腭咽环扎术后并发阻塞性睡眠呼吸暂停低通气综合征的手术治疗

目的:探讨环扎线取出术联合腺样体切除术对腭咽环扎术(VRLP)后阻塞性睡眠呼吸暂停低通气综合征(OSAHS)的治疗作用。方法:应用鼻咽纤维喉镜检查6例VRLP后经多导睡眠监测(PSG)确诊为OSAHS患者的上气道形态和腭咽闭合情况,并对患者实施了环扎线取出术和腺样体切除术。术后随访3个月,并进行多导睡眠监测和鼻咽纤维喉镜检查。应用配对t检验和χ2检验对手术前后PSG各检测指标进行了比较。结果:VRLP后上气道在软腭平面形成一环形嵴,OSAHS患者均有腺样体增生肥大,上气道鼻咽部明显狭窄变形。环扎线取出和腺样体切除后,无1例出现腭咽闭合不全,患者上气道形态平滑,睡眠呼吸障碍得到治愈,临床症状消失,睡眠结构恢复正常。PSG各参数在手术前后有极显著性差异(P<0.01)。结论:环扎线取出术联合腺样体切除术,是治疗VRLP后OSAHS的有效方法。     

Difference in dental arch size between obese and non-obese patients with obstructive sleep apnoea

Summary A large tongue is recognised as a factor that increases the collapsibility of the upper airway in obstructive sleep apnoea (OSA) patients. We hypothesised that the propensity to develop severe OSA could be minimised if the dental arches were enlarged in obese OSA people who are thought to have a large tongue. We therefore compared the size of the dental arches in obese and non‐obese OSA patients. Using a lateral cephalogram and study models, we compared the sizes of the tongue and dental arches in 23 obese and 23 non‐obese Japanese male OSA patients, who were matched for age, apnoea hypopnea index (AHI) and maxillomandibular size. The median age (years) and AHI (events per hour) for the obese and non‐obese groups were 36·5 and 39·0, and 13·4 and 14·3, respectively. The maxillomandibular size was matched with regard to SNA, SNB and lower face cage obtained from cephalometric measurements. The parameters that were measured for the study model included dental arch width, dental arch length, overjet and overbite. Tongue size (P < 0·05) and both upper (P < 0·01) and lower (P < 0·05) dental arch widths were significantly larger in obese than in non‐obese OSA patients, and there was no difference in the severity of OSA between the two groups. These findings suggest that the tongue was larger and dental arches were enlarged in obese patients compared with non‐obese patients under the same disease severity. Wider dental arches in obese OSA patients may help to offset the impact of the enlarged tongue on upper airway patency.     

阻塞性睡眠呼吸暂停低通气综合征患者的牙弓与上气道形态变化及相关性分析

目的：：比较阻塞性睡眠呼吸暂停低通气综合征( OSAHS)患者与正常人牙弓及上气道形态差异,揭示OSAHS牙弓形态改变与上气道容积对应变化的关系。方法：利用上气道CBCT扫描及口腔模型测量经PSG诊断为OSAHS的男性患者( n=22)与正常男性对照(n=19)的牙弓形态与上气道容积变化,并行相关性分析。结果：OSAHS组上颌牙弓长度与腭弓高度分别大于对照组(均P<0.05);OSAHS组鼻咽段、腭咽段截面积及上气道总容积与腭弓高度、上颌牙弓长度呈负相关(均P<0.05),与上颌后段牙弓宽度呈正相关关系(P<0.05)。结论：OSAHS患者上颌牙弓形态的异常与鼻咽段和腭咽段容积的变化有关联。     

Effect of palatine tonsil hypertrophy on tongue posture and maxillofacial dentition: A pharyngeal airway computational fluid dynamics study

ObjectivesThis study aimed to clarify the effect of palatine tonsil hypertrophy-induced ventilation obstruction on maxillofacial dentition morphology using computational fluid dynamics (CFD) to represent tongue posture and maxillofacial dentition three dimensionally.Materials and methodsWe analyzed data of 20 patients with tonsil hypertrophy (tonsil hypertrophy group (TG); 9.0 years old, seven boys) and a comparison group (CG) of 20 patients without tonsil hyperplasia (comparison group; 9.4 years old, 10 boys). Cone-beam computed tomography and CFD data were used to assess the effects of palatine tonsil hypertrophy on pharyngeal airway ventilation, tongue posture, and morphology of the maxillofacial dentition.ResultsThe TG exhibited significantly greater depth, narrower width, smaller cross-sectional area of the pharyngeal airway, and narrower maxillary dental arch with Class II than the CG. Additionally, the tongue was positioned significantly more anteriorly and inferiorly in the TG than that in the CG.ConclusionsOur data suggest that hypertrophy of the palatine tonsils narrows the pharyngeal airway, resulting in a smaller cross-sectional area. Widening of the pharyngeal airway may occur due to compensatory anterior displacement of the tongue to prevent ventilation obstruction. This may decrease palatal support, disturbing the pressure balance of the maxillary molar region between the buccal and palatal sides and resulting in lateral undergrowth of the maxillary bone and narrowing of the maxillary dental arch.     

Reduction of sleep bruxism using a mandibular advancement device: an experimental controlled study

PURPOSE: The objective of this experimental study was to compare the effect on sleep bruxism and tooth-grinding activity of a double-arch temporary custom-fit mandibular advancement device (MAD) and a single maxillary occlusal splint (MOS). MATERIALS AND METHODS: Thirteen intense and frequent bruxors participated in this short-term randomized crossover controlled study. All polygraphic recordings and analyses were made in a sleep laboratory. The MOS was used as the active control condition and the MAD was used as the experimental treatment condition. Designed to temporarily manage snoring and sleep apnea, the MAD was used in 3 different configurations: (1) without the retention pin between the arches (full freedom of movement), (2) with the retention pin in a slightly advanced position (< 40%), and (3) with the retention pin in a more advanced position (> 75%) of the lower arch. Sleep variables, bruxism-related motor activity, and subjective reports (pain, comfort, oral salivation, and quality of sleep) were analyzed with analysis of variance and the Friedman test. RESULTS: A significant reduction in the number of sleep bruxism episodes per hour (decrease of 42%, P < .001) was observed with the MOS. Compared to the MOS, active MADs (with advancement) also revealed a significant reduction in sleep bruxism motor activity. However, 8 of 13 patients reported pain (localized on mandibular gums and/or anterior teeth) with active MADs. CONCLUSIONS: Short-term use of a temporary custom-fit MAD is associated with a remarkable reduction in sleep bruxism motor activity. To a smaller extent, the MOS also reduces sleep bruxism. However, the exact mechanism supporting this reduction remains to be explained. Hypotheses are oriented toward the following: dimension and configuration of the appliance, presence of pain, reduced freedom of movement, or change in the upper airway patency.     

A study on occlusal stability in shortened dental arches

PURPOSE: The aim of this study was to verify the hypothesis that shortened dental arches constitute a risk to occlusal stability. MATERIALS AND METHODS: Using cluster samples, 725 subjects with shortened dental arches comprising intact anterior regions and zero to eight occluding pairs of posterior teeth and 125 subjects with complete dental arches were selected. Subjects with shortened dental arches were classified into eight categories according to arch length and symmetry. Parameters for occlusal stability were interdental spacing, occlusal tooth wear, occlusal contact of incisors in intercuspal position, and vertical and horizontal overlap. Additionally, tooth mobility and overeruption of unopposed teeth were assessed. Influence of independent variables (dental arch category, age, gender, and residence) on the parameters for occlusal stability was assessed by one-way ANOVA and Tukey's multiple range tests. RESULTS: Extreme shortened dental arches (zero to two pairs of occluding premolars) had significantly more interdental spacing, occlusal contact of incisors, and vertical overlap compared to complete dental arches. Occlusal wear and prevalence of mobile teeth were highest in these categories. The category with three to four occluding premolars had significantly more interdental spacing and, for the older age group, more anterior teeth in occlusal contact compared to complete dental arches. Age was consistently associated with increased changes in occlusal integrity. CONCLUSION: Signs of increased risk to occlusal stability seemed to occur in extreme shortened dental arches, whereas no such evidence was found for intermediate categories of shortened dental arches.     

头位及体位对无鼾人群用力吸气流量的影响

目的 探讨无鼾人群的用力吸气流量（forced inspiratory airflow, FIF）是否受到头位及体位变化的影响,为阻塞性睡眠呼吸暂停综合征（obstructive sleep apnea syndrome, OSAS）患者的睡眠体位提供参考。方法 通过氧减饱和指数测量结果筛选出15名无鼾人群,在下颌正中位和下颌前伸位分别进行下列5种头位及体位的FIF测量：直立位、仰卧位、侧卧位、仰卧-头偏转位和俯卧-头偏转位。测量数据进行单因素方差分析和配对t检验,各项分析的检验水准均为α=0.05。结果 在下颌正中位和下颌前伸位,直立位均比其他4种头位及体位获得更高的FIF。在其他4种头位及体位中,仰卧-头偏转位可以得到相对较高的FIF。相同头位和体位下,下颌正中位和下颌前伸位的FIF没有统计学差异。结论 在无鼾人群的各种睡眠体位中,仰卧-头偏转位可以获得较高的FIF,改善气道通气,此头位和体位可以作为OSAS患者的参考睡眠体位。     

Fabrication of an Obstructive Sleep Apnea Prosthesis

Obstructive sleep apnea, a sleep disorder, is becoming more prevalent and requires prompt and effective treatment by the dental and medical specialties. Conservative treatment modalities (ie, intraoral devices that prevent or minimize airway obstruction by the tongue) are recommended for treating mild to moderate forms of OSA. This article describes a simplified technique for fabricating an intraoral OSA prosthesis.     

OSAS患者的颅面上气道结构的矢状面测量分析

目的:研究OSAS患者的颅面上气道形态异常,探讨OSAS患者的结构性致病因素。方法:31名男性OSAS患者与16名无自觉症状的男性组成的对照组进行颅面结构上气道的头影测量比较。结果:与对照组相比,OSAS患者存在ANB角大,颌凸角大,具有安氏II类骨型的趋势。表现出舌骨位置靠前,舌体长大,骨性鼻咽高度降低,软腭后间隙窄。结论:OSAS患者颅面形态倾向于安氏II类骨型,气道狭窄处在鼻咽、腭咽,说明结构性致病因素不容忽视。     

Facial morphology and obstructive sleep apnea

In a sample of 25 adult male subjects with moderate to severe obstructive sleep apnea, the interaction among craniofacial, airway, tongue, and hyoid variables was quantified by means of a canonical correlation analysis. One lateral cephalometric radiograph with the teeth in occlusion was obtained for each subject together with overnight polysomnographic measurements before the initiation of therapy. A principal component analysis reduced the data base and one significant canonical correlation (r1 = 0.994) was identified for the 22 variables. Sleep apnea subjects showed a posteriorly positioned maxilla and mandible, a steep occlusal plane, overerupted maxillary and mandibular teeth, proclined incisors, a steep mandibular plane, a large gonial angle, high upper and lower facial heights, and an anterior open bite in association with a long tongue and a posteriorly placed pharyngeal wall. A multivariate statistical analysis extracted clinically significant associations among craniofacial, tongue, and airway variables. Subjects with sleep apnea demonstrated several alterations in craniofacial form that may reduce the upper airway dimensions and subsequently impair upper airway stability.     

老年人动态咬合下的接触特征的初步研究

目的：通过研究老年人多种颌位的咬合观察及前伸咬合运动中前牙的接触模式与牙弓形状的关系,探讨老年人的动态咬合下的接触特征,为临床修复重建提供理论依据。方法：本研究共86例老年患者,通过口内视诊确定牙弓形态。采用厚度为8um的Bausch咬合测试膜检查下颌各个非正中颌位的接触：侧方移动至包括下颌0.5mm、尖对尖接触位置及前伸移动至前牙切对切接触位置。结果：下颌侧方移动至0.5mm时,30.2%受试者为双侧组牙功能,20.1%为混合尖牙保护和组牙功能。下颌侧方移动至尖对尖接触位置时,45.3%的受试者为双侧尖牙保护,17.4%为双侧组牙功能。下颌向前滑动至上、下前牙切对切接触位置时,80.2%的受试者前牙存在接触,后牙分离。前牙的牙合接触模式与牙列形状的关系：71.4%方圆型牙弓受试者是I型前牙接触模式;63.9%尖圆型牙弓受试者为II型前牙接触模式;对于卵圆型牙弓受试者,前牙接触模式I型和II型均占40%。结论：老年患者具有特殊的动态接触特征。前伸咬合运动中前牙的接触模式与牙弓形状关系密切,修复重建需要考虑这种关系。     

阻塞性睡眠呼吸暂停综合征矫治后的上气道磁共振影响改变

目的探讨阻塞性睡眠呼吸暂停综合征（ｏｂｓｔｒｕｃｔｉｖｅ ｓｌｅｅｐ ａｐｎｅａ ｓｙｎｄｒｏｍｅ，ＯＳＡＳ）患者戴用口腔矫治器后，其上气道磁共振（ｍａｇｎｅｔｉｃ ｒｅｓｏｎａｎｃｅ ｉｍａｇｉｎｇ，ＭＲＩ）影像发生的改变。方法 选择１１例有治疗前后多导睡眠图评价、磁共振影像资料完整的ＯＳＡＳ患者，用于研究矫治器对上气道的形态学改变；另选１１名性别、年龄配比的无睡眠呼吸障碍者，作为ＭＲＩ三维形态     

Dental appliances for the treatment of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a syndrome in which the airflow created from breathing ceases through the upper airway although diaphragm movement continues. Resulting complications include severe daytime sleepiness, morning headaches, loud snoring, and disturbed nighttime sleep. Patients affected with OSA are frequently hypertensive and can have dangerous cardiac arrhythmias. The diagnosis of OSA requires an all-night polysomnographic recording; neither snoring nor other subjective complaints constitute adequate criteria for treatment. The treatment objective for OSA is to maintain airway patency. A potential treatment discussed here is temporary advancement of the mandible or tongue during sleep with the use of dental appliances.     

Obstructive sleep apnea (OSA): a cephalometric analysis of severe and non-severe OSA patients. Part I: Multiple comparison of cephalometric variables

One hundred male obstructive sleep apnea (OSA) patients were classified into 2 groups, on the basis of Apnea-Hypopnea Index (AHI), as severe (AHI > or = 50) and non-severe (AHI < 50). A comprehensive cephalometric analysis of cervicocraniofacial skeletal morphology and upper airway soft tissue morphology was performed in 51 non-severe OSA patients, 49 severe OSA patients, and 36 controls with the purpose of examining the different features among these 3 groups. Sixty-eight cephalometric variables were compared among these 3 groups by 1-way analysis of variance with post hoc Bonferroni test. The results showed that both OSA groups had aberrations of cervicocraniofacial skeletal morphology and upper airway soft tissue morphology versus the controls. Severe OSA patients demonstrated increased maxillo-mandibular retrognathism, with a high mandibular plane angle resulting from increased anterior lower facial height and decreased posterior lower facial height, versus the non-severe OSA group. The craniocervical extension, forward head posture, inferiorly positioned hyoid bone, and the enlarged and elongated soft palate and upright tongue posture were more exaggerated as well. These findings imply that there should be different treatment regimens for the 2 subgroups of OSA patients to achieve treatment success. Cephalometric analysis is therefore highly recommended to verify the aberrant cervicocraniofacial morphology in severe and non-severe OSA patients.     

Cephalometric comparisons between Chinese and Caucasian patients with obstructive sleep apnea.

The purpose of this study was to compare two groups of adult men from different ethnic backgrounds and with obstructive sleep apnea; they were selected by matching age, gender, skeletal pattern, body mass index, and respiratory disturbance index. Pretreatment cephalometric radiographs and overnight polysomnograms of 30 Chinese and 43 Caucasian patients with Class II, Division 1 malocclusions were analyzed to investigate if there were craniofacial and upper airway structural differences between the two ethnic groups. The Chinese group, when compared with the group of Caucasian patients, revealed more severe underlying craniofacial skeletal discrepancies with significantly smaller maxilla and mandibles, more severe mandibular retrognathism, proclined lower incisors, increased total and upper facial heights, and steeper and shorter anterior cranial bases. However, no significant differences were found between the two groups in posterior facial height, ratio of upper to lower anterior facial height, and the position of hyoid bone, maxilla, and upper incisors. With regard to soft tissue and upper airway measurements, there were no significant ethnic differences in tongue and soft palate size, vertical length of oropharynx, and anteroposterior dimensions of the upper airway at most of the levels except for a larger super-posterior airway space, a larger nasopharynx and oropharynx cross-sectional area, and a smaller tongue height in the Chinese group. We conclude that there are a number of craniofacial and upper airway structures that differ between the two ethnic groups that may be relevant to the treatment of obstructive sleep apnea in various ethnic groups.     

A polysomnographic study on masticatory and tongue muscle activity during obstructive and central sleep apnea

Masticatory and tongue muscle activity was examined polysomnographically in 14 patients with sleep apnea syndrome and six snorers. The all‐night polysomnographic recordings included electromyograms (EMG) of the genioglossal, the masseter and the inferior head of the lateral pterygoid muscles, nasal airflow and thoracoabdominal respiratory effort. The apneas were defined and classified into three types (obstructive, central and mixed). EMG amplitudes of each muscle were measured before, during and after the obstructive and central apneas. In the apnea patients the three muscles showed significantly lower EMG amplitudes during the obstructive apnea than before the apnea, and then significantly higher amplitudes after the apnea. These findings indicate that the hypotonia of the muscles during sleep can result in obstructive apnea. There was no significant difference in the pattern of muscle activity during obstructive apnea between the apnea patients and the snorers. On the other hand, a decrease in the mean EMG amplitude during the central apnea was not observed. It is suggested that central apnea occurs independently of masticatory and tongue muscle activity.     

Changes of Hyoid,Tongue and Pharyngeal Airway after Mandibular Setback Surgery by Intraoral Vertical Ramus Osteotomy

Objective:To assess changes in hyoid, tongue, pharyngeal airway, and head posture in patients who had mandibular setback surgery by intraoral vertical ramus osteotomy (IVRO) and to investigate the influence of LeFort I osteotomy.Materials and Methods:Sixty patients with skeletal Class III malocclusion were evaluated. All patients had mandibular setback surgery via IVRO, and 45 patients had additional maxillary impaction surgery via LeFort I osteotomy. Lateral cephalograms were taken before, immediately after, approximately 1 month after, and at least 1 year after surgery. Parameters indicating the hyoid, tongue, pharyngeal airway, and head posture were evaluated.Results:The hyoid significantly moved inferoposteriorly immediately after surgery and relapsed superoanteriorly during observation periods. The tongue significantly moved posteriorly during all periods. The final position of the hyoid and tongue was significantly posterior, and the final pharyngeal airway was significantly narrower compared with its presurgical position. Significant cervical hyperflection occurred during observation periods and was strongly correlated with anterior movement of the hyoid. The hyoid and tongue showed similar positions regardless of the presence of different genders or LeFort I osteotomy after the long-term observation period.Conclusions:The hyoid and tongue moved posteriorly after mandibular setback surgery via IVRO, and there was a tendency to relapse back to its original position. However, the final pharyngeal airway width remained narrower after the long-term observation period. Based on our results, careful monitoring of the airway may be needed after mandibular setback surgery via IVRO.     

Further studies of the pressure from the tongue on the teeth in young adults.

The pressures from the tongue on the teeth were recorded simultaneously in four locations lingual to the upper and lower central incisors, and left first molars in 20 young adults with largely normal occlusion. Measurements in the rest position, and during chewing and swallowing were made with an extra-oral pressure transducer incorporated in a fluid-filled system with intra-oral mouthpieces. The size of the dental arches was determined from dental casts. The median pressures in the rest position were low and negative at the upper incisors. Negative pressures at rest were recorded in a few subjects at all four points of measurement, most frequently at the upper incisors and least frequently at the lower molar. The pressures during swallowing were 2-4 times greater than those during chewing. There were no significant correlations between the pressures found and those recorded in the same individuals at an examination 2 years earlier. Positive correlations were found between the pressures recorded in the four locations during the various functions. This was interpreted as being an effect of the size of the tongue. The relatively few correlations between the pressures and the parameters describing the dental arch size indicated an adaptive role of the tongue within the confines of the dental arches.     

Three-dimensional CT reconstructions of tongue and airway in adult subjects with obstructive sleep apnea

The interaction between airway and tongue structures in a sample of 25 adult men with obstructive sleep apnea was quantified on the basis of a series of preoperative CT slices obtained for each subject. Tracings were completed for tongue, and right and left nasal, nasopharynx, oropharynx, and hypopharynx structures; computer graphics were used to obtain superior and lateral three-dimensional reconstructions of all structures for each subject. In addition, cross-sectional areas of specific sites of airway constriction, surface area, volume, and ratio calculations were completed. The majority of the constrictions occurred in the oropharynx (0.52 +/- 0.18 cm2), but six subjects had two constrictions--one in the oropharynx and one in the hypopharynx. The airway had a mean volume of 13.89 +/- 5.33 cm3, whereas tongue volume ranged from 44.03 to 99.56 cm3 with a mean of 71.96 +/- 13.41 cm3. Subjects with more severe obstructive sleep apnea tended to have larger tongue and smaller airway volumes. The more obese subjects showed larger tongue surface areas and smaller airway surface areas. To determine the structural relationships between airway and tongue variables, a series of logarithmic plots was determined. An isometric relationship characterized tongue surface area and tongue volume. A logarithmic plot of oropharyngeal airway vs. tongue volume showed a negative allometric relationship. Tongue volume increased more rapidly than airway volume in subjects with obstructive sleep apnea. Subjects with large tongue volumes were observed to experience significant complications at the time of surgical treatment. Quantification of the volume of the oropharynx and its relationship to tongue volume provide an overview of the interaction between these structures.     

Effects of a mandibular repositioner on obstructive sleep apnea.

The purpose of this study was to investigate the effects of a mandibular repositioner on airway, sleep, and respiratory variables in patients with obstructive sleep apnea. Twenty-two patients selected for this study were confirmed with a diagnosis of obstructive sleep apnea based on initial nocturnal polysomnography. The patients were fitted with a mandibular repositioner designed to hold the mandible anteroinferiorly. Six months later, an outcome polysomnographic study was undertaken for each patient with the appliance in place. Lateral cephalometric radiographs in the upright position were also obtained before and after 6 months of treatment. The respiratory disturbance index decreased in 21 of the 22 patients with the appliance in place. The mean respiratory disturbance index of the 22 patients decreased significantly from 40.3 to 11.7 events per hour (P <.01). Some 59.1% of subjects were considered a treatment success with follow-up respiratory disturbance index < 10 events per hour. The mean minimum blood oxygen saturation level during sleep also improved significantly from 73.4% to 81.3% (P <. 01). The mandibular repositioner was constructed to position the mandible at 75% of the maximal mandibular advancement and with a 7 mm opening between the upper and lower incisors, and no aberrant effect on temporomandibular joint was noted. The retropalatal airway space increased and the cross-sectional area of the soft palate and the vertical distance of the hyoid bone to the mandibular plane decreased significantly. The tongue posture became significantly flatter. A significant linear correlation was found between the reduction in apnea index and specific craniofacial skeletal structures (length of anterior cranial base, mandibular plane angle, and upper to lower facial height ratios, P <.05). Subjects with a smaller reduction in apnea index tended to have shorter anterior cranial bases, steeper mandibular planes, and smaller upper to lower facial height ratios. We conclude that a mandibular repositioner may be an effective treatment alternative for obstructive sleep apnea and that a reduction in the frequency of apneic episodes is mainly attributed to the effects of the appliance on oropharyngeal structures.