The comparison of biomechanical effects of the conventional and bone-borne palatal expanders on late adolescence with unilateral cleft palate: a 3-dimensional finite element analysis.

BACKGROUND: Patients with unilateral cleft lip and palate were associated with different nasomaxillary complex from the normal population. Although the biomechanical effects of conventional rapid palatal expansion (Hyrax expansion) and bone-borne rapid palatal expansion (micro-implant-assisted expansion) in non-cleft patients have been identified by multiple studies, little is known in patients with unilateral cleft lip and palate. The purpose of this study was to investigate and compare the biomechanical effects of the conventional and bone-borne palatal expanders in a late adolescence with unilateral cleft lip and palate. METHODS: A cone beam CT scan of a late adolescence with unilateral cleft lip and palate was selected to construct the three-dimensional finite element models of teeth and craniofacial structures. The models of conventional and born-borne palatal expanders were established to simulate the clinical maxillary expansion. The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacements in craniofacial structures and teeth. RESULTS: Bone-borne palatal expander achieved more transverse movement than conventional palatal expander in the whole mount of craniofacial regions, and the maximum amount of expansion was occurred anteriorly along the alveolar ridge on cleft-side. The expanding force from born-borne palatal expander resulted in more advancement in nasomaxillary complex than it in conventional palatal expander, especially in the anterior area of the minor segment of maxilla. Stresses from the both expanders distributed in similar patterns, but larger magnitudes and ranges were generated using the bone-borne expander around the maxillary buttresses and pterygoid plates of sphenoid bone. The maximum expanding stresses from born-borne palatal expander were concentrated on palatal slope supporting minscrews, whereas those from conventional palatal expander were concentrated on the anchoring molars. In addition, the buccal tipping effect of teeth generated using the bone-borne expander was less than it using the conventional palatal expander. CONCLUSION: Bone-borne expander generated enhanced skeletal expansion at the levels of alveolar and palate in transversal direction, where the miniscrews contributed increased expanding forces to maxillary buttresses and decreased forces to buccal alveolar. Bone-borne expanders presented a superiority in correcting the asymmetric maxilla without surgical assistant in late adolescence with unilateral cleft lip and palate.

A quantum dot probe conjugated with aß antibody for molecular imaging of Alzheimer's disease in a mouse model.

The treatment of Alzheimer's disease (AD) has been hampered by a lack of sensitive and specific non-invasive diagnostic methods. Quantum dots (QD) are nano-crystals with unique photo-physical properties that bypass some of the limitations of conventional dyes and imaging tools. This study is aimed to evaluate the fluorescence properties of a QD probe conjugated with an anti-Aß antibody (QD-Aß-Ab). Healthy mice and mice bearing mutated human APP695swe and APP717 V-F transgenes received intracerebroventricular injection of the probe for subsequent imaging. Immunohistochemistry revealed that Aß1-42 was distributed in the hippocampus CA1 area in the APP transgenic mice. Fluorescence microscopy demonstrated that fluorescence was mainly observed in the hippocampus area, the cerebral cortex, sagittal septum and striatum of APP transgenic mice. In vivo imaging of mice receiving the QD-Aß-Ab probe showed that healthy mice exhibited a narrow range of fluorescence and lower fluorescence intensity compared with APP transgenic mice. The mean fluorescence intensity of brain tissues of healthy C57BL mice was 12.3784 ± 3.9826, which was significantly lower than that of 10- and 16-month-old APP transgenic mice (45.03 ± 2.66 and 46.69 ± 3.22, respectively; P < 0.05). In this study we present the first direct evidence that QD-Aß-Ab conjugate probes can track in vivo state of Aß accumulation in mice and the findings suggest that such probes may be of potential use for early molecular diagnostic imaging of AD.

Soft-tissue characteristics of operated unilateral complete cleft lip and palate patients in mixed dentition.

PURPOSE: The purpose of the study was to provide quantitative information about the facial soft-tissue characteristics of operated unilateral complete cleft lip and palate (UCCLP) children compared with healthy children during mixed dentition. METHODS: Lateral cephalometric radiographs of 48 children with UCCLP who had been operated on before the age of 2 years were analyzed and compared with those of a control group of 60 healthy children with the same age, sex, and ethnic characteristics. RESULTS: The children with operated UCCLP differed from the control group by having a more concave profile, flatter nasal tip, more retrognathic basis nasi, shorter upper lip, thicker upper and lower lip, reduced upper-lip projection, and increased lower-lip projection. CONCLUSIONS: The facial soft-tissue morphology in operated UCCLP patients differed from normal controls of the same age, sex, and ethnic group. It may be necessary for children with UCCLP operated before 2 years of age to have some preventive treatment.

[Temporospatial expression of bFGF and IGF-I in growing goats with cranial suture distraction osteogenesis].

OBJECTIVE: To investigate the expression patterns of bFGF and IGF-I in the growing goats with distracted cranial suture. METHODS: Coronal suture distraction was performed to 12 growing goats. The suture was expanded using a custom-made distractor with a rate of 0.4 mm/day for 8 days. Four goats were killed at 0, 2, and 4 weeks after the completion of suture distraction osteogenesis, respectively. The expanded sutures were harvested and processed for immunohistochemistry analysis of bFGF and IGF-I. Two goats without suture distraction were also examined as controls. RESULTS: The coronal sutures were expanded successfully. At 0 and 2 weeks after the completion of suture distraction, collagen fiber bundles were strengthened and aligned in the direction of the distraction. Strong expressions of bFGF and IGF-I were detected in the distracted sutures. Expressions of bFGF appeared in the fibroblast-like cells and the osteoblasts cells. Positive signal of IGF-I was mainly localized to the osteoblasts and the newly formed osteocytes. The strongest expressions of bFGF and IGF-I were found 0-2 weeks after the completion of the suture distraction. CONCLUSION: Distraction stimulates the production of bFGF and IGF-I, which may contribute to the formation and remodeling of new bones.