Morphological evaluation of changes in velopharyngeal function following maxillary distraction in patients with repaired cleft palate during mixed dentition.

OBJECTIVE: To describe the morphological changes of nasopharyngeal components after maxillary distraction and clarify whether the morphological characteristics are related to velopharyngeal function (VPF). DESIGN: Perceptual judgments of hypernasality and nasendoscopy were performed before and after treatment. Lateral cephalograms were obtained to describe the morphological changes. SETTING: Department of Oral and Maxillofacial Surgery, Miyazaki Medical College, Miyazaki, Japan. PARTICIPANTS: Nine patients with repaired cleft palate in the mixed dentition stage underwent maxillary distraction using a face mask and an intraoral fixed appliance system. OUTCOME MEASURES: The severity of hypernasality, velopharyngeal insufficiency, and measurements such as pharyngeal depth, velar length, and the rotation of the palatal plane were evaluated. RESULTS: Increase in pharyngeal depth was not always proportional to the amount of advancement. It depended on the posture of the posterior pharyngeal wall and the rotation of palatal plane. CONCLUSION: Cephalometric measurements of the nasopharynx before and after surgery confirmed subsequent changes in VPF. These were suggested to be useful in predicting future VPF. When performing maxillary distraction in patients with cleft palate in the mixed dentition stage, and when velopharyngeal closure is found to occur by velar contact against the hypertrophied adenoid, patients should be counseled about risks of subsequent deterioration in their speech before surgery.

Unilateral advancement of the maxillary minor segment by distraction osteogenesis in patients with repaired unilateral cleft lip and palate: report of two cases.

OBJECTIVE: Collapse of the maxillary minor segment with lateral crossbite is a common feature in patients with repaired unilateral cleft lip/palate because of maxillary alveolar bony defect and palatal scar tissue. Distraction osteogenesis (DOG) is an effective technique of lengthening and augmentation for bone and gingiva. This case report describes the effects of unilateral advancement of the maxillary minor segment by DOG in two patients with the repaired unilateral cleft lip/palate.

Effects of pulsed electromagnetic field (PEMF) stimulation on bone tissue like formation are dependent on the maturation stages of the osteoblasts.

The effects of pulsed electromagnetic field (PEMF, 15 Hz pulse burst, 7 mT peak) stimulation on bone tissue-like formation on osteoblasts (MC3T3-E1 cell line) in different stages of maturation were assessed to determine whether the PEMF stimulatory effect on bone tissue-like formation was associated with the increase in the number of cells and/or with the enhancement of the cellular differentiation. The cellular proliferation (DNA content), differentiation (alkaline phosphatase activity), and bone tissue-like formation (area of mineralized matrix) were determined at different time points. PEMF treatment of osteoblasts in the active proliferation stage accelerated cellular proliferation, enhanced cellular differentiation, and increased bone tissue-like formation. PEMF treatment of osteoblasts in the differentiation stage enhanced cellular differentiation and increased bone tissue-like formation. PEMF treatment of osteoblasts in the mineralization stage decreased bone tissue-like formation. In conclusion, PEMF had a stimulatory effect on the osteoblasts in the early stages of culture, which increased bone tissue-like formation. This stimulatory effect was most likely associated with enhancement of the cellular differentiation, but not with the increase in the number of cells.