Application of obturator to treat velopharyngeal incompetence.
OBJECTIVE: To evaluate the effect of a system of velopharyngeal incompetence (VPI) management after the application of obturator. METHODS: Using nasopharyngofiberoscope (NPF) and a computer analysis system, we quantitatively analyzed the improved state of velopharyngeal incompetence in 100 patients with unilateral and/or bilateral cleft palate. RESULTS: The velopharyngeal closure (VPC) can be greatly improved by using a temporary oral prosthesis (obturator) and speech training. An objective quantitative standard was established to evaluate the change of velopharyngeal closure of cleft palate patients after surgery and conservative treatment. CONCLUSIONS: The method used is more succinct, accurate and practical than previous methods. In order to reflect the state of velopharyngeal incompetence, the concept of improvement rate of velopharyngeal incompetence (IRVPI) is put forward. (+info)
The 22q11.2 deletion syndrome.
The 22q11.2 deletion syndrome (22q11DS) encompasses DiGeorge syndrome, velo-cardio-facial syndrome and conotruncal anomaly face syndrome and is due to a microdeletion of chromosome 22q11.2. This is the most frequent known interstitial deletion found in human with an incidence of 1 in 4,000 live births. A large number of clinical findings have been reported in affected patients, including cardiac defects, characteristic facial features, thymic hypoplasia, cleft palate, hypoparathyroidism, learning difficulties and psychiatric disorders. A comprehensive evaluation and follow-up program is necessary for patients with 22q11DS. A striking aspect of the 22q11DS phenotype is its variability, the basis of which remains unclear, and no phenotype-genotype correlation has been made. The structures primarily affected in patients with 22q11DS are derivatives of the embryonic pharyngeal arches and pouches suggesting that haploinsufficiency of the gene(s) on the deleted region, spanning 2-3 Mb, is important in pharyngeal arch/pouch development. Extensive gene searches have been successful in identifying more than 30 genes in the deleted segment. Although standard positional cloning has failed to demonstrate a role for any of these genes in the syndrome, the use of experimental animal models and advanced genome manipulation technologies in mice have been providing an insight into the developmental role of some of these genes, including TBXI. In this review, the clinical features and management of patients with 22q11DS are integrated with our current understanding of the embryological and molecular basis of this syndrome, as presented at the 1235th Meeting of The Keio Medical Society. (+info)
Frequency of pharyngoplasty after primary repair of cleft palate.
BACKGROUND: The frequency of pharyngoplasty after initial repair of cleft palate is a direct measure of the success or failure of the primary palatal repair with respect to velopharyngeal function. The optimal timing and surgical technique for the repair of cleft palate remain subjects of debate. PURPOSE: To assess the outcome of various techniques for primary palatal repair, specifically the frequency of secondary pharyngoplasty, and to determine the significance, if any, of certain variables to this outcome. METHODS: A pool of 114 patients with cleft lip and palate was compiled from a retrospective analysis of medical records for more than 300 consecutive patients treated over a 15-year period (1980-1995). The review included only patients who had been treated by the same surgeon or by his resident. A 1-stage palatal repair was performed on all patients, in which the hard and the soft palate were closed simultaneously. The following data were collected: patient's sex, patient's date of birth, type of cleft, technique used for initial repair, age at initial repair and date of secondary pharyngoplasty surgery, if performed. RESULTS: The overall frequency of subsequent pharyngoplasty was 25% (28 patients). The rate of secondary surgery was significantly higher for boys (21/63 or 33%) than for girls (7/51 or 14%). There were also significant differences in the rate of secondary pharyngoplasty according to type of cleft: 50% (6/12) for patients with bilateral cleft lip and palate, 44% (7/16) for those with hard and soft cleft palate, 21% (8/38) for those with unilateral cleft lip and palate, 20% (3/15) for those with submucous cleft palate and 12% (4/33) for those with soft cleft palate. Surgical technique for the primary repair (V-Y pushback or von Langenbeck procedure) was not a significant factor in determining the rate of subsequent pharyngoplasty, nor was age at primary repair, although those who underwent primary repair at age 12-14 months were least likely to require pharyngoplasty. CONCLUSION: In this study the frequency of velopharyngeal insufficiency after 1-stage palatoplasty was consistent with previously reported results. Of interest would be a comparison of 1-stage and 2-stage approaches to primary palate repair in young patients. (+info)
Neurogenic effects on the palatopharyngeal muscle in patients with obstructive sleep apnoea: a muscle biopsy study.
Muscle biopsies from the palatopharyngeal muscle of eight patients with obstructive sleep apnoea were performed during uvulopalatopharyngoplasty. Control biopsies were performed during tonsillectomy in seven control patients with no history of symptoms suggesting obstructive sleep apnoea. The diagnosis was based on the patient's history and a whole night recording of arterial oxygen saturation and respiration movements. The mean number of oxygen desaturations > or = 4% per sleeping hour was 39 (range 7-80) in patients with obstructive sleep apnoea. In the control patients the occurrence of muscle fibre type and size relation between type I and type II fibres were comparable to what is found in the quadriceps femoris muscle, but the mean size of the fibres was < 25% of what is found in limb muscles. All biopsies from patients with obstructive sleep apnoea showed abnormalities. Atrophy with a fascicular distribution, increased number of angulated atrophic fibres, a twin or multiple peak distribution of the fibre size spectra, and an abnormal distribution of fibre types in many muscle fascicles corresponding to "type grouping" all points to a neurogenic alteration. This neurogenic lesion may be a primary phenomenon or secondary to the trauma of repetitive and prolonged stretching of the pharyngeal structures during apnoeas. A disturbance of the function of the dilating muscles of the upper airway may be important in causing the abnormal airway collapse seen in obstructive sleep apnoea. (+info)
Effects of mandibular advancement on airway curvature and obstructive sleep apnoea severity.
In a curved tube, the amount of airflow appears to be influenced by the amount of curvature. The purpose of this study was to investigate changes in obstructive sleep apnoea (OSA) severity and awake velopharyngeal curvature in response to an anteriorly titrated mandibular position in 20 male OSA patients. Baseline supine cephalometry was obtained before the initial insertion of a titratable oral appliance and follow-up supine cephalometry was undertaken after titration of the mandibular position with the appliance in place. The mean apnoea/hypopnea index (AHI) before treatment (31.6 +/- 13.0 events x h(-1)) was significantly reduced (9.8 +/- 7.4 events x h(-1)) after titration of the mandibular position in all 20 patients. There was a significant increase in the anteroposterior calibre and the radius of the curvature of the anterior wall of the velopharynx in 14 good responders who exhibited an AHI reduction to < or = 15. Similar observations were not found in six poor responders. To conclude, an anteriorly titrated mandibular position reduced obstructive sleep apnoea severity, enlarged the velopharynx and diminished the curvature of the anterior velopharyngeal wall in good responders. It is proposed that this change in the upper airway curvature associated with mandibular advancement may effect obstructive sleep apnoea severity through its effect on airflow dynamics. (+info)
Air pressure responses to sudden vocal tract pressure bleeds during production of stop consonants: new evidence of aeromechanical regulation.
Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of "puh" using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H2O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. (+info)
A gender-moderated effect of a functional COMT polymorphism on prefrontal brain morphology and function in velo-cardio-facial syndrome (22q11.2 deletion syndrome).
Caused by a microdeletion at the q11.2 locus of chromosome 22, velo-cardio-facial syndrome (also known as VCFS, 22q11 deletion syndrome, DiGeorge sequence, and conotruncal anomalies face syndrome) is associated with a distinctive physical, neurocognitive, and psychiatric phenotype. Increasing interest has centered on identifying the candidate genes within the deleted region that may contribute to this phenotype. One attractive candidate gene is catechol-O-methyltransferase (COMT) because it encodes for a protein that degrades dopamine. Variability in COMT activity is related to a Val158Met polymorphism that has been implicated in prefrontal lobe cognitive and neuropsychiatric function. We examined the effect of this polymorphism on prefrontal anatomy and frontally-mediated neuropsychological function in 58 children with VCFS, 26 who were hemizygous for the Met allele and 32 for the Val allele. We found an allele by gender interaction effect on the volumes of the dorsal prefrontal and orbital prefrontal cortices. We did not find significant allele or gender by allele effects on neuropsychological tasks, although girls with the Met allele tended to perform better on the Wisconsin card sorting task. These data suggest that this functional COMT polymorphism may play a gender-moderated role in determining the neuroanatomic phenotype of individuals with VCFS. Longitudinal evaluation of these children is essential in order to identify potential clinical implications of this allele by gender interaction. (+info)
Anatomic consequences of intrinsic tongue muscle activation.
We recently showed respiratory-related coactivation of both extrinsic and intrinsic tongue muscles in the rat. Here, we test the hypothesis that intrinsic tongue muscles contribute importantly to changes in velopharyngeal airway volume. Spontaneously breathing anesthetized rats were placed in a MRI scanner. A catheter was placed in the hypopharynx and connected to a pressure source. Axial and sagittal images of the velopharyngeal airway were obtained, and the volume of each image was computed at airway pressures ranging from +5.0 to -5.0 cm H2O. We obtained images in the hypoglossal intact animal (i.e., coactivation of intrinsic and extrinsic tongue muscles) and after selective denervation of the intrinsic tongue muscles, with and without electrical stimulation. Denervation of the intrinsic tongue muscles reduced velopharyngeal airway volume at atmospheric and positive airway pressures. Electrical stimulation of the intact hypoglossal nerve increased velopharyngeal airway volume; however, when stimulation was repeated after selective denervation of the intrinsic tongue muscles, the increase in velopharyngeal airway volume was significantly attenuated. These findings support our working hypothesis that intrinsic tongue muscles play a critical role in modulating upper airway patency. (+info)