Effective retropulsion and centralization of the severely malpositioned premaxilla in patients with bilateral cleft lip and palate: a novel modified presurgical nasoalveolar molding device with retraction screw.

PURPOSE: A novel, modified presurgical nasoalveolar molding (MPNAM) device with retraction screw was designed and used in patients with bilateral complete cleft lip and palate (BCCLP) to rapidly retract and centralize the protuberant and malpositioned premaxilla and correct the nasolabial and palatal deformities. The orthopedic effects and possible complications were evaluated. PATIENTS AND METHODS: Nine patients with BCCLP who met the inclusion criteria were selected. After the maxillary model was obtained, the new MPNAM device with retraction screw was designed and worn until cheilorrhaphy. Changes in local deformities and complications were observed continuously, and the orthopedic effect was evaluated. RESULTS: All patients quickly adapted to the MPNAM appliance, and the treatment was finished after 5-8 return visits. The columella was significantly prolonged, the nasal tip was elevated, and the collapsed nasal dome was obviously improved. Simultaneously, the premaxilla was rapidly retracted and rotated, and gradually centralized; the clefts were gradually reduced and closed, and a nearly normal dental arch was formed. Although there were some complications, the orthopedic treatment was continued until cheiloplasty. CONCLUSIONS: The MPNAM device with retraction screw can simultaneously correct nasolabial and palatal deformities and also rapidly retract and centralize the premaxilla.

Low-intensity pulsed ultrasound induces osteogenic differentiation of human periodontal ligament cells through activation of bone morphogenetic protein-smad signaling.

OBJECTIVES: Low-intensity pulsed ultrasound (US) can accelerate fracture healing and osteogenic differentiation. The aim of this study was to investigate the osteogenic effect of low-intensity pulsed US on human periodontal ligament cells and to determine whether bone morphogenetic protein (BMP)-Smad signaling was involved. METHODS: Human periodontal ligament cells were exposed to low-intensity pulsed US at a frequency of 1.5 MHz and intensity of 90 mW/cm(2) for 20 min/d. Osteogenic differentiation was determined by assaying alkaline phosphatase (ALP) and calcium deposition. Expression of BMP-2, BMP-6, and BMP-9 was detected by real-time polymerase chain reaction analysis. Phosphorylated Smad was detected by western blotting; Smad in the cells was labeled by an immunofluorescent antibody and observed by laser-scanning confocal microscopy. RESULTS: The optical density of ALP stimulated by US at 1.5 MHz and 90 mW/cm(2) for 20 min/d was significantly higher than in other groups (P < .01); therefore, this dosage was considered optimal for promoting osteogenic differentiation. After 13 days of US exposure, ALP increased gradually after 5 days, peaked at 11 days, and decreased at 13 days, with a significant difference compared with the control group (P < .05). Osteocalcin production increased from 9 to 13 days and peaked at 15 days, with a significant difference compared with the control group (P < .05). BMP-2 and BMP-6 increased dynamically after exposure for 13 days. BMP-2 increased 6.07-fold at 3 days, 6.39-fold at 11 days, and 5.97-fold at 13 days. BMP-6 expression increased 6.82-fold at 1 day and 51.5-fold at 3 days and decreased thereafter. BMP-9 was not expressed. Phospho-Smad1/5/8 expression was significantly increased after exposure (P< .05) and transferred from the cytoplasm into the nuclei. CONCLUSIONS: Low-intensity pulsed US effectively induced osteogenic differentiation of human periodontal ligament cells, and the BMP-Smad signaling pathway was involved in the mechanism.

Involvement of p38 MAPK pathway in low intensity pulsed ultrasound induced osteogenic differentiation of human periodontal ligament cells.

OBJECTIVE: The purpose of this study was to clarify whether p38 MAPK is involved in the process of low intensity pulsed ultrasound (LIPUS) induced osteogenic differentiation of human periodontal ligament cells (HPDLCs). METHODS: HPDLCs were isolated from premolars extracted for orthodontic reasons from healthy adolescences and used in the study at passage 5. They were pretreated with p38 specific inhibitor SB203580 and exposed daily to LIPUS with frequency of 1 MHz and intensity of 90 mW/cm(2). Osteogenic differentiation was assayed by levels of alkaline phosphatase (ALP) and osteocalcin as well as calcium deposition. The levels of phosphorylated p38 (p-p38) and total p38 in HPDLCs in response to LIPUS for different times were detected by Western blot. RESULTS: The enhanced ALP levels in media and cell lysate, osteocalcin level in media, as well as number of calcium nodules after LIPUS stimulation were decreased by SB203580 treatment. LIPUS stimulation did not change total p38 level, but time-dependently enhanced the level of p-p38; such enhancement was significantly blocked by preincubation with 10 µmol/L SB203580. CONCLUSION: The p38 MAPK is involved in the process of LIPUS-induced osteogenic differentiation of HPDLCs.