RESUMEN
The purpose of this study was to investigate the effect of vitamin B12 on palatal development by co-administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dexamethasone (DEX). We examined the morphological and histological features of the palatal shelf and expression levels of key signaling molecules (transforming growth factor-ß3 (TGF-ß3) and TGF-ß type I receptor (activin receptor-like kinase 5, ALK5)) during palatogenesis among a control group (Group A), TCDD+DEX exposed group (Group B), and TCDD+DEX+vitamin B12 exposed group (Group C). While we failed to find that vitamin B12 decreased the incidence of cleft palate induced by TCDD+DEX treatment, the expression levels of key signaling molecules (TGF-ß3 and ALK5) during palatogenesis were significantly modulated. In TCDD+DEX exposed and TCDD+DEX+vitamin B12 exposed groups, palatal shelves could not contact in the midline due to their small sizes. Our results suggest that vitamin B12 may inhibit the expression of some cleft palate inducers such as TGF-ß3 and ALK5 in DEX+TCDD exposed mice, which may be beneficial against palatogenesis to some degree, even though we were unable to observe a protective role of vitamin B12 in morphological and histological alterations of palatal shelves induced by DEX and TCDD.
Asunto(s)
Fisura del Paladar/inducido químicamente , Fisura del Paladar/prevención & control , Dexametasona/toxicidad , Hueso Paladar/efectos de los fármacos , Hueso Paladar/embriología , Dibenzodioxinas Policloradas/toxicidad , Vitamina B 12/farmacología , Animales , Interacciones Farmacológicas , Femenino , Histocitoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Rastreo , Hueso Paladar/metabolismo , Embarazo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , ARN/química , ARN/genética , Distribución Aleatoria , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Organismos Libres de Patógenos Específicos , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
OBJECTIVE: To establish the optimized surgical procedure in our approach to treat the velopharyngeal insufficiency and improve the articulations of the patients with cleft palate over six years old. METHODS: Thirty-seven subjects over six years (including six years) old underwent the palatoplasty and sphincter pharyngoplasty simultaneously. We assessed the outcome of the surgery by perceptual speech assessment, nasopharyngoscopy and lateral cephalogram 10 to 15 months postoperatively. RESULTS: Twenty-two subjects got complete velopharyngeal closure. The velopharyngeal closure ratio of 15 subjects were over 85% according to the findings of the nasopharyngoscopy. Lateral cephalograms reveal that all the subjects could get their velars raised and well contacted with the posterior pharyngeal wall in dynamic condition. Perceptual speech assessment: The rate of hypernasality and nasal emission decreased significantly, and the consonant articulation increased. CONCLUSION: Our surgical procedure in this study corrected the velopharyngeal insufficiency and improved the articulation of the patients over six years old significantly.
Asunto(s)
Fisura del Paladar , Paladar Blando , Niño , Humanos , Faringe , Resultado del Tratamiento , Insuficiencia VelofaríngeaRESUMEN
BACKGROUND: Velopharyngeal inadequacy (VPI), which has a significant negative impact on speech intelligibility and resonance quality, may be caused by physiological inadequacy. The current study aimed to investigate the maximal velar and pharyngeal motions and levator muscle shortening in the children with repaired cleft palate and different speech outcomes as well as children without cleft palate by using magnetic resonance imaging techniques without general anesthesia. METHODS: Three groups of sex- and age-matched children were recruited: children with repaired cleft palate and adequate velopharyngeal function condition (VPC), children with repaired cleft palate and VPI, and the normal controls (noncleft). The children were trained to perform sustained /a:/, /i:/, /ts:/, and /m:/, while keeping the head still during magnetic resonance imaging scan. The maximal velar elevation and stretch, pharyngeal medial constriction, velopharyngeal ratio (VP ratio), and levator muscle shortening ratio were measured and compared across the 3 groups. RESULTS: The VPI group showed the least maximal velar stretch, lowest maximal velar height, smallest maximal pharyngeal constriction, and lowest maximal VP ratio among the 3 groups. The VPI and VPC groups differed significantly in velar and pharyngeal mobility. The effective VP ratio at rest has a strong correlation with that during sustained phonation across the 3 groups. The maximal velar stretch ratio correlates to the maximal pharyngeal constriction ratio strongly in the VPI group only. CONCLUSIONS: The VPI group had significantly reduced velar and pharyngeal mobility during speech compared with the VPC and noncleft groups. The possible physiological causes of VPI after primary palatal repair were discussed.