Nasal Airway Dimensions Research Articles

Evaluation of nasal septal deviation and maxillary bone and nasal airway dimensions and volumes using cone-beam computed tomography in patients with unilateral palatal canine displacement: a retrospective study.

To detect any association between palatally displaced canine (PDC) and nasal septal deviation (NSD), palatal bone thickness and volume, and nasal airway dimensions and volume. A total of 92 patients were included and subdivided into two groups: group 1, unilateral PDCs (44 patients), and group 2, normally erupted canines (NDCs) (48 subjects). The following variables were measured using cone-beam computed tomography: presence and type of NSD, nasal width, inferior conchae, hard palate and nasal septum thickness, maxillary bone and nasal airway volumes. NSD was detected in 77% and 50% of PDC and NDC subjects, respectively. Within the PDC subjects, significant differences between the displaced and nondisplaced sides were detected. Palate thickness was increased in the canine region and reduced in the molar region. Compared with the control group, PDC subjects had reduced palate thickness and lower nasal airway volume. Two predictors were significant for predicting the odds of PDC occurrence: NSD and maxillary bone volume. NSD is more frequent in PDC subjects. PDC subjects have reduced palate thickness and decreased nasal airway volume. In the presence of NSD, the odds of developing PDC increase by 3.35 times, and for each one-unit increase in the maxillary bone volume, the odds of developing PDC decrease by 20%.

Peak Nasal Inspiratory Flow (PNIF) for Nasal Breathing Evaluation.

Measuring nasal airflow and nasal breathing has been a major goal of rhinology. Many objective methods for measuring nasal airflow or nasal airway resistance or dimensions provide valuable data but are time-consuming and require expensive equipment and trained technicians, thus making these methods less practical for clinical practice. Peak nasal inspiratory flow (PNIF) measurement is fast, unexpensive, noninvasive, and able to provide an objective evaluation of nasal airflow in real-time. Unilateral PNIF measurements allow separated evaluation of each side of the nasal airway and may prove particularly useful when clinical assessment detects significant asymmetry between both nasal cavities.PNIF measurements are most useful for assessing changes in nasal airflow achieved by any form of therapy, including surgical treatment of the nasal airway. These measurements generally correlate with other objective methods for nasal airway evaluation, but not unequivocally with patient-reported evaluation of nasal breathing. Nevertheless, as low PNIF values prevent the sensation of a suitable nasal breathing, PNIF measurement may also prove useful to optimize the decision of how to best address patients with complaints of nasal airway obstruction.

Overview of Nasal Airway and Nasal Breathing Evaluation.

Several methods are available for evaluating nasal breathing and nasal airflow, as this evaluation may be made from several different perspectives.Physiologic methods for nasal airway evaluation directly measure nasal airflow or nasal airway resistance, while anatomical methods measure nasal airway dimensions. Subjective methods evaluate nasal breathing through several validated patient-reported scales assessing nasal breathing. Computational fluid dynamics evaluates nasal airflow through the analysis of several physics' variables of the nasal airway.Being familiar to these methods is of utmost importance for the nasal surgeon to be able to understand data provided by the different methods and to be able to choose the combination of evaluation methods that will provide the information most relevant to each clinical situation.

Algorithm for Nasal Breathing Impairment Evaluation.

Assessing patients with complaints of nasal obstruction has traditionally been done by evaluation of the nasal airway looking for fixed or dynamic obstructive locations that could impair nasal airflow. Not infrequently, however, symptoms of nasal obstruction do not match the clinical examination of the nasal airway. Addressing this subset of patients may be a challenge to the surgeon. Evaluation of patients with symptoms of nasal obstruction should include a combination of a patient-reported assessment of nasal breathing and at least one objective method for measuring nasal airflow or nasal airway resistance or dimensions. This will allow distinction between patients with symptoms of nasal obstruction and low airflow or high nasal airway resistance and patients with similar symptoms but whose objective evaluation demonstrates normal nasal airflow or normal airway dimensions or resistance. Patients with low nasal airflow or high nasal airway resistance will require treatment to increase nasal airflow as a necessary step to improve symptoms, whereas patients with normal nasal airflow or nasal airway resistance will require a multidimensional assessment looking for less obvious causes of impaired nasal breathing sensation.

Which Nasal Airway Dimensions Correlate with Nasal Airflow and with Nasal Breathing Sensation?

Background: Rhinoplasty modifies the nasal pyramid, thereby also modifying the nasal airway. Objectives: To correlate the sensation of nasal breathing, as measured by patient-reported outcome measures, and nasal airflow, as assessed by peak nasal inspiratory flow (PNIF), with nasal airway dimensions, as measured on computed tomography (CT) images. Methods: Fifty Caucasian patients were studied through visual analogue scale (VAS), nasal obstruction symptom evaluation (NOSE) and PNIF. Measurements of the nasal airway were made on CT images: minimal distance between septum and inferior and middle turbinates, nasal valve angle, and nasal valve area. Results: There was a significant association between PNIF and nasal valve area, between VAS and the narrower nasal valve angle and between NOSE and minimal distance between septum and middle turbinate of the narrower side. Conclusions: This study suggests that the dimensions of the nasal valve and of the middle nasal airway have a substantial impact on nasal breathing capacity. It also highlights the importance of unilateral nasal airway obstruction to nasal breathing.

Evaluation of treatment changes with rapid maxillary expansion using computed tomography scan: A comprehensive review

The aim of the study was to review in detail, the skeletal, dental and soft-tissue effects of Rapid Maxillary Expansion in young group of patients using Computed Tomographic Scan. The review is conducted through an electronic and manual searches which includes PubMed, Ovid, Cochrane, and Web of Science using the keywords. Searches includes the original studies which were conducted from the January 2000 to May 2020 amongst patients from 6 to 18 years using Hyrax, Haas-type and butterfly-type expanders. Based on the inclusion criteria, 23 relevant articles containing 298 patients were selected to evaluate changes related to skeletal, dental, soft-tissues and airway by assessing Computed Tomography scan. Significant effects have been observed at the mid-palatal suture due to the separation of two hemi-maxillae that led to an increase in the palatal volume, maxillary arch perimeter and correction of posterior crossbite. Changes were also recorded at the circum-maxillary sutures with maximum effects noted in internasal and nasomaxillary sutures. Other observations includes dental changes like buccal tipping of the maxillary posterior anchored teeth, increase in nasal and upper airway dimensions. Few side-effects of Rapid Maxillary Expansion includes recession of alveolar bone and dehiscence in cases of excessive dental tipping, dorsal hump on the nose with flattening of the nasal tip. Interpreting the outcomes with Computed Tomography scan strengthen the orthodontist’s precision in determining the 3-dimension effects with greater specificity. However, more number of Computed Tomography studies on soft-tissue changes and airway effects are required to understand comprehensive mechanics of the procedure.

Does Presurgical Nasoalveolar Molding Have a Long-Term Effect on Nasal and Upper Airway Dimensions?

To compare nasal and upper airway dimensions in patients with cleft lip and palate (CLP) who underwent nasoalveolar molding (NAM) with those without NAM during infancy using acoustic pharyngometry and rhinometry. Eccovision acoustic pharyngometry and rhinometry (Sleep Group Solutions) was used for assessment of mean area and volume of nasal and upper airway in patients with complete unilateral CLP (age range 16-21 years) treated with NAM (group 1, n = 19) versus without NAM (group 2, n = 22). The mean nasal cross-sectional areas and volume were higher in group 1 compared to group 2 on both cleft (P value <.001) and noncleft side (P value >.05). The mean area and volume of upper airway were also significantly higher in group 1 compared to group 2 (P value <.05). Nasoalveolar molding being one of the first interventions in chronology of treatment of patients with CLP, its long-term outcome on nasal and upper airway patency needs to be ascertained. The results of the present study show that the patients with CLP who have undergone NAM during infancy have better improvement in nasal and upper airway patency compared with those who had not undergone NAM procedure. The basic advantages of being noninvasive, nonionizing and providing dynamic assessment of nasal and upper airway patency make acoustic pharyngometry and rhinometry a diagnostic tool of choice to be used in patients with CLP.

Correlations to Estimate the Key Anatomical Dimensions of Pediatric Nasal Airways using Minimally Invasive Measurements of Intranasal Pressure Gradient.

Background: Understanding the morphology of nasal airways is important in determining the nasal airway deposition of inhaled aerosol. Moreover, objective assessment of the anatomy of human nasal airways is useful to develop a database of reference or normal values as a resource to investigate anatomical abnormalities of airways. Current methods for the objective assessment of the nasal airways are either limited to very few dimensions or can only be performed by specialized researchers. Thus, the main objective of this study was to determine the correlations between the intranasal pressure gradient (Δp) and the key anatomical dimensions of the pediatric nasal airways, which could in turn allow the extrapolation of nasal airway morphology based on simple minimally invasive measurements of pressure. Methods: The anatomical data and Δp were obtained from in vitro studies with nasal airway models of 11 infants ages 3-18 months and 13 children ages 4-14 years old. Key anatomical dimensions were identified based on both rhinology and aerosol dosimetry literature. These anatomic data, including the volume, V, surface area, As, length, L, and the minimum cross-sectional area of the replicas, Amin, were then analyzed for correlation with Δp and flow parameters, using Bernoulli's principle and dimensional analysis. Results: Strong correlations were found between Δp and As/L for children, and between Δp and V/As for infants. Additional pressure gradient correlations were developed with Amin, V/As, , and L. Conclusions: The correlations identified between anatomic data and Δp have clinical implications in pediatric rhinology, suggesting that certain aspects of airway anatomy in infants and children can be predicted through the measurement of Δp. The airway dimensions, predicted using Δp measurement, may be used in tandem with aerosol nasal deposition correlations that account for nasal airway dimensions.

Effects of maxillary expansion on the upper airways: Evidence from systematic reviews and meta-analyses.

Constricted maxilla is frequently associated with reduced nasal airway dimensions. Wheatear skeletal maxillary expansion (ME) is effective on the dimension of the upper airways is still a debated issue. This overview aimed to report the evidence provided by systematic reviews (SRs) on the effect of ME on the upper airways and to assess the methodological quality of the included SRs. Six electronic databases have been explored up to November 2017. After title and abstract screening, SRs addressing the effects of fixed palatal expanders on the dimension and function of the nasal airways were included. The methodological quality of the included SRs was assessed using the updated version of A Measurement Tool to Assess Systematic Review (AMSTAR-2). Eight SRs were included. The methodological quality of most of the included SRs ranged between low and critically low. One SR was rated of high quality. A significant increase in nasal linear dimensions was reported both in the short and long term, but supported by low-/critically low-quality SRs. The significant increase in nasal cavity volume was the only outcome supported by a high-quality SR Controversial results were found with regards to nasal function. Whenever a constricted maxilla is present general dentists, paediatricians and ENTs should be familiar with the potential improvement provided by ME. However, due to the low/critically low quality of SRs supporting these results, ME cannot be indicated only for upper airways enhancement, but should be supported by an orthodontic indication.

In Vitro Assessment of Spray Deposition Patterns in a Pediatric (12Year-Old) Nasal Cavity Model.

Nasal sprays available for the treatment of cold and allergy symptoms currently use identical formulations and devices for adults as well as for children. Due to the obvious differences between the nasal airway dimensions of a child and those of an adult, the performance of nasal sprays in children was evaluated. Deposition patterns of nasal sprays administered to children were tested using a nasal cast based on MRI images obtained from a 12year old child's nasal cavity. Test formulations emitting a range of spray patterns were investigated by actuating the device into the pediatric nasal cast under controlled conditions. The results showed that the nasal sprays impacted in the anterior region of the 12year old child's nasal cavity, and only limited spray entered the turbinate region - the effect site for most topical drugs and the primary absorptive region for systemically absorbed drugs. Differences in deposition patterns following the administration of nasal sprays to adults and children may lead to differences in efficacy between these populations. Greater anterior deposition in children may result in decreased effectiveness, greater anterior dosage form loss, and the increased potential for patient non-compliance.

Comparison of craniodentofacial morphology of children with and without unilateral cleft lip and palate

Background: This retrospective case-control study was done to investigate the cranio-dento-facial morphology of Turkish children with unilateral complete cleft lip and palate from Ege University and compare them with a normal group to highlight the effect of surgical correction on craniofacial development. Methods: 60 patients with unilateral complete cleft lip and palate were compared with 55 control children without cleft at mean ages of 13 and 15 years. The cleft lip was operated with modified Millard technique at 3 months, cleft palate was operated with von Langenbeck technique at 12 months. The patients were not given any orthopaedic or orthodontic treatment also. Angular and linear measurements of cranio-dento-facial complex were measured by using Dolphin Imaging 11.5 software programme, and the resulting data were evaluated statistically. Results: The children with unilateral complete cleft lip and palate had considerable morphological deviations when compared with the matched children without clefts. The most striking findings in the unilateral complete cleft lip and palate group: Maxillary and mandibular complex and nasal projections were retruded when compared with normal (P<0.001). Also, nasal airway dimensions were higher in control group (P<0.001). Soft tissue structure, especially upper lip thickness, upper and lower lip lengths were decreased (P<0.001, P<0.001, P<0.05, respectively) in cleft group. Maxillar anterior height was decreased (P<0.001). Besides, nasolabial angle and upper incisor inclination according to the maxillary occlusal plane (P<0.001) were increased while overjet (Mx1-Md1) were decreased (P<0.001). Conclusion: The surgical technique and the number of operations seem to be the most effective factors for maxillary retrusion in patients with unilateral complete cleft lip and palate.

Ecogeographic variation across morphofunctional units of the human nose.

Although the internal nose is overwhelmingly responsible for heat and moisture exchange during respiration, external nasal morphology is more commonly cited as evincing climatic adaptation in humans. Here, we assess variation across all four morphofunctional units of the complete nasorespiratory tract (external pyramid, nasal aperture, internal nasal fossa, and nasopharynx) to determine which units provide the strongest evidence of climatic adaptation. We employ 20 linear measurements collected on 837 modern human crania from major geographic (Arctic Circle, Asia, Australia, Europe, Africa) and climatic (polar, temperate, hot-arid, tropical) zones. In conjunction with associated climatic and geographic data, these morphological data are employed in multivariate analyses to evaluate the associations between each of these functional nasal units and climate. The external pyramid and nasopharynx exhibit virtually no evidence of climate-mediated morphology across the regional samples, while apparent associations between climate and nasal aperture morphology appear influenced by the geographic (and likely genetic) proximities of certain populations. Only the internal nasal fossa exhibits an ecogeographic distribution consistent with climatic adaptation, with crania from colder and/or drier environments displaying internal nasal fossae that are longer, taller, and narrower (especially superiorly) compared to those from hotter and more humid environments. Our study indicates that the internal nasal fossa exhibits a stronger association with climate compared to other aspects of the human nose. Further, our study supports suggestions that regional variation in internal nasal fossa morphology reflects demands for heat and moisture exchange via adjustment of internal nasal airway dimensions. Our study thus provides empirical support for theoretical assertions related to nasorespiratory function, with important implications for understanding human nasal evolution.

Nasal Airway Dimensions of Children With Repaired Unilateral Cleft Lip and Palate.

To measure cross-sectional areas of the main nasal constrictions as a function of the distance into the nose in children with repaired unilateral cleft lip and palate, as compared with children without cleft, by acoustic rhinometry. Prospective analysis. Craniofacial anomalies hospital. A total of 39 children with repaired unilateral cleft lip and palate and 34 healthy controls without cleft, of both genders, aged 6 to 9 years. Interventions/Variables : Nasal cross-sectional areas measured at the three main deflections of the rhinogram (CSA1, CSA2, CSA3) and distances from the nares (dCSA1, dCSA2, dCSA3) were assessed by means of an Eccovision Acoustic Rhinometer, before and after nasal decongestion. Differences were analyzed at a significance level of 5%. At the cleft side, mean CSA1, CSA2, and CSA3 values ± standard deviation obtained before nasal decongestion were 0.17 ± 0.12, 0.29 ± 0.20, and 0.40 ± 0.28 cm(2), respectively, and dCSA1, dCSA2, and dCSA3 values ± standard deviation were 2.02 ± 0.40, 3.74 ± 0.51, and 5.50 ± 0.44 cm, respectively. At the noncleft side, these were 0.33 ± 0.11, 0.65 ± 0.28, and 0.90 ± 0.43 cm(2), respectively, and 1.69 ± 0.48, 3.67 ± 0.53, and 5.60 ± 0.70 cm, respectively. Increased cross-sectional area means were seen after nasal decongestion in the control and cleft groups. Mean cross-sectional area values at the cleft side were significantly smaller than noncleft side and control values, and the mean dCSA1 value was smaller at the noncleft side before and after decongestion. Objective assessment of internal nasal dimensions has shown that children with unilateral cleft lip and palate have a significant impairment of nasal patency due to the reduced cross-sectional areas seen at the cleft side.

Orthodontic widening of the palate may provide a cure for selected children with therapy‐resistant enuresis

According to a number of small case series, orthodontic treatment may have anti-enuretic effects. Thus, we evaluated whether widening of the palate can alleviate enuresis and whether prognostic information can be gained from examining children's nocturnal respiration and nasal airway dimensions. Children with therapy-resistant enuresis underwent polysomnography, focusing on nocturnal respiration, and had their nasal airways examined. Rapid maxillary expansion was performed, widening the maxilla by approximately 0.5 cm. The dental appliance was removed after 6 months. Enuresis frequency was evaluated four times: at baseline, with the orthodontic apparatus in situ, after completed maxillary expansion and 1 year post-treatment. Of the 34 children recruited, one dropped out due to oral discomfort. The numbers of wet nights per week on the four assessment occasions were 5.48 ± 1.48, 5.12 ± 1.73, 3.09 ± 2.49 and 2.63 ± 2.81; p < 0.001. The proportions of responders, intermediate responders and non-responders during treatment were 21.2%, 27.3% and 51.5%, respectively. Responders were found to have a lower enuresis frequency at baseline (p = 0.001) and to have larger nasal airway dimensions (p = 0.01). Orthodontic widening of the palate may be curative in a subgroup of children with therapy-resistant enuresis.

Do urologists need an orthodontist in order to optimize the treatment of nocturnal enuresis?

Nocturnal enuresis (NE) is a common disease that can be troubling for children and their families. The etiopathogenesis of NE is multifactorial and complex. Over the past few decades, extensive research on NE has been performed; however, many queries remain unclear regarding its exact pathophysiology [1]. The most probable pathomechanisms of NE should be considered as follows: 1) the lack of vasopressin release leading to nocturnal polyuria, 2) the reduction of nocturnal functional urinary bladder capacity, and 3) the impairment of the arousal response to urinary bladder fullness during sleep. The obstruction of the upper airway tracts as a factor in NE development has been discussed previously and, recently, several papers mentioned NE as a common symptom among patients with sleep apnea and other breathing abnormalities [2]. Since there are a few studies investigating the effects of rapid maxillary expansion (ME) on NE, the authors of the paper, entitled “Effects of maxillary expansion and placebo effect of appliances on nocturnal enuresis – preliminary results”, evaluated the effect of slow ME and placebo effect of the removable appliances on NE. The results presented seem to be relevant, since they discuss the association of ME with a positive effect on NE treatment [3]. ME is a routine procedure in orthodontics, with its main aim to expand the maxilla in children with transverse maxillary constriction and a deep palatal vault. ME has no negative side effects and complications. Moreover, ME has a positive effect on breathing pattern, conductive hearing loss and NE in some growing children [4]. According to data from the literature, ME has a positive effect on reducing and/or ceasing NE in about 70% of children [5]. Different potential mechanisms describing the healing effect of ME on NE were described. Firstly, ME results in improvement in breathing and blood oxygen saturation due to an increase in nasal and nasopharyngeal airway dimensions. Secondly, ME improves nasal breathing and reduces apnoic episodes leading to better lymphatic circulation and increases the antidiuretic function of the pituitary gland. Thirdly, ME improves breathing capacity and provides better oxygen saturation, which might have a beneficial effect on sleep and it may cause the children to wake up more easily because of bladder fullness. Fourthly, more sufficient blood oxygenation may have a positive effect on neuromuscular coordination and control of bladder sphincter during sleep. Moreover, ME may have a placebo effect [5–8]. When all above–mentioned potential mechanisms of nocturnal enuresis development are taken into consideration, it can be seen that orthodontists should be involved in the treatment process of nocturnal enuresis resistant to standard urological treatment options (e.g. supportive, alarm and medication treatment).

Measurements of normal nasal airway assessed by 3-dimensional computed tomography in Chinese children and adolescents

ObjectiveTo establish normative data of nasal airway dimensions in Chinese children and adolescents by age and sex. MethodsCT images of 281 Chinese children and adolescents (140 girls and 141 boys) aged from 6 to 18 years (yr) were selected among the patients who visited in Shanghai Ninth People's Hospital from September 2009 to August 2010. Subjects were divided into four age groups as group 1 (6–9yr), group 2 (10–12yr), group 3 (13–15yr), and group 4 (16–18yr). Child was defined as 6–12yr, and adolescent as 13–18yr. Nasal parameters were as follow: nasal volume (NV), length of nasal airway (NL), minimal cross-section area (CSA 1) and its location (D 1), inferior turbinate head's location (D 2) and its airway cross-section area (CSA 2), and cross-sectional area of choanal (CSA 3). ResultsThere was no significant sex dimorphism in nasal parameters in children (group 1 and group 2). In adolescents, male's nasal dimension were larger than female's. CSA 1, D 1, CSA 2, CSA 3, NL and NV correlated with age in male and female respectively. ConclusionsVolume, length and cross-section area of nasal airway were correlated with age in Chinese children and adolescents aged from 6 to 18yr. In children, nasal conformations of male and female are similar. In adolescents, sex dimorphisms in nasal parameters were significant.

Confirming Nasal Airway Dimensions Observed on Panoramic and Posterior-Anterior Cephalometric Radiographs Using An Acoustic Rhinometer

This study aimed to confirm the nasal airway dimensions observed in standard dental radiographs through analysis of the anterior nasal cross-sectional area and nasal volume with acoustic rhinometry. Participants were chosen from the patient population under consideration for interceptive orthodontic treatment at Tufts University's Pediatric Dentistry Clinic. A total of 55 Caucasian subjects, of both sexes (males=28, females =27), and ranging from age 6-9 years (mean= 7.33) were enrolled. Utilizing the ImageJ program, the subjects' panoramic and PA cephalometric radiographs were analyzed for radiolucent anterior nasal cross-sectional area. Subjects were then examined with the Eccovision Acoustic Rhinometer, which measured anterior nasal cross-sectional area and nasal volume. Data were grouped together, and areas and volume gathered from the radiographs and rhinometer analyzed for any correlation. Statistical analysis was performed using the SPSS program. Data was further divided into right and left nasal side, and a Pearson Correlation Matrix was created for 8 predictor variables (right and left panoramic area, right and left cephalometric area, right and left rhinometer area, and right and left rhinometer volume). Values in this correlation matrix ranged from 0.712 to 0.988; all were statistically significant at the <0.01 level (2-tailed test). A very strong correlation was found between the anterior nasal cross-sectional area calculated from the radiographs, and the anterior nasal cross-sectional area and nasal volume from the rhinometer.

Rapid Palatal Expansion Effects on Nasal Airway Dimensions as Measured by Acoustic Rhinometry

To evaluate available information on the effects of rapid maxillary expansion on nasal airway minimal cross-sectional area and volume, as measured by acoustic rhinometry. An electronic database search was conducted. Based on abstracts/titles, articles were initially selected; then full articles were retrieved and were further sorted according to secondary, more stringent criteria. References from selected articles were hand-searched for potential missed publications. Clinical trials using acoustic rhinometry on subjects undergoing rapid maxillary expansion therapy were included. Syndromic or medically compromised patients and absence of an untreated control group were reasons for exclusion. Selected studies thereafter were evaluated methodologically. Only four articles reached final selection, and their overall methodology scores were low, limiting the applicability of results. After rapid maxillary expansion, three of four studies found statistically significant increases in minimal cross-sectional area, and two of three studies reported statistically significant increases in nasal cavity volume as compared with control groups. It appears that any increase is less stable if a traditional technique is used on patients who have passed their peak growth spurt. Although some increases in nasal dimensions have been reported, the changes in nasal volume were small and should not be presented to patients as a clinically significant indication for therapeutic maxillary expansion.

Objective measurement of nasal airway dimensions and resistance using acoustic rhinometry and rhinomanometry in habitual snorers compared with non-snorers

Snorers represent a heterogeneous group that requires adequate assessment before recommending surgical treatment. Most studies of the pathophysiology of snoring and obstructive sleep apnea have emphasized anatomical abnormalities in the oropharyngeal and hypopharyngeal airways. It is still unclear if nasal airway restriction plays an important role in sleep-disordered breathing and there is no general consensus if treatment of nasal pathology should be included in the management of patients with snoring or sleep apnea. The aim of this study was to compare nasal dimensions and airflow resistance of habitual snorers with non-snoring individuals by means of acoustic rhinometry and rhinomanometry. Sixty individuals were enrolled in this analytical cross-sectional study. They were divided in two groups: group A (case) consisted of 30 patients with a main complaint of chronic snoring referred to ear, nose, and throat (ENT) clinic of Hazrat-e-Rasoul University Hospital, Tehran, Iran. Group B (control) consisted of 30 individuals without any complaint of snoring. The subjects were assessed objectively with acoustic rhinometry and rhinomanometry. Nasal dimensions and airflow resistance were recorded for all individuals. The most common site of minimum cross-sectional area (MCA) was at the left concha-notch in both snoring and non-snoring individuals. Significant reduction of cross-sectional area of both isthmus and concha notches was seen in habitual snorers (P < 0.05). The mean total airflow resistances in both pressures of 75 and 150 Pa was higher in habitual snorers. Whereas, these differences were not statistically significant (P > 0.05). The results of our study illustrate that acoustic rhinometry, rhinomanometry may be helpful methods for quantitative assessments of nasal airway respiratory function, and configuration in snorers; especially to evaluate site of MCA, decreased nasal cross-sectional area and increased nasal airflow resistance in habitual snorers which may lead to OSA.

Long-term effects of symphyseal distraction and rapid maxillary expansion on pharyngeal airway dimensions, tongue, and hyoid position

The aim of this study was to evaluate the effects of mandibular symphyseal distraction osteogenesis (MSDO) followed by rapid maxillary expansion (RME) on the pharyngeal and nasal airway dimensions and the tongue and hyoid positions. The material consisted of lateral and posteroanterior cephalometric radiographs of 13 female and 7 male patients (mean age, 20.0 +/- 2.3 years). Records were taken before treatment, after distraction (11.4 +/- 2.2 days after surgery), after RME (94.9 +/- 5.8 days after surgery), and at follow-up appointments (24.1 +/- 4.2 months after surgery). MSDO was performed with a custom-made tooth-and-bone-borne device. RME was performed with an acrylic bonded device. The average amounts of mandibular and maxillary expansion were 8.1 +/- 1.7 and 5.9 +/- 1.0 mm, respectively. Posteroanterior cephalometric analysis showed significant transversal width increases between the mandibular canines and molars. No significant pharyngeal or transverse nasal airway changes occurred with MSDO except for a significant decrease in tongue length. However, MSDO followed by RME caused statistically significant but clinically small changes in oropharyngeal width (+1.0 mm), tongue length (-2.2 mm), vertical airway length (-2.3 mm), and vertical position of the hyoid bone (-1.4 mm), which were all stable at the 2-year follow-up. The results suggest that MSDO alone or MSDO followed by RME does not significantly affect the pharyngeal airway dimensions or the hyoid position in adults. Any changes caused by these procedures might have been counteracted by the reflex mechanisms that protect airway potency.