Anatomy of oral respiration: morphology of the oral cavity and pharynx

The anatomical states of the oral cavity and pharynx during mouth breathing in children with adenoid hypertrophy and in adults confirmed the speculation that mouth breathing is disadvantageous compared with nose breathing. In addition, comparison of the anatomical state between wakefulness and sleep in normal adults showed slight depression of the tongue root and slight narrowing of the oropharynx and hypopharynx during sleep. Obstructive sleep-disordered breathing occurs due to a variety of factors, such as paranasal sinus disease, tonsil and adenoid hypertrophy, hypertrophy and morphological abnormalities of the soft palate and palatine uvula, low-set soft palate, micrognathia, macroglossia, obesity and tongue root depression. Narrowing or obstruction of the middle pharynx and hypopharynx is more marked in patients with obstructive sleep-disordered breathing than in normal people and is especially marked during sleep. Therefore, morphological (i.e. anatomical) changes during mouth breathing may provide useful information for evaluating the pathology of snoring and sleep apnea.     

The utility of cephalometry with the Muller maneuver in evaluating the upper airway and its surrounding structures in Chinese patients with sleep-disordered breathing

OBJECTIVE: The objective was to simultaneously measure the size and collapsibility of the upper airway in Chinese patients with sleep-disordered breathing using cephalometry with the Muller maneuver. STUDY DESIGN: Prospective study of 100 consecutive Chinese patients evaluated for sleep-disordered breathing at a sleep center. METHODS: Each patient received overnight polysomnography and two lateral cephalograms (at the end-expiration phase and the Muller maneuver, respectively) to evaluate the upper airway and its surrounding structures (soft palate, tongue, and hyoid bone). After excluding 15 subjects from this study because of unclear cephalograms, 85 patients with sleep-disordered breathing were enrolled, including 32 with snoring or mild obstructive sleep apnea and 53 with moderate to severe obstructive sleep apnea. RESULTS: Patients with varying degrees of severity of sleep-disordered breathing significantly differed in terms of the structure and function of the upper airway and the surrounding structures. The Muller maneuver may result in dynamic changes in the retropalatal airway and pharyngeal length, and the levels of dynamic changes were related to the severity of sleep-disordered breathing. Pearson correlation analysis revealed that the decrease in the minimum retropalatal dimension during the Muller maneuver in patients with snoring or with mild obstructive sleep apnea was related to the thickening of the soft palate and posterior displacement of tongue. Meanwhile, the decrease in the minimum retropalatal dimension in patients with moderate to severe obstructive sleep apnea was related to lengthening of the soft palate, increased tongue height, and downward displacement of the tongue and hyoid bone. CONCLUSION: Cephalometry with the Muller maneuver may provide further insight into the pathogenesis of various levels of severity of sleep-disordered breathing.     

鼾症患者模拟打鼾与药物诱导睡眠内镜下鼾声来源部位的对比研究

目的 对单纯打鼾(SS)及轻度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的患者,通过鼻咽纤维喉镜观察清醒状态下模拟打鼾及药物诱导睡眠下打鼾时的鼾声来源,研究这两种检查方法判断鼾声来源部位的一致性及模拟打鼾判断鼾声来源的可靠度。 方法 经多导睡眠监测(PSG)诊断为单纯打鼾患者及轻度OSAHS患者共40例,依次进行清醒状态下模拟打鼾及药物诱导睡眠,通过纤维鼻咽喉镜观察患者仰卧位打鼾时咽部组织的振动情况。 结果 在模拟打鼾及药物诱导睡眠两种状态下咽部组织的振动情况有所不同。统计学McNemar检验结果显示,两种方法对软腭振动及会厌/舌根振动判断的差异无统计学意义(P=0.774, 0.077),对咽侧壁振动判断的差异有统计学意义(P=0.002)。两种检查对软腭及会厌/舌根振动的检出率差异无统计学意义(P=0.770,0.110), 药物诱导睡眠对咽侧壁振动的检出率远高于模拟打鼾(P=0.005)。 结论 与药物诱导睡眠内镜检查相比,模拟打鼾能较好地判断软腭振动,其次为舌根/会厌,对咽侧壁振动则较难判断。     

Neuromuscular function of the soft palate and uvula in snoring and obstructive sleep apnea: A systematic review

Objective

A collapsible upper airway is a common cause of obstructive sleep apnea. The exact pathophysiology leading to a more collapsible airway is not well understood. A progressive neuropathy of the soft palate and pharyngeal dilators may be associated with the progression of snoring to OSA. The purpose of this study is to systematically review the international literature investigating the neurophysiologic changes in the soft palate and uvula that contribute to progression from snoring to OSA.

The differentiation of snoring mechanisms using sound analysis

Ten subjects known to suffer from heavy snoring but not obstructive sleep apnoea were studied using the technique of sleep nasendoscopy. The mechanism of snoring was noted for each and sound recordings of the snoring noise were made. Six subjects were observed to snore using their soft palate only, three snored using only their tongue base and one snored using a combination of palate and tongue base. The sound recordings were subjected to computer analysis of waveform and frequency. Palatal flutter snoring and tongue base snoring appear to have distinct waveform and frequency patterns which allows them to be differentiated from each other.     

Snoring—a simple surgical solution

In this paper a new palatal surgical technique for the treatment of snoring is described and evaluated. All 22 patients were severe snorers with no significant obstructive sleep apnoea, as confirmed by detailed sleep studies. The aim of the surgical technique was to eliminate the vibration of the soft palate and the posterior pillars which occurs during snoring. This was achieved under general anaesthetic by making a 1.5 cm vertical full thickness incision in the soft palate from the superior pole of the tonsil towards the pterygoid hamulus using monopolar cutting diathermy. Specifically designed daily pain questionnaires were completed by the patients during the first 2 post-operative weeks and the level of snoring was assessed by the patient's sleeping partner at 2, 6 and 12 weeks. The presence of any complications was also documented at these times. The results demonstrate that this surgical technique is effective, quick, simple and bloodless. The post-operative pain created is mild and quickly resolves. All patients experienced a dramatic diminution of their snoring and in 55% complete cessation was achieved.     

Oral appliances in the treatment of snoring

There are many methods of snoring treatment from conservative and prosthetic to surgical. The snoring sound is produced by vibration of the soft tissues of the pharynx, soft palate and also uvula. Snoring occurs in 50% of the adult male population and it can be isolated or sign of the obstructive sleep apnoea syndrome. Oral appliances modify the position of the mandibule, the tongue and other structures in oral cavity. Oral appliances are recommended for the treatment of snoring and mild obstructive sleep apnoea syndrome. That is why we constructed the study to assess wheather oral appliances correct snoring. 12 mails (aged 43-57) with intensive snoring for at least 50% of the sleep time were qualified to the treatment with oral appliances. The decision about the type of the device were made by ENT surgeon and maxillo-facial surgeon. The various oral appliances were used; some of which were modyfied by us. During the treatment snoring was tested with Poly-Mesam device. The best results were obtained with the use of devices that correct the position of soft palate and uvula. All the devices decreased snoring significantly. They were tolerated by the majority of patients.     

Can anatomical and functional features in the upper airways predict sleep apnea? A population-based study in females

CONCLUSION: The importance of clinical findings in the nose and throat, including fiberoptic endoscopy during the Muller maneuver, in predicting sleep apnea is greater in normal-weight than in overweight women. OBJECTIVES: The aim of this study was to identify clinical features that could predict sleep apnea in women. METHOD: From 6817 women who previously answered a questionnaire concerning snoring habits, 230 women who reported habitual snoring and 170 women from the whole cohort went through a full-night polysomnography. A nose and throat examination including fiber endoscopic evaluation of the upper airways during the Muller maneuver was performed in a random selection of 132 women aged 20-70 years. RESULTS: Sleep apnea was defined as an apnea-hypopnea index of > or = 10. The influence of clinical features on the prevalence of sleep apnea varied between normal-weight and overweight women. A low soft palate, retrognathia, the uvula touching the posterior pharyngeal wall in the supine position, and a 75% or more collapse at the soft palate during the Muller maneuver were all significant predictors of sleep apnea in women with a body mass index (BMI) < 25 kg/m2 but not in overweight women.     

Laser Assisted Uvulopalatoplasty: an objective evaluation of the technique and results

The operation of Laser Assisted Uvulopalatoplasty (LAUP) as described by Kamami is now becoming more commonly used in the treatment of snoring and obstructive sleep apnoea. The authors have treated 95 snoring patients, varying the lengths of the soft palate incisions and percentage of uvula excised. All operations were carried out under general anaesthesia using a CO₂ laser. Pilot studies showed incisions that are 25% of the distance between the free edge of the soft palate to the hard palate junction and excision of 50% of the uvula give good results with minimal complications. A further study using these parameters was conducted and postoperative evaluation including polysomnography confirmed this procedure to be effective in reducing snoring levels both subjectively and objectively.     

How can one recognize a velum snorer?

In ten habitually snoring subjects and ten patients with obstructive sleep apnea syndrome, preoperative snoring sounds above a preset sound pressure level were recorded and a frequency spectrum analysis by means of time series Fast Fourier Transformation was performed. All patients underwent uvulopalato-pharyngoplasty after which the snoring sounds were recorded again and analysed under the same conditions. Preoperative frequency spectra in heavy snorers were dominated by a component which results from the movement of the soft palate and uvula and which presents as a low-frequency vibration of 25 to 50 c/s and its harmonics up to several hundred c/s. After UPPP the sound pressure level of the snoring noise in heavy snorers was reduced by 20 to 30 decibels and could not be recorded any more. The frequency spectrum of snoring noises in patients with obstructive sleep apnea syndrome differed from those of heavy snorers. In apnea patients the snoring noise usually consisted of other and higher frequency components which masked the vibration of the soft palate and uvula to a more or less high degree. An extreme degree of masking is reached in snoring noises following apneic episodes when identification of the movement of the soft palate is impossible. After performing UPPP in an apneic patient the low-frequency content of the spectrum below about 400 Hz was reduced dramatically but higher frequency parts were still present. This resulted in only minor reduction of snoring noise sound pressure level. Our results are in agreement with other authors in showing that UPPP is not successful when the site of obstruction is not in the velo-pharyngeal plane.(ABSTRACT TRUNCATED AT 250 WORDS)     

Somnoplasty for simple snoring--a pilot study

A prospective pilot study was conducted to investigate the efficacy of radiofrequency thermal ablation (RFTA) of the soft palate to treat simple snoring. Ten consecutive, consenting patients were recruited following history, examination, Epworth scoring, sleep nasendoscopy and full polysomnography. All the patients received two treatments of three lesional RFTA of the soft palate under local anaesthesia, using the Somnus S2 generator. Each treatment was separated by 6 weeks. Patients completed a questionnaire which used visual analogue scales to score pain during the procedure as well as the postoperative period. Snoring was also scored on visual analogue scales by both the patient and the partner. Objective assessment was based on full polysomnography 3 months after the second treatment. Sixty per cent of patients subjectively reported improvement in snoring. Objectively, only 30% showed improvement in duration of snoring (38-48% better) with no change in intensity. There was high patient acceptability of the procedure.     

Sound frequency analysis and the site of snoring in natural and sedation induced sleep

Frequency analysis of snoring sounds has been shown to correlate with the site of upper airway narrowing. The aim of this study was to compare the sound frequency spectra of snores generated during induced snoring at sleep nasendoscopy with those during natural sleep. The sound of 11 subjects snoring overnight and during sleep nasendoscopy was digitally recorded. The observed site of vibration was noted for each snore sample recorded at sleep nasendoscopy. A Fast Fourrier Transformation was used to produce frequency spectra. At sleep nasendoscopy observed palatal snores (76) had a median peak frequency at 136 Hz, tongue based snores (10) at 1243 Hz and simultaneous palate and tongue (six) at 190 Hz. The median power ratios (defined as the area under the frequency spectra below 750 Hz/area above 750 Hz) were 33 for palatal snores, 0.2 for tongue base snores and 5 for simultaneous palate and tongue. Natural snores (275) had a dominant median peak at 132 Hz with a ratio of 88. A comparison of overnight snores (200) of those subjects (eight) with observed palatal snores (76) was made. Neither the peak frequency nor power ratio of natural and induced snores were significantly different (P = 0.85 and P = 0.13, respectively). The power ratio in four of the subjects individually was significantly different (P < 0.05). These results suggest that sedation-induced snores contain a high frequency component consistent with an element of tongue base snoring, not evident in natural snores. Thus sleep nasendoscopy may not accurately reflect snoring during natural sleep. Sound frequency analysis during natural sleep may therefore be a better predictive investigation for the success of palatal surgery.     

Treatments for Snoring: A Comparison of Somnoplasty and an Oral Appliance

Objectives Objectives of the study are 1) to test the effectiveness of somnoplasty (radiofrequency volumetric tissue reduction of the soft palate) for the control of loud, socially disruptive, snoring; 2) to test the long‐term efficacy of this treatment by spouse report; and 3) to compare the effectiveness of somnoplasty with another treatment. Study Design Twenty patients with complaints of loud snoring and a respiratory disturbance index no greater than 15 respiratory events per hour with sleep‐related episodes of oxygen desaturation no lower than 80% were offered an experimental treatment. Ten were treated with somnoplasty, and a comparison group of 10 matched patients used an oral appliance. All were restudied in the laboratory wearing a device programmed to count minutes of sleep during which snoring was loud, soft, or absent. Methods For the 10 somnoplasty patients, a spouse rating of snoring determined whether the patient received one or more treatments. Five patients had a single treatment to three sites, and five others had two such treatments. Ten patients wore an oral appliance of the tongue‐retaining type (Snore X, Fremont, CA). Results Seven of the 10 somnoplasty patients met the improvement criteria set for reduced loud snoring (a spouse rating of 3 or less on a 10‐point scale, and 10% or less of sleep time in loud snoring in the laboratory). The comparison group also had a significant improvement in the percentage of sleep time in loud snoring while wearing the Snore X appliance. Conclusion Since there was no significant difference between the two groups in percentage of sleep time spent in loud snoring while treated, the choice of method to control snoring must be based on factors other than efficacy.     

Somnoplasty® for simple snoring – a pilot study

A prospective pilot study was conducted to investigate the efficacy of radiofrequency thermal ablation (RFTA) of the soft palate to treat simple snoring. Ten consecutive, consenting patients were recruited following history, examination, Epworth scoring, sleep nasendoscopy and full polysomnography. All the patients received two treatments of three lesional RFTA of the soft palate under local anaesthesia, using the Somnus^® S2 generator. Each treatment was separated by 6 weeks. Patients completed a questionnaire which used visual analogue scales to score pain during the procedure as well as the postoperative period. Snoring was also scored on visual analogue scales by both the patient and the partner. Objective assessment was based on full polysomnography 3 months after the second treatment. Sixty per cent of patients subjectively reported improvement in snoring. Objectively, only 30% showed improvement in duration of snoring (38–48% better) with no change in intensity. There was high patient acceptability of the procedure.     

悬雍垂-软腭折叠成形术治疗阻塞性睡眠呼吸暂停低通气综合征

目的　改进经典悬雍垂腭咽成型术 (uvulopalatopharyngoplasty ,UPPP)的手术方法 ,提高治疗阻塞性睡眠呼吸暂停低通气综合征 (obstructivesleepapnea hypopneasyndrome ,OSAHS)的治疗效果 ,减少术后并发症。方法　用新改进的术式治疗OSAHS患者 3 6例 ,轻度 8例 ,中度 2 1例 ,重度 7例。在常规UPPP手术基础上完整保留悬雍垂及腭肌 ,切除软腭口咽面下段 1/ 3～ 1/ 2的黏膜及黏膜下部分脂肪组织 ,再将软腭自游离缘向上折叠并与上切缘缝合 ,形成新软腭。保留软腭的活动与功能。结果　 3 1例 ( 86 1% )诉睡眠时鼾声、白天嗜睡和晨起头痛等症状明显改善。术后 6个月复查 ,3 0例( 83 3 3 % )低通气指数下降超过 5 0 % ,19例 <5次 /h ,9例≤ 2 0次 /h ,6例≤ 40次 /h。没有出现术后出血、开放性鼻音、长期饮食返流、鼻咽腔瘢痕性狭窄等并发症。结论　此改进术式在有效扩大咽腔 ,尤其是软腭后间隙的基础上 ,避免了腭咽关闭不全、饮食返流、鼻咽腔瘢痕性狭窄等并发症 ,疗效良好     

Histopathologic changes of the soft palate in snoring and obstructive sleep apnea syndrome patients

Histology of the soft palate and uvula in snorers and patients with OSA syndrome has been a subject of investigation of many authors. In majority of specimens the hypertrophy of the salivary glands as well as congestion and dilation of the thin-walled vessels were observed. Some of the samples presented atrophy of the muscle bundles. Also, the inflammatory changes as lymphocytic infiltrations were proven. In each case adults served as a control group. In this study the histologic analysis of the soft palate and uvula samples from patients suffering from snoring and OSA syndrome was performed. The uvula samples from the newborn who died on the first day of their lives were chosen as a control group. The choice of such a group excluded the influence of vibration force on the soft palate structure. Comparisons among the groups were made by Fisher exact two-tailed test. The muscular atrophy was observed only in patients with airway disturbances. No case of neonatal tissue sample with this pathology was found. Less dilation and congestion of the blood vessels were observed in the newborn group. Significantly more frequent superficial salivary glands localized between the muscle bundles and epithelium were found in the OSA and snoring patients. Our results showed distinct differences between the tissues of the patients with airway disturbances and the control group. These differences may be caused by the influence of the vibration on the soft palate and uvula, but on the other hand they may be the reason for excessive flaccidity of these structures and disturbances occurring during sleep.     

Histopathological and ultrastructural effects of cutting radiofrequency energy on palatal soft tissues: a prospective study

Radiofrequency (RF) surgery has gained popularity as a safe and effective method for treating patients with snoring and mild obstructive sleep apnoea (OSA). Both interstitial and cutting radiofrequency energy may be used for multi-segmental management of the upper airway. Little is known about the effect of cutting radiofrequency energy on human soft palate. Excessive collateral injury may have an impact on tissue healing and functional outcomes. A histological analysis of specimens of human soft palate and uvula following resection with cutting RF energy was performed. In addition, ultrastructural analysis using scanning electron microscopy of excision margins was performed and compared with CO₂ LASER. Twelve patients were included. In ten patients, specimens of redundant uvula and faucial pillars were collected and underwent formal histological analysis. The maximum depth of tissue injury was 1 mm in two specimens and overall average depth of injury was 0.15 mm. Injury depth was independent of tissue subtype at the resection margin. Ultrastructural analysis demonstrated accurate incision when compared to CO₂ LASER. Cutting RF energy causes minimal collateral injury to the soft palate during resection for the treatment of snoring and mild OSA. A detailed knowledge of local effects on resection specimens allows accurate inference of in vivo tissue injury at the resection margin and may enable more precise prediction of healing patterns and repair.     

悬雍垂—软腭折叠成形术治疗阻塞性睡眠呼吸暂停低通气综合征

OBJECTIVE: To explore the effect of the modified (Uvulopalatopharyngoplasty, UPPP) where uvula is reserved completely and the soft palate is folded in the operation. METHODS: 36 patients with the obstructive sleep apnea-hypopnea syndrome (OSAHS) (30 men, 6 women) underwent operation. The uvula and the muscles of the soft palate were reserved completely, and the soft palate was folded during the operation. RESULTS: 31 patients (86.1%) reported improvement of snoring and daytime somnolence. 30 patients (83.33%) showed a decrease of at least 50% in the apnea and hypopnea indices (AHI). No velopalatal insufficiency occurred. CONCLUSION: The modified UPPP not only enlarges pharyngeal cavity, but also avoids the postoperative complications. The modified UPPP could be better than the traditional operation.     

A comparison of tonsillar size and oropharyngeal dimensions in children with obstructive adenotonsillar hypertrophy

Hypertrophy of the tonsils and adenoids is the most common cause of obstructive sleep apnea in children. There is relatively little known about the occurrence of subclinical variations in the dimensions of the oropharynx which may predispose to the development of obstructive sleep apnea in children without obvious craniofacial abnormalities. Fifty-one children (3-10 years) were divided into two groups: the first group consisted of 18 patients with small tonsils and no history of snoring who underwent tonsillectomy for chronic tonsillitis. They were compared to a second group of 33 patients with large tonsils who underwent tonsillectomy and adenoidectomy for symptoms of obstructive sleep apnea. Age, height, weight, body surface area and tonsil weight were correlated to the dimensions of the oropharynx obtained by direct measurement intraoperatively including the length of the soft palate, anterior-posterior depth of the nasopharynx and the distances between the medial tonsillar surfaces, anterior tonsillar pillars and lateral pharyngeal walls at mid-tonsil level. Increased patient height, weight and surface area correlated positively to increased distance between the lateral pharyngeal walls and to the length of the soft palate in the patients with small tonsils. No such correlation existed in the patients with obstructive adenotonsillar hypertrophy. In addition, the distance between the lateral pharyngeal walls was significantly decreased in the group with large, obstructing tonsils as compared to those with small tonsils and no history of obstruction (P less than 0.01). However, the patients with small tonsils and no obstruction had significantly longer soft plates (P less than 0.01) and less depth tot eh nasopharynx (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)