Mean Pharyngeal Area Research Articles

Effect of Mandibular Advancement Surgery on Tongue Length and Height and Its Correlation with Upper Airway Dimensions.

The spatial position and dimensions of oral and pharyngeal soft tissues change post-mandibular advancement (MA) surgery which involves changes in position of soft palate, tongue and associated musculature. There is no study which simultaneously evaluates changes in tongue length and height post-MA surgery and correlates these changes with changes in upper airway dimensions and the amount of MA. Treatment records of 18 patients that underwent MA with bilateral sagittal split ramus osteotomy were evaluated at T1 (01week before surgery) and T2 (06months post-surgery). Linear airway and tongue measurements were done on lateral cephalogram. Mean volume and mean pharyngeal area values were recorded from the acoustic pharyngometry (AP) records of patients. A statistically significant increase in tongue length (P value < 0.001) and nonsignificant change in tongue height were observed at T2 (P value > 0.05). A statistically significant increase in airway parameters recorded on both lateral cephalogram and AP was observed at T2 (P value < 0.001). Correlation analysis did not show a statistically significant correlation of change in tongue length and tongue height at T2 with the amount of MA, change in airway parameters on lateral cephalogram and AP (P value > 0.05). Mandibular advancement surgery is a viable option for improvement in pharyngeal airway in skeletal Class II patients with retrognathic mandible. Changes in tongue length observed in our study may correspond to the stretch of protruders of tongue, especially genioglossus, and may point toward possible relapse on a long-term follow-up.

The utility of acoustic pharyngometry and rhinometry in pediatric obstructive sleep apnea syndrome

ObjectiveOur objective was to evaluate the usefulness of acoustic pharyngometry and rhinometry in assessing obstructive sleep apnea (OSA) syndrome in children. Patients/MethodsPatients who were hospitalized for polysomnography underwent acoustic pharyngometry and rhinometry in sitting and supine positions to measure anatomical (pharyngeal and nasopharyngeal) volumes and collapsibility characteristics (reduction of pharyngeal volume, estimated pharyngeal compliance, and reduction of nasopharyngeal volume). ResultsIn this study, we prospectively enrolled 103 children (median age, 10.4 years; 47 girls). Measures obtained from rhinometry correlated with height and were further height-normalized whereas measures obtained from pharyngometry did not correlate with height. Sleep apnea was ruled out in 51 subjects, while 52 children fulfilled OSA criteria (35 with obstructive apnea-hypopnea index ≥ 2 and < 5.h−1 [mild] and 17 with an index ≥ 5). The three groups differed on the z-score of BMI, the reduction of pharyngeal volume when supine, the estimated pharyngeal compliance and the supine normalized nasopharyngeal volume. These four factors linearly correlated with the apnea index even though children without OSA and mild OSA were found to be similar overall. A multivariate analysis with apnea index as the dependent variable and BMI z-score, neck circumference, mean pharyngeal area in supine position, estimated pharyngeal compliance and normalized nasopharyngeal volume as independent variables, showed that only BMI z-score and estimated compliance remained independent predictors of obstructive apnea (r2 value = 0.25, p < 0.0001). ConclusionAn increase in pharyngeal compliance is an independent risk factor of OSA syndrome in children; it can be measured using acoustic pharyngometry while awake.

Altered pharyngeal structure and dynamics among patients with cervical kyphosis.

Deformities of the anterior cervical spine are an established cause of dysphagia. Whereas osteophytes and spinal fusion hardware have been reported to alter bolus flow and contribute to swallowing dysfunction, the relationship between abnormal spine curvature and swallowing dysfunction is not established. The purpose of this investigation was to evaluate the association between cervical kyphosis and objective measures of swallowing dysfunction on videofluoroscopy. Case-control study of patients presenting to tertiary dysphagia center. All videofluoroscopic swallow studies (VFSS) performed at our institution, between August 1, 2014, and August 1, 2015, were retrospectively reviewed to identify patients with abnormal cervical kyphosis, according to Cobb and Jackson angle measurements. Patients with kyphosis were age- and gender-matched to persons without kyphosis. VFSS and demographic parameters were collected and compared between groups. Thirty-six patients with cervical kyphosis exceeding two standard deviations (SD) beyond established age-specific normal ranges were identified. The mean age of the entire cohort was 61.6 (SD ±19.1) years. Mean pharyngeal area was 3.34 cm2 greater in kyphosis patients compared to controls (95% confidence interval [CI]: 0.47-5.21 cm2 ; P = .0007). This was associated with increased hypopharyngeal transit time (0.57 seconds, 95% CI: 0.045-1.09 seconds, P = .034), and higher prevalence of penetration (P = .014). There was no significant difference in the pharyngeal constriction ratio (PCR), a surrogate measure of pharyngeal strength (P = .83). Patients with cervical spine kyphosis have a significantly dilated pharynx (P = .0007), elongated hypopharyngeal transit time (P = .034), and worsened penetration aspiration scores (P = .021). Absence of a difference in PCR suggests adequate compensation as a group. 3b. Laryngoscope, 127:1832-1837, 2017.

Short- and long-term effects of CPAP on upper airway anatomy and collapsibility in OSAH

In obstructive sleep apnea hypopnea (OSAH) patients, an increase of upper airway (UA) collapsibility has been described together with a reduced UA caliber due to inflammation, edema, and fat accumulation in pharyngeal walls. CPAP is the main treatment of OSAH and acts mechanically by increasing pressure inside UA. The aim of this study was to assess the short- and long-term effects of CPAP on UA caliber and collapsibility in severe OSAH patients. Ten obese patients (nine male, age 55+/- 9 yr, BMI 35.1 +/- 6.1, Epworth sleepiness scale 12.3 +/- 3.6 point, AHI 58.8 +/- 27.1) had measurements of oropharingeal junction area (OPJ), mean pharyngeal area (APmean), maximal pharyngeal area (APmax) by acoustic pharyngometry and determination of expired volume in the first 0.5 s after the application at the mouth of -5 cmH(2)O negative expiratory pressure (V,NEP(0.5)) during wakefulness in the supine position under basal conditions (baseline) and after 1 week and 6 months of CPAP treatment. OPJ was 0.74 +/- 0.28 cm(2) at baseline, 0.90 +/- 0.24 cm(2) after 1 week and 1.05 +/- 0.31 cm(2) after 6 months (1 week and 6 months vs baseline p < 0.05). APmax was 2.28 +/- 0.74 cm(2) at baseline, 2.79 +/- 0.90 cm(2) after 1 week and 2.94 +/- 0.33 cm(2) after 6 months (1 week and 6 months vs baseline p < 0.05). APmean was 1.43 +/- 0.46 cm(2) at baseline, 1.82 +/- 0.45 cm(2) after 1 week and 1.94 +/- 0.35 cm(2) after 6 months (1 week vs baseline p < 0.01; 6 months vs baseline; p < 0.05). V,NEP(0.5) was 290 +/- 73 mL at baseline, 291 +/- 65 mL after 1 week and 338 +/- 67 mL after 6 months (6 months vs baseline p < 0.05; 1 week vs 6 months p < 0.01). Our data suggest that CPAP treatment might be effective in OSAH patients not only by causing a mechanical splint of UA but also by inducing an improvement on anatomical (early) and functional (later on) aspects of UA that can be observed during wakefulness.

Upper airway size is related to obesity and body fat distribution in women

The aim of this study is to analyze the relationships between obesity, fat distribution and pharyngeal transversal area in women. Cross-sectional areas of the pharynx at the oro-pharyngeal junction and at the glottis and mean pharyngeal area were measured by acoustic pharyngometry in 145 women (age 42.9 +/- 15.1 years; range 14-82 years). Body weight, waist, hip and neck circumferences, and sagittal abdominal diameter (SAD) were determined. Pharyngeal area at the oro-pharyngeal junction, measured both in orthostatic and in lying position, was negatively related to BMI, waist, hip and SAD. Mean pharyngeal area was negatively related to BMI and to SAD only in orthostatic position. No significant correlations were found between pharyngeal areas at the glottis and any anthropometric measurements. In multiple regression analysis, only SAD retained independent relationship with pharyngeal area at the level of the oro-pharyngeal junction in both the positions and with mean pharyngeal area in the orthostatic position. We demonstrated an inverse association between upper airways size and both adiposity and visceral fat distribution in women.

Acoustic pharyngometry patterns of snoring and obstructive sleep apnea patients

Objective Anatomic narrowing of the pharyngeal airway increases the relative negative pressure generated during inspiration, thus affecting the dynamic behavior of the upper airway. The aim of this work was to measure pharyngeal area in snoring patients with and without obstructive sleep apnea (OSA), as categorized by polysomnography and by acoustic pharyngometry, and to analyze the different curve patterns obtained from patients of both groups. Methods We examined 50 snorers who were divided into 2 groups matched for age, gender, and body mass index. Results Mean Apnea Index (AI) in nonapneic snorers (group 1) was 4, and mean pharyngeal area was 2.41 cm 2. In snoring patients with OSA (group 2), mean AI was 25.9 with a mean pharyngeal area of 1.589 cm 2 ( P < 0.001). In both groups, the dependent variable (AI) can be predicted from a linear relation with the independent variable (pharyngeal area) with normality and constant variance tests passed. In group 1, the resulting curve can be 1 of 2 types depending on the relative area of the pharyngeal segment to the velopharyngeal area. In group 2, the curve pattern can be categorized into 3 patterns depending on the possible pathology of pharyngeal obstruction. Conclusion The acoustic reflection technique is reproducible, noninvasive, and free from potential side effects. The good correlation between AI and pharyngeal area adds to the potential of acoustic pharyngometry. Careful study of the pharyngeal cross-sectional area and curve topography may give a good idea about the site of upper airway obstruction.

Lung volume dependence of pharyngeal cross-sectional area by acoustic pharyngometry.

Pharyngeal size and the dynamic behavior of the pharynx may be important factors in the modulation of pharyngeal airflow. There are two measures of pharyngeal function: changes in pharyngeal area with lung volume and changes in pharyngeal area in response to externally applied positive pressure. Both measurements have been used for the assessment of pharyngeal function, and both reflect pharyngeal "floppiness." The aim of the present study was to examine the relationship between pharyngeal cross-sectional area, using acoustic reflection technique, and different lung volumes (tidal volume, inspiratory reserve volume, and expiratory reserve volume), to determine whether there are differences in mechanical properties of the pharynx of normal volunteers in response to changes in intrapharyngeal pressure. The acoustic technique was used to assess the pharyngeal cross-sectional area of 40 healthy volunteers (29 men and 11 women) at tidal volume, inspiratory reserve volume, and expiratory reserve volume. In men, the mean pharyngeal area at tidal volume was 3.191 cm2, the mean pharyngeal area at inspiratory reserve volume was 2.976 cm2, and the mean pharyngeal area at expiratory reserve volume was 2.975 cm2. In women, the corresponding pharyngeal area measurements were 2.832, 2.484, and 2.492 cm2. Statistical analysis of results showed that men have a larger pharyngeal cross-sectional area and the pharyngeal airways of men and women act in a similar manner in response to changes in intrapharyngeal pressure, with men having a greater change. Examination of the pharyngeal compliance by acoustic pharyngometry adds to the potential of this technique as a tool for the evaluation of the pharyngeal airway in terms of area and dynamic behavior assessment. This may be of relevance in promotion of the development of upper airway assessment in patients with obstructive sleep apnea.

Normal standard curve for acoustic pharyngometry

Pharyngeal size, compliance, and the dynamic behavior of the upper airway are important factors in the production of obstructive sleep apnea. Assessment of the upper airway for possible site(s) of obstruction is one of the keys to a successful management of the condition. Acoustic pharyngometry has the potential for localizing such sites, however, standardizing the operating technique and producing a standard normal curve is a prerequisite before exploring the potential of this equipment. A total number of 350 normal volunteers (271 males and 79 females) were examined by acoustic pharyngometry and a coefficient of variance of 5% to 7% was obtained from each of them. Mean and standard deviation of pharyngeal area at each point of X-axis (distance) was obtained and analyzed statistically to produce a general standard curve. Using special techniques during examination, the oropharyngeal junction and glottis were located, and thus a mapped acoustic pharyngogram was produced. Mean pharyngeal area was 3.194 cm 2 in males (SD 0.311) and 2.814 cm 2 in females (SD 0.331). Mean glottic area was 1.06 cm 2 in males (SD 0.119) and 0.936 cm 2 in females (SD 0.108). A minimal pharyngeal area is probably needed as a “golden standard” to evaluate patients with obstructive sleep apnea. (Otolaryngol Head Neck Surg 2001;124:323-30.)

Reproducibility of measurements of upper airway area by acoustic reflection

To evaluate the extent and nature of the variability of measurements of upper airway area by acoustic reflection (AAAR), we made repeated measures of pharyngeal AAAR in 10 normal adult volunteers. We selected mean pharyngeal area as a better index of upper airway size than peak pharyngeal area or pharyngeal volume. Within-run variability of this measure was 8 +/- 4% (SD) (coeff of variation). This variability could not be explained by changes in lung volume or differences in phase of respiration. Five subjects had tracheal and pharyngeal area measured by using both the custom-made wax mouthpiece (W) and a commercial rubber pulmonary function mouthpiece (R). Reproducibility of pharyngeal AAAR was within 10% (coeff of variation) using R, but measurements of pharyngeal AAAR varied with the different types of mouthpiece, as W/R ranged from 0.72 to 1.70. In contrast, measurements of midtracheal area were similar for both mouthpiece types [mean W/R = 0.97 +/- 14 (SD)]. The acoustic reflection technique yields a reproducible index of pharyngeal size that does not vary with phase of respiration or modest changes in lung volume. Either W or R may be used to make clinical measurements, but the type of mouthpiece should be consistent and specified.

Effect of mouthpiece, noseclips, and head position on airway area measured by acoustic reflections.

To investigate whether it is possible to simplify the methodology of measuring airway area by acoustic reflections, we measured upper airway area in 10 healthy subjects during tidal breathing according to seven different protocols. Three protocols employed custom-made bulky mouthpiece with or without nose-clips, two protocols used a scuba-diving mouthpiece and cotton balls placed in the nostrils instead of noseclips, and two protocols employed neck flexion and extension. We found no significant difference in average pharyngeal, glottic, and tracheal areas for any of the protocols except for neck flexion, which was associated with a significantly lower mean pharyngeal area. Intraindividual variabilities were comparable for all protocols, except for protocol employing the customary bulky mouthpiece and no noseclips, which consistently resulted in the most variable measurements of area for all three airway segments: pharynx, glottis, and trachea. Furthermore, we found that the protocol employing the scuba-diving mouthpiece with or without cotton balls in the nostrils resulted in the lowest number of unacceptable measurements. We conclude that measurements of airway area by acoustic reflections may be further simplified by using a scuba-diving mouthpiece without noseclips; furthermore, control of head position during measurements is not critical provided there is no obvious neck flexion.