Medium-term effects of rapid maxillary expansion on nasal cavity and pharyngeal airway volumes considering age as a factor: A retrospective study.

OBJECTIVES: The medium-term effects of rapid maxillary expansion (RME) on nasal cavity (NC) and upper airway (UA) dimensions based on chronological age are still unclear. This retrospective study evaluated the medium-term changes occurring in the NC and pharyngeal airways (PA) after RME in two distinct age-based cohorts of patients. METHODS: This retrospective study included 48 subjects who underwent RME grouped in two cohorts: a 6-9-year-old group (EEG group: early expansion group - 25 subjects) and an 11-14-year-old group (LEG group: late expansion group - 23 subjects). NC and PA volumes were analyzed from CBCT imaging segmentation before RME (T0) and twelve months after RME (T1). The amount of maxillary expansion (PW) and minimal cross-sectional area (CSmin) were also considered. RESULTS: All PAs' volumetric sub-regions, CSmin and PW showed a significant volumetric increment (p < 0.05). Inter-group comparisons showed significant differences (p < 0.05) for nasopharynx and CSmin parameters (p < 0.05), while no significant changes were recorded for the other UA's sub-regions and PW (p > 0.05). According to a deviation analysis, part of the UA increase (more marked for the nasopharynx area) may have occurred due to reduced adenotonsillar tissues, which were larger in the EEG group. CONCLUSIONS: Twelve months after treatment, clinicians should not expect changes in the UAs dimensions to be solely related to treatment effects of RME; instead, normal craniofacial growth changes and spontaneous regression of the adenotonsillar tissue could represent the most significant factors influencing UAs changes. CLINICAL SIGNIFICANCE: From the clinical perspective, the results of the present study encourage caution when considering the therapeutic effects of RME on airways dimensions.

Análisis bidimensional de la permeabilidad de vías aéreas con el tamaño de senos maxilares y su relación con el desarrollo de la clase esqueletal en una población mexicana / Two-dimensional analysis of airway permeability with maxillary sinus size and its relationship with the development of skeletal class in a Mexican population

Comparar la permeabilidad de las vías aéreas y el tamaño de los senos maxilares en relación con la clase esqueletal. se midieron 90 radiografías lateral de cráneo, divididas en 3 grupos, comparando las 3 clases esqueletales, las cuales se determinaron con la medida ANB de Steiner, y estas a su vez en dos subgrupos que fueron hombres y mujeres, en las cuales se utilizó el análisis de McNamara para el análisis de vías aéreas y para el área del seno maxilar se tomaron dos medidas una antero-posterior y cefálica-caudal. Al comparar los hombres con las mujeres se identificó significancia estadística en vía área superior de clase II (p=≤0.017), vía aérea inferior de clase III (p=≤0.006). Al comparar las clases esqueletales en hombres se identificó diferencias en la vía aérea superior en las clases I vs III (p=≤0.05), inferior en la clase I vs III (p=≤0,001) y II vs III (p=≤0.044). Con respecto a mujeres se identificó significancia en la vía aérea superior al comparar la clase I vs II (p=≤0,043), vía aérea inferior en la clase II vs III (p=≤0.05), longitud del seno maxilar al comparar clase I vs II (p=≤0.017). Entre la clase I esqueletal y la clase II, el tamaño de los senos maxilares resulto menor en longitud en las mujeres de clase II esqueletal. Entre la clase I y clase III esqueletal en hombres, se encontró una longitud menor en la vía aérea superior e inferior en la clase I. Las vías aéreas resultaron en menor tamaño en sujetos de clase II.

SUMMARY: To compare the airway permeability and the size of the maxillary sinuses in relation to the skeletal class. 90 lateral skull radiographs were divided into 3 groups, comparing the 3 skeletal classes, which were determined with Steiner's ANB measurement, and these were once in two subgroups that were men and women, in any McNamara analysis was used for the analysis of airways and for the maxillary sinus area measurements were made an antero-posterior and cephalic-caudal. When comparing males with females, statistical significance was identified in the upper class II route (p=≤0,017), lower class III airway (p=≤0.006). At least skeletal classes in men, differences were identified in the upper airway in classes I vs III (p=≤0.05), lower in class I vs III (p=≤0.001) and II vs III (p=≤0.044). With respect to women, significance was identified in the upper airway when comparing class I vs II (p=≤0.043), lower airway in class II vs. III (p=≤0.05), maxillary sinus length to class I vs II (p=≤0.017). Between skeletal class I and class II, maxillary sinus size was shorter in length in skeletal class II women. Between class I and skeletal class III in men, a lower length was found in the upper and lower airways in class I. The airways were found to be smaller in class II subjects.

ANATOMICAL RATIONALE FOR CHOOSING A BLADE FOR POWER-ASSISTED ADENOIDECTOMY IN CHILDREN DEPENDING ON DENTITION.

OBJECTIVE: The aim: To study the anatomic features of the facial skull structures in children of various ages depending on dentition. PATIENTS AND METHODS: Materials and methods: One hundred and forty-four children aged 2-12 years were divided into 4 groups depending on dentition. They underwent anthropometric measure¬ments during adenoidectomy. Based on the cosine theorem, the calculated values were obtained. RESULTS: Results: The distance from choana to the free edge of the retracted soft palate gradually increases from 2.01±0.61 cm in children with stable primary dentition up to 3.09±1.02 cm with mixed dentition. Palato-nasopharyngeal angle in children with stable primary dentition is 126.25±8.76°, in children with aging primary dentition - 132.81±12.21°, and in children with mixed dentition - 120.54±13.72°. CONCLUSION: Conclusions: The optimal configuration of the blade for power-assisted adenoidectomy in children with stable primary dentition has an angle of 53.53±8.76°, and the length of the working part of 2.01±0.61 cm, in children with aging primary dentition - 47.18±12.21° and 2.10±0.71 cm, with mixed dentition - 59.45±13.72° and 3.09±1.02 cm, respectively.

Clinical perspectives on nasopharyngeal morphology in humans.

The nasopharynx is an integral component of the upper aerodigestive tract, whose morphologic features share an intimate relationship with a vast array of clinical, functional, and quality of life conditions related to contemporary humans. Its composite architecture and central location amidst the nasal cavity, pharyngotympanic tube, palate, and skull base bears implications for basic physiologic functions including breathing, vocalization, and alimentation. Over the course of evolution, morphological modifications of nasopharyngeal anatomy have occurred in genus Homo which serve to distinguish the human upper aerodigestive tract from that of other mammals. Understanding of these adaptive changes from both a comparative anatomy and clinical perspective offers insight into the unique blueprint which underpins many clinical pathologies currently encountered by anthropologists, scientists, and otorhinolaryngologists alike. This discussion intends to familiarize readers with the fundamental role that nasopharyngeal morphology plays in upper aerodigestive tract conditions, with consideration of its newfound clinical relevance in the era of the COVID-19 pandemic.

Complications of Nasopharyngeal Swabs and Safe Procedures for COVID-19 Testing Based on Anatomical Knowledge.

Nasopharyngeal swabs have been widely to prevent the spread of coronavirus disease 2019 (COVID-19). Nasopharyngeal COVID-19 testing is a generally safe and well-tolerated procedure, but numerous complications have been reported in the media. Therefore, the present study aimed to review and document adverse events and suggest procedural references to minimize preventable but often underestimated risks. A total of 27 articles were selected for the review of 842 related documents in PubMed, Embase, and KoreaMed. The complications related to nasopharyngeal COVID-19 testing were reported to be rarely happened, ranging from 0.0012 to 0.026%. Frequently documented adverse events were retained swabs, epistaxis, and cerebrospinal fluid leakage, often associated with high-risk factors, including severe septal deviations, pre-existing skull base defects, and previous sinus or transsphenoidal pituitary surgery. Appropriate techniques based on sufficient anatomical knowledge are mandatory for clinicians to perform nasopharyngeal COVID-19 testing. The nasal floor can be predicted by the line between the nostril and external ear canal. For safe testing, the angle of swab insertion in the nasal passage should remain within 30° of the nasal floor. The swab was gently inserted along the nasal septum just above the nasal floor to the nasopharynx and remained on the nasopharynx for several seconds before removal. Forceful insertion should be attempted, and alternative examinations should be considered, especially in vulnerable patients. In conclusion, patients and clinicians should be aware of rare but possible complications and associated high-risk factors. The suggested procedural pearls enable more comfortable and safe nasopharyngeal COVID-19 testing for both clinicians and patients.

Efeitos do posicionamento sagital da mandíbula na morfometria das vias aéreas superiores / Efects of sagital positioning of the mandibule in upper airway morphometry

O objetivo do presente estudo foi analisar as dimensões das vias aéreas superiores (VAS) em indivíduos com diferentes posicionamentos sagitais da mandíbula, bem como a sua relação com o comprimento efetivo mandibular (CoGn). A amostra foi constituída por 63 exames de tomografia computadorizada de feixe cônico (TCFC) de indivíduos com idade entre 13 e 35 anos, alocados em três grupos conforme os valores angulares de SNB: grupo com retrognatismo mandibular (RMand); grupo com posicionamento normal da mandíbula (NMand) e grupo com prognatismo mandibular (PMand). Com o auxílio do programa Dolphin Imaging® (versão 11.95 Premium), as VAS foram subdivididas em Nasofaringe (NF), Orofaringe (OF) e Hipofaringe (HF), e o volume (Vol) e área axial mínima (Axmin) de cada região mensurados, assim como a altura (Alt) da OF e HF. A medida linear CoGn também foi averiguada e sua influência sobre as dimensões das VAS avaliada. MANCOVA foi utilizada para comparar o conjunto de variáveis das VAS entre os grupos de acordo com o padrão mandibular. Além disso, modelos de regressão linear foram implementados para estimar, independentemente, o efeito x do SNB e CoGn nas dimensões das VAS. Indivíduos com prognatismo mandibular apresentaram medidas significativamente maiores para NF-Axmin e OF-Vol, quando comparados aos indivíduos que mostraram normalidade e retrognatismo mandibular (P < 0,05). Não foram observadas diferenças entre os grupos para quaisquer das outras medidas consideradas no estudo. A variável CoGn foi relacionada às medidas de volume de todas as regiões avaliadas das VAS e também à HF-Alt. Concluiu-se que indivíduos com prognatismo mandibular apresentaram, de modo expressivo, maior área axial mínima da Nasofaringe e maior volume da Orofaringe quando comparados àqueles com normalidade e retrognatismo mandibular; destacando-se que o comprimento efetivo mandibular demonstrou ser um preditor mais relevante nas dimensões das VAS em comparação ao SNB. (AU)

The aim of the present study was to analyze the dimensions of the upper airways (UA) in individuals with different sagittal positioning of the mandible, as well as its relationship with the effective mandibular length (CoGn). The sample consisted of 63 cone beam computed tomography (CBCT) scans of individuals aged between 13 and 35 years, allocated into three groups according to the angular values of SNB: Group with Mandibular Retrognathism (RMand); Group with Normal Jaw and Group with Mandibular Prognathism (PMand). Using Dolphin Imaging® program (version 11.95 Premium), the UA were subdivided into Nasopharynx (NP), Oropharynx (OP) and Hypopharynx (HP), and the volume (Vol) and minimum axial area (Axmin) of each region measured, as well as the total height (Ht) of the OP and HP. The linear measure CoGn was also investigated and its influence on the dimensions of the VAS evaluated. MANCOVA was used to compare the set of VAS variables between the groups according to the mandibular pattern. In addition, linear regression models were implemented to independently estimate the effect of SNB and CoGn on UA xii dimensions. Individuals with mandibular prognathism had significantly higher measurements for NP-Axmin and OP-Vol, when compared to individuals with harmony and mandibular retrognathism (P < 0.05). No differences were observed between groups for any of the other measures considered in the study. The CoGn variable was related to the volume measurements of all the evaluated regions of the UA and also to the HP-Ht. It was concluded that individuals with mandibular prognathism significantly presented a greater minimum axial area of the Nasopharynx and greater volume of the Oropharynx when compared to those with harmony and mandibular retrognathism; highlighting that the effective mandibular length proved to be a more relevant predictor in the dimensions of the UA compared to the SNB. (AU)

Three-dimensional evaluation of upper airway changes following rapid maxillary expansion: A retrospective comparison with propensity score matched controls.

BACKGROUND: The aim of this study is to evaluate upper airway changes three-dimensionally following rapid maxillary expansion (RME) and compare the changes with matched controls. MATERIALS AND METHODS: Seventeen patients (mean age 12.6 ± 1.8 years) with maxillary transverse deficiency were treated with RME. Using the propensity score matching method, 17 patients (mean age 12.3 ± 1.5 years) were selected from a non-RME control group of 33. Case-control matching was performed based on 5 covariates: age, gender, CBCT scan interval, sagittal skeletal pattern, and tongue posture. Airway volumes of nasopharynx and oropharynx and minimum cross-sectional areas (MCA) of oropharynx were measured and compared between the case and control groups in CBCT scan images. RESULTS: In the case group, significant increases from before to after RME were found in all measurements except MCA of the retroglossal segment of oropharynx. Before treatment, there were no significant differences between case group and control group. While comparing the case group with the control group after treatment showed overall greater increases in the case group. In particular, MCA of retropalatal segment showed statistically significant differences. CONCLUSION: The results of this study indicate that RME causes an increase in upper airway dimensions.

Aerodynamic characteristics in upper airways among orthodontic patients and its association with adenoid nasopharyngeal ratios in lateral cephalograms.

BACKGROUND: Adenoid hypertrophy among orthodontic patients may be detected in lateral cephalograms. The study investigates the aerodynamic characteristics within the upper airway (UA) by means of computational fluid dynamics (CFD) simulation. Furthermore, airflow features are compared between subgroups according to the adenoidal nasopharyngeal (AN) ratios. METHODS: This retrospective study included thirty-five patients aged 9-15 years having both lateral cephalogram and cone beam computed tomography (CBCT) imaging that covered the UA region. The cases were divided into two subgroups according to the AN ratios measured on the lateral cephalograms: Group 1 with an AN ratio < 0.6 and Group 2 with an AN ratio ≥ 0.6. Based on the CBCT images, segmented UA models were created and the aerodynamic characteristics at inspiration and expiration were simulated by the CFD method for the two groups. The studied aerodynamic parameters were pressure drop (ΔP), maximum midsagittal velocity (Vms), maximum wall shear stress (Pws), and minimum wall static pressure (Pw). RESULTS: The maximum Vms exhibits nearly 30% increases in Group 2 at both inspiration (p = 0.013) and expiration (p = 0.045) compared to Group 1. For the other aerodynamic parameters such as ΔP, the maximum Pws, and minimum Pw, no significant difference is found between the two groups. CONCLUSIONS: The maximum Vms seems to be the most sensitive aerodynamic parameter for the groups of cases. An AN ratio of more than 0.6 measured on a lateral cephalogram may associate with a noticeably increased maximum Vms, which could assist clinicians in estimating the airflow features in the UA.

Horse choanae are directionally asymmetric / Las coanas de los caballos son direccionalmente asimétricas

SUMMARY: Studies related to the upper respiratory pathway asymmetries are still scarce in the veterinary literature. We present here a study of choanae asymmetries of a pure horses belonging to "Cavall Pirinenc Català" (Pyrenean Horse Breed). For this goal, the palates of 23 dry skulls with no apparent pathologies were photographed and evaluated using geometric morphometrics. On each photo, we identified and digitized a total of 26 points (subset of 2 mid-sagittal, 4 paired landmarks (discrete homologous points) and 10 semilandmarks (points on an outline determined by extrinsic criteria) per side on the choana. Both fluctuating and directional asymmetries appeared statistically significant, the latter accounting more than half of the total variation. The lateral bend observed in horse choanae may be due to the asymmetrically positioned nasal passages. So detected equine choana asymmetry must rather be considered functional, with no clinical implication and presents an important consideration when equine choanae shape.

RESUMEN: Los estudios relacionados con las asimetrías de las vías respiratorias superiores aún son escasos en la literatura veterinaria. Presentamos un estudio de coanas asimetrías de un caballo puro perteneciente al "Cavall Pirinenc Català" (Raza del Caballo de los Pirineos). Para ello, se fotografiaron y evaluaron los paladares de 23 cráneos secos sin patologías aparentes mediante morfometría geométrica. En cada foto, identificamos y digitalizamos un total de 26 puntos (subconjunto de 2 puntos medio sagitales, 4 puntos de referencia emparejados (puntos homólogos discretos) y 10 puntos semillanos (puntos en un contorno determinado por criterios extrínsecos) por lado de la coana. Ambos fluctúan Las asimetrías direccionales aparecieron estadísticamente significativas, representando estas últimas más de la mitad de la variación total. La curvatura lateral observada en las coanas de caballo puede deberse a los conductos nasales asimétricamente posicionados. Por lo tanto, la asimetría de coanas equinas detectada debería considerarse funcional, sin implicación clínica y presenta una importante consideración cuando se forman coanas equinas.

Accessioning and automation compatible anterior nares swab design.

The COVID-19 pandemic has resulted in an unparalleled need for viral testing capacity across the world and is a critical requirement for successful re-opening of economies. The logistical barriers to near-universal testing are considerable. We have designed an injection molded polypropylene anterior nares swab, the Rhinostic, with a screw cap integrated into the swab handle that is compatible with fully automated sample accessioning and processing. The ability to collect and release both human and viral material is comparable to that of several commonly used swabs on the market. SARS-CoV-2 is stable on dry Rhinostic swabs for at least 3 days, even at 42 °C, and elution can be achieved with small volumes. To test the performance of the Rhinostic in patients, 119 samples were collected with Rhinostic and the positive and negative determinations were 100 % concordant with samples collected using Clinical Laboratory Improvement Amendments (CLIA) use approved nasal swabs at a clinical lab. The Rhinostic swab and barcoded tube set can be produced, sterilized, and packaged cost effectively and is designed to be adopted by clinical laboratories using automation to increase throughput and dramatically reduce the cost of a standard SARS-CoV-2 detection pipeline.

Further Research Needed to Understand Relationship Between Tubarial Glands and Eustachian Tube Dysfunction.

The pathophysiology of eustachian tube dysfunction (ETD) remains poorly characterized, and it may result in significant patient morbidity. A recent study has identified a collection of previously unidentified salivary glands in the nasopharynx that overlay the torus tubarius. While salivary gland tissue has been described in the nasopharynx, the newly discovered salivary gland tissue has been denoted tubarial glands (TGs) and theorized to be a distinct organ. The TGs have been suggested to aid in lubrication of the oropharynx and nasopharynx. However, the exact clinical significance of TGs is unknown. Given the proximity of the TG to the eustachian tube, it is possible that the TGs may be related to the development of ETD. Future studies of the TGs and related pathophysiology may improve approaches to developing future ETD treatments.

Comparison of the selection of nasotracheal tube diameter based on the patient's sex or size of the nasal airway: A prospective observational study.

When selecting the nasotracheal tube diameter for nasotracheal intubation, atraumatic introduction of the tube through the nasal passage and a safe location of the tube's cuff and tip should be ensured simultaneously. To maintain safety margin for the tube's cuff and tip from the vocal cords and carina (2 cm and 3 cm, respectively), the maximum allowable proximal-cuff-to-tip distance was calculated as 5 cm less than the measured vocal cords-to-carina distance. The primary aim of this study was to find a single predictive preoperative factor of the nostril size and maximum allowable proximal-cuff-to-tip distance of nasotracheal tubes. The secondary aim was to compare the difference in the safety margin between the maximum allowable proximal-cuff-to-tip distance based on the patient's airway and the actual proximal-cuff-to-tip distance of the selected tube. We used fiberoptic bronchoscope to measure the distance from the vocal cords to the carina for the calculation of the maximum allowable proximal-cuff-to-tip distance. We analyzed the association of preoperative characteristics such as age, sex, height, and weight with the nostril size and maximum allowable proximal-cuff-to-tip distance. The proportion of patients with appropriate locations of both the cuff and tip was evaluated. Sex and height were significant predictive factors of the nostril size and maximum allowable proximal-cuff-to-tip distance, respectively (p = 0.0001 and p = 0.0048). The difference in the safety margin was significantly decreased when the tube diameter was selected based on the nostril size rather than by sex (p<0.0001). The proportion of patients who had the appropriate cuff/tip location was significantly larger (75.2%) when the tube diameter was selected by sex compared to when it was selected by the nostril size (65%) (p<0.0001). It is more suitable to select the nasotracheal tube diameter based on sex rather than by nostril size to ensure the safe location of the tube's cuff and tip simultaneously.

Evaluating the effect of midpalatal corticotomy-assisted rapid maxillary expansion on the upper airway in young adults using computational fluid dynamics.

Midpalatal corticotomy-assisted rapid maxillary expansion (MCRME) is a minimally invasive treatment of maxillary transverse deficiency (MTD) in young adults. However, the effect of MCRME on respiratory function still needs to be determined. In this study, we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics (CFD). Twenty patients with MTD (8 males, 12 females; mean age 20.55 years) had cone-beam computed tomography (CBCT) images taken before and after MCRME. The CBCT data were used to construct a three-dimensional (3D) upper airway model. The upper airway flow characteristics were simulated using CFD, and measurements were made based on the CBCT images and CFD. The results showed that the widths of the palatal bone and nasal cavity, and the intermolar width were increased significantly after MCRME. The volume of the nasal cavity and nasopharynx increased significantly, while there were no obvious changes in the volumes of the oropharynx and hypopharynx. CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment. Our results suggest that in these young adults with MTD, increasing the maxillary width, upper airway volume, and quantity of airflow by MCRME substantially improved upper airway ventilation.

Anatomy of teleost fish immune structures and organs.

The function of a tissue is determined by its construction and cellular composition. The action of different genes can thus only be understood properly when seen in the context of the environment in which they are expressed and function. We now experience a renaissance in morphological research in fish, not only because, surprisingly enough, large structures have remained un-described until recently, but also because improved methods for studying morphological characteristics in combination with expression analysis are at hand. In this review, we address anatomical features of teleost immune tissues. There are approximately 30,000 known teleost fish species and only a minor portion of them have been studied. We aim our review at the Atlantic salmon (Salmo salar) and other salmonids, but when applicable, we also present information from other species. Our focus is the anatomy of the kidney, thymus, spleen, the interbranchial lymphoid tissue (ILT), the newly discovered salmonid cloacal bursa and the naso-pharynx associated lymphoid tissue (NALT).

Correlation between craniofacial structures, anthropometric measurements, and nasopharyngeal dimensions in black adolescents.

OBJECTIVES: To evaluate the correlation between craniofacial structures, anthropometric measurements, and bony and soft tissue nasopharyngeal dimensions in African Black adolescents. METHODS: This retrospective cross-sectional study was conducted on 483 healthy adolescents (250 females and 233 males), randomly selected from one dental clinic. The inclusion criteria were skeletal and dental Class I, Black ethnicity, pubertal growth period as determined by the Greulich and Pyle atlas criteria, and no history of orthodontic treatment. Anthropometric measurements (stature, upper body height, lower body height, and BMI) and radiographic records (hand-wrist radiographs, and lateral cephalograms) were obtained. One investigator traced and analysed all cephalograms to determine three skeletal craniofacial parameters (maxillary length [Ar- ANS], mandibular length [Ar-Gn], and lower anterior facial height [ANS-Me]), and 14 (8 skeletal and 6 soft tissue) nasopharyngeal parameters. Pearson correlation coefficients and stepwise multiple linear regression analyses were conducted. RESULTS: The mean skeletal ages of females and males were 11.31±2.31y and 12.66±1.85y, respectively. Multiple linear regression analyses showed that stature, posterior height of nasal cavity (S-PNS), length of nasal floor (AA-PNS), and mean area of bony nasopharynx (Area 1) were significantly correlated with maxillary length, P<.001. Stature, BMI, S-PNS, vertical angle of nasopharynx (Ba-S-PNS), Area 1, adenoid height (AD), and linear hyoid bone measurements (H-AA, H-RGN, H-Ax) were all correlated with mandibular length, P<.05. Lower facial height showed sexual dimorphism and was significantly associated with vertical nasopharyngeal measurements, BMI and upper body height. CONCLUSIONS: Craniofacial structures were significantly associated with stature and upper body height. Maxillary growth was associated with bony nasopharyngeal variables. Mandibular growth and lower facial height were associated with bony and soft tissue nasopharyngeal variables. The sexual dimorphism in lower facial height warrants future studies to fully understand and manage the craniofacial complex and nasopharyngeal airway in African Black adolescents.

Navigation-Guided Measurement of the Inferior Limit Through the Endonasal Route to the Craniovertebral Junction.

BACKGROUND: The endoscopic endonasal approach (EEA) has been accepted as an alternative option for diseases at the craniovertebral junction. However, the inferior destination through the endoscopic endonasal approach is anatomically higher than that of the transoral approach. Therefore, preoperative assessment of accessibility is mandatory for appropriate selection of indication. Using a navigation system, we examined the inferior limit through the endonasal route and evaluated the relationships between surrounding anatomicl structures and the lowest point. METHODS: This study included patients who underwent endoscopic transsphenoidal surgery for intrasellar lesions at our hospital (N = 23). At the start of surgery, the lowest point (target point [TP]) was marked with a straight probe under guidance of the navigation system. We measured 4 parameters on preoperative computed tomography: nasal length, hard palate length, anterior-posterior diameter of the nasopharynx, and nasopalatine angle. Patients were classified into groups depending on whether the TP was at or above (group A) or below (group B) the hard palatine line. RESULTS: TPs were above the hard palatine line in 15 patients (group A) and below the hard palatine line in 8 patients (group B). No TPs reached the nasopalatine line. Nasal length (P = 0.03) and nasopalatine angle (P = 0.01) were larger in group B than in group A. There were no significant differences in anterior-posterior diameter of the nasopharynx or hard palate length. CONCLUSIONS: The hard palatine line is a reliable parameter for assessing the inferior limit of the endoscopic endonasal approach. Nostril size affects accessibility with surgical instruments.

Evaluation of the pharyngeal recess with cone-beam computed tomography.

PURPOSE: To evaluate the radiological anatomy of the pharyngeal recess (PR) by gender and age. METHODS: Images of patients who underwent cone-beam computed tomography (CBCT) were analyzed retrospectively. A total of 600 PRs (140 male, 160 female) were examined. PR depths, distances between the posterior nasal spine (PNS) and the posterior wall of the pharynx, right and left torus levatorius lengths, and distances between the right and left torus levatorius were measured on the axial plane passing through the PNS-basion point. RESULTS: PR depths differed significantly between age groups (right p = 0.030, left p = 0.047). The PR depths of individuals under 35 years of age were significantly higher than those of individuals aged 35 and over. Further, the distances between the PNS and the posterior wall of the pharynx differed significantly between age groups and between gender groups. The distances between the PNS and the posterior wall of the pharynx were shorter in patients under 35 years of age (p = 0.000). In terms of gender, these distances were significantly longer in males (p = 0.014). The distances between the right and left torus levatorius were also significantly longer in males (p = 0.029). CONCLUSION: The PR is the region in which nasopharyngeal carcinoma originates most frequently and is very important for early diagnosis. The present results indicated that this region can be examined with CBCT.