain and limited-mouth-opening are rarely observed. Therefore, these tumors are often detected after the development of changes in occlusion and mandibular midline deviation. We encountered a very rare patient with mandibular condyle osteoma who showed acute pain and markedly limited-mouth-opening.

Multidisciplinary treatment of mandibular prognathism with multiple congenitally missing teeth.

Surgical orthodontic treatment and dental implant therapy were performed on a man (aged 18 years 8 months) with mandibular prognathism and seven congenitally missing teeth: upper canines, first and second premolars and lower right second premolar. After 17 months of preoperative orthodontic treatment at age 20 years 1 month, sagittal split ramus osteotomy was performed using the remaining upper deciduous teeth as an anchor for intermaxillary fixation. In postoperative orthodontic treatment, the remaining deciduous teeth were extracted, and fixture installation was performed. The entire therapy required 4 years to complete (age 22 years 8 months). After completion of orthodontic treatment, superstructures were put in place. This patient had many dental problems, so multidisciplinary care was performed in conjunction with other departments to improve oral function and facial esthetics.

A mutation in RYK is a genetic factor for nonsyndromic cleft lip and palate.

OBJECTIVE: The RYK, EPHB2, and EPHB3 genes are attractive candidates for cleft lip and/or palate and cleft palate only pathogenesis. Both the Ryk-deficient mouse and Ephb2/Ephb3 (genes for interaction molecules with RYK) double-mutant mouse show cleft palate. SETTING: Mutation searches for RYK, EPHB2, and EPHB3 were carried out in a large number of Japanese and Vietnamese patients with cleft lip and/or palate and cleft palate only. Case-control study and transmission disequilibrium tests were performed also, using three single nucleotide polymorphisms within a linkage disequilibrium block in RYK. Seven haplotypes were constructed from the single nucleotide polymorphisms. RESULTS: A missense mutation, 1355G>A (Y452C), in RYK was identified in one Vietnamese patient with cleft lip and/or palate. This mutation was not found among 1646 Vietnamese, Japanese, and Caucasians, including 354 cleft lip and/ or palate and cleft palate only patients. Colony formation assay using NIH3T3 cells transfected with mutant cDNA revealed that mutant RYK had significantly reduced protein activity, compared with those with wild-type RYK, implying that the transformation ability of RYK is depleted by this mutation. Although a case-control study and transmission disequilibrium tests on three individual single nucleotide polymorphisms provided no evidence for association with oral clefts, a case-control study on one rare haplotype suggested a positive association in Japanese patients with cleft lip and/or palate and cleft palate only. No mutations in EPHB2 and EPHB3 were found in any patients examined. CONCLUSION: The findings suggested that a missense mutation, 1355G>A, and one rare single nucleotide polymorphisms haplotype may play a role in the development of cleft lip and/or palate in the Vietnamese, and cleft lip and/ or palate and cleft palate only in the Japanese.