Effect of Bimaxillary Orthognathic Surgery on Pharyngeal Airway Volume / Efecto de Cirugía Ortognática Bimaxilar en el Volumen de la Vía Aérea Faríngea

SUMMARY: Subjects with maxillary skeletal classes II and III not only express alterations in the hard and soft maxillofacial tissues, but also in the morphology and dimensions of the upper airway. A small space in the upper airway has been associated with sleep disorders, such as snoring and mainly obstructive sleep apnea/hypopnea syndrome (OSAHS). Consequently, interest has increased due to the influence of orthognathic surgery in the airway space. Although there are studies in the literature that have compared upper airway spaces, most have evaluated the changes using two-dimensional images, mainly lateral skull X-rays. The present study aimed to determine the airway volume in subjects with skeletal classes II and III who underwent bimaxillary orthognathic surgery. 80 CBCT exams from 40 subjects obtained before and 6 months after surgery were used. There were 20 class II and 20 class III subjects. For the volumetric analysis, a 3D rendering of the upper airway was made in previously established segments, and then the airway volume was calculated using the 3D Slicer® software version 4.11 (Slicer, USA). The statistical analysis by t-test of related samples revealed statistically significant volumetric increases in the nasopharynx, laryngopharynx, and total volume in class II patients. However, in class III patients, there were significant increases in the nasopharynx and total volume, while the volume was maintained in the oropharynx and laryngopharynx.

Sujetos con clases esqueletales II y III maxilares, no solamente expresan alteraciones en los tejidos duros y blandos maxilofaciales, sino también en la morfología y dimensiones de la vía aérea superior. Un espacio reducido a nivel de la vía aérea superior se asocia a trastornos del sueño como ronquidos y principalmente el síndrome de apnea/hipoapnea obstructiva del sueño (AOS); debido a esto, ha aumentado el interés por la influencia de la cirugía ortognática en el espacio de la vía aérea. Si bien existen en la literatura estudios que han comparado los espacios de la vía aérea superior, la mayoría de los estudios han evaluado los cambios utilizando imágenes bidimensionales, principalmente radiografías laterales de cráneo. El objetivo del presente estudio fue determinar el volumen de la vía aérea en sujetos con clases esqueletales II y III sometidos a cirugía ortognática bimaxilar. Se utilizaron 80 exámenes CBCT pertenecientes a 40 sujetos obtenidos previo a la cirugía y 6 meses después de realizada. Veinte sujetos clase II y 20 clase III. Para el análisis volumétrico se realizó un renderizado 3D de la vía área superior en segmentos previamente establecidos y posteriormente se calculó el volumen de dicha vía aérea con la utilización del software 3D Slicer ®versión 4.11 (Slicer, USA). El análisis estadístico realizado por t-test de muestras relacionadas, arrojó en pacientes clase II aumentos volumétricos estadísticamente significativos en nasofaringe, laringofaringe y volumen total. Mientras que en pacientes clase III, se observó aumentos significativos en Nasofaringe y volumen total y mantención de volumen en orofaringe y laringofaringe.

Three-dimensional pharyngeal airway space changes after bimaxillary advancement

ABSTRACT Introduction: The probability of improvement in the upper airway space (UAS) with orthognathic surgery should be considered during the surgical-orthodontic treatment decision, providing not only an esthetic, but also a functional benefit for the patient. Objective: The purpose of this study was to evaluate the 3D changes in the upper airway space after maxillomandibular advancement surgery (MMA). Methods: A retrospective analysis of 56 patients, 21 male and 35 female, with a mean age of 35.8 ± 10.7 years, who underwent MMA was performed. Pre- and postoperative cone-beam computed tomography scans (CBCT) were obtained for each patient, and the changes in the UAS were compared using Dolphin Imaging 11.7 software. Two parameters of the pharyngeal airway space (PAS) were measured: airway volume (AV) and minimum axial area (MAA). Paired t-test was used to compare the data between T0 and T1, at 5% significance level. Results: There was a statistically significant increase in the UAS. Bimaxillary advancement surgery increased the AV and the MAA, on average, by 73.6 ± 74.75% and 113.5 ± 123.87%, respectively. Conclusion: MMA surgery tends to cause significant increase in the UAS; however, this increase is largely variable.

RESUMO Introdução: A probabilidade de melhoria do espaço aéreo superior (EAS) com cirurgia ortognática deve ser considerada durante a decisão do tratamento ortodôntico-cirúrgico, proporcionando não somente um benefício estético, mas também funcional, para o paciente. Objetivo: O objetivo do presente estudo foi avaliar as alterações 3D no espaço das vias aéreas superiores após a cirurgia de avanço maxilomandibular (AMM). Métodos: Foi realizada uma análise retrospectiva de 56 pacientes, 21 homens e 35 mulheres, com média de idade de 35,8 ± 10,7 anos, submetidos a AMM. Foram obtidas tomografias computadorizadas de feixe cônico (TCFC) pré- e pós-operatórias para cada paciente, e as alterações no EAS foram comparadas usando o software Dolphin Imaging v. 11.7. Foram medidos dois parâmetros do espaço aéreo faríngeo (EAF): volume das vias aéreas (VVA) e área axial mínima (AAM). Foi utilizado o teste t pareado para comparar os dados entre T0 e T1, com nível de significância de 5%. Resultados: Houve um aumento estatisticamente significativo no EAS. A cirurgia de avanço bimaxilar aumentou o volume das vias aéreas (VVA) e a área axial mínima (AAM) em média 73,6 ± 74,75% e 113,5 ± 123,87%, respectivamente. Conclusão: A cirurgia de AMM tende a causar o aumento significativo do EAS; no entanto, esse aumento é altamente variável.

Relationship between transoral atlantoaxial reduction screw-rod system fixation and oropharyngeal airway stenosis / 中国组织工程研究

BACKGROUND: In patients undergoing transoral atlantoaxial reduction and internal fixation, anterior atlantoaxial plate placement, soft tissue swelling and other factors may affect oropharyngeal space. Up to now no anatomical factors regarding dysphagia or dyspnea after anterior approach for atlantoaxial dislocation have been reported. OBJECTIVE: To observe the spatial changes of oropharyngeal airway after atlantoaxial dislocation and internal fixation with transoral atlantoaxial reduction screw-rod system and analyze the related influencing factors. METHODS: Sixty-six patients with atlantoaxial dislocation undergoing transoral atlantoaxial reduction screw-rod system surgery were retrospectively included from January 2012 to December 2016 in the General Hospital of Southern Theater Command. There were 38 males and 28 females aged from 11 to 71 years. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. The narrowest oropharyngeal airway space, thickness of soft tissue before C2 vertebra, anterior atlantodental interval, O-C2 angle, and C2-C6 angle were measured in the neutral position before and after surgery. Changes of postoperative data and their effects on the narrowest airway distance in oropharynx were analyzed. RESULTS AND CONCLUSION: (1) The narrowest airway distance in oropharynx, anterior atlantodental interval and C2-C6 angle were significantly decreased after surgery compared with that before surgery (P <0.001). Thickness of soft tissue before C2 vertebra and O-C2 angle increased significantly after surgery compared with that before surgery (P < 0.001). (2) In the multiple regression analysis, the change in the anterior atlantodental interval (0=7.070) and thickness of soft tissue before C2 vertebra 03=0.387) were significant variables related to the change in the narrowest airway distance in oropharynx. On the contrary, there was no significant correlation with the O-C2 angle. (3) It is indicated that reduction of atlantoaxial dislocation and the thickness of soft tissue before C2 vertebrae have negative effect on the oropharyngeal airway space. Therefore, reduction of atlantoaxial dislocation during transoral reduction screw-rod surgery may cause postoperative dysphagia despite maintenance of the O-C2 angle.

Three-dimensional analysis of changes in airway space after bimaxillary orthognathic surgery with maxillomandibular setback and their association with obstructive sleep apnea / 대한악안면성형재건외과학회지

BACKGROUND: Bimaxillary orthognathic surgery with maxillomandibular setback is often accompanied by changes in airway space. We analyzed the changes in airway space before and after surgery and assessed their association with obstructive sleep apnea. METHODS: This study is based on the cohort of 13 adult patients (9 males, 4 females, average age 23.85 years) who underwent bimaxillary orthognathic surgery with maxillomandibular setback. We performed computed tomography and portable polysomnography before and after the surgery to assess changes in airway space and Apnea-Hypopnea Index (AHI) values (total, supine, non-supine). RESULTS: The oropharyngeal airway volume decreased by 29% after the surgery, which was statistically significant (p < .05). The upper airway volume and hypopharyngeal airway volume were decreased, but not significantly (4 and 19%, respectively). The changes in airway surface area were statistically significant at all levels examined (p < .05). Changes in the maximum anteroposterior width of the airway were also significant at all levels (p < .05). However, the changes in maximum lateral width were only statistically significant at C2 level (p < .05). AHI values were increased after the surgery but not significantly at any position. CONCLUSIONS: Although bimaxillary surgery with maxillomandibular setback significantly reduces the airway space, it does not affect AHI values or induce obstructive sleep apnea.

Effects of bodily retraction of mandibular incisors versus mandibular setback surgery on pharyngeal airway space: A comparative study / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to compare the changes induced in the pharyngeal airway space by orthodontic treatment with bodily retraction of the mandibular incisors and mandibular setback surgery without extraction. METHODS: This retrospective study included 63 adult patients (32 men and 31 women). Thirty-three patients who had been treated via four-bicuspid extraction and bodily retraction of the mandibular incisors (incisor retraction, IR group) were compared with 30 patients who had been treated via mandibular setback surgery (MS group) without extraction. Lateral cephalograms were acquired and analyzed before (T1) and after treatment (T2). RESULTS: The superior pharyngeal airway space did not change significantly in either group during treatment. The middle pharyngeal airway space decreased by 1.15 ± 1.17 mm and 1.25 ± 1.35 mm after treatment in the IR and MS groups, respectively, and the decrease was comparable between the two groups. In the MS group, the inferior pharyngeal airway space (E-IPW) decreased by 0.88 ± 1.67 mm after treatment (p < 0.01). The E-IPW was larger in the MS group than in IR group at T1, but it did not differ significantly between the two groups at T2. No significant correlation was observed between changes in the pharyngeal airway space and the skeletal and dental variables in each group. CONCLUSIONS: The middle pharyngeal airway space decreased because of the posterior displacement of the mandibular incisors and/or the mandibular body. The E-IPW decreased only in the MS group because of the posterior displacement of only the mandibular body.

The structural changes of pharyngeal airway contributing to snoring after orthognathic surgery in skeletal class III patients / 대한악안면성형재건외과학회지

BACKGROUND: Two-jaw surgery including mandibular and maxillary backward movement procedures are commonly performed to correct class III malocclusion. Bimaxillary surgery can reposition the maxillofacial bone together with soft tissue, such as the soft palate and the tongue base. We analyzed changes of pharyngeal airway narrowing to ascertain clinical correlations with the prevalence of snoring after two-jaw surgery. METHODS: A prospective clinical study was designed including a survey on snoring and three-dimensional (3D) computed tomography (CT) in class III malocclusion subjects before and after bimaxillary surgery. We conducted an analysis on changes of the posterior pharyngeal space find out clinical correlations with the prevalence of snoring. RESULTS: Among 67 subjects, 12 subjects complained about snoring 5 weeks after the surgical correction, and examining the 12 subjects after 6 months, 6 patients complained about the snoring. The current findings demonstrated the attenuation of the largest transverse width (LTW), anteroposterior length (APL), and cross-sectional area (CSA) following bimaxillary surgery given to class III malocclusion patients, particularly at the retropalatal level. The average distance of maxillary posterior movements were measured to be relatively higher (horizontal distance 3.9 mm, vertical distance 2.6 mm) in case of new snorers. CONCLUSIONS: This study found that bimaxillary surgery could lead to the narrowing of upper airway at the retropalatal or retroglossal level as well as triggering snoring in subjects with class III malocclusion. Based on the current clinical findings, we also found that upper airway narrowing at retropalatal level may contribute to increasing the probability of snoring and that polysonography may need to be performed before orthognathic surgery in subjects with class III malocclusion.

Avaliação das alterações nas vias aéreas superiores através de tomografia computadorizada Cone-Beam em pacientes submetidos à cirurgia ortognática de avanço bimaxilar / Three-dimensional upper airway space changes after bimaxillary advancement by Cone-Beam Computed Tomography

Introdução: O descontentamento com a estética facial é considerado o fator motivador mais frequente na procura pela cirurgia ortognática, visto que este é o procedimento indicado nos casos de severas discrepâncias dentoesqueléticas em pacientes adultos. A anatomia das vias aéreas superiores (VAS) permite que fatores como obesidade, hipotonia muscular e deficiência mandibular favoreçam sua obstrução, podendo gerar a Apneia Obstrutiva do Sono (AOS), caracterizada por episódios recorrentes de obstrução parcial ou completa das VAS durante o sono. As cirurgias de avanço bimaxilar estão associadas ao aumento do espaço aéreo, no entanto, as alterações morfológicas e volumétricas ainda não são bem conhecidas. Objetivos: Avaliar as alterações em 3D do espaço aéreo faríngeo frente aos procedimentos de cirurgia ortognática de avanço bimaxilar em pacientes Classe I e II esqueléticos. Material e Métodos: A análise da área axial mínima e do volume da aérea superior foi realizada em pré-operatório (T0) e pós-operatório (T1) de 56 pacientes, sendo 21 do sexo masculino e 35 do sexo feminino, com média de idade de 35,8 (±10,7) anos, submetidos ao avanço bimaxilar pela técnica da osteotomia sagital de mandíbula bilateral associada ao avanço de maxila por meio de osteotomia Le Fort I. As avaliações foram feitas através de tomografia computadorizada Cone-beam, utilizando-se o Programa Dolphin Imaging 11.7. Foi utilizado o teste t pareado para comparar os dados pré e pós-operatórios. Todos os testes foram realizados com o programa Statistica, adotando-se um nível de significância de 5%. Resultados: No estudo do erro do método, não houve erro casual nem sistemático entre a primeira e a segunda medição das variáveis (p >0,05 em todas as medidas). A cirurgia de avanço bimaxilar apresentou uma média de 73,6% (± 74,75%) de aumento volumétrico e 113,5% (±123,87%) de aumento na área axial mínima. Conclusões: Podemos concluir que a cirurgia de avanço bimaxilar proporciona um aumento volumétrico significativo no espaço aéreo superior, bem como na área axial mínima, no entanto, esse ganho nem sempre ocorre na mesma magnitude para todos os pacientes.(AU)

Introduction: Facial aesthetics dissatisfaction is considered the most common motivating factor in the search for orthognathic surgery. This procedure may be used in cases of severe dental and skeletal discrepancies in adult patients. The restricted space anatomy of the upper airway space (UAS) allows features such as obesity, muscular hypotonia and mandibular deficiency favor clogging, which may lead to obstructive sleep apnea (OSA), characterized by recurrent episodes of partial or complete obstruction of the UAS during sleep. Surgeries of bimaxillary advancement are associated with increased UAS, however, the morphological and volumetric changes are not well known. Objectives: to evaluate changes in 3D pharyngeal airway in front of orthognathic surgery procedures of skeletal Class I and II subjects. Material and Methods: 3D pharyngeal airway was evaluated preoperative (T0) and postoperative (T1), with the aid of the analysis of the minimum axial area and airway volume. Fifty-six patients 21 male and 35 female, with a mean age of 35.8 (± 10.7) years undergo bimaxillary advancement by the technique of bilateral sagittal split osteotomy of the mandible associated with maxillary advancement through Le Fort I osteotomy. Measurements were made using Cone-beam Computed Tomography, using the Dolphin Imaging program 11.7. Paired t test was used to compare to the data between T0 and T1. All tests were performed with the Statistica Program, adopting a 5% significance level. Results: In the method error of the study, there was no casual or systematic error between the first and second measurement variables (p > 0.05 for all measures). The bimaxillary advancement surgery showed an average of 73.6% (± 74.75%) of increase in volume and 113.5% (±123.87%) increase in the minimum axial area. Conclusions: We concluded that the maxillomandibular advancement surgery provides a significant increase in volume in the UAS as well as the minimum axial area; however, this gain is not always in the same magnitude for all patients.(AU)

Dimensional change in soft tissues with complete dental prosthesis and its effect on airway space and natural head position.

Background: Insertion of the intraoral prosthesis causes deflection of the tongue, soft palate affecting the patency of the airway. Aims: To evaluate the cephalometric soft tissue variation in tongue, soft palate, and its effect on posterior airway space in edentulous patients with the insertion of the denture. Settings and Design: Randomized controlled trial. Materials and Methods: Complete denture (CD) prosthesis was fabricated for first time denture wearers comprising 22 males and 18 females within the age range of 50–65 years. Lateral skull radiographs were taken for each of the subjects in their resting position without CDs (T0), with CDs (T1) at least 1‑week postinsertion and after 6 months of usage (T2), respectively. The reference points, lines, and angles on the cephalometric films were used to evaluate the position or inclination of the head, variations in tongue position and length, the changes in the anteroposterior dimension of the soft palate, and posterior airway space variations. Intra‑investigator error variance was not found to be statistically significant (P < 0.05). Statistical Analysis Used: Using Statistical Package for the Social Sciences (SPSS) v16.0 the significant difference in the paired samples (without CD and with CD) was found using the paired t‑test. The probability value P = 0.05 is considered as a significant level. Results: On comparison of T1 and T0, the heads were more extended with the downward position of the tongue with an increase in its length and the posterior airway space was decreased in T1. Significant differences in values were not observed between T1 and T2. Conclusions: With CDs, the change in airway space was related to alteration in soft palate and tongue dimension. There were no changes in dimension at 6 months follow‑up.

Retrospective study on change in pharyngeal airway space and hyoid bone position after mandibular setback surgery

OBJECTIVES: The purpose of this study was to evaluate changes in the pharyngeal airway space and hyoid bone position after mandibular setback surgery with bilateral sagittal split ramus osteotomy (BSSRO) and to analyze the correlation between the amount of mandibular setback and the amount of change in pharyngeal airway space or hyoid bone position. MATERIALS AND METHODS: From January 2010 to February 2013, a total of 30 patients who were diagnosed with skeletal class III malocclusion and underwent the same surgery (BSSRO) and fixation method in the Division of Oral and Maxillofacial Surgery, Department of Dentistry at the Ajou University School of Medicine (Suwon, Korea) were included in this study. Lateral cephalograms of the 30 patients were assessed preoperatively (T1), immediately postoperatively (T2), and 6 months postoperatively (T3) to investigate the significance of changes by time and the correlation between the amount of mandibular setback and the amount of change in the airway space and hyoid bone position. RESULTS: Three regions of the nasopharynx, oropharynx, and hypopharynx were measured and only the oropharynx showed a statistically significant decrease (P<0.01). A significant posterior and inferior displacement of the hyoid bone was found 6 months after surgery (P<0.01). Analysis of the correlation between the amount of mandibular setback and the amount of final change in the airway space and hyoid bone position with Pearson's correlation showed no significant correlation. CONCLUSION: In this study, the oropharynx significantly decreased after mandibular setback surgery, and changes in the surrounding structures were identified through posteroinferior movement of the hyoid bone during long-term follow-up. Therefore, postoperative obstructive sleep apnea should be considered in patients who plan to undergo mandibular setback surgery, and necessary modifications to the treatment plan should also be considered.

Retrospective study of changes in pharyngeal airway space and position of hyoid bone after mandibular setback surgery by cephalometric analysis / 대한악안면성형재건외과학회지

BACKGROUND: The posterior movement of mandible was known as the main cause of the changes in the pharyngeal airway space (PAS) and the postoperative obstructive sleep apnea (OSA). The purpose of this study was to know the changes of PAS and position of hyoid bone. METHODS: Lateral cephalographies of 13 patients who had undergone sagittal split ramus osteotomy (SSRO) setback surgery were taken preoperatively (T1), postoperatively within 2 months (T2), and follow-up after 6 months or more (T3). On the basis of F-H plane, diameters of nasopharynx, oropharynx, and hypopharynx were measured. The movements of the soft palate, tongue, and hyoid bone were also measured. RESULTS: The amount of mandible setback was 7.5 +/- 3.8 mm. In the measurements of PAS, there was a statistically significant decrease of 2.8 +/- 2.5 mm in nasopharynx (P < 0.01), and 1.7 +/- 2.4 mm in oropharynx (P < 0.01) were observed after surgery. The hypopharynx decreased 1.0 +/- 2.1 mm after surgery and continuously decreased 1.0 +/- 2.8 mm at follow-up. The changes in hyoid bone position showed the posterior movement only after surgery and posteroinferior movement at follow-up. CONCLUSIONS: The PAS such as nasopharynx, oropharynx, and hypopharynx showed relatively high correlation with the amount of mandibular setback. The change of resistance in upper airway may be important for the prevention of OSA after mandibular setback surgery.

Changes of the Airway Space and the Position of Hyoid Bone after Mandibular Set Back Surgery Using Bilateral Sagittal Split Ramus Osteotomy Technique / 대한악안면성형재건외과학회지

PURPOSE: Although there have been several studies of reduced airway space after mandibular setback surgery using the sagittal split ramus osteotomy technique, research on the risk factors for changes of the airway space is lacking. Therefore, this study was performed to examine airway changes and the position of the hyoid bone after orthognathic surgery, and to assess possible risk factors. METHODS: In this retrospective study, 50 patients who underwent posterior displacement of the mandible by the bilateral sagittal split ramus osteotomy technique were included. Changes of the position of the hyoid bone and the airway space were analyzed over various follow-up periods, using cephalometric radiography taken preoperatively, immediately after surgery, eight weeks after surgery, six months after surgery, and one year after surgery. To identify risk factors, multiple regression analysis of age, gender, body mass index (BMI), posterior mandibular movement, and the presence of genioplasty was performed. RESULTS: Inferor and posterior movement of the hyoid bone was observed postoperatively, but subsequent observations showed regression towards the anterosuperior aspect. The airway space also significantly decreased after surgery (P<0.05), and increased slightly up until six months after surgery. The airway space significantly decreased (beta=0.47, P<0.01) as the amount of mandibular setback increased. However, age, sex, BMI, and presence of genioplasty were not associated with airway reduction. CONCLUSION: The amount of mandibular set back was significantly associated with postoperative reduction of airway space. It is necessary to establish a treatment plan considering this factor.

X-cephalometric study of different parts of the upper airway space and changes in hyoid position following mandibular fractures / Estudio cefalométrico con rayos X de diferentes partes del espacio de las vías respiratorias superiores y cambios en la posición hioidea tras fracturas mandibulares

OBJECTIVE: This study analyses the different parts of the upper airway space and the changes in hyoid position. The results provide a clinical reference for developing timely and effective treatment programmes for patients with mandibular fractures caused by maxillofacial trauma. METHODS: Standard X-cephalometric measurements of the lateral skull of 210 subjects were taken. The subjects were divided into four fracture groups: condylar, mandibular angle, mandibular body, and parasymphyseal. RESULTS: The radiographs of the mandibular fracture groups were compared with the normal occlusion group to analyse the upper airway space and the changes in hyoid position. Different types of fractures have different effects on the upper airway space. Bilateral mandibular body fracture and the parasymphyseal fracture have a significant influence on the lower oropharyngeal and laryngopharyngeal airway spaces, with serious obstructions severely restricting the ventilatory function ofpatients. CONCLUSIONS: Fractures at different parts of the mandibular structure are closely related to the upper airway and hyoid position.

OBJETIVO: Este estudio analiza las diferentes partes del espacio de las vías respiratorias superiores y los cambios de posición hioidea. Los resultados proporcionan una referencia clínica para desarrollar programas de tratamiento oportuno y eficaz para los pacientes con fracturas de la mandíbula, causadas por trauma maxilofacial. MÉTODOS: Se hicieron mediciones X-cefalométricas estándares del cráneo lateral a 210 sujetos. Los sujetos fueron divididos en cuatro grupos de fractura: ángulo mandibular, condilar, cuerpo mandibular y parasinfisaria. RESULTADOS: Las radiografías de los grupos de fractura mandibular fueron comparadas con el grupo de oclusión normal para analizar el espacio de las vías respiratorias superiores y los cambios de posición hioidea. Diferentes tipos de fracturas tienen diferentes efectos sobre el espacio de las vías respiratorias superiores. La fractura de cuerpo mandibular bilateral y la fractura de parasinfisaria tienen una influencia significativa en los espacios de las vías respiratorias orofaríngea y laringofaríngea inferiores, con serios obstáculos restringiendo severamente la función respiratoria de los pacientes. CONCLUSIONES: Las fracturas en diferentes partes de la estructura mandibular se hallan estrechamente vinculadas a las vías respiratorias superiores y a la posición hioidea.

A influência da má oclusão Classe II e do uso do aparelho extraoral no espaço aéreo nasofaríngeo / The influence of Class II malocclusion and the use of headgear appliance over nasopharyngeal airway space

A redução do espaço aéreo nasofaríngeo pode estar associada a vários fatores, em especial à hipertrofia das tonsilas. Estudos mais recentes, entretanto, apontam que este estreitamento também pode ser decorrente de más oclusões esqueléticas, em especial da Classe II. Objetivou-se com esta revisão de literatura estudar a influência desta displasia e o tratamento da mesma com aparelho extraoral, no tamanho do espaço aéreo nasofaríngeo.

Nasopharyngeal airway space reduction can be associated to various factors, especially to hypertrophic tonsils. Most recent studies, however, demonstrate that this constriction can also be related to skeletal malocclusions, most specifically, the Class II malocclusion. The purpose of this literature review was to report the influence of this skeletal dysplasia, and its treatment with headgear appliances, on the size of the nasopahryngeal airway.

Changes of Pharyngeal Airway Space after Mandibular Setback Surgery in Computed Tomography Images

An Investigation of Hyoid Bone Position and Airway Space in Class III Malocclusion after Orthognathic Surgery

Avaliação do espaço aéreo faríngeo por meio da tomografia computadorizada de feixe cônico / Assessment of pharyngeal airway space using Cone-Beam Computed Tomography

INTRODUÇÃO: a avaliação do espaço aéreo superior faz parte da rotina na elaboração do diagnóstico e plano de tratamento ortodôntico. A radiografia cefalométrica em norma lateral tem sido usada rotineiramente na avaliação da permeabilidade do espaço aéreo, esbarrando na limitação de fornecer uma imagem bidimensional de uma estrutura tridimensional. A Tomografia Computadorizada de Feixe Cônico (TCFC) tem entrado na realidade ortodôntica trazendo um arsenal de informações concernentes ao espaço aéreo superior. Por fornecer uma imagem tridimensional, possibilita determinar de maneira precisa a área de maior estreitamento da faringe, que ofereceria maior resistência à passagem aérea. OBJETIVOS: o propósito deste artigo é esclarecer o ortodontista quanto aos recursos disponíveis na TCFC para o diagnóstico de possíveis barreiras físicas que possam diminuir a permeabilidade das vias aéreas superiores.

INTRODUCTION: Evaluation of upper airway space is a routine procedure in orthodontic diagnosis and treatment planning. Although limited insofar as they provide two dimensional images of three-dimensional structures, lateral cephalometric radiographs have been used routinely to assess airway space permeability. Cone-Beam Computed Tomography (CBCT) has contributed to orthodontics with information concerning the upper airway space. By producing three-dimensional images CBCT allows professionals to accurately determine the most constricted area, where greater resistance to air passage occurs. OBJECTIVES: The purpose of this article is to enlighten orthodontists on the resources provided by CBCT in the diagnosis of possible physical barriers that can reduce upper airway permeability.

Comparison of Posterior Pharyngeal Airway Space at Sitting and Supine Positions in the PACU after Uvulopalatopharyngoplasty in Patients with Obstructive Sleep Apnea Syndrome / 대한마취과학회지

BACKGROUND: Uvulopalatopharyngoplasty (UPPP) is one of the most common treatments for patients with obstructive sleep apnea syndrome (OSAS) who suffer from repetitive apnea and oxygen desaturation during sleep. It is important to properly manage the patient's airway in the PACU after surgery in order to prevent potential airway-related postoperative complications. METHODS: 20 patient cases of ASA I or II who were over 20 years old and had undergone UPPP under general anesthesia were reviewed. In PACU, Posterior pharyngeal airway space (PAS) was measured on a lateral cranial radiograph at both supine and sitting positions and the blood pressure and oxygen saturation were measured. RESULTS: PAS significantly increased in the sitting position (avg. 11.7 mm in supine, 15.7 mm in sitting, P < 0.05) but there was no influence on the blood pressure or oxygen saturation. CONCLUSIONS: PAS is associated with the patency of the airway and the increase of PAS in patients in the sitting position while in the PACU is helpful to airway management following UPPP.

A study of upper airway dimensional change according to maxillary superior movement after orthognathic surgery / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the upper airway dimensional change according to maxillary superior movement after orthognathic surgery and to identify the relationship between the amount of maxillary movement and upper airway dimensional changes. METHODS: The samples consisted of 24 adult patients (9 males and 15 females) who had a skeletal discrepancy and had received presurgical orthodontic treatment. They underwent Le Fort I superior impaction osteotomy and mandibular setback surgery. Cephalometric x-rays were taken at 3 stages - T0 (before orthognathic surgery), T1 (just or within 2 weeks after orthognathic surgery), T2 (6 months after surgery) RESULTS: 1, Pharyngeal airway space (PAS (R)-nasopharynx) was decreased after surgery (T1) but recovered at 6 months after surgery; 2, Pharyngeal airway space (PAS (NL)-palatal plane) was increased after surgery and at 6 months after surgery; 3, Pharyngeal airway space (PAS (OL)-occlusal plane) was increased at T1 and was decreased at T2; 4, Soft palate thickness was increased at T1 but it became the same or thinner at T2; 5, There is no statistically significant relation between the amount of maxillary superior movement and pharyngeal airway space. CONCLUSIONS: These findings suggested that the maxillary superior movement of about an average of 4.40 +/- 1.14 mm did not affect upper pharyngeal airway space changes.

A study on the correlation between airway space and facial morphology in Class III malocclusion children with nasal obstruction / 대한치과교정학회지

OBJECTIVE: The aim of this study was assessment of the relationship between airway space and facial morphology in Class III children with nasal obstruction. METHODS: For this study, 100 Class III children (50 boys and 50 girls) were chosen. All subjects were refered to ENT, due to nasal obstruction. Airway space measurements and facial morphology measurements were measured on lateral cephalometric radiograph. Pearson correlation analysis was used to assess the relationship between airway space and facial morphology. RESULTS: Ramal height, SNA, SNB, PFH, FHR and facial plane angle were positively related to upper PAS, and sum of saddle angle, articular angle, and gonial angle, SN-GoGn, Y-axis to SN and FMA negatively related to upper PAS. Gonial angle, FMA were positively related to lower PAS, and articular angle, facial depth, PFH and FHR negatively related to lower PAS. PCBL, ramal height, Mn. body length, Mn. body length to ACBL, facial depth, facial length, PFH and AFH were positively related to tonsil size. Sum of saddle angle, articular angle, gonial angle, facial length, AFH, FMA and LFH were positively related to tongue gap, and IMPA and overbite was negatively related to tongue gap. Upper PAS, related to size of adenoid tissue, was mainly related to posterior facial dimension following a vertical growth pattern of face and mandibular rotation. Lower PAS and tonsil size, related to anterior-posterior tongue base position, were significantly related to each other. Lower PAS was related to growth pattern of mandible, and tonsil size was related to size of mandible and horizontal growth pattern of face. Tongue gap was related to anterior facial dimension following a vertical growth pattern of face. CONCLUSION: Significant relationship exists between airway space and facial morphology.

A radiographic study of changes of upper respiratory airway space after orthognathic surgery of both jaws in patients with skeletal class III malocclusion