Relationship between pharyngeal airway depth and ventilation condition in mandibular setback surgery: A computational fluid dynamics study

Shirazawa, Yoshito; Iwasaki, Tomonori; Ooi, Kazuhiro; Kobayashi, Yutaka; Yanagisawa‐Minami, Ayaka; Oku, Youichirou; Yokura, Anna; Ban, Yuusuke; Suga, Hokuto; Kawashiri, Shin‐ya; Yamasaki, Yuichi

doi:10.1111/ocr.12371

Cited by 15 publications

(14 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mandibular setback causes the compression of the pharyngeal airway space, thus increasing airflow velocity, which reaches its peak value in the narrow oropharyngeal area. [30,31] In the present study, although the procedure achieved considerable mandibular setback in all the patients, the increase in the airflow velocity (12%) was not noticeable.…”

Section: Discussioncontrasting

confidence: 52%

Changes in Tongue Area, Pharyngeal Area, and Pharyngeal Airway Velocity after Correction of Mandibular Prognathism

Chen

Chou

et al. 2021

JCM

View full text Add to dashboard Cite

This study aimed to investigate the correlation between the amount of mandibular setback, and the related changes of the tongue area, pharyngeal area, and pharyngeal airflow velocity. Twenty-five patients treated for mandibular prognathism, and serial cephalograms were obtained (T1: preoperation, T2: more than one year postoperation). The postoperative area of the tongue, pharyngeal airway space, and pharyngeal airflow velocity were investigated. Statistical analysis was performed with the Student t-test and Pearson correlation. The amount of mandible setback was significant after surgery (12.8 mm; p < 0.001). The pharyngeal area was significantly reduced 115.5 mm2 (p = 0.046). There was a slight reduction of the tongue area (43.2 mm2; p = 0.305) and an increase of pharyngeal airflow velocity (0.3 m/s; p = 0.133). The Pearson correlation coefficient test showed no statistical significance among the amount of horizontal setback and vertical movement of the mandible, such as the reductions in the tongue area, the pharyngeal airway space, and the increase in pharyngeal airflow velocity. Larger amounts of mandibular setback caused a significant reduction of pharyngeal airway area, but without significant changes of the tongue area and pharyngeal airflow velocity.

show abstract

Section: Discussioncontrasting

confidence: 52%

Changes in Tongue Area, Pharyngeal Area, and Pharyngeal Airway Velocity after Correction of Mandibular Prognathism

Chen

Chou

et al. 2021

JCM

View full text Add to dashboard Cite

show abstract

“…19 Relationships between constricted pharyngeal airway cross sections and negative pharyngeal airway pressure were reported to show the inversely proportional relationship, similar to the earlier study. 20,21 Previous studies reported negative pressure increases when cross sections of the pharyngeal airway were 100 mm 2 or less. 20,21 In our study, a change of pressure was measured at 50 mm 2 or less.…”

Section: Discussionmentioning

confidence: 99%

“…20,21 Previous studies reported negative pressure increases when cross sections of the pharyngeal airway were 100 mm 2 or less. 20,21 In our study, a change of pressure was measured at 50 mm 2 or less. Because our patients were children (mean age 6.6 years old), this discrepancy may be due to the smaller size of the pharyngeal airway and a subsequent change in flow rate.…”

Section: Discussionmentioning

confidence: 99%

“…This study determined that the relationship between CSA and pressure was similar to that in previous studies. 20,21 When CSA min was 30 mm 2 or less, the pharyngeal airway exhibited increased negative pressure, and collapse of the pharyngeal airway was expected due to muscle relaxation. Previous studies showed that CSA in children with OSA is small.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of adenoids and tonsil tissue on pediatric obstructive sleep apnea severity determined by computational fluid dynamics

Iwasaki

Sugiyama

Yanagisawa‐Minami

et al. 2020

Journal of Clinical Sleep Medicine

Self Cite

View full text Add to dashboard Cite

Study Objectives: Obstructive sleep apnea (OSA) is a respiratory disorder caused by the obstruction of the upper airway during sleep. The most common cause of pediatric OSA is adenotonsillar hypertrophy. Adenotonsillectomy is the first-line treatment for pediatric OSA; however, OSA persists in a significant number of patients due, in part, to the method of evaluating enlarged adenoids and tonsil tissue. The reason for these effects on OSA severity is not clear. This study aimed to establish a method to diagnose the need for adenoidectomy or tonsillectomy. Methods: Twenty-seven Japanese children (mean age 6.6 years) participated in this study, undergoing polysomnography and computed tomography examination. Pharyngeal airway morphology (adenoids and tonsil tissue size, volume, and cross-sectional area [CSA]) and pressure on the upper airway were evaluated at each site using computational fluid dynamic analysis. Results: Apnea-hypopnea index (AHI) showed a strong linear association with maximum negative pressure (P max ) (AHI = −0.055* events/h P max −1.326, R 2 = .805). The relationship between minimum CSA (CSA min ) and P max was represented by an inversely proportional fitted curve (P max = −4797/CSA min −5.1, R 2 = .507). The relationship between CSA min and AHI was also represented by an inversely proportional fitted curve (AHI = 301.6 events/h/CSA min 1.22 , R 2 = .680). P max greatly increased if CSA min became ≤ 30 mm 2 . The negative pressure of each site increased when CSA measured ≤ 50 mm 2 . Conclusions: In children, when the CSA for each site is ≤ 50 mm 2 , AHI is likely to be elevated, and the patient may require tonsillectomy or adenoidectomy.

show abstract

“…Computational fluid dynamics CFD analysis evaluates upper airway disorders and evaluates both the morphology and airway ventilation status in contrast to computed tomography CT that can only evaluate the morphology 1 . Many studies have described the use of CFD analysis for examining patients with obstructive sleep apnea syndrome OSAS and skeletal malocclusion; however, few reports have performed a quantitative evaluation of the pressure and velocity [2][3][4][5] . Studies show CFD analysis has been used to examine the nasal airway for nasal septal perforation 6,7 and the effect of surgical effects on simulation 8,9 , however, all these studies enrolled healthy adults.…”

Section: Introductionmentioning

confidence: 99%

Computational fluid dynamics analysis in patients with nasal disease

Masuda¹,

Ishizaki²,

Hirano

et al. 2021

Showa Univ J Med Sci

Self Cite

View full text Add to dashboard Cite

Computational fluid dynamics (CFD) analysis is useful for quantitative assessment in patients with upper airway obstructions. We compared CFD analysis with rhinomanometry (RM) and acoustic rhinometry (AR) . Twenty patients with nasal and paranasal diseases who required computed tomography assessment underwent RM and AR. We measured the pressure and velocity at four parts of the upper airway using CFD analysis. Then we evaluated the correlation among CFD analysis, RM, and AR. CFD analysis detected obstruction sites in the nasal airway and pharynx in 14 and 2 patients, respectively. High negative pressure accompanied the nasal obstruction, even behind the nasal cavity. Nasal airway pressure measured using CFD analysis strongly correlated with nasal resistance in RM (Spearman correlation coefficient ＝ 0.853) . CFD analysisʼs sensitivity and specificity to detect the obstruction were 84.6％ and 57.1％, respectively (compared to those of RM) and 83.3％ and 50.0％, respectively (compared to those of AR) . The CFD analysisʼs ability to detect obstruction was comparable to that of RM and AR; therefore, it may help evaluate the upper airways in patients with nasal and paranasal diseases. We found impaired nasal ventilation also affected other parts of the upper airway. Further studies with a larger sample size are required to validate the use of CFD analysis for assessing the degree of upper airway ventilation disorders.

show abstract

Relationship between pharyngeal airway depth and ventilation condition in mandibular setback surgery: A computational fluid dynamics study

Cited by 15 publications

References 33 publications

Changes in Tongue Area, Pharyngeal Area, and Pharyngeal Airway Velocity after Correction of Mandibular Prognathism

Changes in Tongue Area, Pharyngeal Area, and Pharyngeal Airway Velocity after Correction of Mandibular Prognathism

Effect of adenoids and tonsil tissue on pediatric obstructive sleep apnea severity determined by computational fluid dynamics

Computational fluid dynamics analysis in patients with nasal disease

Contact Info

Product

Resources

About