Biomedical subjects

Eiji Tanaka

Publications and source records attributed to Eiji Tanaka.

At least 37 records · Page 2Linked to original sources

PubMed2006

Fulminant hepatitis after allogenic bone marrow transplantation caused by reactivation of hepatitis B virus with gene mutations in the core promotor region.

Under immunosuppressive conditions after hematopoietic stem cell transplantation (HSCT), even if hepatitis B virus (HBV) antigen is negative but hepatitis B surface antibody (HBsAb) or hepatitis B core antibody (HBcAb) is presented, HBV reactivates and sometimes causes fulminant hepatitis. However, it remains unclear which patients will develop fulminant hepatitis, or whether fulminant hepatitis is caused by host-related factors or by virus-related factors. A 30-yr-old man with a history of aplastic anemia since 3 yr of age underwent allogenic BMT, when HBsAb and HBcAb were positive but HBs antigen (HBsAg) was negative. The donor was negative for HBsAg, HBsAb and HBcAb. After transplantation, the patient was complicated by acute graft-vs.-host disease (GVHD), cytomegalovirus infection, intestinal thrombotic microangiopathy and aspergillus colitis. Chronic GVHD was well controlled by FK506 and prednisolone. Twenty months after transplantation, the patient was admitted with general fatigue and liver dysfunction and was found to be positive for HBsAg and HBeAg. His serum HBV-DNA level was >8.8 log of the genome equivalent (LGE)/mL. Therefore, he was diagnosed as having hepatitis B caused by HBV reactivation and 100 mg/d lamivudine treatment was started. However, jaundice and hepatic failure deteriorated and became fatal. On analysis of the HBV-DNA, two adjacent gene mutations in the core promoter region (T1762/A1764) were detected. Increased replication of the mutated HBV might have caused HBV reactivation which progressed to fulminant hepatitis.

Acute Disease↗

PubMed2006

Age-associated changes in viscoelastic properties of the bovine temporomandibular joint disc.

To test the hypothesis that compressive properties of the temporomandibular joint (TMJ) disc change with age, we investigated its viscoelastic properties and stress-relaxation behavior under compression. Compressive stress-relaxation tests were performed in different regions of bovine discs of various ages. For each disc, specimens were derived from three different regions (anterior, central, and posterior). For four strain levels (5, 10, 15, and 20%), a stress-relaxation test was conducted over a 5-min period. Values of the instantaneous modulus, E(0), appeared to be larger in the anterior than in the posterior region of the disc, irrespective of age. The E(0) value increased with age, especially in the central region. Values of the relaxed modulus, E(R), also increased significantly with age. There were no regional differences in values of the relaxed modulus. Under stress-relaxation, the relaxation time became longer with age, especially in the posterior region. The results suggest that the compressive properties, instantaneous and relaxed moduli, increase with age, while the relaxation time becomes longer. This implies that the TMJ disc becomes harder with age. Furthermore, the compressive properties of the TMJ disc are region-specific. As a result of the harder disc, it is likely that the TMJ becomes more vulnerable to secondary damage, such as fracture and tissue degradation.

Aging↗

PubMed2006

Three-dimensional finite-element model of the human temporomandibular joint disc during prolonged clenching.

In the temporomandibular joint (TMJ), overloading induced by prolonged clenching appears to be important in the cascade of events leading to disc displacement. In this study, the effect of disc displacement on joint stresses during prolonged clenching was studied. For this purpose, finite-element models of the TMJ, with and without disc displacement, were used. Muscle forces were used as a loading condition for stress analysis during a time-period of 10 min. The TMJ disc and connective tissue were characterized as a linear viscoelastic material. In the asymptomatic model, large stresses were found in the central and lateral part of the disc through clenching. In the retrodiscal tissue, stress relaxation occurred during the first 2 min of clenching. In the symptomatic model, large stresses were observed in the posterior part of the disc and in the retrodiscal tissue, and the stress level was kept constant through clenching. This indicates that during prolonged clenching the disc functions well in the asymptomatic joint, meanwhile the retrodiscal tissue in the symptomatic joint is subject to excessive stress. As this structure is less suitable for bearing large stresses, tissue damage may occur. In addition, storage of excessive strain energy might lead to breakage of the tissue.

Adult↗

PubMed2005

Timing of interferon therapy and sources of infection in patients with acute hepatitis C.

BACKGROUND/AIMS: Controversy over the selection of patients and optimum therapeutic method for acute hepatitis C has continued. The aims of this study were to investigate the source of infection, and to evaluate the timing of interferon (IFN) therapy in patients with acute hepatitis C in Japan. METHODS: The records of 102 patients from 12 facilities in Japan who developed acute hepatitis C after 1990 were investigated. In the patients treated with IFN, we performed multivariate analysis to investigate factors related to sustained virological response (SVR). RESULTS: Medical procedure was the most common source of infection, accounting for 32.4% in the 102 patients (33/102). Of 81 patients treated with IFN, 71 patients were followed after IFN therapy, and 57/71 (80.3%) had SVR. The SVR rate was significantly higher in patients treated with IFN within 24 weeks from onset of symptoms than the SVR rate in those treated after 25 weeks (P=0.0016). Multivariate analysis revealed that only the duration between onset of symptoms and initiation of IFN therapy (within 24 weeks) was related to SVR. CONCLUSIONS: Our multicenter cooperative survey revealed that medical procedure was the most frequent source of infection in acute hepatitis C. As concerns the therapy, interferon treatment should be initiated within 24 weeks after onset of symptoms.

Journal Article↗

PubMed2005

Multidifferentiation potential of mesenchymal stem cells in three-dimensional collagen gel cultures.

Mesenchymal stem cells (MSCs) have a great therapeutic potential resulting from their ability to differentiate into multiple tissues when cultured under specific conditions. However, it has not been clearly demonstrated whether or not MSCs exhibit a multidifferentiation potential in three-dimensional collagen gel cultures. This study was conducted to explore the multidifferentiation potential of MSCs cultured in three-dimensional collagen gels. Human MSCs were cultured in 0.3% collagen gel for 20 days in chondrogenic differentiation medium (CDM), and for 14 days in osteogenic differentiation medium (ODM). Increases in GAG deposits, intensity of toluidine blue staining, and mRNA expressions of chondrogenic markers (type II collagen and type X collagen) were found in human MSCs cultured in the collagen gel maintained in CDM. Positive staining for alkaline phosphatase (ALP) activity and alizarin red, and increases in mRNA expressions of osteogenic markers (type I collagen, bone sialoprotein and ALP) were noted in the MSCs maintained in ODM. These findings emphasize that human MSCs have an ability to differentiate into both bone and cartilaginous tissues in three-dimensional collagen gel cultures, indicating potential clinical applications of MSC transplant therapy with collagen gel as a scaffold for bone or cartilage regeneration in complicated tissue defects.

Base Sequence↗

PubMed2005

Assessment of KL-6 as a tumor marker in patients with hepatocellular carcinoma.

AIM: To investigate the clinical significance of KL-6 as a tumor marker of HCC in two different ethnic groups with chronic liver disease consecutively encountered at outpatient clinics. METHODS: Serum KL-6 was measured by the sandwich enzyme immunoassay method using the KL-6 antibody (Ab) as both the capture and tracer Ab according to the manufacturer's instructions (Eisai, Tokyo, Japan). Assessment of alpha fetoprotein (AFP) and protein induced vitamin K deficiency or absence (PIVKA-II) was performed in both groups using commercially available kits. RESULTS: A significantly higher mean serum KL-6 (556+/-467 U/L) was found in HCC in comparison with non-HCC groups either with (391+/-176 U/L; P<0.001) or without (361+/-161 U/L; P<0.001) liver cirrhosis (LC). Serum KL-6 level did not correlate with either AFP or PIVKA-II serU/Levels. Using receiver operating curve analysis for KL-6 as a predictor for HCC showed that the area under the curve was 0.574 (95%CI = 0.50-0.64) and the KL-6 level that gave the best sensitivity (61%) was found to be 334 U/L but according to the manufacturer's instructions; a cut-off point of 500 U/L was used that showed the highest specificity (80%) in comparison with AFP and PIVKA-II (78% vs 72% respectively). Combining the values of the three markers improved specificity of AFP for HCC diagnosis from 78% for AFP alone; 93% for AFP plus PIVKA-II to 99% for both plus KL-6 value (P<0.001). Mean serum alkaline phosphatase level was significantly higher in KL-6 positive (564+/-475) in comparison with KL-6 negative (505+/-469) HCC patients (P = 0.021), but such a difference was not found among non-HCC corresponding groups. CONCLUSION: KL-6 is suggested as a tumor for HCC. Its positivity may reflect HCC-associated cholestasis and/or local tumor invasion.

Adult↗

PubMed2005

Efficacy of lamivudine for preventing hepatocellular carcinoma in chronic hepatitis B: A multicenter retrospective study of 2795 patients.

A retrospective survey of Japanese patients histologically diagnosed with chronic hepatitis B was conducted to determine the effectiveness of lamivudine in preventing hepatocellular carcinoma (HCC). Of the 2795 patients who satisfied criteria for analysis after treatment from any of 30 medical institutions, 657 had received lamivudine and the remaining 2138 had not. A Cox regression model with liver biopsy as the starting point revealed seven factors related to HCC: lamivudine therapy, gender, family clustering of hepatitis B, age at liver biopsy, hepatic fibrosis stage, serum albumin level, and platelet count. In a matched case-controlled study, 377 patients in a lamivudine-treated group and 377 matched patients in a non-treated group were selected based on their propensity scores. The mean follow-up period was 2.7 years in the lamivudine group and 5.3 years in the control group. In the lamivudine group, HCC occurred in four patients (1.1%) with an annual incidence rate of 0.4%/(patient/year), whereas in the control group HCC occurred in 50 patients (13.3%) for a rate of 2.5%/(patient/year). A comparison of the cumulative HCC incidence between the two groups by the Kaplan-Meier method showed a significantly lower incidence of HCC in the lamivudine group (p<0.001). These findings suggest that lamivudine effectively reduces the incidence of HCC in patients with chronic hepatitis B.

Journal Article↗

PubMed2005

Clinical significance of osteopontin in esophageal squamous cell carcinoma: comparison with common tumor markers.

OBJECTIVE: Osteopontin (OPN) is a secreted integrin-binding glycophosphoprotein that may have a role in head and neck squamous cell carcinoma (SCC). To evaluate the clinical significance of OPN in esophageal squamous cell carcinoma (ESCC), we compared plasma OPN levels with those of common tumor markers. METHODS: Preoperative plasma OPN levels were measured by enzyme immunoassay in 103 ESCC patients. Serum SCC antigen, Cyfra 21-1, and carcinoembryonic antigen (CEA) levels were also measured routinely at admission by radioimmunoassay. RESULTS: Plasma OPN levels ranged from 82.8 to 1,980 ng/ml. High OPN level was associated with lymph node metastasis (p = 0.05), but not with tumor histology or depth of invasion. The overall survival of the patients with high OPN levels was worse than that of those with low OPN levels (p = 0.02). SCC antigen and Cyfra 21-1 levels were associated with the depth of tumor invasion, the tumor diameter, lymph node metastasis, and the overall survival, but CEA was not associated with these clinicopathological factors. Combined evaluation of OPN plus Cyfra 21-1 or OPN plus SCC antigen was useful as an independent prognostic indicator. CONCLUSION: Measurement of the plasma OPN level, as well as serum SCC antigen and Cyfra 21-1, may help to predict the progression of ESCC.

Aged↗

PubMed2005

Hepatitis B virus DNA-negative dane particles lack core protein but contain a 22-kDa precore protein without C-terminal arginine-rich domain.

DNA-negative Dane particles have been observed in hepatitis B virus (HBV)-infected sera. The capsids of the empty particles are thought to be composed of core protein but have not been studied in detail. In the present study, the protein composition of the particles was examined using new enzyme immunoassays for the HBV core antigen (HBcAg) and for the HBV precore/core proteins (core-related antigens, HBcrAg). HBcrAg were abundant in fractions slightly less dense than HBcAg and HBV DNA. Three times more Dane-like particles were observed in the HBcrAg-rich fraction than in the HBV DNA-rich fraction by electron microscopy. Western blots and mass spectrometry identified the HBcrAg as a 22-kDa precore protein (p22cr) containing the uncleaved signal peptide and lacking the arginine-rich domain that is involved in binding the RNA pregenome or the DNA genome. In sera from 30 HBV-infected patients, HBcAg represented only a median 10.5% of the precore/core proteins in enveloped particles. These data suggest that most of the Dane particles lack viral DNA and core capsid but contain p22cr. This study provides a model for the formation of the DNA-negative Dane particles. The precore proteins, which lack the arginine-rich nucleotide-binding domain, form viral RNA/DNA-negative capsid-like particles and are enveloped and released as empty particles.

Antibodies, Monoclonal↗

PubMed2005

Prognostic significance of fascin overexpression in human esophageal squamous cell carcinoma.

PURPOSE: Fascin, an actin bundling protein, induces membrane protrusions and increased cell motility in various transformed cells. The expression of fascin in epithelial neoplasms has been described only recently, and the role of fascin in esophageal squamous cell carcinoma (ESCC) is still unknown. EXPERIMENTAL DESIGN: Paraffin sections of 200 patients with ESCC were immunohistochemically investigated. The expression levels of fascin mRNA in 20 ESCC tissues were compared with that in corresponding normal esophageal epithelium by semiquantitative reverse transcription-PCR. We also examined fascin protein expression in 33 ESCC cell lines. The role of fascin in cell motility and invasiveness in ESCC cells was assessed by the vector-based small interfering RNA. RESULTS: In immunohistochemical study, the intensity of fascin expression was usually increased in the tumor compared with that in normal epithelium. Fascin overexpression was significantly associated with a poor prognosis (immunoreactive rate, P = 0.033; immunoreactive intensity, P = 0.031). The fascin immunoreactive rate was associated with extent of the tumor (P = 0.002) and lymph node metastasis (P = 0.003). Multivariate analysis showed that fascin expression intensity was an independent prognostic factor, but the immunoreactive rate was not. In addition, up-regulation of fascin mRNA was found in 60% (12 of 20) of patients. In vitro study revealed that all 33 ESCC cell lines expressed fascin protein at a certain level. KYSE170, one of the fascin-overexpressed cells, decreased its motile and invasive properties after down-regulation of fascin expression. CONCLUSION: Our findings suggest that fascin overexpression may play an important role in the progression of ESCC.

Adult↗

PubMed2005

Vascular endothelial growth factor plays an important autocrine/paracrine role in the progression of osteoarthritis.

Vascular endothelial growth factor (VEGF) plays an essential role in the angiogenesis of growing cartilage. Although VEGF expression in cartilage vanishes in normal adults, VEGF is known to be expressed in chondrocytes of osteoarthritic (OA) cartilage. As little information is available on the VEGF expression in the cartilage of OA-like lesions of the temporomandibular joint (TMJ), VEGF expression in the condylar cartilage of TMJs of rats affected with OA was examined. To evoke OA, mechanical stress was applied by forced jaw opening for 10 or 20 days. After 20 days, marked OA-like lesions were observed in the condyle. VEGF was expressed in the chondrocytes of the mature and hypertrophic cell layers of the intermediate and posterior region of the condyle. The percentage of VEGF immunopositive chondrocytes significantly increased with the period of applied mechanical stress. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining of the condylar cartilage showed significant increment of osteoclasts in the mineralized layer subjacent to the hypertrophic layer where high VEGF expression could be detected. The results suggest that VEGF plays an important role in the progression of OA.

Acid Phosphatase↗

PubMed2005

Pancreatectomy using the no-touch isolation technique followed by extensive intraoperative peritoneal lavage to prevent cancer cell dissemination: a pilot study.

CONTEXT: In pancreatic cancer, even for patients who have undergone curative resection (R0), survival analysis has revealed a poor survival rate due to cancer recurrence. Because the operation itself might have caused the dissemination of these cancer cells, the no-touch isolation technique and extensive intraoperative peritoneal lavage may be a potential operative procedure for improving the outcome. PATIENTS: Eight patients treated by the no-touch isolation technique were compared with 10 patients treated using conventional techniques. MAIN OUTCOME MEASURES: Cancer cell detection rates in the portal venous blood, frequency of recurrence, and survival rate. We also analyzed the lymphatic fluid squeezed from the resected cancerous pancreatic tissue. RESULTS: In 5 out of 10 cases (50%) in the conventional procedure group, CEA mRNA was identified in the portal blood after tumor manipulation, while only 1 out of 8 cases (13%) in the no-touch isolation technique group was positive for portal CEA mRNA. All lymphatic fluid samples squeezed from the resected cancerous pancreatic tissue were positive (8/8) for CEA mRNA. The recurrence rate was 90% (9/10) in the conventional procedure group, and 38% (3/8) in the no-touch isolation technique group (P=0.043). In the conventional procedure group, hepatic metastasis, local recurrence, peritoneal dissemination, and extraabdominal recurrence were identified in 6 (60%), 4 (40%), 4 (40%), and 2 patients (20%), respectively. On the other hand, among the no-touch isolation technique group, recurrence was identified in 1 (13%), 1 (13%), 0 (0%), and 1 patient (13%), respectively. There was no peritoneal dissemination along with the decreased hepatic recurrence rate. Mean (+/-SEM) survival time was 21.2+/-5.8 months for the conventional procedure group and 41.5+/-5.6 months for the no-touch isolation technique group (P=0.018). The 3-year survival rate was 12.5+/-11.5% for the conventional procedure group and 75.0+/-21.7% for the no-touch isolation technique group. CONCLUSION: This study presented the potential of cancer dissemination during the intraoperative manipulation of tumors and its contribution to cancer recurrence, as well as the significance of the no-touch isolation technique and extensive intraoperative peritoneal lavage for pancreatic cancer surgery.

Carcinoembryonic Antigen↗

PubMed2005

The clinical significance of Aurora-A/STK15/BTAK expression in human esophageal squamous cell carcinoma.

PURPOSE: Aurora-A/STK15/BTAK (Aurora-A) encodes a Serine/Threonine kinase associated with chromosomal distribution, and its up-regulation induces chromosomal instability thereby leading to aneuploidy and cell transformation in several types of cancer. In this study, we investigated the role of Aurora-A in human esophageal squamous cell carcinoma (ESCC). EXPERIMENTAL DESIGN: The expression levels of Aurora-A mRNA were compared in 33 ESCC tissues with that in corresponding normal esophageal epithelium by semiquantitative reverse transcription-PCR, and the distribution patterns and expression levels of Aurora-A protein were immunohistochemically investigated in the ESCC tumors of 142 patients. The results were then separately compared with the clinicopathologic findings of the patients, and the expression of Aurora-A was examined in nine ESCC cell lines and a normal esophageal epithelial cell line using Western blot analysis. RESULTS: The up-regulation of Aurora-A mRNA was found in 30% (10 of 33) of the tumors by semiquantitative reverse transcription-PCR, and protein up-regulation was found in 53% (75 of 142) of the patients by immunohistochemistry. mRNA and protein up-regulation of Aurora-A were correlated with distant lymph node metastasis (P = 0.05 and P = 0.04, respectively), and patients with Aurora-A mRNA or protein up-regulation had a poorer prognosis (P = 0.003 and P = 0.0009, respectively). Furthermore, multivariate analysis revealed that up-regulation of the Aurora-A protein was an independent prognostic factor. In addition, Aurora-A expression in all ESCC cell lines was higher than that in a normal esophageal epithelial cell line. CONCLUSIONS: The up-regulation of Aurora-A expression may reflect the malignant behavior of ESCC and may prove useful information as a prognostic factor for ESCC patients.

Aged↗

PubMed2005

Genetic analysis of the HLA region of Japanese patients with type 1 autoimmune hepatitis.

BACKGROUND/AIMS: Genetic predisposition to type 1 autoimmune hepatitis (AIH) is linked mainly to HLA-class II genes. The aim of this study is to scan the HLA region for additional genes which may contribute to type 1 AIH susceptibility. METHODS: We performed association analysis using HLA class I and II alleles and 18 polymorphic microsatellite markers distributed throughout the HLA region. We specifically assessed tumor necrosis factor (TNF)-alpha gene polymorphisms. RESULTS: The frequencies of HLA-DRB1*0405, DRB4 and DQB1*0401 alleles were significantly higher in AIH patients. The association study revealed the presence of three segments in the HLA region showing significantly low P (Pc) values. The first segment was located around the HLA-DR/-DQ subregion, the second was around the HLA-B54 allele, and the third was around two microsatellites near the TNF gene cluster. However, stratification analysis for the effect of DRB1*0405 eliminated association of the latter two segments. Haplotype D of the TNF-alpha promoter gene polymorphisms was weakly associated with susceptibility, but was found to be not significant after stratification analysis. CONCLUSIONS: The most influential gene on type 1 AIH pathogenesis in Japanese is the HLA-DRB1. Other genes in the HLA region, including TNF-alpha, have little or no association with type 1 AIH susceptibility.

Adult↗

PubMed2005

Nucleotide mutations associated with hepatitis B e antigen negativity.

One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity.

Adolescent↗

PubMed2005

Identification of novel HCV subgenome replicating persistently in chronic active hepatitis C patients.

In an effort to clarify the life cycle of HCV, the HCV genome in liver biopsies taken from chronic active hepatitis C patients undergoing interferon treatment was investigated. Molecular cloning by long distance reverse-transcription polymerase chain reaction (RT-PCR) revealed that the HCV genome in two patients with high viral loads in the liver had in-frame deletions of approximately 2 kb between E1 and NS2, which encode the E1-NS2 fusion protein and six other HCV proteins: core, NS3, NS4A, NS4B, NS5A, and NS5B. Among the remaining 21 chronic active hepatitis C patients, these types of deletion were found in another two patients and in two hepatocellular carcinoma patients. Out-of-frame deletions in the structural region were isolated from the other five patients, but the dominant RT-PCR products were non-truncated genomes. Retrospective analysis of a series of serum samples taken from a patient carrying the subgenome with the in-frame deletion revealed that both the subgenome and the full genome persisted through the 2-year period of investigation, with the subgenome being predominant during this period. Sequence analysis of the isolated cDNA suggested that both the subgenome and the full genome evolved independently. Western blotting analysis of HCV proteins from the HCV subgenome indicated that they were processed in the same way as those from the full genome. HCV subgenomes thus appear to be involved in the HCV life cycle.

Amino Acid Sequence↗

PubMed2005

Longitudinal measurements of tooth mobility during orthodontic treatment using a periotest.

The present study was designed to investigate the alteration of tooth mobility through orthodontic treatment using a Periotest. Eighty-three crowding cases without severe skeletal discrepancies were used as subjects. For each subject, the mobility of the central and lateral incisors on both arches (U1, U2, L1, and L2) was measured immediately before and after orthodontic treatment (T1 and T2 stages) and after retention (T3 stage) by use of a Periotest. No significant differences of all the measurements were found between the left and right sides. At T1 stage, the mean values were 10.8, 10.4, 9.3, and 7.4 for U1, U2, L1, and L2, respectively. At T2 stage, the Periotest values for all the teeth increased in comparison with those at T1 stage, and significantly decreased at T3 stage compared with those at T2 stage. Negative correlations were found between the Periotest value and age, which imply that tooth mobility decreases with age. The durations of treatment and retention had low correlation with the change of tooth mobility for all the teeth. It is suggested that the tooth mobility before treatment and after retention may be one of the useful indicators for determination of the retention period.

Adolescent↗

PubMed2005

An adult case of skeletal open bite with a large lower anterior facial height.

Control of the height of posterior dentoalveolar regions is of great importance for the correction of skeletal open bite. Traditionally, second premolar extraction facilitates the closure of open bite by inducing a counterclockwise mandibular rotation without molar intrusion. This article reports treatment for a 24-year six-month-old female patient with an open bite and large anterior facial height. She complained of occlusal disturbances and difficulty of lip closure because of the open bite. Overjet and overbite were +3.0 mm and -3.0 mm, respectively. To correct open bite and crowding, the bilateral extraction of the maxillary and mandibular second premolars plus multibracket appliances for mesial movement of the molars was selected as the treatment plan. After a two-year treatment, an acceptable occlusion was achieved, the lower anterior facial height was decreased, and the lips showed less tension in a lip closure. An acceptable occlusion was maintained without recurrence of the open bite during a three-year retention period, indicating a long-term stability of the occlusion. The results of this treatment indicated that the correction of open bite with no or less molar intrusion or incisor extrusion is of great importance for achieving stable occlusion and avoiding the relapse of open bite.

Adult↗