Influences of head positions and bite opening on collapsibility of the passive pharynx

Isono, Shiroh; Tanaka, Atsuko; Tagaito, Yugo; Ishikawa, Teruhiko; Nishino, Takashi

doi:10.1152/japplphysiol.00907.2003

Cited by 128 publications

(99 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Mandibular advancement by an oral appliance in the present study had no effect on the volume of the upper airway soft tissues. Thus, quite apart from modulation of upper airway dilator muscle activity, we speculate that protrusion of the mandible itself acts to change the position and size of the bony enclosure, thereby reducing Ptissue in awake OSA patients as reported by Isono et al [17] when they succeeded in decreasing Ptissue in the passive pharynx in patients with OSA. This speculation is also supported by a recent animal study in which mandibular advancement reduced the anterior and lateral soft tissue pressure in anesthetized rabbits [18].…”

Section: Discussionmentioning

confidence: 54%

Functional contribution of mandibular advancement to awake upper airway patency in obstructive sleep apnea

Tsuiki¹,

Ryan²,

Lowe

et al. 2007

Sleep Breath

View full text Add to dashboard Cite

In the narrowed upper airway of patients with obstructive sleep apnea (OSA), a neuromuscular compensatory mechanism augments the activity of the upper airway dilator muscles in defense of upper airway patency, particularly during inspiration. We hypothesized that mechanical enlargement of the upper airway by a mandibular advancement oral appliance would permit a reduction in this neuromuscular compensation during wakefulness. To test this hypothesis, we focused on changes in the cross-sectional (CS) area of the upper airway before and after emplacement of a ventrally titrated oral appliance in 12 awake OSA patients. The CS areas at the end of tidal expiration (CS area-EET) and at the nadir of intraluminal pressure during inspiration (CS area-IN) were obtained using videoendoscopy. The median apnea-hypopnea index decreased with mandibular advancement. Before mandibular advancement, there was no difference between CS area-EET and CS area-IN in the velopharynx, oropharynx, and hypopharynx. This indicates that upper airway dilator muscle activity increased during inspiration to counteract the intraluminal negative pressure of the upper airway. After mandibular advancement, CS area-EET increased in the velopharynx, oropharynx, and hypopharynx, but CS area-IN was unchanged at any level and was less than CS area-EET in the velopharynx and oropharynx. These findings suggest that mandibular advancement enlarges the upper airway and may reduce upper airway dilator muscle activity during inspiration. We conclude that oral appliances act to return the upper airway towards a normal configuration and pattern of muscle function in OSA patients.

show abstract

Section: Discussionmentioning

confidence: 54%

Functional contribution of mandibular advancement to awake upper airway patency in obstructive sleep apnea

Tsuiki¹,

Ryan²,

Lowe

et al. 2007

Sleep Breath

View full text Add to dashboard Cite

show abstract

“…Moreover, patients identified as higher risk secondary to muscle weakness can be selected for further individualized assessments with the aim of safe and adequate nutrition. 50 The additional assessments may involve bedside FEES or radiological evaluations, to assist in deciding which interventions are most appropriate, and may include: direct exercises (practicing correct swallows with food boluses), indirect exercises (strengthening neuromotor controls and the swallowing process without food), 50,51 rehabilitative measures such as swallow therapy, 52 and dietary modifications specific to the patient's swallowing ability. 50,53 Muscle strength is not the only factor leading to proper swallowing.…”

Section: Critical Care Medicinementioning

confidence: 99%

Muscle Weakness Predicts Pharyngeal Dysfunction and Symptomatic Aspiration in Long-term Ventilated Patients

et al. 2013

View full text Add to dashboard Cite

Background: Prolonged mechanical ventilation is associated with muscle weakness, pharyngeal dysfunction, and symptomatic aspiration. The authors hypothesized that muscle strength measurements can be used to predict pharyngeal dysfunction (endoscopic evaluation-primary hypothesis), as well as symptomatic aspiration occurring during a 3-month follow-up period. Methods: Thirty long-term ventilated patients admitted in two intensive care units at Massachusetts General Hospital were included. The authors conducted a fiberoptic endoscopic evaluation of swallowing and measured muscle strength using medical research council score within 24 h of each fiberoptic endoscopic evaluation of swallowing. A medical research council score less than 48 was considered clinically meaningful muscle weakness. A retrospective chart review was conducted to identify symptomatic aspiration events.Results: Muscle weakness predicted pharyngeal dysfunction, defined as either valleculae and pyriform sinus residue scale of more than 1, or penetration aspiration scale of more than 1. Area under the curve of the receiver-operating curves for muscle strength (medical research council score) to predict pharyngeal, valleculae, and pyriform sinus residue scale of more than 1, penetration aspiration scale of more than 1, and symptomatic aspiration were 0.77 (95% CI, 0.63-0.97; P = 0.012), 0.79 (95% CI, 0.56-1; P = 0.02), and 0.74 (95% CI, 0.56-0.93; P = 0.02), respectively. Seventy percent of patients with muscle weakness showed symptomatic aspiration events. Muscle weakness was associated with an almost 10-fold increase in the symptomatic aspiration risk (odds ratio = 9.8; 95% CI, 1.6-60; P = 0.009). Conclusion: In critically ill patients, muscle weakness is an independent predictor of pharyngeal dysfunction and symptomatic aspiration. Manual muscle strength testing may help identify patients at risk of symptomatic aspiration.

show abstract

“…In the anatomical balance theory, the skeletal tissues form a "rigid box," and the upper airway can be regarded as a "collapsible tube" encircled by soft tissue including the adeontonsillar tissue and tongue within the rigid box. 26,27 The cross-sectional area of the tube, which reflects upper airway patency, depends on the amount of soft tissue relative to the skeletal size. [28][29][30] AT can be successful when the upper airway is narrowed only by a hypertrophic adenoid and palatine tonsil (Figure 3A and 3B).…”

Section: Discussionmentioning

confidence: 99%

Craniofacial Contribution to Residual Obstructive Sleep Apnea after Adenotonsillectomy in Children: A Preliminary Study

Maeda

Tsuiki

Nakata

et al. 2014

Journal of Clinical Sleep Medicine

View full text Add to dashboard Cite

). Written informed consent was obtained from each participant after the aim and potential risks were fully explained.The Japanese patients enrolled in this study were diagnosed as having OSA based on the following criteria: (1) an apnea hypopnea index (AHI) ≥ 1 (/h) on overnight polysomnogram Study Objectives: Pediatric obstructive sleep apnea (OSA) is frequently associated with adenotonsillar hypertrophy, and the fact that about 30% of affected children continue to show OSA after adenotonsillectomy (AT) suggests the presence of some other predisposing factor(s). We hypothesized that abnormal maxillofacial morphology may be a predisposing factor for residual OSA in pediatric patients. Methods: A total of 13 pediatric OSA patients (9 boys and 4 girls, age [median (interquartile range)] = 4.7 (4.0, 6.4) y, body mass index (BMI) z score = -0.3 (-0.8, 0.5)) who had undergone AT were recruited for this study. Maxillomandibular size was measured using an upright lateral cephalogram, and correlations between size and the apnea hypopnea index (AHI) values obtained before (pre AT AHI) and about 6 months after AT (post AT AHI) were analyzed.Results: AHI decreased from 12.3 (8.9, 26.5)/h to 3.0 (1.5, 4.6)/h after AT (p < 0.05). Residual OSA was seen in 11 of the 13 patients (84.6%) and their AHI after AT was 3.1 (2.7, 4.7)/h. The mandible was smaller than the Japanese standard value, and a signifi cant negative correlation was seen between maxillomandibular size and post AT AHI (p < 0.05). Conclusions: These fi ndings suggest that the persistence of OSA after AT may be partly due to the smaller sizes of the mandible in pediatric patients. We propose that the maxillomandibular morphology should be carefully examined when a treatment plan is developed for OSA children. Keywords: obstructive sleep apnea, pediatric, small mandible Citation: Maeda K, Tsuiki S, Nakata S, Suzuki K, Itoh E, Inoue Y. Craniofacial contribution to residual obstructive sleep apnea after adenotonsillectomy in children: a preliminary study. J Clin Sleep Med 2014;10(9):973-977. S C I E N T I F I C I N V E S T I G A T I O N ST he prevalence of obstructive sleep apnea (OSA) in children has been estimated to be 1% to 3%, 1,2 and unstable sleep brought about by this disorder may cause decreased neurocognitive performance and behavioral impairments, both of which may lead to degraded school performance.3-8 Most cases of OSA in children have been believed to be associated with adenotonsillar hypertrophy, and adenotonsillectomy (AT) has been widely accepted as the fi rst choice of treatment. However, many reports have suggested that 20% to 40% of pediatric OSA patients continue to show OSA after AT. [9][10][11][12] This phenomenon implies that other predisposing factors may be present in patients with pediatric OSA.An abnormality of the maxillofacial morphology, especially small mandibular size relative to oropharyngeal soft tissue, has been revealed to play an important role in the development of OSA in adults. 13 Similarly, a small mandible has been reported...

show abstract

Influences of head positions and bite opening on collapsibility of the passive pharynx

Cited by 128 publications

References 24 publications

Functional contribution of mandibular advancement to awake upper airway patency in obstructive sleep apnea

Functional contribution of mandibular advancement to awake upper airway patency in obstructive sleep apnea

Muscle Weakness Predicts Pharyngeal Dysfunction and Symptomatic Aspiration in Long-term Ventilated Patients

Craniofacial Contribution to Residual Obstructive Sleep Apnea after Adenotonsillectomy in Children: A Preliminary Study

Contact Info

Product

Resources

About