Hypopharyngeal Airway Space Research Articles

Correlation between the three-dimensional hyoid bone parameters and pharyngeal airway dimensions in different sagittal and vertical malocclusions

ObjectiveThis study aimed to explore the relationship between three-dimensional (3D) measurements of the hyoid bone (HB) and pharyngeal airway space (PAS) in relation to sagittal and vertical malocclusion. MethodsA total of 368 cone-beam computed tomography (CBCT) scans were classified into three skeletal groups (Class I, II, and III) and subdivided by vertical growth patterns (hypodivergent, normodivergent, and hyperdivergent). PAS dimensions, including nasopharyngeal, oropharyngeal, hypopharyngeal, and total airway spaces, were measured in surface area, volume, minimum constricted area (MCA), length, and width, HB position and dimension were analyzed in 3D using InVivo 6.0.3 and Dolphin 11.8 software. Data were analyzed using two-way ANOVA, and Bonferroni post-hoc tests, with P ≤ 0.05 considered significant. ResultsThe study found that patients with skeletal Class III and hypodivergent growth pattern had the highest sagittal position of the hyoid bone, while those with skeletal Class II and hyperdivergent pattern had the lowest hyoid length. Nasopharyngeal airway space width was significantly lower in skeletal Class III patients, while volume and area were lower in hyperdivergent patients. Oropharyngeal and hypopharyngeal dimensions were also affected by skeletal class and growth pattern, with hyperdivergent patients having the lowest values. Total pharyngeal volume, area, and minimum constricted area were also affected, with hyperdivergent patients having the lowest values and skeletal Class II patients having the lowest minimum constricted area. ConclusionPharyngeal airway dimensions and hyoid bone parameters vary with malocclusions. The hyoid bone's position influences the airway, identifying patients at risk for airway obstruction and sleep-disordered breathing.

Sexual dimorphism in hypopharyngeal airway space and effective length of mandible with twin block appliance therapy: A prospective study

To evaluate changes in hypopharyngeal airway space and effective length of mandible in skeletal Class II patients following Twin Block Appliance (TBA) therapy. Further, the study also aims to compare the post functional changes being observed between males and females. This is a prospective study on 15 Pre-adolescents (08 males and 07 females; mean age: 10.75 ± 0.91years) who underwent functional jaw orthopaedics with TBA. Lateral cephalogram at Pre treatment stage (T1) and post functional phase of TBA (T2) were obtained. The cephalometric parameters were measured and paired t test was done for comparison of pre and post functional changes. The mean period of functional phase of TBA therapy was 18 ± 02 months. The cephalometric changes post functional jaw orthopaedics were statistically insignificant when compared males Vs females (P > 0.05). However, mean increase of in the effective length of mandible and hypopharyngeal space (T2-T1) was 4.0± 1.16 mm and 1.47±0.57 mm respectively, which were statistically highly significant (P<0.5). 1. TBA therapy in skeletal Class II patients significantly increases the effective mandibular length and hypo-pharyngeal space post functional phase; 2. No significant differences were observed between males and females with respect to post functional cephalometric changes in mandibular length and hypopharyngeal space.

Volumetric analysis of pharyngeal airway dimensions and hyoid bone position following orthognathic surgery in skeletal class III patients: a cross sectional cephalometric study

Background: Objective of the study was to determine linear and volumetric changes in pharyngeal airway dimensions in class III patients treated by different modalities of orthognathic surgery and to compare the results of different orthognathic surgical modalities, and determine the change at the position of the hyoid bone. Methods: Pre and post-treatment lateral cephalogram of 53 class III adult patients who were treated by different modalities of orthognathic surgery studied to assess the changes in pharyngeal airway dimensions and hyoid bone position after orthognathic surgery. 28 patients were treated with mandibular set back, and 25 patients were treated with Bijaw surgery. Lateral cephalogram records were taken before treatment (T1), after surgery (T2), the end of the fixed treatment (T3) and 1 year after debonding (T4). Results: Interception of both surgical modalities has significant impact on various skeletal and pharyngeal parameters i.e., BMeH (0.00), PNS (0.009), MPS (0.13), GOP (0.001), IPS (0.007), SAS (0.006), and MAS (0.00). OJ (overjet) and OB (overbite) was significant especially after time interval of one year. In Bijaw groups, PPST4 parameter was significantly increased (0.0000), SPST4 (0.000), GOP (0.000), EPS (0.000) and IPS parameter was significantly decreased (0.045). Significant difference was observed in T4 time interval in superior pharyngeal airway space, posterior airway space and middle airway space with (p<0.05). Conclusions: Pharyngeal airway is significantly altered following orthognathic surgery in class III patients and it depends on the type of surgical modality employed were Bijaw surgery has significant impact on oropharyngeal and hypopharyngeal airway space.

Three-dimensional evaluation of upper pharyngeal airway, hyoid bone, and craniocervical changes following stabilization splint therapy in adult patients with temporomandibular joint disorders and mandibular deviation: A retrospective study

ObjectiveThis study aimed primarily to analyze the three-dimensional (3D) changes in the pharyngeal airway (PA), and secondarily, the hyoid bone (HB) and the craniocervical (CC) following stabilization splint (SS) therapy in adult patients with temporomandibular joint disorders (TMD) and mandibular deviation (MD). MethodsThirty-five adult patients with TMD and MD, who were treated using SS with a mean age of 25.14 ± 6.11 years, were enrolled in this retrospective clinical study. Pre- and post-therapeutic cone-beam computed tomography (CBCT) scans were analyzed. PA dimension,nasopharyngeal, oropharyngeal, hypopharyngeal, sub-hypopharyngeal, and total pharyngeal airway spaces were measured in surface area, volume, minimum constricted area (MCA) and width, HB position, and CC posture were analyzed three-dimensionally using InVivo 6.0.3 and Dolphin 11.95 software. Wilcoxon rank-sum or Paired t-test was conducted, and P < 0.05 was considered significant. ResultsSS therapy was administered for a period of 9.49 ± 4.02 months. The oropharyngeal airway space showed a significant decrease in sagittal width. The hypopharyngeal surface area, volume, MCA, and sagittal width decreased significantly. In terms of HB, hyoid–mandibular plane (H-MP), retrognathia–third vertebra's most inferior–anterior (RGN-C3ia), and retrognathia–Sella (RGN-S) distances significantly decreased. The Nasion–Sella line and the line that passes through C2ip to the odontoid process posterior tangent (NSL-OPT) angle in CC posture also decreased significantly. ConclusionSS therapy in TMD patients with MD mainly results in narrowing of the hypopharyngeal region, no change in HB position and improvement in head posture. These results undoubtedly assist in diagnosis and treatment of clinical conditions.

The Efficacy of the Partial Glossectomy for Prevention of Airway Volume Reduction in Orthognathic Surgery of Class III Patients

The aim of this study was to evaluate the effects of a partial glossectomy on volumetric changes of pharyngeal airway space (PAS) in patients with mandibular setback surgery. Overall, 25 patients showing clinical features related to macroglossia treated with mandibular setback surgery were included in this retrospective study. Subjects were divided into two groups: the control group (G1, n = 13, with BSSRO) and the study group (G2, n = 12, with both BSSRO and partial glossectomy). The PAS volume of both groups was measured by the OnDemand 3D program on CBCT taken shortly before operation (T0), 3 months post-operative (T1), and 6 months post-operative (T2). A paired t-test and repeated analysis of variance (ANOVA) were used for statistical correlation. Total PAS and hypopharyngeal airway space were increased after operation in Group 2 compared to Group 1 (p < 0.05), while oropharyngeal airway space showed no significant statistical difference with the tendency of increasing. The combination of partial glossectomy and BSSRO surgical techniques had a significant effect on increasing the hypopharyngeal and total airway space in class III malocclusion patients (p < 0.05).

Cephalometric characteristics of the upper respiratory tract in Ukrainian young men and young women with an orthognathic bite without and with the type of face taken into account

The upper respiratory tract is a component of the respiratory system, which ensures the performance of several key human functions at once. The variability of cephalometric indicators of this structure of the human body, depending on the peculiarities of body structure, nationality, sex, and other factors, is one of the current topics of discussion among modern scientists. The purpose of the study is to establish the peculiarities of the cephalometric characteristics of the upper respiratory tract in young people without pathology of the upper respiratory tract with an orthognathic bite without and taking into account the type of face. For 72 Ukrainian young women and 46 young men with an orthognathic bite and the absence of pathology of the upper respiratory tract, taken from the database of the research center and the pediatric dentistry department of National Pirogov Memorial Medical University, Vinnytsya, determination of cephalometric parameters of the upper respiratory tract itself was carried out. The face type of young women and young men was determined using Garson's morphological index. The statistical analysis of the obtained results was carried out in the licensed statistical package “Statistica 6.0” using non-parametric estimation methods. In Ukrainian young women and young men without and taking into account the type of face, the percentile range of cephalometric parameters of the upper respiratory tract proper was established (distance PASmin – the size of the retroglossal oropharyngeal airway space, distance PM-UPW – the size of the nasopharyngeal airway space, distance U-MPW – the size of the retropalatal oropharyngeal airway space, distance V-LPW – the size of the hypopharyngeal airway space, area UAA – the size of the upper airway area). Sex differences (significantly greater, or a tendency towards greater values in young men) of distance V-LPW values were found in representatives without taking into account the face type by 13.8 %, with a wide face type – by 11.6 % and with a narrow face type – by 15.9 %; as well as the size of the UAA area in representatives without taking into account the face type by 20.6%, with a very wide face type – by 21.2 %, with a wide face type – by 21.6 % and with an average face type – by 23.1 %. Both in young women and in young men, no reliable differences or trends in the magnitude of the cephalometric parameters of the upper respiratory tract between representatives with different types of faces were established.

Influence of Fixed Orthodontic Therapy on Pharyngeal Airway Dimensions after Correction of Class-I, -II and -III Skeletal Profiles in Adolescents.

The aim was to compare the influence of fixed orthodontic therapy (OT) on the pharyngeal airway space dimensions after correction of class-I, -II and -III skeletal profiles and among untreated adolescent patients. A control group comprising of untreated patients was also included. Demographics and OT-related information was retrieved from patients’ records. Measurements of airway spaces in the nasopharynx, oropharynx and hypopharynx were performed on lateral cephalograms. p-values under 0.05 were considered statistically significant. The results showed no statistically significant differences in the naso-, oro- and hypo-pharyngeal airway spaces among patients with class-I, -II and -III skeletal profiles and individuals in the control group. There were no statistically significant differences when naso-, oro- and hypo-pharyngeal airway spaces were compared among patients with class-I, -II and -III skeletal profiles. In conclusion, in non-extraction cases without maxillary expansion, fixed OT does not affect the naso-, oro- and hypo-pharyngeal airway spaces in patients with skeletal Class-I, -II and -III skeletal profiles. Further studies involving patients undergoing ME and premolar extraction are needed to elucidate the influence of fixed OT on the naso-, oro- and hypo-pharyngeal airway spaces.

Quantifying Upper Airway Changes Following Mandibular Orthognathic Surgery.

The aim of this study was to quantify upper airway changes following mandibular orthognathic surgery. Treatment records of 50 patients who underwent mandibular orthognathic surgery were divided into 2 groups, that is, Group 1: Cases treated with Mandibular Advancement Surgery and Group 2: Cases treated with Mandibular Setback Surgery with 25 patients in each group. The Lateral Cephalogram and Acoustic Pharyngometry records of both groups were studied at T0 (01 week before surgery) and T1 (01 year postsurgery) for changes in linear airway measurements (Nasopharyngeal Airway Space - NAS, Superior Airway Space - SAS, Posterior Airway Space - PAS and Hypopharyngeal Airway Space (HAS)), hyoid bone position (Mandibular Plane Hyoid distance), mean area and mean volume. The percentage change and change in these parameters per millimeter advancement or setback of mandible at T1 was calculated. A significant increase in linear airway parameters (SAS and PAS); decrease in hyoid distance; and increase in volume and area of upper airway was observed at T1 in Group 1 and reverse was observed in Group 2. The change in airway parameters (SAS, PAS, mean volume and area) was more significant in Group 1 as compared to Group 2. In the current airway centric approach, meticulous assessment and prediction of long-term airway changes post surgery should be an integral part of ortho-surgical diagnosis and treatment planning and suitable modifications in the treatment plan must be made to cater for any potential adverse effects on airway.

Predictability of pharyngeal airway space dimension changes after orthognathic surgery in class II patients: A mathematical approach

IntroductionAngle Class II malocclusion due to mandibular retrognathia is a common dentofacial deformity. It is well known that mandibular advancement increases pharyngeal airway dimensions. The aim of this study was to evolve a mathematical method for predicting posterior pharyngeal airway space (PAS) changes based on 2D lateral cephalographic radiographs (LCRs) and expected extent of mandibular advancement prior to BSSO. Materials and methodsLinear regression analyses were performed in order to investigate the relation between the posterior airway space and mandibular advancement. LCRs where carried out to assess skeletal landmarks and pharyngeal airway space pre- (T0) and postoperatively (T1). To detect changes postoperatively, the posterior airway space was divided into three units: nasopharyngeal airway space (superior airway space — SPAS), oropharyngeal airway space (mid airway space — MAS) and hypopharyngeal airway space (inferior airway space — IAS). The differences between the distances of distinct measurement points (DIFF) were measured pre- and postoperatively. DOA referred to the distance of mandibular advancement and DP to the distance between the measurement points preoperatively. The parameters a, b1 and b2 were the regression coefficients that were determined separately for each unit (SPAS, MAS, and IAS). Results49 patients (16 male and 33 female) with a mean age of 27.2 years (SD: 10.09), ranging from 18 to 51 years, who underwent mandibular advancement surgery (BSSO) were enrolled in this study. The mean distance of mandibular advancement was 5.05 mm (SD: 1.63). Regarding SPAS and IAS, mandibular advancement did not affect dimensions significantly: SPAS DIFF, 0.33 mm ± 1.13 mm (b1, p = 0.0881; b2, p = 0.087); IAS DIFF, 0.66 mm ± 2.45 mm (b1, p = 0.342; b2, p = 0.765). DOA and DP did not influence DIFF significantly in both sections. Regarding MAS, the mean effect of mandibular advancement was an expansion of 2.47 mm ± 2.24. The linear regression model showed a statistically significant (b1, p = 0.0064; b2, p = 0.0240) influence of DOA and DP on DIFF in posterior airway dimensions pre- and postoperatively. DiscussionBased on preoperative LCR imaging data, a linear regression model was developed as a mathematical approach to allow prediction of PAS development in patients with Angle Class II malocclusions of different degrees. Increasing mandibular advancement was shown to be linked to increasing PAS, while a greater distance between the measuring points preoperatively led to smaller predicted PAS increases postoperatively. ConclusionPredicting pharyngeal airway space (PAS) development after mandibular advancement by analysing lateral cephalometric radiographs (LCR) may be useful in the screening and treatment of obstructive sleep apnea syndrome (OSAS) patients. Our mathematical approach is a simple and sustainable prediction tool based on LTR data for patients with Class II malocclusions.

Silent Changes in Sleep Quality Following Mandibular Setback Surgery in Patients with Skeletal Class III Malocclusion: A Prospective Study

Mandibular setback surgery (MSS) for skeletal class III patients can result in a relative reduction of pharyngeal airway space (PAS). Consequently, there is a possibility of the decline of sleep quality after surgery. We investigated changes in sleep quality measured by overnight polysomnography (PSG) and the three-dimensional (3D) volumes of PAS following MSS with or without Le Fort I osteotomy (LF I) in class III patients (N = 53). Overnight PSG and cone beam computed tomography were conducted at preoperative stage (T0) and postoperative 3 months (T1). Measurements of PAS volumes were performed, and the subjective symptoms of sleep were evaluated by self-questionnaires. There were significant increases in respiratory disturbance index (RDI) and total respiratory effort-related arousal (RERA) index during T0-T1. The 3D volumes of PAS showed significant decreases in the oropharyngeal airway, hypopharyngeal airway, and total airway spaces. No significant changes were observed in subjective symptoms of sleep. MSS with or without LF I for class III patients could worsen sleep quality by increasing sleep parameters such as the RDI and RERA in PSG, and reduce volumes of PAS at postoperative 3 months. Although subjective symptoms may not show significant changes, objective sleep quality in PSG might decrease after MSS.

Cephalometric appraisal of the effects of orthodontic treatment on total airway dimensions in adolescents

AimThis retrospective study was performed to rule out any jeopardizing effect of extraction therapy of four first premolars on airway at any level of its anatomic course. Materials and methodsLateral cephalograms of 50 adolescent patients divided into two groups of 25 each, based on orthodontic treatment by first premolar extraction as group I and without extraction as group II, were selected for the study. 13 angular and 11 linear measurements were compared pre-and post-treatment via statistical analyses using SPSS (Version 17.5, SPSS, Chicago) software. Paired ‘t’ tests were used to assess the variability. P-value < 0.05 was considered to be statistically significant. ResultsComparison of angular parameters showed that the average percentage (%) change in SNA, SNB, ANB, IMPA, FMA, saddle, articulare, gonial, total angle and hyoid did not differ significantly across two study groups (P > 0.05), but values of UI/LI, UI/NA, LI/NB, differed significantly among both groups. Similarly, linear parameters showed that the average % change in nasopharyngeal airway space (NAS) and width of soft palate differed significantly across two study groups (P-value<0.05), whereas the average % change in posterior airway space (PAS), hypopharyngeal airway space (HAS), hyoid distance and length of tongue did not differ significantly (P-value>0.05). However, no significant differences were observed during intragroup and intergroup comparisons of the combined angular and linear measurements of both groups. ConclusionsPresent study showed no significant change on airway after therapeutic orthodontic tooth movement with or without extraction treatment.

A retrospective cephalometric study on upper airway spaces in different facial types

BackgroundCraniofacial growth pattern has been correlated with variations in size of the upper airway spaces. The objective of this study was to evaluate the nasopharyngeal, oropharyngeal, and hypopharyngeal airway spaces variations according to the craniofacial growth pattern, by comparing brachyfacial, mesofacial, and dolichofacial in Angle Class I individuals.MethodsTo measure the spaces, 45 lateral teleradiographs were used and divided into 3 groups per the craniofacial growth pattern, determined by the Tweed cephalometry angular measurements: FMA and Y-axis. To evaluate the airways, sleep apnea cephalometry was used, containing 28 points that compose 14 factors. Three groups were compared relative to each of the 14 sleep apnea cephalometry measurements. Adherence test to the normal curve was performed. For the non-normally distributed data—measurement of the inferior pharyngeal space—the Kruskal-Wallis test was used for comparison between the groups. For the remaining data, the distribution was normal and ANOVA test was used.ResultsStatistically significant difference was verified among the groups for the measurement of the median posterior-palatal space, with the difference being pointed out by the post hoc test between the brachyfacial and dolichofacial groups. For the other measurements, there was no statistically significant difference.ConclusionsIt could be concluded that there was difference in the median posterior-palatal space measurement, in the oropharynx region, which was reduced for individuals with a dolichofacial pattern.

Pharyngeal Airway Space and Hyoid Bone Positioning After Different Orthognathic Surgeries in Skeletal Class II Patients

To obtain good profiles, patients with severe skeletal Class II malocclusion require orthognathic surgery, which might change their airway space and, hence, influence their quality of sleep. The present study aimed to 1) determine the effect of different orthognathic surgeries on pharyngeal airway space and hyoid bone position in patients with skeletal Class II malocclusion and 2) evaluate the stability of changes in the pharyngeal airway space and hyoid bone position after orthognathic surgeries. Patients with severe skeletal Class II malocclusion who underwent mandibular advancement (MA) or mandibular advancement and maxillary setback (MAMS) were included in this retrospective cohort study. Changes in the pharyngeal airway space and hyoid bone position were evaluated as the primary outcome variables. Measurements were obtained before surgery (T1), 1month after surgery (T2), and 2years after surgery (T3) using Dolphin Imaging Software 11.0. Differences in measurements between T2 and T1 and between T3 and T1 were calculated and imported into SPSS 22.0 for data analysis. Fifty patients were included (25 in MA group and 25 in MAMS group). Oropharyngeal and hypopharyngeal airway cross-dimensions and areas were significantly increased in the MA group (P<.05) and the increases were stable at T3. In the MAMS group, the nasopharyngeal airway cross-dimension and area were decreased (P>.05), but the hypopharyngeal cross-dimension and area were significantly increased (P<.05). The hyoid bone moved superiorly and forward after surgery in the MA group (P<.05), and the movement was stable at T3. MA can widen the oropharyngeal and hypopharyngeal airway space, and maxillary setback can narrow the nasopharyngeal airway space. Some relapse related to the width of the oropharynx and hypopharynx was found at the long-term observation. The hyoid bone moved superiorly and forward in the MA group.

Pharyngeal airway analysis in obese and non-obese patients with obstructive sleep apnea syndrome

BackgroundSleep disorders are a group of disorders characterized by abnormalities of respiration during sleep. OSA (Obstructive Sleep Apnea) is characterized by the repetitive episodes of complete or partial collapse of the upper airway during sleep, causing a cessation or a significant reduction of airflow. MethodThe study population consisted of 30 control patients (AHI ≤ 5) events per hour, 74 patients with OSAS, including 34 Obese (BMI ≥ 27) and 40 non-obese (BMI ≤ 27). Polysomnography and measurements of 21 cephalometric variables were carried out for all patients with OSAS. ResultsObese patient with OSAS showed significant difference in following cephalometric parameters: (1) PAS (2) MPT (3) MPH (4) PNS-P (5) SAS. In addition, obese patient had longer tongue (TGL), more anteriorly displaced hyoid bones (H-VL) and more anterior displacement of mandible (G-VL) when compared with control groups. The findings of non-obese patients when compared to controls showed all the findings of obese patients and in addition to that narrow bony oropharynx were significant. Step wise regression analysis showed the significant predictors for all patients were MPH, PNS-P, bony nasopharynx (PNSBa), MPT, and palatal length (ANS-PNS) for AHI. The significant predictors for obese OSA (obstructive sleep apnea) group were MAS while for non-obese OSA group ANS-PNS was significant predictor for AHI (apnea-hypopnea index). ConclusionCraniofacial landmarks such as increase in hyoid distance, longer tongue and soft palate with increased thickness and narrowing of superior pharyngeal, oropharyngeal and hypopharyngeal airway space may be important risk factors for development of OSAS.

Comparison of the change in pharyngeal airway space, tongue and hyoid bone positions according to the orthognathic surgical methods of mandibular prognathism

Abstract Comparison of the Change in the Pharyngeal Airway Space, Tongue and Hyoid Bone Positions according to the Orthognathic Surgical Met hods of Mandibular Prognathism Yoon-Sun Lee, Se-Jin Han Department of Oral and Maxillofacial Surgery, College of Dentistry, Dankook UniversityPurpose: The purpose of this study was to compare the changes in the pharyngeal airway space, tongue and hyoid bone positions according to the orthognathic surgical methods of man dibular prognathism.Methods: The subjects included 30 patients (16 males, 14 females) with the skeletal class III malocclusion. Group 1 (10 patients) underwent bilateral sagittal split ramus osteotomy (B SSRO) only; group 2 (10 patients) underwent BSSRO with genio-plasty; and group 3 (10 patients) underwent BSSRO, Le Fort I os teotomy. We measured the lines between the selected upper air way, hyoid bone and tongue landmarks on the lateral cephalo metric x-ray films of skeletal class III. The measurements were made preoperation, within 1 week after the operation, 3∼6 months after the operation and 1 year after the operation. We compared and analyzed the measurements with matched paired t -test and independent samples t-test.Results: There were no postoperative changes in the nasopharyngeal airw ay space in group 3. The measurements of group 3 also increased during the follow-up period as compared to the preoperative measurements. In group 1, 2 and 3, the immediate postoperative oropharyngeal and hypopharyngeal airway spaces we re decreased. In the following period, the hypopharyngeal airway space returned to the preoperative positions, but the or opharyngeal airway space was not significantly changed. The upper and lower tongue was posteriorly repositioned immediately after the surgery. During the follow-up period, the lower tongue position returned to the preoperative position, and the upper tongue position was not significantly changed. Immediatel y after the surgery, the B point was moved to the posterior posit ion, and a slight anterior advancement was found in the follow-up period.Conclusion: Patients who received the mandibular setback surgery showed a decrease in the posterior airway space, and those who underwent max illary advancement showed a significant increase of the nasopha ryngeal airway space, which remained stable during the evaluation period. The change of the airway s pace, position of the hyoid bone and tongue did not differ according to the presence or absence of genioplasty.Key words:Mandibular prognathism, Bilateral sagittal split ramus osteotom y, Cephalometry, Genioplasty, Orthognathic surgeries

Craniofacial modifications in Ivorian melanoderm children with chronic retronasal obstruction

ObjectiveTo determine the influence of the chronic retro nasal airway obstruction on craniofacial morphology. MethodsIt was a case–control study which included fifty-eight melanoderm children aged from 3 to 6 years (31 males and 27 females), divided in 2 samples. A studied group of 29 habitual snorers presenting chronic retro nasal obstruction due to enlarged adenoid and a control group of 29 age matched children selected among patients consulting for routine evaluation. Patients who had used topical or systemic medication for the nose, as well as those who had undergone adenoidectomy were excluded from the study.Children were submitted to history taking then ENT and orthodontic examination. Linear and angular cephalometric measurements were used for craniofacial features evaluation. ResultsSignificant craniofacial anomalies were found in patients presenting chronic retro nasal obstruction: shortened cranial base and mandibular plane length, widened cranio-cervical flexure, forwardness of hyoid bone, reduced nasopharyngeal airway space, widened of oropharyngeal and hypopharyngeal airway space. ConclusionsOur study suggests that craniofacial modifications due to chronic retro nasal obstruction lead to pharyngeal airway readjustment. Persistent retro nasal obstruction should be corrected early in life in order to avoid skeletal modifications appearance.

Hyoid Expansion With Titanium Plate and Screw

Hyoid expansion with suspension can potentially increase the upper airway at the hypopharyngeal level, benefitting patients with sleep-related breathing disorder. To document the effect of hyoid expansion using titanium plate and screw on retrolingual hypopharyngeal airway dimension and to compare the airway dimension after isolated hyoid expansion with hyoid expansion + hyomandibular suspension. Anatomical cadaveric dissection study. This study was performed in a laboratory setting using human cadavers. This is an anatomical feasibility study of hyoid expansion using titanium plate and screw on 10 cadaveric human heads and necks. The hyoid bone is trifractured with bony cuts made just medial to the lesser cornu. The freed hyoid body and lateral segments are expanded and stabilized to a titanium adaptation plate. Computer-assisted airway measurement (CAM) was used to measure the airway dimension at the hypopharynx at the level of the tongue base before and after the hyoid expansion. The expanded hyoid bone was then suspended to the mandible, and the airway dimension was measured again with CAM. Airway dimension after isolated hyoid expansion with hyoid expansion with hyomandibular suspension. RESULTS Hyoid expansion with titanium plate and screw resulted in statistical significant increase in the retrolingual hypopharyngeal airway space in all of the 10 human cadavers. The mean (SD) increase in retroglossal area was 33.4 (13.2) mm² (P < .005) (range, 6.0-58.7 mm²). Hyoid expansion with hyomandibular suspension resulted in a greater degree of airway enlargement. The mean (SD) increase in retroglossal area was 99.4 (15.0) mm² (P < .005) (range, 81.9-127.5 mm²). The retrolingual hypopharyngeal airway space increased with hyoid expansion using titanium plate and screw in our human cadaveric study, measured using CAM. The degree of increase is further augmented with hyomandibular suspension.

하악 전돌증 환자에서 악교정 수술방법에 따른 설골과 혀의 위치 및 기도량 변화의 비교

Purpose: The purpose of this study was to compare the changes in the pharyngeal airway space, tongue and hyoid bone positions according to the orthognathic surgical methods of mandibular prognathism. Methods: The subjects included 30 patients (16 males, 14 females) with the skeletal class III malocclusion. Group 1 (10 patients) underwent bilateral sagittal split ramus osteotomy (BSSRO) only; group 2 (10 patients) underwent BSSRO with genioplasty; and group 3 (10 patients) underwent BSSRO, Le Fort I osteotomy. We measured the lines between the selected upper air way, hyoid bone and tongue landmarks on the lateral cephalometric x-ray films of skeletal class III. The measurements were made preoperation, within 1 week after the operation, 3~6 months after the operation and 1 year after the operation. We compared and analyzed the measurements with matched paired t-test and independent samples t-test. Results: There were no postoperative changes in the nasopharyngeal airway space in group 3. The measurements of group 3 also increased during the follow-up period as compared to the preoperative measurements. In group 1, 2 and 3, the immediate postoperative oropharyngeal and hypopharyngeal airway spaces were decreased. In the following period, the hypopharyngeal airway space returned to the preoperative positions, but the oropharyngeal airway space was not significantly changed. The upper and lower tongue was posteriorly repositioned immediately after the surgery. During the follow-up period, the lower tongue position returned to the preoperative position, and the upper tongue position was not significantly changed. Immediately after the surgery, the B point was moved to the posterior position, and a slight anterior advancement was found in the follow-up period. Conclusion: Patients who received the mandibular setback surgery showed a decrease in the posterior airway space, and those who underwent maxillary advancement showed a significant increase of the nasopharyngeal airway space, which remained stable during the evaluation period. The change of the airway space, position of the hyoid bone and tongue did not differ according to the presence or absence of genioplasty.

A magnetic appliance for treatment of snoring patients with and without obstructive sleep apnea

The aim of this intraindividual study was to investigate the effects of an intraoral magnetic appliance on snoring, daytime sleepiness, and blood oxygen saturation, as well as to analyze the effects on the craniomandibular complex and investigate the response of the device to craniofacial structure. Twenty-five male patients (mean age 54.1 years, SD 11.44) with handicapping snoring or obstructed sleep apnea (OSAS) participated in the study. The appliance consisted of a maxillary and a mandibular occlusal acrylic splint. In each splint, four cylindrical neodymium-iron-boron magnets were embedded and oriented to produce intermaxillary forces that pulled the mandible forward. After a treatment period of 6 months, questionnaires were used for registration of the patients' subjective rating of daytime sleepiness and their close relatives' opinions about the snoring. The treatment effects on the temporomandibular joint were evaluated, according to Helkimos' anamnestic and dysfunctional index, and nightly registration of blood oxygen saturation was performed before and after 6 months of treatment. The effects on craniofacial skeletal and soft tissue profiles were analyzed cephalometrically. All patients easily accepted the magnetic appliance. The main symptoms, snoring and daytime sleepiness, decreased significantly when the magnet appliance was inserted ( p = 0.0001 and p = 0.0002, respectively). The blood oxygen saturation during sleep was also improved ( p = 0.012). The treatment had no aberrant effects on the temporomandibular joint status. The appliance made the mandible rotate downward and backward, mean 7.8°, and this rotation mostly camouflaged the forward movement of the mandible. There was no significant influence on the hyoid bone position, but the hypopharyngeal airway space increased, the tongue base was lowered, and the contact between the tongue and soft palate was reduced significantly.(Am J Orthod Dentofacial Orthop 1998;113:144-055)

Cephalometric analysis of long-term airway space changes with maxillary osteotomies

The cephalometric radiographs of 13 patients without sleep apnea who had undergone isolated maxillary surgery were studied. The authors found increases in both the nasopharyngeal and hypopharyngeal airway spaces 3 to 5 years after surgery. The results suggest that adaptive processes occur in both the upper and lower jaw, which contribute to an enlarged airway after surgery.