Efficacy of laser in re-osseointegration of dental implants-a systematic review.

Despite their high success rates, peri-implantitis can affect the stability and function of dental implants. Various treatment modalities have been investigated for the treatment of peri-implantitis to achieve re-osseointegration. An electronic literature search was performed supplemented by a manual search to identify studies published until January 2022. Articles that evaluated re-osseointegration in peri-implantitis sites in animal models following laser therapy or antimicrobial photodynamic therapy (aPDT) were included. Case reports, case series, systematic reviews, and letters to the editor were excluded. Risk of bias and GRADE assessment were followed to evaluate the quality of the evidence. Six studies out of 26 articles identified on electronic search were included in this review. The studies included animal studies conducted on canine models. Four out of six studies reported a higher degree of re-osseointegration following treatment of implants with laser therapy. The findings suggest that laser decontamination shows potential in enhancing re-osseointegration, particularly with the Er: YAG laser, which effectively decontaminated implant surfaces. However, conflicting outcomes and limitations in the evidence quality warrant caution in drawing definitive conclusions. Based on the limited available evidence, laser therapy may show a higher degree of re-osseointegration of implants than mechanical debridement.

Nonsurgical orthodontic treatment for a patient with Sotos syndrome.

Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. The purpose of this article is to describe the nonsurgical orthodontic treatment of a 10-year-old boy with a skeletal mandibular protrusion, unilateral posterior crossbite, and Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved because of mandibular clockwise rotation, whereas the facemask had a marginal effect. After growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. One year postretention, few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during the peripubertal period associated with Sotos syndrome, more attention should be paid to the early orthopedic treatment with the facemask and/or chincap.

Surgical Orthodontic Treatment of Skeletal Mandibular Protrusion with Multiple Impacted Ankylosed Teeth Treated with Alveolar Corticotomy.

AIM: To present a case of skeletal mandibular protrusion with multiple impacted ankylosed teeth, which were treated with conventional orthognathic surgery and alveolar corticotomy, respectively. BACKGROUND: Tooth ankylosis is characterized by the fusion of a root surface with the surrounding alveolar bone. Various treatment modalities for tooth ankylosis have been developed and are used commonly in the clinic. Corticotomy is defined as the application of intentional surgical injury to the cortical bone to mobilize a tooth with the adjacent bone and soft tissues. The corticotomy technique has been improved in recent years to avoid possible risks such as periodontal damage, tooth devitalization, and osseous necrosis due to an inadequate blood supply. CASE DESCRIPTION: A female patient aged 16 years and 3 months was diagnosed with anterior crossbite and the impaction and ankylosis of multiple canines. After the confirmation of ankylosis, alveolar corticotomy was performed on the maxillary left and mandibular right canines. After 6 months of traction (patient age, 19 years and 7 months), both canines had extruded successfully. After the completion of preoperative treatment, bilateral intraoral vertical ramus osteotomy was performed to correct the anterior crossbite involving a skeletal mandibular protrusion. The amounts of mandibular setback on the right and left sides were approximately 7 and 5 mm, respectively. The total treatment period was 55 months. Acceptable occlusion with a balanced profile was maintained over a 5-year retention period, indicating the long-term stability and success of the treatment. CONCLUSION: Our results indicate that alveolar corticotomy should be considered to facilitate the treatment of multiple impacted ankylosed teeth. CLINICAL SIGNIFICANCE: This report proposes an efficacy of alveolar corticotomy for extrusion of impacted ankylosed teeth.

Long-term Management of a Patient with Apert Syndrome.

AIM AND OBJECTIVE: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. BACKGROUND: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. CASE DESCRIPTION: A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. CONCLUSION: Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. CLINICAL SIGNIFICANCE: The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

A Long-term Follow-up of Mandibular Deviation Caused by Congenital Cervical Lymphangioma Treated with an Orthodontic Approach.

AIM: To report a treatment case of mandibular deviation caused by congenital cervical lymphangioma with traditional orthodontic techniques, following-up by 10-year retention. BACKGROUND: Lymphangiomas, developmental anomalies, can induce various disturbances of swallowing, mastication, speech, breathing, and skeletal deformities as well as psychological stress and anxiety for the patient and their family. Lymphangiomas are benign with virtually no possibility of turning into a malignant lesion, so clinical management aims to treat the patient functionally. CASE DESCRIPTION: A girl, aged 6 years and 4 months, complained about facial asymmetry and anterior crossbite caused by congenital cervical lymphangioma. Her facial profile was the straight type with an adequate lip position. Anterior and right-side posterior crossbites were observed. On the frontal cephalogram, the menton shifted 3.0 mm to the right. A functional appliance with an expander was placed to correct her dental midline deviation and posterior crossbite. After 2-year treatment, the anterior and right-side posterior crossbites were improved. Multibracket treatment began after the growth spurt. After 44-month active treatment, a functional occlusion, including a Class I molar relationship with a proper interincisal relationship, was achieved. A functional occlusion was maintained during a 10-year retention period, while a mandibular downward growth was observed through the retention period. CONCLUSION: Conventional orthodontic techniques enable functional and stable occlusion even in patients with mandibular deviation caused by congenital cervical lymphangioma, although only using early orthodontic management by itself may have some limitations. CLINICAL SIGNIFICANCE: The hybrid technique combining functional appliance and intermaxillary elastics proves to be an effective therapy for correcting occlusal cant and mandibular deviation caused by cervical lymphangioma.

The C-terminal region including the MH6 domain of Msx1 regulates skeletal development.

MSX1 is a causative gene for oligodontia in humans. Although conventional Msx1-deficient mice die neonatally, a mutant mouse lacking the C-terminus MH6 domain of MSX1 (Msx1ΔMH6/ΔMH6) showed two different phenotypes; newborn homozygotes with cleft palates died neonatally, whereas those with thin palates remained alive and had craniofacial dysplasia and growth retardation compared with wild-type mice, with most mice dying by the age of 4-5 weeks. In a previously reported case of human oligodontia caused by a heterozygous defect of the Msx1 MH6 domain, a small foramen was observed on the occipital bone. The aim of this study was to test the hypothesis that the Msx1 MH6 domain is involved in bone formation in vivo. In Msx1ΔMH6/ΔMH6 mice, cranial suture fusion was delayed at embryonic day 18.5, and the anteroposterior cranial diameter was smaller and long bone length was decreased at 3 weeks of age. The femoral epiphysis showed no change in the trabecular number, but decreased bone mass, bone density, and trabecular width in Msx1ΔMH6/ΔMH6 mice. In addition, cancellous bone mass was reduced and the cartilage layer in the growth plate was thinner in Msx1ΔMH6/ΔMH6 mice. The mRNA expression levels of major osteoblast and chondrocyte differentiation marker genes were decreased in Msx1ΔMH6/ΔMH6 mice compared with wild-type mice. These findings suggest that the C-terminal region including the MH6 domain of MSX1 plays important roles not only in tooth development and palatal fusion, but also in postnatal bone formation.

Low-intensity pulsed ultrasound enhances the rate of lateral tooth movement and compensatory bone formation in rats.

INTRODUCTION: Because mechanical stimulation of the periodontal ligament by low-intensity pulsed ultrasound (LIPUS) has been shown to increase the speed of bone remodeling, this study aimed to examine the effects of LIPUS stimulation on the rate of tooth movement and bone remodeling during lateral tooth movement. METHODS: Twelve-week-old Wistar rats were divided into 2 groups. The LIPUS group received experimental tooth movement with LIPUS stimulation, and the tooth movement (TM) group were provided experimental tooth movement without LIPUS. For each group, the upper right first molars were moved buccally with fixed appliances. LIPUS exposure was placed in the region corresponding to the right maxillary first molar. Three days after tooth movement, tartrate-resistant acid phosphatase was examined. Fourteen days after tooth movement, the intermolar width, bone mineral content, and bone volume fraction were analyzed by micro-computed tomography, and newly formed bone was measured histomorphometrically. RESULTS: The number of TRAP-positive cells in the compressed region was higher in the LIPUS group. The intermolar width was significantly higher in the LIPUS group than in the TM group. The alveolar bone around the maxillary first molar showed no differences in bone mineral content and bone volume fraction between the LIPUS and TM groups. The LIPUS group exhibited a more significant amount of newly formed alveolar bone than the TM group. CONCLUSIONS: The present study provides evidence of the beneficial effects of LIPUS on the lateral tooth movement.

Hemifacial Microsomia Caused by First and Second Brachial Arch Syndrome Treated with Orthodontic Approach: A Case Report.

AIM AND OBJECTIVE: To present a growing patient with unilateral mandibular hypoplasia and microtia involved in the first and second branchial arch syndrome (FSBAS) treated with functional appliance. BACKGROUND: The FSBAS comprises several developmental facial hypoplasia in ear and maxillofacial bones, resulting in hemifacial microsomia. Treatment for hemifacial microsomia varies greatly depending on the grade of mandibular deformities. Functional appliance treatment during growth period is available for mild to moderate mandibular deformities. However, there are few reports of hemifacial microsomia treated with functional appliance. CASE DESCRIPTION: The patient, an 8-year-and-5-month-old girl, had a chief complaint of mandibular deviation. She had been diagnosed with the FSBAS at birth. Her facial profile was straight and panoramic radiograph indicated that the mandibular ramal height of the affected side was about 60.4% compared to the unaffected side. The occlusal cant was 6°, and the right maxilla and mandible showed severe growth deficiency. At the age of 10 years, functional appliance with expander was used; for 2 years 6 months, the maxillomandibular growth was controlled and from panoramic radiograph, the ramus height of the affected side was increased to 65.0% compared to the unaffected left mandibular ramus. At the age of 12 years and 8 months, multibracket treatment was initiated. After 32 months of active treatment, proper occlusion with functional Class I canine and molar relationships was obtained, although facial asymmetry associated with the difference of ramus heights still existed. The resulting occlusion was stable during 1.5-year retention period. CONCLUSION: Our results indicated the importance of orthopedic treatment during growth period in the patient with hemifacial microsomia involving the FSBAS. CLINICAL SIGNIFICANCE: This report proposes an efficacy of conventional orthodontic treatment for growing patients with hemifacial microsomia involved in the FSBAS.

A teleomorph of the ustilaginalean yeast Moesziomyces antarcticus on barnyardgrass in Japan provides bioresources that degrade biodegradable plastics.

The basidiomycetous yeast Moesziomyces antarcticus (often cited as Pseudozyma antarctica), originally isolated from a sediment sample obtained from Lake Vanda in Antarctica, was asexually typified but closely related to the smut fungus Moesziomyces bullatus (Ustilaginales). We found a smut fungus on an ovary of barnyardgrass (Echinochloa crus-galli) in Japan, which had been identified as M. bullatus. The teliospores germinated and formed yeast-like colonies. Physiological and phylogenetic studies revealed that the characteristics of the yeast-like isolates coincided with those of "P. antarctica." We thus recognised the smut fungus as the teleomorph of M. antarcticus, and then emended the description of M. antarcticus based on the holomorph. The identified fungus could degrade certain biodegradable plastics and produce mannosylerythritol lipids (MELs) in similar qualities as the "P. antarctica" type strain. This discovery provides a significant bioresource, as genetically diverse M. antarcticus isolates could be obtained from the smut fungus.

Hepatic Angiosarcoma with Kasabach-Merritt Phenomenon: A Case Report and Review of the Literature.

A 76-year-old woman was referred to our hospital due to massive gingival bleeding following teeth extraction. Laboratory findings suggested disseminated intravascular coagulopathy (DIC). Enhanced computed tomography and magnetic resonance imaging disclosed multiple hypervascular liver masses of 2-6 cm in diameter, the largest of which displaying an irregular enhancement pattern. We considered that her DIC was caused by the multiple liver masses and commenced repeated erythrocyte/fresh frozen plasma infusión and gabexate mesilate administration. However, the DIC proved uncontrollable and trans-arterial embolization could not be attempted. The patient eventually died 4 months after admission due to spontaneous hepatic tumor rupture and hepatic failure. Post-mortem hepatic tumor biopsy led to a final diagnosis of hepatic angiosarcoma with Kasabach-Merritt phenomenon (KMP). Among the 7 cases of hepatic angiosarcoma representing KMP found in the literature, mortality occurred within 4 months of the appearance of bleeding tendency primarily due to abdominal bleeding and hepatic failure. The possibility of hepatic angiosarcoma should be considered in patients with DIC and hypervascular liver tumors. Since treatment is uncertain and prognosis is poor, novel diagnostic and therapeutic advances are needed for angiosarcoma.

Effect of pulsed ultrasound toothbrush on Streptococcus mutans biofilm removal.

PURPOSE: To evaluate the effect of pulsed ultrasound toothbrush on the removal of biofilm formed by Streptococcus mutans (S. mutans). METHODS: S. mutans biofilm grown on apatite pellet was destructed with four different sonic action toothbrushes: 1) pulsed ultrasound with sonic vibration (PUV); 2) continuous ultrasound with sonic vibration (CUV); 3) sonic vibration only (SV); and 4) no ultrasound nor sonic vibration (control). After 3 minutes of noncontact brushing, the amount of water-insoluble glucan was measured, and the residual biofilm was observed by scanning electron microscopy. RESULTS: PUV group revealed the smallest amount of the residual water-insoluble glucans (32 ± 19%), followed by the CUV group (54 ± 12%) and the SV group (64 ± 13%). The PUV group showed a significantly lower amount of the residual water-insoluble glucan than the SV group, while no significant difference was found between SV and CUV. The bacterial adherence and aggregation notably decreased in the PUV group, compared to the remaining three groups. CLINICAL SIGNIFICANCE: The sonic vibration with pulsed ultrasound showed more reduction of the biofilm compared to the control and the sonic vibration with and without continuous ultrasound. Thus, pulsed ultrasound action may be beneficial for biofilm removal of interproximal regions.

Long-term follow-up of a patient with achondroplasia treated with an orthodontic approach.

We successfully treated a patient with achondroplasia with conventional orthodontic techniques. It was followed by long-term retention. The patient, a 12-year-old boy, had chief complaints of occlusal disturbance and mandibular protrusion. He had been diagnosed with achondroplasia and had growth hormone treatment in his early teenage years. His facial profile was concave with a bulging forehead and a retrognathic maxilla. It was characterized by a skeletal Class III jaw-base relationship with a retropositioned maxilla. At the age of 12 years 9 months, maxillary protraction was initiated with a reverse headgear; for 2 years 6 months, the maxillomandibular growth was controlled. After the growth spurt, at the age of 15 years 6 months, leveling and alignment of both dental arches were started with preadjusted edgewise appliances. After 83 months of multibracket treatment, an acceptable occlusion with a Class I molar relationship and an adequate interincisal relationship was achieved, despite the simultaneous marked vertical growth of the mandible. The resultant occlusion was stable during a 6-year retention period, although considerable forward-downward mandibular growth was observed. Conclusively, our results indicated the necessity of long-term observation in this patient with achondroplasia, especially because of the persistent mandibular growth.

Amelotin gene expression is temporarily being upregulated at the initiation of apoptosis induced by TGFß1 in mouse gingival epithelial cells.

Amelotin (AMTN) is expressed and secreted by ameloblasts in the maturation stage of amelogenesis and persist with low levels in the junctional epithelium (JE) of erupted teeth. The purpose of this study is to investigate the transcriptional regulation of the AMTN gene by transforming growth factor beta1 (TGFß1) in gingival epithelial (GE1) cells in the apoptosis phase. Apoptosis was evaluated by the fragmentation of chromosomal DNA and TUNEL staining. A real-time PCR was carried out to examine the AMTN mRNA levels induced by TGFß1 and Smad3 overexpression. Transient transfection analyses were completed using the various lengths of mouse AMTN gene promoter constructs with or without TGFß1. Chromatin immunoprecipitation (ChIP) assays were performed to investigate the Smad3 bindings to the AMTN gene promoter by TGFß1. TGFß1-induced apoptosis in GE1 cells were detected at 24 and 48 h by DNA fragmentation and TUNEL staining. AMTN mRNA levels increased at 6 h and reached maximum at 24 h in GE1 cells. Luciferase activities of the mouse AMTN gene promoter constructs were induced by TGFß1. The results of the ChIP assays showed that there was an increase in Smad3 binding to Smad-binding element (SBE)#1 and SBE#2 after stimulation by TGFß1. Immunohistochemical localization of AMTN was detected in the JE, and the AMTN protein levels in Smad3-deficient mice were decreased compared with wild-type mice. AMTN mRNA levels were induced at the initiation of apoptosis by TGFß1, which mediated through the Smad3 bindings to SBEs in the mouse AMTN gene promoter.

Smad3 deficiency leads to mandibular condyle degradation via the sphingosine 1-phosphate (S1P)/S1P3 signaling axis.

Temporomandibular joint osteoarthritis is a degenerative disease that is characterized by permanent cartilage destruction. Transforming growth factor (TGF)-ß is one of the most abundant cytokines in the bone matrix and is shown to regulate the migration of osteoprogenitor cells. It is hypothesized that TGF-ß/Smad3 signaling affects cartilage homeostasis by influencing sphingosine 1-phosphate (S1P)/S1P receptor signaling and chondrocyte migration. We therefore investigated the molecular mechanisms by which crosstalk may occur between TGF-ß/Smad3 and S1P/S1P receptor signaling to maintain condylar cartilage and to prevent temporomandibular joint osteoarthritis. Abnormalities in the condylar subchondral bone, including dynamic changes in bone mineral density and microstructure, were observed in Smad3(-/-) mice by microcomputed tomography. Cell-free regions and proteoglycan loss characterized the cartilage degradation present, and increased numbers of apoptotic chondrocytes and matrix metalloproteinase 13(+) chondrocytes were also detected. Furthermore, expression of S1P receptor 3 (S1P3), but not S1P1 or S1P2, was significantly down-regulated in the condylar cartilage of Smad3(-/-) mice. By using RNA interference technology and pharmacologic tools, S1P was found to transactivate Smad3 in an S1P3/TGF-ß type II receptor-dependent manner, and S1P3 was found to be required for TGF-ß-induced migration of chondrocyte cells and downstream signal transduction via Rac1, RhoA, and Cdc42. Taken together, these results indicate that the Smad3/S1P3 signaling pathway plays an important role in the pathogenesis of temporomandibular joint osteoarthritis.

Unilateral mandibular condylar osteochondroma treated with ipsilateral condylectomy and contralateral ramus osteotomy.

We successfully treated a 32-year-old woman who had facial asymmetry and unilateral mandibular condylar osteochondroma using ipsilateral mandibular condylectomy and contralateral ramus osteotomy. Mirror image analysis with a noncontact 3-dimensional image scanner showed that the soft tissue on the deviated side was protruded more than 5.50 mm compared with the nondeviated side. The patient was diagnosed as having facial asymmetry with a skeletal Class III jaw-base relationship caused by unilateral mandibular condylar osteochondroma. After 18 months of preoperative orthodontic treatment, an ipsilateral condylectomy and a contralateral sagittal split ramus osteotomy were performed. As the result of postoperative orthodontic treatment for 20 months, an ideal occlusion with a Class I molar relationship and an adequate interincisal relationship was achieved. Facial asymmetry and mandibular protrusion were dramatically improved, and the total differences between the deviated and nondeviated sides were decreased to less than 1.11 mm. The acceptable occlusion and the symmetric face were maintained throughout the 1-year retention period. Our results indicated stability after condylectomy without condylar reconstruction in a patient with unilateral condylar osteochondroma.

Long-term stability of maxillary group distalization with interradicular miniscrews in a patient with a Class II Division 2 malocclusion.

We successfully treated a Class II Division 2 patient with maxillary group distalization using interradicular miniscrews. A woman, aged 28 years 11 months, had a convex profile and an excessive overjet caused by a skeletal Class II jaw-base relationship. After leveling and alignment, titanium miniscrews were obliquely implanted between the maxillary second premolar and first molar. To distalize the maxillary dentition, nickel-titanium closing coil springs with a 2-N load were placed between the screws and the hooks on the archwire. After 28 months of active orthodontic treatment, a proper facial profile and an acceptable occlusion were achieved with a 4-mm distalization of the maxillary dentition. The resultant occlusion was stable throughout a 5-year retention period. Interradicular miniscrews were useful to distalize the maxillary dentition for correcting a Class II malocclusion. This new strategy, group distalization with miniscrews, can make the treatment simpler with greater predictability.

Genome-wide association study identifies a PSMD3 variant associated with neutropenia in interferon-based therapy for chronic hepatitis C.

Cytopenia during interferon-based (IFN-based) therapy for chronic hepatitis C (CHC) often necessitates reduction of doses of drugs and premature withdrawal from therapy resulting in poor response to treatment. To identify genetic variants associated with IFN-induced neutropenia, we conducted a genome-wide association study (GWAS) in 416 Japanese CHC patients receiving IFN-based therapy. Based on the results, we selected 192 candidate single nucleotide polymorphisms (SNPs) to carry out a replication analysis in an independent set of 404 subjects. The SNP rs2305482, located in the intron region of the PSMD3 gene on chromosome 17, showed a strong association when the results of GWAS and the replication stage were combined (OR = 2.18, P = 3.05 × 10(-7) in the allele frequency model). Logistic regression analysis showed that rs2305482 CC and neutrophil count at baseline were independent predictive factors for IFN-induced neutropenia (OR = 2.497, P = 0.0072 and OR = 0.998, P < 0.0001, respectively). Furthermore, rs2305482 genotype was associated with the doses of pegylated interferon (PEG-IFN) that could be tolerated in hepatitis C virus genotype 1-infected patients treated with PEG-IFN plus ribavirin, but not with treatment efficacy. Our results suggest that genetic testing for this variant might be useful for establishing personalized drug dosing in order to minimize drug-induced adverse events.

Histomorphometric analysis of overloading on palatal tooth movement into the maxillary sinus.

INTRODUCTION: Our objective was to evaluate the effect of overloading on the palatal movement of the maxillary molar. METHODS: The maxillary first molars of male C57Bl/6 mice were moved palatally with loads of 10 or 30 g for 14 days, and the amount of tooth movement was longitudinally measured on microcomputed tomography images. Bone remodeling around the molar root with the 30-g load was evaluated at days 3, 5, 7, and 14 after the start of tooth movement using histomorphometry and immunodetection of bone-restricted interferon inducible transmembrane-like protein, a novel marker of active bone formation. RESULTS: In the 10-g load group, the amount of tooth movement increased dramatically between days 5 and 7 and increased gradually thereafter. Tooth movement at days 5 and 7 was significantly lower in the 30-g-load group than in the 10-g load group; however, the total tooth movement at 14 days was similar in the 2 groups. An orthodontic load of 30 g stimulated bone formation on the sinus wall, but bone resorption on the periodontal ligament side was delayed because of hyalinization, which means that strong force application did not accelerate tooth movement. Moreover, some root resorption was induced by the excessive force. CONCLUSIONS: Root penetration into the sinus and bone height reduction do not occur because new bone formation on the maxillary sinus is induced before bone resorption on the periodontal side, even though an excessive orthodontic force is applied. However, an excessive force can induce root resorption.

Effectiveness of cationic liposome-mediated local delivery of myostatin-targeting small interfering RNA in vivo.

This study evaluated the effectiveness of local administration of cationic liposome-delivered myostatin-targeting siRNA. Myostatin (Mst)-siRNA and scrambled (scr)-siRNA-lipoplexes were injected into the masseter muscles of wild type and dystrophin-deficient mdx mice, which model Duchenne muscular dystrophy. One week after injection, the masseter muscles were dissected for histometric analyses. To evaluate changes in masseter muscle activity, masseter electromyographic (EMG) measurements were performed. One week after local administration of Mst-siRNA-lipoplexes, masseter muscles and myofibrils were significantly larger compared to control masseter muscles treated with scr-siRNA-lipoplexes. Real-time polymerase chain reaction (PCR) analyses revealed significant upregulation of the myogenic regulatory factors MyoD and myogenin and significant downregulation of the adipogenic transcription factors peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer binding protein-α (CEBPα) in masseter muscles treated with Mst-siRNA-lipoplexes. The duty times of masseter muscle activity exceeding 5% showed a slight tendency to increase in both wild type and mdx mice. Therefore, cationic liposome-mediated local administration of Mst-siRNA could increase muscular size and improve muscle activity. Since cationic liposomes delivered siRNA to muscles effectively and are safe and cost-effective, they may represent a therapeutic tool for use in treating muscular diseases.