Structure-function relationships in the nasal cavity of Arctic and subtropical seals.

The heating and moistening of inhaled air, and the cooling and moisture removal from exhaled air, are crucial for the survival of animals under severe environmental conditions. Arctic mammals have evolved specific adaptive mechanisms to retain warmth and water and restrict heat loss during breathing. Here, the role of the porous turbinates of the nasal cavities of Arctic and subtropical seals is studied with this in mind. Mass and energy balance equations are used to compute the time-dependent temperature and water vapor profiles along the nasal passage. A quasi-1D model based on computed tomography images of seal nasal cavities is used in numerical simulations. Measured cross-sectional areas of the air channel and the perimeters of the computed tomography slices along the nasal cavities of the two seal species are used. The model includes coupled heat and vapor transfer at the air-mucus interface and heat transfer at the interfaces between the tissues and blood vessels. The model, which assumes constant blood flow to the nose, can be used to predict the temperature of the exhaled air as a function of ambient temperature. The energy dissipation (entropy production) in the nasal passages was used to measure the relative importance of structural parameters for heat and water recovery. We found that an increase in perimeter led to significant decreases in the total energy dissipation. This is explained by improved conditions for heat and water transfer with a larger complexity of turbinates. Owing to differences in their nasal cavity morphology, the Arctic seal is expected to be advantaged in these respects relative to the subtropical seal.

Strategies of vascularization of the ethmoid labyrinth in selected even-toed ungulates (Artiodactyla) and carnivores (Carnivora).

The anatomy of the nasal cavity and its structures, as well as other elements building a scaffold for olfactory organs, differs significantly among various groups of mammals. Understanding anatomical conditions of quality of olfaction are being studied worldwide and is a complex problem. Among many studies regarding bone and epithelial structures of turbinates and connected anatomical structures, few studies describe the vascularization of turbinates. Ethmoid turbinates are above all covered in olfactory epithelium containing branched axons that receive olfactory stimuli and as olfactory nerves penetrate the cribriform lamina of the ethmoid bone conveying information from smell receptors to the brain. Differences in vascularization of the cribriform plate and turbinates may add crucial information complementing studies regarding the olfactory organ's bone and soft tissue structures. In the study, we describe the vascularization of the cribriform plate of the ethmoid bone of 54 Artiodactyla and Carnivora.

Convergent evolution of olfactory and thermoregulatory capacities in small amphibious mammals.

Olfaction and thermoregulation are key functions for mammals. The former is critical to feeding, mating, and predator avoidance behaviors, while the latter is essential for homeothermy. Aquatic and amphibious mammals face olfactory and thermoregulatory challenges not generally encountered by terrestrial species. In mammals, the nasal cavity houses a bony system supporting soft tissues and sensory organs implicated in either olfactory or thermoregulatory functions. It is hypothesized that to cope with aquatic environments, amphibious mammals have expanded their thermoregulatory capacity at the expense of their olfactory system. We investigated the evolutionary history of this potential trade-off using a comparative dataset of three-dimensional (3D) CT scans of 189 skulls, capturing 17 independent transitions from a strictly terrestrial to an amphibious lifestyle across small mammals (Afrosoricida, Eulipotyphla, and Rodentia). We identified rapid and repeated loss of olfactory capacities synchronously associated with gains in thermoregulatory capacity in amphibious taxa sampled from across mammalian phylogenetic diversity. Evolutionary models further reveal that these convergences result from faster rates of turbinal bone evolution and release of selective constraints on the thermoregulatory-olfaction trade-off in amphibious species. Lastly, we demonstrated that traits related to vital functions evolved faster to the optimum compared to traits that are not related to vital functions.

Morphometric differences in normal bony nasolacrimal anatomy: comparison between four ethnic groups.

PURPOSE: To compare bony nasolacrimal duct anatomy between ethnic groups. METHODS: A retrospective observational study of patients of four ethnic groups who had high-resolution CTs between 2004 and 2019 covering the full length of their nasolacrimal ducts in two hospitals in Essex, England. Only normal ducts were included; patients with tearing or radiological abnormalities were excluded. Measurements were taken of the nasolacrimal duct and surrounding anatomy based on measurements found in the existing literature. RESULTS: More females (n = 114) than males (n = 40) were included. South Asian (Indian subcontinent), Afro-Caribbean and European groups were equivocal demographically (n = 25-29, mean age 40-45); however, the Oriental group was fewer in number (n = 13) and slightly older (mean age 51). South Asian and European ducts had no significant differences. Afro-Caribbean ducts were wider and shorter than European. Afro-Caribbean faces are wider and their noses flatter and wider than European. Oriental ducts were wider and longer than European, but Europeans have taller noses. CONCLUSION: The results from our Oriental group fits with the published data in Orientals. The bony nasolacrimal duct is greater in calibre (inner diameter) if the patient is of Afro-Caribbean or Oriental origin compared to European or South Asian. Acquired nasolacrimal duct obstruction in Afro-Caribbean or Oriental patients may be more likely due to secondary causes.

Reduction of olfactory and respiratory turbinates in the transition of whales from land to sea: the semiaquatic middle Eocene Aegyptocetus tarfa.

Ethmoturbinates, nasoturbinates, and maxilloturbinates are well developed in the narial tract of land-dwelling artiodactyls ancestral to whales, but these are greatly reduced or lost entirely in modern whales. Aegyptocetus tarfa is a semiaquatic protocetid from the middle Eocene of Egypt. Computed axial tomography scans of the skull show that A. tarfa retained all three sets of turbinates like a land mammal. It is intermediate between terrestrial artiodactyls and aquatic whales in reduction of the turbinates. Ethmoturbinates in A. tarfa have 26% of the surface area expected for an artiodactyl. These have an olfactory function and indicate that early whales retained a sense of smell in the transition from land to sea. Maxilloturbinates in A. tarfa have 6% of the surface area expected for an artiodactyl. These have a respiratory function and their markedly reduced size suggests that rapid inhalation and exhalation was already more important than warming and humidifying air, in contrast to extant land mammals. Finally, the maxilloturbinates of A. tarfa, although greatly reduced, still show some degree of similarity to those of artiodactyls, supporting the phylogenetic affinity of cetaceans and artiodactyls based on morphological and molecular evidence.

Comparative growth in the olfactory system of the developing chick with considerations for evolutionary studies.

Despite the long-held assumption that olfaction plays a relatively minor role in the behavioral ecology of birds, crown-group avians exhibit marked phylogenetic variation in the size and form of the olfactory apparatus. As part of a larger effort to better understand the role of olfaction and olfactory tissues in the evolution and development of the avian skull, we present the first quantitative analysis of ontogenetic scaling between olfactory features [olfactory bulbs (OBs) and olfactory turbinates] and neighboring structures (cerebrum, total brain, respiratory turbinates) based on the model organism Gallus gallus. The OB develops under the predictions of a concerted evolutionary model with rapid early growth that is quickly overcome by the longer, sustained growth of the larger cerebrum. A similar pattern is found in the nasal cavity where the morphologically simple (non-scrolled) olfactory turbinates appear and mature early, with extended growth characterizing the larger and scrolled respiratory turbinates. Pairwise regressions largely recover allometric relationships among the examined structures, with a notable exception being the isometric trajectory of the OB and olfactory turbinate. Their parallel growth suggests a unique regulatory pathway that is likely driven by the morphogenesis of the olfactory nerve, which serves as a structural bridge between the two features. Still, isometry was not necessarily expected given that the olfactory epithelium covers more than just the turbinate. These data illuminate a number of evolutionary hypotheses that, moving forward, should inform tradeoffs and constraints between the olfactory and neighboring systems in the avian head.

Safety and efficacy of superior turbinate biopsies as a source of olfactory epithelium appropriate for morphological analysis.

PURPOSE: There is no standardized approach for preserving olfactory function in the side of the nose where biopsy of the olfactory epithelium (OE) is performed. Moreover, a gold standard technique for obtaining human OE in vivo is still lacking. We determined the efficacy of obtaining good-quality OE specimens suitable for pathological analysis from the lower half of the superior turbinate and verified the safety of this procedure in maintaining bilateral and unilateral olfactory function. METHODS: In 21 individuals without olfactory complaints and who had undergone septoplasty and inferior turbinectomy OE biopsy was made during septoplasty. Olfactory function, both unilateral and bilateral, was assessed using the University of Pennsylvania Smell Identification Test (UPSIT) before and 1 month after the procedure. Specimens were marked with the olfactory marker protein for confirmation of OE presence. RESULTS: Ninety percent of the samples contained OE, although clear histological characterization was possible from only 62%. There was no deterioration of UPSIT scores either bilaterally or unilaterally on the side of the biopsy. Patients also maintained the ability to identify individual odorants. CONCLUSION: Biopsies of the lower half of the superior turbinate do not affect olfactory function and show strong efficacy in yielding OE tissue and moderate efficacy for yielding tissue appropriate for morphological analysis. Future studies are needed to assess the safety of this procedure in other OE regions.

Analysis of anatomical variation of the inclination of lamellas attached to the skull base and its correlation with the anterior ethmoidal artery floating in the ethmoid sinus for use in endoscopic sinus surgery.

PURPOSE: Attention to the inclination of lamellas attached to the skull base, including the basal lamella of the middle turbinate, facilitates the intraoperative identification of each lamella without requiring the use of a navigation system. We classified the inclination between the lamella and the skull base in preoperative computed tomography (CT) images and examined the relationship between the lamellas attached to the skull base, including the basal lamella of the middle turbinate, and the position of the anterior ethmoidal artery (AEA). We aimed to develop a preoperative classification to help prevent intraoperative injury of the AEA. METHODS: We retrospectively investigated the paranasal sinus sagittal section CT slices of 366 sides of 183 patients to assess the inclination of lamellas attached to the skull base and the AEA location. We also reviewed the AEA position, its correlation with the supraorbital ethmoid cell, and the lateral lamella of the cribriform plate. RESULTS: We classified the lamella inclination at the skull base as the anterior direction, perpendicular direction, and posterior direction types. Lamellas containing a floating AEA inclined in the anterior direction toward the skull base were observed in 68.9% of sides, inclination in the perpendicular direction was noted in 30.5% of sides, and inclination in the posterior direction was noted in 0.5% of sides. CONCLUSION: It is easier to identify the AEA intraoperatively when the lamella inclination of the skull base attachment is recognized based on preoperative CT findings. This approach could be applied to all paranasal sinus lamellas and assist in identifying the AEA and other nearby structures.

Equine Nasal Endoscopy: Treating Bullae Disease and Sinus Disease.

The nasal conchal bullae (dorsal and ventral) are separate, air-filled structures within their respective dorsal and ventral nasal conchae. Computed tomography scans have assisted with the increasing diagnosis of empyema of the nasal conchae. This condition is usually associated with dental or sinus disease. Drainage of affected bullae is considered critical for resolution of clinical signs. The ventral conchal bullae can be easily viewed with a standard 10 mm diameter flexible endoscopy via the middle nasal meatus. This approach can also be used for fenestration of the bullae, using a diode laser, equine laryngeal forceps, or bipolar vessel sealing device.

The sagittal grooves of the middle nasal turbinate determine paradoxical curvatures and bifidities.

BACKGROUND: Paradoxical curvature of the middle nasal turbinate (MT) is a common anatomic variant, usually found and reported on coronal CT slices. However, less attention has been paid to the sagittal groove (SG) which is determining it. AIM: The study aimed to determine paradoxical curvatures and bifidities in the sagittal groves of middle nasal turbinate. MATERIAL AND METHOD: A retrospective CBCT study on the archived files of 52 adult patients was performed. RESULTS: Different patterns of MT bifidity were found: (1) unilateral bifid MTs; (2) bifid and trifid MTs and "wandering" single SGs; (3) bilateral bifid middle turbinates and double SGs, (4) bilateral false bifid appearance due to middle and superior turbinates fusion and (5) bifid concha bullosa media. Digital "dissections" of patients' files allowed us to conclude that paradoxical curvature as well as bifidity of MTs relate to the placement and number of the SGs on the MTs. Such SGs were previously documented in prenatal MTs since the 14th week, as well as in pædiatric patients. CONCLUSIONS: It seems reasonable to speculate that paradoxical curvature, as well as bifidity of MT, this later being previously undocumented, are just adult vestiges of the primitive MT morphology. Nevertheless, documentation of the MT morphology should not rely exclusively on coronal CTs, as combined morphologies of that turbinate could occur.

Climatic adaptation in human inferior nasal turbinate morphology: Evidence from Arctic and equatorial populations.

OBJECTIVES: The nasal turbinates directly influence the overall size, shape, and surface area of the nasal passages, and thus contribute to intranasal heat and moisture exchange. However, unlike the encapsulating walls of the nasal cavity, ecogeographic variation in nasal turbinate morphology among humans has not yet been established. Here we investigate variation in inferior nasal turbinate morphology in two populations from climatically extreme environments. MATERIALS AND METHODS: Twenty-three linear measurements of the inferior turbinate, nasal cavity walls, and airway passages were collected from CT scans of indigenous modern human crania from Equatorial Africa (n = 35) and the Arctic Circle (n = 35). MANOVA and ANCOVA were employed to test for predicted regional and sex differences in morphology between the samples. RESULTS: Significant morphological differences were identified between the two regional samples, with no evidence of significant sexual dimorphism or region-sex interaction effect. Individuals from the Arctic Circle possessed superoinferiorly and mediolaterally larger inferior turbinates compared to Equatorial Africans. In conjunction with the surrounding nasal cavity walls, these differences in turbinate morphology produced airway dimensions that were both consistent with functional expectations and more regionally distinct than either skeletal component independently. CONCLUSION: This study documents the existence of ecogeographic variation in human nasal turbinate morphology reflecting climate-mediated evolutionary demands on intranasal heat and moisture exchange. Humans adapted to cold-dry environments exhibit turbinate morphologies that enhance contact between respired air and nasal mucosa to facilitate respiratory air conditioning. Conversely, humans adapted to hot-humid environments exhibit turbinate morphologies that minimize air-to-mucosa contact, likely to minimize airflow resistance and/or facilitate expiratory heat-shedding.

Anatomic variations associated with antrochoanal polyps.

OBJECTIVE: Although more than a century has passed since antrochoanal polyps (ACPs) were first defined, etiopathogenesis still remains unclear. The aim of this study was to investigate the relationship between ACPs and sinonasal cavity variations. SUBJECTS AND METHODS: One hundred and forty-four patients with ACP on paranasal sinus computed tomography scans (ACP group) and 160 paranasal sinuses without ACP (control group) were included into the study. The study group was evaluated in respect of the presence of retention cyst in the contralateral maxillary sinus and sinus bone wall sclerosis thickening. Both groups were also compared with respect to the frequency of sinonasal anatomic variations, nasal septal deviation, variations of the uncinate process insertion, concha bullosa, paradoxical middle turbinate, and accessory maxillary sinus ostium. In the ACP group, the cases with septal deviation (SD) were also evaluated whether the deviation convexity was towards the polyp side or the opposite side. In addition, the posterior extension of ACPs were evaluated in three groups as middle meatus, nasopharynx, and oropharynx extension. RESULTS: The prevalence of retention cyst, sinus wall sclerosis thickening, SD, and accessory maxillary ostium was significantly higher in the ACP group. A negative directional correlation was determined between the SD side and ACP side. When the ACP extensions were examined, middle meatus extension was seen in 32.6%, nasopharynx in 56.3%, and oropharynx in 11.1%. CONCLUSION: Accessory ostium may be an accelerating factor in the transformation of retention cyst to ACP. Furthermore, the changes in the nasal passage airflow on the opposite side suggest that SD contributes to this process.

Vertical and sagittal combinations of concha bullosa media and paradoxical middle turbinate.

Common anatomic variants of the middle nasal turbinate include its pneumatization (i.e. concha bullosa media) and its paradoxical curvature. We report here two cases of differently combined variations of the middle turbinate which were documented in cone beam computed tomography (CBCT). The first report presents the vertical combination of a double or septated lamellar concha bullosa with the paradoxical curvature of middle turbinate. This combined variant associated (coincidental findings): ipsilateral paradoxical superior turbinate and contralateral paradoxical middle turbinate, concha bullosa superior and concha bullosa suprema. In the second case was found the sagittal combination of successive anterior concha bullosa media and posterior paradoxical curvature of the middle turbinate. An ethmoidal sinolith was found embedded in lamella basalis. The contralateral superior turbinate was pneumatized. These rare findings demonstrate that sound knowledge of possible anatomical variations, supported by a complete use of the tools available for the CBCT documentation of cases, is able to enrich the picture of human anatomic variations, with a direct impact on clinical and surgical practice. The septa-containing lamellar concha bullosa and paradoxical middle concha combination is a variation that affects surgical practice.

Rare anatomic variation: true bifid inferior turbinate.

Nasal anatomic variations are relevant during nasal surgical and endoscopic procedures. The extent of imaging methods, such as the cone beam computed tomography (CBCT), allows a better characterization of such peculiar anatomic traits. The bifid inferior turbinate (BIT) is a rare finding, being previously reported less than ten times. It was found and described on CT scans of patients, being usually associated with the absence of the uncinate process (UP). We hereby report for the first time a bilateral true BIT which differs from the previously reported BITs by the fact that the UPs were present and the bifidity was oriented laterally. In the light of this new find, we consider that the variant resulted from UP displacement should be regarded as a false bifid, or double, inferior turbinate. Bifidity of the inferior turbinate was not previously evaluated in CBCT, as well as in three-dimensional volume renderizations. So, CBCT proves as an efficient tool to investigate prevalence of rare anatomical variants. Noteworthy, CT studies of patients on a case-by-case basis allows a better performance of surgical and endoscopic procedures.

Evaluation of superior concha bullosa by computed tomography.

OBJECTIVE: Concha bullosa is generally regarded as pneumatisation of the middle turbinate in the nose. However, pneumatisation may also be seen in the superior and inferior turbinate. Computed tomography (CT) of paranasal sinuses is extremely helpful for the examination of this inaccessible area. Coronal CT sections of paranasal sinuses are particularly useful for surgical anatomy, as these images show nearly the same regions as the endoscopic examinations. The aim of this retrospective study was to evaluate the presence, incidence and unilaterality-bilaterality of superior turbinate pneumatisation and concomitant nasal pathologies. METHODS: A total of 1000 patients who underwent CT of the paranasal sinuses because of headaches, nasal obstructions, anosmia, facial pain or facial trauma were evaluated retrospectively. RESULTS: Among the 1000 patients, superior pneumatized turbinate was seen on CT images of the paranasal sinuses in 149 (14.9%) cases. Of these patients, 84 were female, 65 were male, and the mean age was 38.14 years. Among 149 patients, 58 patients had bilateral superior pneumatized turbinate and the remaining 91 patients had unilateral superior pneumatized turbinate. 60.4% of the patients with superior pneumatized turbinate also had middle pneumatized turbinate. CONCLUSION: The superior pneumatized turbinate is an anatomical variation with an incidence ranging from 12.2 to 50%. The present study revealed that there is no relationship between volume size of the superior pneumatized turbinates and sinusitis, nasal septum deviation and paradoxical middle concha. It is very important to define anatomical variations in the preoperative CT evaluation of the paranasal sinuses.

Nasal obstructive disorders induce medical treatment failure in paediatric persistent allergic rhinitis (The NODPAR Study).

BACKGROUND: Allergic rhinitis (AR) is the most common chronic disease among children. To characterize the disease, a modified classification of severity (m-ARIA) has recently been validated in AR children. When medical treatment fails, surgery for nasal obstructive disorders (NOD) may be a therapeutic option. Our objective was to assess the prevalence of NOD and their influence in medical treatment response among children with persistent AR (PER). METHODS: In a prospective, real-life study, 130 paediatric PER patients (13.1 ± 2.8 years, females 31.5%, severe rhinitis 49%) referred from Allergy to ENT department were assessed for their response (R, responders; NR, non-responders) to medical treatment (intranasal steroids and antihistamines or antileukotrienes) by direct questioning and nasal symptom visual analogue scale, the presence of NOD (septal deformity, turbinate enlargement and adenoidal hyperplasia), comorbidities, nasal symptoms, rhinitis severity (modified ARIA criterion) and asthma control (International Consensus On Pediatric Asthma criterion). RESULTS: After 2 months of treatment, the NR group presented a higher prevalence of obstructive septal deformity and severe inferior turbinate enlargement when compared with the R group. Higher septal deformity and turbinate enlargement scores were strongly associated with treatment refractoriness. The prevalence of severe PER was also higher for the NR group. Higher asthma control scores were associated with the probability of treatment-induced improvement. CONCLUSIONS: In paediatric PER patients, medical therapy refractoriness was associated with NOD, mainly septal deformity and turbinate enlargement. In those patients, ENT examination will facilitate an early NOD diagnosis in order to indicate potential corrective surgery.

The association of superior attachment of uncinate process with pneumatization of middle turbinate: a computed tomographic analysis.

The frontal sinus outflow pathway is complex and can be influenced by the configuration of the uncinate process (UP). The UP can attach superior to the lamina papyracea, skull base, and middle turbinate. The factors associated with superior attachment remain unclear. This study analyzed the relationships between different types of superior UP attachment and characteristics of the surrounding structures including the agger nasi cell, skull base, and middle turbinate. This retrospective study utilized computed tomography images of 836 sides with identifiable sinus structure from 434 Taiwanese patients. Types of superior UP attachment, height of the ethmoid cribriform plate, prevalence of agger nasi cell, and degree of pneumatization of the middle turbinate were analyzed. In the current study, neither the presence of an agger nasi cell nor height of the cribriform plate had significant relationship with superior UP attachment type. However, UP attachment type was statistically significantly associated with pneumatized middle turbinate (PMT) type (p < 0.01). The PMT group had a higher incidence of UP attachment to the middle turbinate (38%) than the non-PMT group (18%). In the extensive PMT group, the incidence of UP attachment to the middle turbinate was high to 49%. In conclusion, superior UP attachment to the middle turbinate was associated with pneumatization of the middle turbinate. The UP has a greater tendency to attach to the middle turbinate in cases with more PMT.

The Significance of Rhinologic Evaluation and Pretreatment for Patients Undergoing Two-Jaw Surgery Through Nasotracheal Intubation.

The aim of this study is to determine whether rhinologic preoperative evaluation and pretreatments reduce intranasal trauma and decrease postoperative complications, such as nasal obstruction and epistaxis, in patients undergoing 2-jaw surgery with nasotracheal intubation. This study included 360 patients with malocclusion (Class III) who underwent 2-jaw surgery under general anesthesia via nasotracheal intubation in our hospital from January to December 2013 and categorized into 3 groups. Nasotracheal intubation was performed according to the nasal cavity the patient was able to breathe comfortably (Group I). The site of nasotracheal intubation was decided by 1 rhinologic specialist who evaluated preoperative dental computed tomography (Group II). The site of nasotracheal intubation was decided upon nasal endoscopic findings, dental computed tomography evaluation, and rhinologic pretreatment (Group III).Group II and Group III showed less damage to the nasal mucosa compared with the nasal status of Group I. Upon comparing Group II and Group III, Group III showed better overall status of the nasal mucosa compared with Group II. Visual analogue scale scores for nasal obstruction were pretty similar for all groups on the first postoperative day. In Group III, the nasal mucosa, however, was improved to that of preoperative status on the third postoperative day.In conclusion, it may be useful to pre-evaluate the mucosal and anatomical status of the nasal cavity to select patients requiring rhinologic pretreatment and decide the site for nasotracheal intubation to minimize complications arising from nasotracheal intubation.

A unilateral septal flap based on the anterior ethmoidal artery (Castelnuovo's flap): CT cadaver study.

OBJECTIVE: We describe our experience for repair septal perforation with a septal flap and we analyse the route of the septal branch of the anterior ethmoidal artery (AEA) in the septum area with a radiological anatomy study in order to perform this flap. STUDY DESIGN: We carry out a prospective analysis with computed tomography scan in the cadaver heads and we perform an endoscopic technique in the patients. METHODS: Ten nasal cavities were analysed in five adult cadaveric heads and two patients diagnosed with anterior septal perforation were surgically treated. Measurements in the cadaveric heads were obtained from a sagittal plane of the nasal septum. The anterior point corresponds to the projection of the anterior insertion of the middle turbinate in the frontal process of the maxilla over the nasal septum. The posterior point was obtained with a vertical line passing through the entrance of the AEA in the nasal septum. RESULTS: The mean distance between the anterior point and the posterior point was 7.35 mm with a standard deviation of 0.95 mm. The lowest value was 5.5 mm and the highest value was 8.7 mm. We observed good epithelialisation and closure of the perforation in all patients. CONCLUSION: The unilateral septal flap pedicle by anterior ethmoidal artery may be used for small and medium perforations with a pedicle smaller than 1 cm posterior to the axilla.

The posterior pedicled inferior turbinate-nasoseptal flap: a potential combined flap for skull base reconstruction.

OBJECTIVES: To develop a combined pedicled flap comprising the mucoperiosteum and mucoperichondrium of the inferior turbinate, lateral nasal wall, nasal floor, and nasal septum based on the posterior lateral nasal artery, a branch of the sphenopalatine artery, for the reconstruction of skull base defects resulting from endoscopic expanded endonasal approaches. METHODS: Eleven fresh adult cadaver heads were dissected. Arterial distribution patterns of the inferior turbinate, lateral nasal wall, nasal floor, and nasal septum were investigated. The posterior pedicled inferior turbinate-nasoseptal flap was designed, measured, and harvested, and its ability to cover ventral skull base defects was examined. RESULTS: The inferior turbinate artery and/or posterior lateral nasal artery had 3.19 ± 1.47 (range 2-7) branches [mean outer diameter of largest branch, 0.40 ± 0.10 (range 0.24-0.60) mm] that anastomosed with the nasoseptal artery. These anastomosing arteries allowed the posterior lateral nasal artery to supply arterial blood to the nasoseptal mucoperichondrium and mucoperiosteum. Mean flap length was 100.65 ± 5.61 (range 91.43-109.44) mm, and minimum and maximum widths were 25.21 ± 2.29 (range 22.36-30.23) and 44.53 ± 5.02 (range 36.45-54.10) mm, respectively. Mean flap area was 3090.69 ± 288.08 (range 2612.97-3880.09) mm(2). The flap covered defects extending from the frontal sinus to the foramen magnum in all specimens. CONCLUSIONS: Harvesting of a posterior pedicled inferior turbinate-nasoseptal flap is feasible. It should be considered a useful option for the reconstruction of large defects involving the anterior skull base, planum sphenoidale, sella turcica, and/or clivus.