Tooth movement into the maxillary sinus

Objectives: To evaluate the effect of overloading on the palatal movement of the maxillary molar. Materials and methods: The maxillary first molar of male C57Bl/6 mice was moved palatally with 10-g or 30-g load for 14 days, and amount of tooth movement was longitudinally measured on micro-computed tomography images (each group, N=5). Bone remodeling around the molar root under the 30-g load was evaluated at days 3, 5, 7, and 14 after the starting of tooth movement using histomorphometry and immunodetection of bone-restricted Ifitm (interferon inducible transmembrane)-like protein, a novel marker of active bone formation (each group, N=5). Result: In the 10-g load group, the amount of tooth movement increased dramatically between day 5 to day 7, and gradually increased thereafter. In 30-g load group, tooth movement at day 5 and day 7 was significantly lower than those in the 10-g load group; however, total tooth movement for 14 days was similar in both groups. Orthodontic load of 30-g stimulated bone formation on the sinus wall, but bone resorption on the periodontal ligament side was delayed because of the hyalinization, which means strong force application was not accelerate tooth movement. Moreover, some root resorption was induced under the excessive force application. Conclusion: Root penetration into sinus and bone height reduction does not occur because new bone formation on the maxillary sinus is induced prior to bone resorption on the periodontal side, even though excessive orthodontic force is applied. However, excessive force is subject to induce root resorption

LIPUSはミニスクリューインプラント周囲の骨形成を促進する

Miniscrew implants (MSIs) are currently used to provide absolute anchorage in orthodontics; however, their initial stability is an issue of concern. Application of low-intensity pulsed ultrasound (LIPUS) can promote bone healing. Therefore, LIPUS application may stimulate bone formation around MSIs and enhance their initial stability. Aim. To investigate the effect of LIPUS exposure on bone formation after implantation of titanium (Ti) and stainless steel (SS) MSIs. Methods. MSIs made of Ti-6Al-4V and 316L SS were placed on rat tibiae and treated with LIPUS. The bone morphology around MSIs was evaluated by scanning electron microscopy and threedimensional micro-computed tomography. MC3T3-E1 cells cultured on Ti and SS discs were treated with LIPUS, and the temporary expression of alkaline phosphatase (ALP) was examined. Results. Bone-implant contact increased gradually from day 3 to day 14 after MSI insertion. LIPUS application increased the cortical bone density, cortical bone thickness, and cortical bone rate after implantation of Ti and SS MSIs (P < 0.05). LIPUS exposure induced ALP upregulation in MC3T3- E1 cells at day 3 (P < 0.05). Conclusion. LIPUS enhanced bone formation around Ti and SS MSIs, enhancing the initial stability of MSIs

低出力パルス超音波は自己免疫疾患での唾液腺炎による唾液分泌低下を改善する

Introduction: Low-intensity pulsed ultrasound (LIPUS) has been known to promote bone healing by nonthermal effects. In recent studies, LIPUS has been shown to reduce inflammation in injured soft tissues. Xerostomia is one of the most common symptoms in Sjögren syndrome (SS). It is caused by a decrease in the quantity or quality of saliva. The successful treatment of xerostomia is still difficult to achieve and often unsatisfactory. The aim of this study is to clarify the therapeutic effects of LIPUS on xerostomia in SS. Methods: Human salivary gland acinar (NS-SV-AC) and ductal (NS-SV-DC) cells were cultured with or without tumor necrosis factor-α (TNF-α; 10 ng/ml) before LIPUS or sham exposure. The pulsed ultrasound signal was transmitted at a frequency of 1.5 MHz or 3 MHz with a spatial average intensity of 30 mW/cm2 and a pulse rate of 20 %. Cell number, net fluid secretion rate, and expression of aquaporin 5 (AQP5) and TNF-α were subsequently analyzed. Inhibitory effects of LIPUS on the nuclear factor κB (NF-κB) pathway were determined by Western blot analysis. The effectiveness of LIPUS in recovering salivary secretion was also examined in a MRL/MpJ/lpr/lpr (MRL/lpr) mouse model of SS with autoimmune sialadenitis. Results: TNF-α stimulation of NS-SV-AC and NS-SV-DC cells resulted in a significant decrease in cell number and net fluid secretion rate (p < 0.01), whereas LIPUS treatment abolished them (p < 0.05). The expression changes of AQP5 and TNF-α were also inhibited in LIPUS treatment by blocking the NF-κB pathway. Furthermore, we found that mRNA expression of A20, a negative feedback regulator, was significantly increased by LIPUS treatment after TNF-α or interleukin 1β stimulation (NS-SV-AC, p < 0.01; NS-SV-DC, p < 0.05). In vivo LIPUS exposure to MRL/lpr mice exhibited a significant increase in both salivary flow and AQP5 expression by reducing inflammation in salivary glands (p < 0.01). Conclusions: These results suggest that LIPUS upregulates expression of AQP5 and inhibits TNF-α production. Thus, LIPUS may restore secretion by inflamed salivary glands. It may synergistically activate negative feedback of NF-κB signaling in response to inflammatory stimulation. Collectively, LIPUS might be a new strategic therapy for xerostomia in autoimmune sialadenitis with SS

Additional file 4: Figure S4. of Low-intensity pulsed ultrasound rescues insufficient salivary secretion in autoimmune sialadenitis

Bands of Western blot analysis for the cropped images in Fig. 3a (A), 3b (B) and 3c (C) are provided in this file. (TIFF 5449 kb

Additional file 3: Figure S3. of Low-intensity pulsed ultrasound rescues insufficient salivary secretion in autoimmune sialadenitis

Bands of Western blot analysis for the cropped images in Fig. 2c are provided in this file. (TIFF 1856 kb

Additional file 1: Figure S1. of Low-intensity pulsed ultrasound rescues insufficient salivary secretion in autoimmune sialadenitis

Schematic representation of the in vitro LIPUS system used. A cell culture plate with medium was placed in the ultrasound field at a distance of about 1 mm from the transducer to optimize beam uniformity across the target region. (TIFF 1093 kb

Additional file 2: Figure S2. of Low-intensity pulsed ultrasound rescues insufficient salivary secretion in autoimmune sialadenitis

Quantification of the fluorescence intensity in Fig. 1C. **p < 0.01 (n = 4). (TIFF 897 kb