Nasopharyngeal Obstruction Research Articles

Pathophysiology of dorsal displacement of the soft palate in horses.

Dorsal displacement of the soft palate (DDSP) is an intermittent obstructive upper airway condition that occurs in athletic horses during high-intensity exercise. The pathogenesis of this condition is unknown, but may involve epiglottic hypoplasia, malformation, or neuromuscular dysfunction. In this paper, we report on investigations into the pathophysiology of DDSP. In 3 separate experiments, Standardbred horses were exercised on a high-speed treadmill at speeds corresponding to 50, 75 and 100% of maximum heart rate. The upper airway was evaluated by videoendoscopy and measurement of tracheal pressures. In experiment 1, we examined the effect of bilateral hypoglossal and glossopharyngeal nerve block on epiglottic function in exercising horses. This nerve block caused epiglottic retroversion and inspiratory upper airway obstruction. However, DDSP did not occur. In experiment 2, we evaluated the hypothesis that tensor veli palatini muscle dysfunction is involved in the pathogenesis of DDSP. Bilateral tensor veli palatini muscle tenectomy did not cause DDSP, but caused instability of the rostral half of the soft palate and a modest inspiratory upper airway obstruction. In experiment 3, we hypothesised that palatinus and palatopharyngeal dysfunction causes DDSP. The pharyngeal branch of the vagus nerve was blocked bilaterally in the guttural pouch. This block caused DDSP in all horses within 2-15 min after nerve block. Furthermore, DDSP created an expiratory nasopharyngeal obstruction. Because the pharyngeal branch of the vagus nerve is in close proximity to the retropharyngeal lymph node chain, we suggest that retropharyngeal lymphadenopathy may cause neural dysfunction and thereby be involved in the pathogenesis of clinical DDSP.

Radiographic evaluation of children with nasopharyngeal obstruction due to the adenoid.

The adenoidal-nasopharyngeal ratio (ANR) was proposed as a convenient and practical method to evaluate adenoidal enlargement. We analyzed cephalometric radiographs of 150 children divided into 6 subgroups according to clinical assessment (possible adenoidectomy candidates [PACs] and controls) and age. Our purpose was to investigate the predictive reliability of different ANRs calculated on the same reference line. Each of the ANRs described in this study presented statistically significant differences between PACs and control groups, and highly significant correlations with clinical symptoms of nasal obstruction. Further, the mean adenoidal depth was significantly larger in PACs than in normals, and it was found that the adenoidal depth in PACs did not show a significant decrement with age. in contrast to normals. On the other hand, although nasopharyngeal depth was not different between PACs and normals, an age-dependent increment was observed in PACs, in contrast to normals. Thus, it could be said that the ANR is a more reliable method for determining whether adenoidal hyperplasia is clinically significant or not, rather than the size of the adenoid or nasopharynx.

Effect of adenoid hyperplasia on nasal airflow

Adenoid hyperplasia is one of the most common reasons for nasal obstruction in childhood. The consequences of a nasopharyngeal obstruction on the airflow in the nasal cavity and the epipharynx were investigated. In a model of a nose we conducted experiments with adenoids of different size, documenting their influence on inspiratory and expiratory nasal flow. Rhinoresistometry was performed to obtain further information concerning resistance and turbulence. The flow experiments showed no alterations of the inspiratory nasal flow regardless of adenoid size. Instead the adenoid had a significant influence on the direction of the expiratory nasal flow in the cavity. Depending on the extension of the hyperplasia, parts of the nasal cavity were excluded from the flow. Rhinoresistometry showed that relation between nasopharyngeal obstruction and nasal resistance was nonlinear. Adenoid hyperplasia affects only expiratory nasal flow. In our model a critical mass seemed to be reached in case of more than 60% nasopharyngeal obstruction. A narrowing of the epipharynx up to 50% of its volume has no significant effects on nasal resistance.

Influences of nasal respiratory obstruction on craniofacial growth in young Macaca fuscata monkeys

This study was conducted to investigate the influences of artificial nasal respiratory obstruction on craniofacial growth in young Macaca fuscata monkeys. Eleven monkeys were used; seven monkeys served as the experimental animals and the remaining four as the control animals. Further, the experimental animals were divided into light and heavy obstruction groups. Nasal respiratory obstruction was created by injecting dental impression material into the nasopharyngeal region. Nasal respiratory function was evaluated in terms of nasal airway resistance. Craniofacial structure in the experimental monkeys was compared with the control animals by means of cephalometric analysis. Nasopharyngeal respiratory obstruction was associated with downward and backward rotation of the mandible, upward and backward growth of the condyle, divergent gonial angle, anterior open bite, and spaced dental arch in the lower anterior region. These changes were significantly greater in the experimental monkeys with heavy respiratory obstruction. The current findings support the hypothesis that nasal obstruction existing before and during pubertal growth may result in permanent craniofacial deformities pertinent to skeletal open bite. (Am J Orthod Dentofac Orthop 1997;111:38-43.)

Assessment of the infant airway with videorecorded flexible laryngoscopy and the objective analysis of vocal fold abduction

Accurate diagnosis of upper airway abnormalities by flexible laryngoscopy in infants is hampered by rapid laryngeal motion and lack of patient cooperation. This study evaluates the added role of videorecorded flexible laryngoscopy and the objective measurement of vocal fold abduction in improving the diagnosis of upper airway abnormalities in infants. Seventy-eight infants had videorecorded flexible laryngoscopy performed as part of their evaluation of a suspected airway disorder. These recordings were reviewed by three otolaryngologists for confirmation of the clinical diagnosis. From the video image, the maximum angle of vocal fold abduction was measured with image analysis software. Of 78 patients 40 had supraglottic or glottic abnormalities, 9 had nasal or nasopharyngeal obstruction, 9 had subglottic abnormalities (diagnosed subsequent to videolaryngoscopy), and 15 patients had normal findings on examination. Of those with laryngeal abnormalities, laryngomalacia was the most common diagnosis (23 of 78). Vocal fold paralysis was present in 4 patients. A separate group (9 of 78) of patients was identified as having symmetric bilateral limitation of vocal fold abduction. Laryngeal dyskinesia was diagnosed in these 9 patients. The mean values of maximal vocal fold abduction were as follows: (1) normals, 59.5 degrees; (2) laryngomalacia, 57.0 degrees; (3) paralysis, 26.6 degrees; and (4) incomplete abduction with laryngeal dyskinesia, 27.6 degrees. Videolaryngoscopy is a valuable tool for documentation, parent education, and analysis of infant laryngeal abnormalities. Repeat viewing of the video examination and frame-by-frame analysis improve the diagnostic accuracy. Using this approach, we have calculated the anterior glottic abduction angle in the normal and abnormal infant larynx. In addition, we have identified a group of infants with incomplete abduction of the vocal folds that appears to be different from that found in vocal cord paralysis. (Otolaryngol Head Neck Surg 1996;114:554-61.)

Assessment of the infant airway with videorecorded flexible laryngoscopy and the objective analysis of vocal fold abduction.

Accurate diagnosis of upper airway abnormalities by flexible laryngoscopy in infants is hampered by rapid laryngeal motion and lack of patient cooperation. This study evaluates the added role of videorecorded flexible laryngoscopy and the objective measurement of vocal fold abduction in improving the diagnosis of upper airway abnormalities in infants. Seventy-eight infants had videorecorded flexible laryngoscopy performed as part of their evaluation of a suspected airway disorder. These recordings were reviewed by three otolaryngologists for confirmation of the clinical diagnosis. From the video image, the maximum angle of vocal fold abduction was measured with image analysis software. Of 78 patients 40 had supraglottic or glottic abnormalities, 9 had nasal or nasopharyngeal obstruction, 9 had subglottic abnormalities (diagnosed subsequent to videolaryngoscopy), and 15 patients had normal findings on examination. Of those with laryngeal abnormalities, laryngomalacia was the most common diagnosis (23 of 78). Vocal fold paralysis was present in 4 patients. A separate group (9 of 78) of patients was identified as having symmetric bilateral limitation of vocal fold abduction. Laryngeal dyskinesia was diagnosed in these 9 patients. The mean values of maximal vocal fold abduction were as follows: (1) normals, 59.5 degrees; (2) laryngomalacia, 57.0 degrees; (3) paralysis, 26.6 degrees; and (4) incomplete abduction with laryngeal dyskinesia, 27.6 degrees. Videolaryngoscopy is a valuable tool for documentation, parent education, and analysis of infant laryngeal abnormalities. Repeat viewing of the video examination and frame-by-frame analysis improve the diagnostic accuracy. Using this approach, we have calculated the anterior glottic abduction angle in the normal and abnormal infant larynx. In addition, we have identified a group of infants with incomplete abduction of the vocal folds that appears to be different from that found in vocal cord paralysis.

Sleeping positions and dental arch dimensions in children with suspected obstructive sleep apnea syndrome.

The present paper analyzed the association between children's sleeping positions and dental arch morphology. The sleeping patterns of 27 children, aged 3 to 10 yr, suspected of having the obstructive sleep apnea syndrome (OSAS) were studied by polysomnography (PSG) and videotape recordings under laboratory conditions. The PSG recordings were used to calculate the apnea index (AI) and the relative time spent sleeping on the back, and the videotapes to categorize distinctly different sleep and head postures. Plaster casts were made for the assessment of dental arch morphology. Sleeping predominantly on one's back, was associated with a reduced maxillary intercanine width, while prolonged head extension during sleep correlated inversely with the overjet. The subjects with the highest AI scores (> 4) had larger dental arches. We suggest that sleeping on the back causes a more posterior tongue position, reducing its moulding effect on the anterior dental arch. As nasopharyngeal airway obstruction in OSAS-patients might trigger an anterior tongue position to secure a free airway passage, there will be increased lingual pressure on the dental arches, leading to their dimensional increase.

咽頭扁桃肥大による成人OSAS症例

Surgical treatment using Nd-YAG laser was performed on a 39-year-old man with sleep apnea syndrome (OSAS). According to the results of sleep study, the apnea index and the lowest Sa02 indicated severe OSAS. Radical examination, including MRI, showed that the obstructed region in the respiratory system was mainly in the nasopharynx, not the mesopharynx, and that a hypertrophic pharyngeal tonsil caused the obstruction in the nasopharynx. It is thought that the cases of OSAS involving nasopharyngeal obstruction due to a hypertrophic pharyngeal tonsil are common in children but rare in adults. Resection of the hypertrophic tissue was performed using an Nd-YAG laser at the midsection of the soft palate.Tracheostomy was also performed. The symptoms and results of sleep study were remarkably improved post-operatively, and the decrement in the region of obstruction was confirmed by a radiological analysis. The results showed that surgical resection of the pharyngeal tonsil using a laser is an effective and safe methods of treating OSAS in adults.

Sleep apnea and sleep-related breathing disorders in patients with craniofacial synostosis.

Seventeen patients with craniofacial synostosis (CFS) have been treated at the Department of Plastic and Reconstructive Surgery at Osaka Medical College during the past 10 years. Six patients were thoroughly evaluated at the Department of Otolaryngology by polysomnography (PSG), cephalometric X-ray and nasopharyngoscopy during sleep. In 4 of the patients PSG showed obstructive sleep apnea syndromes (OSAS). Heavy snoring without apnea and paradoxical respiration were noted in the other 2 patients. Thus, all of the patients had sleep-related breathing disorders (SRBD). It is assumed that the incidence of SRBD in CFS is high. Cephalometric analysis and profilogram showed maxillomandibular hypoplasia in each patient, and it was assumed that the main cause of SRBD in CFS was stenosis of the upper airway tract caused by maxillo-mandibular hypoplasia. Nasopharyngoscopy was performed during sleep in 2 patients with OSAS secondary to CFS. One patient with adenotonsillar hypertrophy had nasopharyngeal obstruction and another patient whose posterior airway space (PAS) on cephalometric radiograph was 3 mm (normal value: 11 mm) had obstruction at the tongue base.

Quantitative bacterial culture from adenoid lymphatic tissue with special reference to Haemophilus [corrected

Homogenized adenoid tissue from 55 children (28-153 months) undergoing adenoidectomy because of nasopharyngeal obstruction was investigated by means of quantitative aerobic bacterial culture. The children were divided into two groups, the hypertrophy alone group--AH (n = 29)--and the hypertrophy with longstanding secretory otitis media group--SOM (n = 26). A nasopharyngeal culture was obtained preoperatively from 38 of the cases. Non-typeable H. influenzae (NTHI) was found in twice as many cases in the AH group as in the SOM group, 21/29 (72%) compared to 11/26 (42%) (p < 0.05) and in a significantly higher mean concentrations, 5.7 x 10(5) CFU/g compared to 1.9 x 10(5) CFU/g (p = 0.02). For the other aerobic potentially pathogenic bacteria no such difference was found. The bulk of the NTHI-positive cases and the cases with the highest concentrations were found in the children below the age of 6 years. In the nasopharyngeal cultures NTHI alone or together with S. pneumoniae and/or B. catarrhalis was found in 29% of the cases in both the AH group and SOM group. NTHI was found in only 50% of the nasopharyngeal cultures corresponding to a positive quantitative culture (10/20). These findings suggest that NTHI is harboured within the adenoid and could thereby chronically stimulate the local immune defense. However, the present study indicates that there is no aerobic bacterial overload in the adenoid tissue in children with SOM compared to children without middle-ear disease.

Lateral Cervical Radiographs and Adenoid Size: Do They Correlate?

Clinicians have questioned the value of lateral soft tissue neck x-ray (LSTN) in assessing adenoid size. Elaborate cephalometric assays have been devised to measure degree of nasopharyngeal obstruction secondary to adenoid hypertrophy. This study prospectively studied 73 children, aged 11 months to 13 years, with clinical evidence of adenoid hypertrophy to assess how well a LSTN correlates with direct intraoperative observation of adenoid size and nasopharyngeal obstruction. We found a relatively weak correlation (Pearson coefficient r = 0.34) between x-ray and operative observations. We conclude that LSTN is an appropriate examination in the preoperative assessment of children being considered for adenoidectomy. However, this test must be interpreted by recognizing the inherent limitations of evaluating a dynamic structure, such as the nasopharynx, through a non-dynamic modality.

Mandibular and maxillary growth after changed mode of breathing

The amount of maxillary and mandibular growth and the direction of maxillary growth were studied in 38 children during the 5 years after adenoidectomy for correction of severe nasopharyngeal obstruction. The amount of mandibular growth measured between successive gnathion points on superimposed radiographs was significantly greater in the group who had an adenoidectomy than in the matched controls. In the boys the difference was 3.8 mm ( p < 0.001), and in the girls the difference was 2.5 mm ( p < 0.01). The boys also showed a tendency toward greater growth in the maxilla as measured between successive subnasal points (1.2 mm, p < 0.05). We detected no difference in the direction of maxillary growth between who had undergone adenoidectomy and the controls. (A M J O RTHOD D ENTOFAC O RTHOP 1991;100:1-18.)

Effect of enlarged adenoids on arterial blood gases in children

The enlarged adenoid is a common disorder in children resulting in nasopharyngeal obstruction. Many authors suggest that increased nasal resistance to respiration may cause disturbances in the pulmonary ventilation and carry the risk of obstructive sleep apnoea and/or cardiopulmonary syndrome. This study comprised 30 children complaining of long-standing nasal obstruction due to enlarged adenoids. Adenoidectomy was performed and the arterial blood gases were measured before and one month after surgery. Twelve normal children were also included as controls. Statistical evaluation of the results showed that O2 saturation and arterial O2 tension (PaO2) were significantly low before the operation, and increased significantly after surgery. Arterial CO2 tension (PaCO2) was insignificantly low before operation, but decreased significantly after adenoidectomy. It was concluded that enlarged adenoid may be associated with ventilatory impairment which is reversible after adenoidectomy.

EFFECT OF GENERAL ANAESTHESIA ON THE PHARYNX

Conventional lateral radiography was used in 18 elderly male patients to investigate the changes induced by general anaesthesia in the upper airway. The effect of tongue traction under anaesthesia was studied similarly in another 11 patients. Following induction of anaesthesia, there were highly significant approximations to the posterior pharyngeal wall of the soft palate (median change 1.3 mm, 95% confidence interval (Cl) 0.3-2.6 mm; P = 0.006), tongue base (mean change 6.5 mm, 95% Cl 5.3-7.7 mm; P less than 0.001) and epiglottis (mean change 3.8 mm, 95% Cl 3.1-4.5 mm; P less than 0.001). Apparent radiographic occlusion of the airway occurred most consistently at the level of the soft palate (17 of 18 patients), sometimes at the level of the epiglottis (four patients), but the tongue base did not touch the posterior pharyngeal wall in any patient. Traction on the tongue failed to clear the nasopharyngeal obstruction. Attempted inspiration under anaesthesia caused major secondary collapse of the pharynx, with multiple sites of obstruction, similar to that found in obstructive sleep apnoea.

Nasopharyngeal Obstruction

The causes of nasopharyngeal obstruction are described. The diagnosis and treatment of each type of nasopharyngeal obstruction are presented in detail.

Retronasopharyngeal Lipoma: A Case Report

We present an unusual and challenging case of impending upper airway obstruction in a pediatric patient that resulted from a benign disease process. Although rare, a lipoma should be considered in the differential diagnosis of nasopharyngeal obstruction. When a nasopharyngeal lipoma is discovered, radiologic and histopathologic studies should be performed to rule out an aggressive lipoma, such as an infiltrating (intramuscular) lipoma or angiolipoma. The use of CT scanning or magnetic resonance imaging is invaluable in diagnosis, evaluation of extent of disease, adn management of this condition. Close followup is imperative.

The Effect of Mouth Breathing Due to Nasopharyngeal Obstruction by Adenoids on the Tongue, Mandible and Hyoid Bone Position

This study was made to investigate the influence of mouth breathing to tongue, mandible and hyoid bone position. It has been clinically suggested that the mouth breathing is induced by the respiratory dysfunction of nasopharyngeal airway causing by the Adenoids. The author used the 50 children, who were the nasal breathes with normal occlusion as the control group, and 50 children, who were mouth breathers with Adenoid as the experimental group. Results were as following: 1. In experimental group, the tongue was positioned more anterior and lower than that of the normal children. 2. In experimental group, the mandible was positioned more lower than that of the normal children. 3. In experimental group, the hyoid bone was positioned more anterior and lower than that of the normal children.

Craniofacial muscular adaptation in response to nasopharyngeal obstruction: An electromyographic analysis: H. Dixon Taylor IIIUniversin, of Tennessee, Memphis, 1985

Craniofacial muscular adaptation in response to nasopharyngeal obstruction: An electromyographic analysis: H. Dixon Taylor IIIUniversin, of Tennessee, Memphis, 1985

Mandibular growth direction following adenoidectomy

The purpose of this article is to test the hypothesis that the establishment of nasal respiration in children with severe nasopharyngeal obstruction can be eliminated as a factor in determining mandibular growth direction. The article describes the changes in mandibular growth direction (MGD) in a 5-year period after adenoidectomies and the establishment of nasal breathing in a population of Swedish children. Measurements of mandibular growth directions were obtained from serial cephalometric radiographs after adenoidectomies in 38 Swedish children aged 7 to 12 years with previous nasopharyngeal obstructions. These were compared with the growth directions in a control sample of 37 Swedish children with clear airways and matched for age and sex. The adenoidectomy sample initially showed significantly longer lower face heights, steeper mandibular plane angles, and more retrognathic mandibles than the matched controls. Analysis showed that during the 5 years after adenoidectomies, the girls had a more horizontal MGD (P < 0.02) than did the female controls. A corresponding but not significant trend was found for the boys. The individual growth directions that were obtained following adenoidectomies were more variable than those found in the controls.

Aerodynamic assessment of the results of pharyngeal flap surgery: a preliminary investigation.

Voice-quality (i.e., nasality) judgments are commonly used to evaluate the results of pharyngeal flap surgery. However, these are subjective judgments of questionable validity and reliability. This project was designed to systematically evaluate the outcome of pharyngeal flap surgery utilizing objective, quantifiable physiologic (pressure-flow) information. Thirty-one patients who had undergone pharyngeal flap surgery were selected. Pressure-flow measurements and perceptual judgments of speech were obtained following surgery. Results indicated that using pressure-flow criteria, only 52 percent of the outcomes were considered successful. Results also indicated that 35 percent of the cases were characterized by substantial nasopharyngeal airway obstruction. In the present study, these findings, along with the related perceptual phenomenon of denasality, were considered unsuccessful. Finally, results suggest that aerodynamic measurements can be used to assess other surgical techniques designed to correct velopharyngeal insufficiency.