Effect of obesity and erect/supine posture on lateral cephalometry: relationship to sleep-disordered breathing.
Craniofacial and upper airway anatomy, obesity and posture may all play a role in compromising upper airway patency in patients with the sleep apnoea/hypopnoea syndrome. The aim of this study was to investigate the relationship between obesity, facial structure and severity of sleep-disordered breathing using lateral cephalometric measurements and to assess the effect of body posture on cephalometric measurements of upper airway calibre variables in obese and non-obese subjects. Lateral cephalometry was carried out in erect and supine postures in 73 awake male subjects randomly selected from patients referred for polysomnography who had a wide range of apnoea/hypopnoea frequencies (1-131 events x h sleep(-1)). Subjects were divided into non-obese (body mass index (BMI) < 30 kg x m(-2); n=42) and obese (BMI > or = 30 kg x m(-2); n=31) groups. Significant but weak correlations were found between apnoea/hypopnoea index (AHI) and measurements reflecting upper airway dimensions: uvular protrusion-posterior pharyngeal wall (r=-0.26, p<0.05) and hyoid-posterior pharyngeal wall (r=0.26, p<0.05). Multiple regression using both upper airway dimensions improved the correlation to AHI (r=0.34, p=0.01). Obese subjects had greater hyoid-posterior pharyngeal wall distances than non-obese subjects, both erect (42+/-5 versus 39+/-4 mm, respectively (mean+/-SD) p<0.01) and supine (43+/-5 versus 40+/-4 mm, p<0.05). Skeletal craniofacial structure was similar in obese and non-obese subjects. In conclusion, measurements reflecting upper airway size were correlated with the severity of sleep-disordered breathing. Differences in upper airway size measurements between obese and non-obese subjects were independent of bony craniofacial structure. (+info)
Cephalometric abnormalities in non-obese and obese patients with obstructive sleep apnoea.
The aim of this work was to comprehensively evaluate the cephalometric features in Japanese patients with obstructive sleep apnoea (OSA) and to elucidate the relationship between cephalometric variables and severity of apnoea. Forty-eight cephalometric variables were measured in 37 healthy males and 114 male OSA patients, who were classed into 54 non-obese (body mass index (BMI) <27 kg x m(-2), apnoea-hypopnoea index (AHI)=25.3+/-16.1 events x h(-1)) and 60 obese (BMI > or = 27 kg x m(-2), AHI=45.6+/-28.0 events h(-1)) groups. Diagnostic polysomnography was carried out in all of the OSA patients and in 19 of the normal controls. The non-obese OSA patients showed several cephalometric defects compared with their BMI-matched normal controls: 1) decreased facial A-P distance at cranial base, maxilla and mandible levels and decreased bony pharynx width; 2) enlarged tongue and inferior shift of the tongue volume; 3) enlarged soft palate; 4) inferiorly positioned hyoid bone; and 5) decreased upper airway width at four different levels. More extensive and severe soft tissue abnormalities with a few defects in craniofacial bony structures were found in the obese OSA group. For the non-obese OSA group, the stepwise regression model on AHI was significant with two bony structure variables as determinants: anterior cranial base length (S-N) and mandibular length (Me-Go). Although the regression model retained only linear distance between anterior vertebra and hyoid bone (H-VL) as an explainable determinant for AHI in the obese OSA group, H-VL was significantly correlated with soft tissue measurements such as overall tongue area (Ton), inferior tongue area (Ton2) and pharyngeal airway length (PNS-V). In conclusion, Japanese obstructive sleep apnoea patients have a series of cephalometric abnormalities similar to those described in Caucasian patients, and that the aetiology of obstructive sleep apnoea in obese patients may be different from that in non-obese patients. In obese patients, upper airway soft tissue enlargement may play a more important role in the development of obstructive sleep apnoea, whereas in non-obese patients, bony structure discrepancies may be the dominant contributing factors for obstructive sleep apnoea. (+info)
Exhalation flow and pressure-controlled reservoir collection of exhaled nitric oxide for remote and delayed analysis.
BACKGROUND: Expiratory flow rate, soft palate closure, and dead space air may influence exhaled levels of nitric oxide (NO). These factors have not been evaluated in the reservoir collection of NO. METHODS: Exhaled NO was collected into a reservoir during a single flow and pressure controlled exhalation. RESULTS: NO collected in a reservoir containing silica gel was stable for 24 hours. Nasally delivered 4.8% argon measured by mass spectrometry did not contaminate exhaled argon levels (0.1 (0.02)%) in five volunteers during exhalation against a resistance (10 (0.5) cmH2O), hence proving an effective soft palate closure. Exhaled NO in the reservoir was 11 (0.2) ppb, 8.6 (0.1) ppb, 7.1 (0.6) ppb, and 6.6 (0.4) ppb in five normal subjects and 48.3 (18) ppb, 20.3 (12) ppb, 16.9 (0.3) ppb and 10.1 (0.4) ppb in 10 asthmatic subjects at four studied expiratory flows (5-6, 7-8, 10-11, and 12-13 l/min, respectively), with NO levels equal to direct measurement (7.3 (0.5) ppb and 17.4 (0.5) ppb for normal and asthmatic subjects respectively, p < 0.05) at the flow rate 10-11 l/min. Elimination of dead space proved necessary to provide NO levels comparable to the direct measurement. Exhaled NO collected into the reservoir without dead space during flow controlled exhalation against mild resistance provided close agreement (mean (SD) difference -0.21 (0.68), coefficient of variation 4.58%) with direct measurement in 74 patients (NO range 1-69 ppb). CONCLUSIONS: Flow and pressure controlled collection of exhaled NO into a reservoir with silica gel provides values identical to the direct measurement and may be used to monitor asthma at home and where analysers are not on site. (+info)
Immunohistochemical localization of carbonic anhydrase isozyme II in the gustatory epithelium of the adult rat.
The distribution of carbonic anhydrase isozyme II (CA II)-like immunoreactivity (-LI) in the gustatory epithelium was examined in the adult rat. In the circumvallate and foliate papillae, CA II-LI was observed in the cytoplasm of the spindle-shaped taste bud cells, with weak immunoreaction in the surface of the gustatory epithelium. No neuronal elements displayed CA II-LI in these papillae. There was no apparent difference in the distribution pattern between the anterior and posterior portions of the foliate papillae. In immunoelectron microscopy, immunoreaction products for CA II were diffusely distributed in the entire cytoplasm of the taste bud cells having dense round granules at the periphery of the cells. No taste bud cells displaying CA II-LI were detected in the fungiform papillae, but a few thick nerve fibers displayed CA II-LI. In the taste buds of the palatal epithelium, neither taste bud cells nor neuronal elements exhibited CA II-LI. The present results indicate that CA II was localized in the type I cells designated as supporting cells in the taste buds located in the posterior lingual papillae of the adult animal. (+info)
The incidence of cleft lip and palate deformities in the south-east of Scotland (1971-1990).
This retrospective study reports the incidence of infants born with the cleft lip and palate anomaly within the Edinburgh Cleft Units catchment area, between 1 January, 1971, and 31 December, 1990. The importance of accurate data collection for local, regional, and national data bases is discussed with reference to the recent CSAG report on cleft lip and palate services in the UK. Five-hundred-and-two cleft lip and palate patients were identified (291 males, 211 females). The incidence is reported as 1.4 per 1000 live births (1 in 711). Twenty-five per cent of clefts affected the primary palate, 45 per cent affected the secondary palate, and the remaining 30 per cent were clefts of both the primary and secondary palate. Overall, a higher percentage of males were affected (58 per cent males to 42 per cent females). Clefts of the secondary palate, however, were more common in females (56 per cent females to 44 per cent males). Data presented in this study is similar to that previously reported from UK centres. It is suggested the accuracy of the UK cleft lip and palate data collection needs to be improved. Prospective data collection in a standardized format carried out on a national basis has to be a priority as recommended by the CSAG report. (+info)
Unpredictable results of laser assisted uvulopalatoplasty in the treatment of obstructive sleep apnoea.
BACKGROUND: Laser assisted uvulopalatoplasty (LAUP) is increasingly offered for the treatment of obstructive sleep apnoea (OSA), although there is a lack of objective data to support its indications and efficacy. A study was undertaken to determine the treatment response to LAUP. METHODS: Overnight polysomnography was performed before and at least three months after surgery in 44 consecutive patients with symptomatic mild to moderate OSA (apnoea + hypopnoea index (AHI) >10/h). Pharyngeal dimensions were measured by videoendoscopy (n = 11) and disease-specific quality of life, sleepiness and snoring frequency (n = 16) before and after surgery were determined in subgroups of patients. LAUP was performed under local anaesthesia as a one stage resection of the uvula and soft palate by one of two experienced otolaryngologists. RESULTS: Twelve patients (27%) had a good response (AHI 50% of pre-LAUP value); and 13 (30%) patients were worse (AHI >100% of pre-LAUP value). The velopharyngeal cross sectional area and anteroposterior diameter increased following LAUP (p<0.05). Quality of life indices improved significantly in all domains and sleepiness decreased. The snoring index did not decrease significantly. No preoperative anthropometric or videoendoscopic measures were predictive of a good response to LAUP. Patients who were worse after LAUP had milder baseline apnoea severity than those in the other response groups. CONCLUSIONS: The treatment response to LAUP is variable and unpredictable, and only a few patients achieve a satisfactory response. There appears to be no relationship between subjective and objective measures of treatment efficacy. (+info)
Characterisation of human soft palate muscles with respect to fibre types, myosins and capillary supply.
Four human soft palate muscles, and palatopharyngeus, the uvula, the levator and tensor veli palatini were examined using enzyme-histochemical, immunohistochemical and biochemical methods and compared with human limb and facial muscles. Our results showed that each palate muscle had a distinct morphological identity and that they generally shared more similarities with facial than limb muscles. The palatopharyngeus and uvula muscles contained 2 of the highest proportions of type II fibres ever reported for human muscles. In contrast, the levator and tensor veli palatini muscles contained predominantly type I fibres. A fetal myosin heavy chain isoform (MyHC), not usually found in normal adult limb muscles, was present in a small number of fibres in all palate muscles. The mean muscle fibre diameter was smaller than in limb muscles and the individual and intramuscular variability in diameter and shape was considerable. All palate muscles had a high capillary density and an unusually high mitochondrial enzyme activity in the type II fibres, in comparison with limb muscles. No ordinary muscle spindles were observed. The fibre type and MyHC composition indicate that the palatopharyngeus and uvula muscles are functionally involved in quick movements whereas the levator and tensor veli palatini muscles perform slower and more continuous contractions. The high aerobic capacity and the rich capillarisation suggest that the palate muscles are relatively fatigue resistant. Absence of ordinary muscle spindles indicates a special proprioceptive control system. The special morphology of the palate muscles may be partly related to the unique anatomy with only one skeletal insertion, a feature consistent with muscle work at low load and tension and which may influence the cytoarchitecture of these muscles. Other important factors determining the special morphological characteristics might be specific functional requirements, distinct embryological origin and phylogenetic factors. (+info)
Computerized endopharyngeal myotonometry (CEM): a new method to evaluate the tissue tone of the soft palate in patients with obstructive sleep apnoea syndrome.
This study compared the tissue tone of the soft palate in nonsnoring subjects and patients with obstructive sleep apnoea syndrome (OSAS) during wakefulness. Here, tissue tone means the biomechanical property of the tissue which can be characterized by two main parameters: stiffness and elasticity. Tissue tone includes both structural and neural components. A new method to evaluate the tissue tone of the soft palate was used - computerized endopharyngeal myotonometry (CEM). This method records and analyses the response of the soft palate tissues to a brief mechanical impact. The method enabled us to evaluate the most important parameters of tissue tone: stiffness, which is expressed as a frequency; and elasticity, expressed as a logarithmic decrement of the damped oscillation. First, a self-reported questionnaire was completed about the medical history of the subjects. Subjects then underwent a physical examination of the oropharynx and polysomnography with overnight pulse oximetry. The results of the CEM method indicated that patients with OSAS show an increased stiffness of the soft palate tissues (20.3, SD 4.7 Hz) compared with nonsnoring subjects (12.2, SD 1.8 Hz). In patients with sleep apnoea, elasticity is not increased in a similar way to stiffness. Thus, the disproportion between tissue stiffness and elasticity of the soft palate is a measure of the pathological changes in patients with sleep apnoea. (+info)