Nasosinusal Endoscopic Anatomy and Physiology

The present article focuses on the analysis of the nasal cavity's anatomy succinctly and descriptively. This essay was carried out through a bibliographic review, directed to the detailed anatomy of the nasal cavity, and the structures that form its sinuses. We have identified the need formore studies directed to the related anatomical area so that the improved knowledge of this region ensures a nasoendoscopic treatment with better effectiveness and no complications.

Venous networks in the upper airways of bats: A histological and diceCT study.

Our knowledge of nasal cavity anatomy has grown considerably with the advent of micro-computed tomography (CT). More recently, a technique called diffusible iodine-based contrast-enhanced CT (diceCT) has rendered it possible to study nasal soft tissues. Using diceCT and histology, we aim to (a) explore the utility of these techniques for inferring the presence of venous sinuses that typify respiratory mucosa and (b) inquire whether distribution of vascular mucosa may relate to specialization for derived functions of the nasal cavity (i.e., nasal-emission of echolocation sounds) in bats. Matching histology and diceCT data indicate that diceCT can detect venous sinuses as either darkened, "empty" spaces, or radio-opaque islands when blood cells are present. Thus, we show that diceCT provides reliable information on vascular distribution in the mucosa of the nasal airways. Among the bats studied, a nonecholocating pteropodid (Cynopterus sphinx) and an oral-emitter of echolocation sounds (Eptesicus fuscus) possess venous sinus networks that drain into the sphenopalatine vein rostral to the nasopharynx. In contrast, nasopharyngeal passageways of nasal-emitting hipposiderids are notably packed with venous sinuses. The mucosae of the nasopharyngeal passageways are far less vascular in nasal-emitting phyllostomids, in which vascular mucosae are more widely distributed in the nasal cavity, and in some nectar-feeding species, a particularly large venous sinus is adjacent to the vomeronasal organ. Therefore, we do not find a common pattern of venous sinus distribution associated with nasal emission of sounds in phyllostomids and hipposiderids. Instead, vascular mucosa is more likely critical for air-conditioning and sometimes vomeronasal function in all bats.

Anterior Pedicled Lateral Nasal Wall Flap for Endonasal Lining: A Radiologic and Anatomical Study.

OBJECTIVES/HYPOTHESIS: The objective of this radiological/anatomical study was to evaluate the feasibility of a new endoscopic technique that uses the anterior pedicled lateral nasal flap (APLNW) for the endonasal lining in complex nasal reconstructions. STUDY DESIGN: An anatomical study was performed on 20 nasal fossae of cadaverous specimens to measure the area and lengths of the anterior pedicled nasal lateral wall flap. In addition, a radiological analysis with computed tomography was performed in 150 nostrils to determine the potential donor of the simple and extended flap in the nasal fossa floor. Complex nasal reconstruction with nasofrontal flap and internal lining using the lateral wall pedicled flap was performed in 3 patients. RESULTS: Complete reconstruction for the inner lining of the nasal tip and lateral nasal wall was achieved in the cadaveric study (10 specimens). The surface areas of the simple and extended APLNW flaps were 7.53 (standard deviation [SD] 1.25) cm2 and 24.6 (SD 3.14) cm2 , respectively. Using computed tomography scans, we determined that to reconstruct defects secondary to full-thickness nasal defects, the APLNW flap surface for the simple and extended versions was 7.90 (SD 1.68) cm2 and 23.64 (SD 4.7) cm2 . We present one case were the APLNW flap was used. CONCLUSIONS: The simple or expanded APLNW flap represents a feasible option to reconstruct the internal lining in complex nasal reconstruction. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E1462-E1467, 2021.

Comparative studies on the histological characteristics of equine nasomaxillary aperture and paranasal sinus mucosa considering topographic and age-related differences.

BACKGROUND: Horses may acquire a range of paranasal sinus diseases. Clinical studies show slight differences regarding anatomical regions and age. Histopathological examination of tissue samples could play an important role in the diagnostic process. Therefore, detailed knowledge of the histological appearance of the paranasal sinus mucosa (PSM) and the nasomaxillary aperture mucosa (NAM) is essential. The objective of this study was to determine topographic and age-related differences within the healthy equine PSM. In addition, we aimed to gain detailed knowledge of the histological appearance of the NAM in comparison to the PSM. RESULTS: The PSM had an average height of 75.72 ± 44.48 µm with a two-row pseudostratified columnar epithelium of 13.52 ± 4.78 µm. The parameters mucosal height, epithelial height and number of goblet cells revealed significant dependency of the sample site and age group. The maxillary and dorsal conchal sinus showed the highest values for these parameters. In terms of age, younger horses showed a significantly higher total mucosal height in contrast to a significantly lower epithelial height than older horses. Positive correlation was seen between the epithelial height and number of goblet cells. The NAM had an average height of 820.27 ± 653.21 µm. Its pseudostratified epithelium was usually arranged in three rows and had an average height of 44.9 ± 12.78 µm. The number of goblet cells in the NAM was five times higher than in the PSM. Serous glands were found in only 4% of the PSM samples and 100% of the NAM samples. CONCLUSIONS: There are significant histological differences between different paranasal sinus sites and between different groups of age. This may be related to an altered susceptibility for certain pathologies. The striking difference in the histological appearance of the NAM compared to the PSM could be due to an enhanced role in mucociliary clearance. Further studies are necessary to improve the understanding of mucosal function in specific paranasal sinus compartments and mucosal changes generated by different diseases.

Schneiderian membrane thickness variation following endodontic procedures: a retrospective cone beam computed tomography study.

BACKGROUND: To assess the change of the Schneider membrane thickness measured by CBCT before and after root canal treatment, retreatment and pulp capping procedures. METHODS: This retrospective study was conducted on CBCT scans of a patient population of Guy's Hospital NHS Foundation Trust, London. Three groups of patients were studied: Group 1 consisted of patients referred for primary endodontic treatment; Group 2 for endodontic retreatment; Group 3 for indirect pulp capping procedures (serving as a control group). Follow up scans were carried out 1 year after treatment. Measurements were carried out on CBCT scans and data were analysed statistically by Wilcoxon Signed Rank Test. Linear regression was used to assess predictive parameters for membrane thickness. RESULTS: A statistically significant reduction of the Schneider membrane thickness was observed one year after endodontic treatment and retreatment (P < 0.05) but no significant reduction was observed after pulp capping procedures. Linear regression showed that age and gender were significant predictors influencing the Schneider membrane thickness. CONCLUSIONS: Within the limitations of this retrospective study, following root canal treatment and re-treatment a Schneiderian membrane thickness reduction occurred at 1-year follow-up. The removal of odontogenic infection following endodontic treatment may help reducing the thickness of the Schneider membrane.

Red-green-blue analysis of nasal mucosa discolouration in allergic rhinitis.

OBJECTIVE: To evaluate the colour values of nasal mucosa for the purpose of presenting an objective parameter of allergic rhinitis. METHODS: Seventy-three patients with allergic rhinitis (allergy group) and 73 normal healthy individuals (control group) were included in the study. Endoscopic examinations were conducted, and endoscopic photographs of the septum and both inferior turbinates were taken. The Adobe Photoshop Elements 7.0 software program was used to measure the numerical values of red-green-blue (RGB) colour components in the endoscopic photographs of nasal mucosa. RESULTS: The G and B values were significantly higher in the allergy group compared to the control group (both p < 0.05). Cumulative R, G and B values of all measurement points were significantly higher in the allergy group compared to the control group (p < 0.05). CONCLUSION: Nasal mucosa discolouration can be measured objectively with RGB analysis to aid the diagnosis of allergic rhinitis.

Chlorpheniramine maleate containing chitosan-based nanoparticle-loaded thermosensitive in situ gel for management in allergic rhinitis.

The aim of the present study was to fabricate a thermosensitive gel containing chlorpheniramine maleate (CPM)-loaded nanoparticles following intranasal administration for effective treatment of allergic rhinitis. Chitosan-based nanoparticles were prepared by a precipitation method followed by the addition of developed NPs within the poloxamer 407- and carbopol 934P-based mucoadhesive thermoreversible gel. Developed formulations were evaluated for particle size, PDI, % entrapment efficiency, and % cumulative drug permeation. NP3 formulation was found to be optimized on the basis of minimum particle size (143.9 nm), maximum entrapment efficiency (80.10 ± 0.414%), and highest drug permeation (90.92 ± 0.531%). The optimized formulation NP3 was then formulated into thermoreversible in situ gel. This intensifies the contact between the nasal mucosa and the drug and increases and facilitates the drug absorption which results in increased bioavailability. G4 formulation was selected as the optimized formulation on the basis of gelation ability and mucoadhesive strength. Histology was carried out to examine the damage caused by the optimized G4 formulation. Results revealed no visual signs of tissue damage thus indicated safe nasal delivery of nanoparticulate in situ gel formulation G4. Thus, intranasal CPM NP-loaded in situ gel was found to be a promising formulation for the management of allergic rhinitis.

Anatomical basis and physiological role of cerebrospinal fluid transport through the murine cribriform plate.

Cerebrospinal fluid (CSF) flows through the brain, transporting chemical signals and removing waste. CSF production in the brain is balanced by a constant outflow of CSF, the anatomical basis of which is poorly understood. Here, we characterized the anatomy and physiological function of the CSF outflow pathway along the olfactory sensory nerves through the cribriform plate, and into the nasal epithelia. Chemical ablation of olfactory sensory nerves greatly reduced outflow of CSF through the cribriform plate. The reduction in CSF outflow did not cause an increase in intracranial pressure (ICP), consistent with an alteration in the pattern of CSF drainage or production. Our results suggest that damage to olfactory sensory neurons (such as from air pollution) could contribute to altered CSF turnover and flow, providing a potential mechanism for neurological diseases.

Anatomical considerations in endoscopic lacrimal surgery.

PURPOSE: To provide a review of the anatomy of the lacrimal drainage system and lateral wall of the nose pertaining to endoscopic dacryocystorhinostomy. METHODS: The authors performed a PubMed search of articles published pertaining to the anatomy of the lateral wall of the nose and the anatomy of endonasal and external dacryocystorhinostomy surgery. RESULTS: The article covers the regional surface and surgical anatomy for endoscopic dacryocystorhinostomy (DCR), including the maxillary line, middle turbinate, agger nasi air cell, lacrimal sac and fossa and the upper portion of the nasolacrimal drainage system. It also explores the dimensions and location of bony ostium formation to ensure full exposure and marsupialisation of the lacrimal sac. Finally, it covers the anatomy of potential complications of endoscopic DCR surgery including penetration of the skull base and orbit, inadvertent entry to the maxillary sinus and breach of the skin. CONCLUSION: A good understanding of the anatomy of the lacrimal drainage system and the lateral wall of the nose will increase the likelihood of successful surgery and minimize the risk of complications and damage to neighbouring structures such as the orbit and skull base.

Cranial Pair 0: The Nervus Terminalis.

Originally discovered in elasmobranchs by Fritsh in 1878, the nervus terminalis has been found in virtually all species, including humans. After more than one-century debate on its nomenclature, it is nowadays recognized as cranial pair zero. The nerve mostly originates in the olfactory placode, although neural crest contribution has been also proposed. Developmentally, the nervus terminalis is clearly observed in human embryos; subsequently, during the fetal period loses some of its ganglion cells, and it is less recognizable in adults. Fibers originating in the nasal cavity passes into the cranium through the middle area of the cribiform plate of the ethmoid bone. Intracranially, fibers joint the telencephalon at several sites including the olfactory trigone and the primordium of the hippocampus to reach preoptic and precommissural regions. The nervus terminalis shows ganglion cells, that sometimes form clusters, normally one or two located at the base of the crista galli, the so-called ganglion of the nervus terminalis. Its function is uncertain. It has been described that its fibers facilitates migration of luteinizing hormone-releasing hormone cells to the hypothalamus thus participating in the development of the hypothalamic-gonadal axis, which alteration may provoke Kallmann's syndrome in humans. This review summarizes current knowledge on this structure, incorporating original illustrations of the nerve at different developmental stages, and focuses on its anatomical and clinical relevance. Anat Rec, 302:394-404, 2019. © 2018 Wiley Periodicals, Inc.

Intranasal Filtration of Inhaled Aerosol in Human Subjects as a Function of Nasal Pressure Drop.

BACKGROUND: Intersubject variability in nasal deposition of inhaled aerosol is significant because of the differences in nasal anatomy and breathing rate. The notable limitation of the majority of previously developed predictive correlations is including a limited number of subjects. A few recent studies have considered a wide age range of subjects, but the resulting correlations require the knowledge of the dimensions of the nasal airways and the properties of inhaled gas. In this study empirical correlations are proposed to predict aerosol deposition in nasal airways of subjects of different age as a function of intranasal pressure drop and the particle aerodynamic diameter. METHODS: The experimental nasal deposition and pressure drop data in anatomically correct nasal replicas of 5 adults, 13 children aged 4-14 years, and 11 infants aged 3-18 months were reanalyzed. The range of aerodynamic diameter was 0.5-5.3 µm and physiological breathing at different activity levels was considered. Correlations between nasal deposition and a deposition parameter including the aerodynamic size of inhaled aerosol and nasal pressure drop were developed with nonlinear least-square algorithms. The general coefficient of determination r2 was used to evaluate the fitting accuracy for each correlation. RESULTS: New correlations were developed to predict the intranasal deposition of particles as a function of intranasal pressure drop and particle size for pediatric and adult subjects. The intranasal deposition fraction in adults and children can be calculated using the same correlation, whereas the intranasal deposition in infants followed a different trend line because of higher intranasal pressure drop in infants. CONCLUSION: This study was the first offering correlations to predict intranasal deposition in multiple age groups using only the aerodynamic size of inhaled aerosol and nasal pressure drop. These correlations include the effects of intersubject variability in nasal deposition within each age group and among different age groups.

Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study with endoscopic validation.

OBJECTIVE: To endoscopically determine the incidence of Schneiderian membrane perforation during transcrestal maxillary sinus floor elevation (SFE), in relation to the bone preparation technique, amount of bone graft, membrane elevation height and different surgical steps. MATERIALS AND METHODS: Seven cadaver heads corresponding to 12 maxillary sinuses were used to perform three SFE via transcrestal approach per sinus (36 elevations). Each sinus was randomly assigned to either the Sinus Crestal Approach (SCA) drill kit technique (experimental group) or the conventional osteotome technique (control group). During all phases of the surgery, the integrity of the sinus membrane was monitored through endoscopic examination. RESULTS: A significant difference was found in the incidence of perforation (p = 0.007) and vertical elevation height (p < 0.001) between the study groups, favoring the experimental group. A safety elevation threshold of 5 mm without bone graft and implant placement was estimated. A significant correlation was observed between the residual ridge height and the incidence of perforation (p < 0.001; OR = 0.51). CONCLUSION: The SCA drill kit may demonstrate superior osteotomy preparation and membrane elevation capabilities to the osteotome technique, and significantly when a 6-mm SFE is indicated. Residual ridge height and vertical elevation height are risk determinant factors.

Dimensional changes in the sinus membrane following maxillary sinus augmentation.

OBJECTIVE: The aim of this retrospective study was to measure the sinus membrane's dimensional changes following maxillary sinus augmentation via a lateral approach, and to examine the variables affecting changes in the membrane's thickness. METHOD AND MATERIALS: Sixty-six sinuses corresponding to 50 patients (15 males and 35 females) who underwent lateral wall maxillary sinus augmentation (34 unilateral and 16 bilateral) were retrospectively evaluated. The sinus membrane thickness was measured on cross-sectional cone beam computed tomography (CBCT) scans which were performed prior to and 9 to 11 months' post maxillary sinus augmentation. The Wilcoxon signed-rank test and the Mann Whitney U test were both used to compare between baseline and postoperative sinus membrane thickness. Pearson correlation tests were used to analyze correlations between graft height and sinus membrane thickness changes. RESULTS: The mean age was 53 ± 4 years (45 to 71 years). A total of 132 CBCT scans were analyzed pre- and postoperatively (n = 66). The mean thickness of the sinus membrane before the procedure was 2.61 ± 3.61 mm, while the mean thickness of the membrane after the procedure was 2.94 ± 3.51 (P > .20). Thin membranes at baseline (< 1.56 mm) thickened by a mean of 2.21 ± 2.34 mm, range -0.413 to 10.62 mm, (P < .0001); thicker membranes (≥ 1.56 mm) lost 1.46 ± 3.96 mm thickness, range -7.8 to 9.31 mm (P < .0001). A moderate negative correlation between the baseline membrane thickness and change in thickness was observed (P < .0001, r = -.52). No correlation was found between the graft height and changes in the sinus membrane thickness. CONCLUSION: Lateral wall maxillary sinus augmentation seems to affect the sinus membrane thickness. These changes are associated with the preoperative thickness of the membrane.

Kaempferol-loaded mucoadhesive nanoemulsion for intranasal administration reduces glioma growth in vitro.

In order to search for new approaches to treat glioma, intranasal administration has been proposed as an alternative route to deliver drugs into the brain. Among the drug alternatives, kaempferol (KPF) has been reported to induce glioma cell death. This study aimed to prepare nanoemulsions containing KPF with and without chitosan to investigate their potential for brain delivery following intranasal administration, and to evaluate their antitumor activity against glioma cells. KPF-loaded nanoemulsion (KPF-NE) and KPF-loaded mucoadhesive nanoemulsion (KPF-MNE) were prepared by high-pressure homogenization technique and were characterized for their globule size, zeta potential, drug content, pH, viscosity, mucoadhesive strength and morphology. KPF from KPF-MNE showed significantly higher permeation across the mucosa in ex vivo diffusion studies. Histopathological examination suggests both nanoemulsions to be safe for the nasal mucosa and able to preserve KPF antioxidant capability. KPF-MNE enhanced significantly the amount of drug into rat's brain following intranasal administration (5- and 4.5-fold higher than free drug and KPF-NE, respectively). In addition, KPF-MNE reduced C6 glioma cell viability through induction of apoptosis to a greater extent than either free KPF or KPF-NE. The mucoadhesive nanoemulsion developed for intranasal administration may be a promising system for delivery to the brain, and KPF-MNE is a candidate for further antiglioma trials.

Measurement and implications of the distance between the sphenopalatine ganglion and nasal mucosa: a neuroimaging study.

BACKGROUND: Historical reports describe the sphenopalatine ganglion (SPG) as positioned directly under the nasal mucosa. This is the basis for the topical intranasal administration of local anaesthetic (LA) towards the sphenopalatine foramen (SPF) which is hypothesized to diffuse a distance as short as 1 mm. Nonetheless, the SPG is located in the sphenopalatine fossa, encapsulated in connective tissue, surrounded by fat tissue and separated from the nasal cavity by a bony wall. The sphenopalatine fossa communicates with the nasal cavity through the SPF, which contains neurovascular structures packed with connective tissue and is covered by mucosa in the nasal cavity. Endoscopically the SPF does not appear open. It has hitherto not been demonstrated that LA reaches the SPG using this approach. METHODS: Our group has previously identified the SPG on 3 T-MRI images merged with CT. This enabled us to measure the distance from the SPG to the nasal mucosa covering the SPF in 20 Caucasian subjects on both sides (n = 40 ganglia). This distance was measured by two physicians. Interobserver variability was evaluated using the intraclass correlation coefficient (ICC). RESULTS: The mean distance from the SPG to the closest point of the nasal cavity directly over the mucosa covering the SPF was 6.77 mm (SD 1.75; range, 4.00-11.60). The interobserver variability was excellent (ICC 0.978; 95% CI: 0.939-0.990, p < 0.001). CONCLUSIONS: The distance between the SPG and nasal mucosa over the SPF is longer than previously assumed. These results challenge the assumption that the intranasal topical application of LA close to the SPF can passively diffuse to the SPG.

Immunohistochemical study on the distribution of ß-defensin 1 and ß-defensin 2 throughout the respiratory tract of healthy rats.

The distributions of ß-defensin 1 and 2 in secretory host defense system throughout respiratory tract of healthy rats were immunohistochemically investigated. In the nasal epithelium, a large number of non-ciliated and non-microvillous cells (NCs) were immunopositive for both ß-defensin 1 and 2, whereas a small number of goblet cells (GCs) were immunopositive only for ß-defensin 1. Beta-defensin 2-immunopositive GCs were few. In the nasal glands, a small number of acinar cells and a large number of ductal epithelial cells were immunopositive for both ß-defensins. In the laryngeal and tracheal epithelia, a very few NCs and GCs were immunopositive for both ß-defensins. In laryngeal and tracheal glands, a very few acinar cells and a large number of ductal epithelial cells were immunopositive for both ß-defensins. In the extra-pulmonary bronchus, a small number of NCs were immunopositive for both ß-defensins. A small number of GCs were immunopositive for ß-defensin 1, whereas few GCs were immunopositive for ß-defensin 2. From the intra-pulmonary bronchus to alveoli, a very few or no epithelial cells were immunopositive for both ß-defensins. In the mucus and periciliary layers, ß-defensin 1 was detected from the nose to the extra-pulmonary bronchus, whereas ß-defensin 2 was weakly detected only in the nose and the larynx. These findings suggest that the secretory sources of ß-defensin 1 and 2 are mainly distributed in the nasal mucosa and gradually decrease toward the caudal airway in healthy rats.

Mechanical characteristics of the maxillary sinus Schneiderian membrane ex vivo.

OBJECTIVES: It has been speculated that certain Schneiderian membrane thickness (SMT) might be more prone to perforation. This investigation was aimed at studying the mechanical characteristics of the Schneiderian membrane under one- and two-dimensional tests and their correlation to the histological SMT in human samples. MATERIAL AND METHODS: Sixteen Schneiderian membranes were collected from 11 cadaver heads treated with Thiel's embalming method. The samples were processed and analyzed clinically and histologically. One-dimensional maximum elongation until perforation and two-dimensional resistance to ball penetration were performed after the biopsy. Data was analyzed by using the Wilcoxon rank test and the Spearman's rank correlation. RESULTS: The histological SMT was 1.36 ± 0.42 mm, whereas the clinical thickness was 0.27 ± 0.21 mm, yielding statistical significance (p = 0.000). The resistance under ball penetration was 0.59 ± 0.43 N and the mean maximum elongation in the one-dimension test 11.19 ± 7.14 mm. Expressed in percentage, the mean stretch was 241.36 ± 227.97% (range 31.5 up to 947%). A weak positive correlation was found between the ball penetration test and the SMT (r = 0.10, p = 0.711), while a weak negative correlation was found between stretching test and the SMT (r = -0.021, p = 0.94). CONCLUSIONS: Mechanical tests seem to indicate that SMT might not significantly predispose to Schneiderian membrane perforation. Hence, other anatomical and operator's factors should be considered of surpassing importance. CLINICAL RELEVANCE: Thinner SM might be more prone to perforation when detaching it from the maxillary sinus antrum; however, a thick membrane is not prevented to tear, as their resistance under elastic forces is not higher than thinner ones.

Impact of Sex, Age, and Season on Sinus Membrane Thickness.

PURPOSE: Sinus membrane thickness has been associated with the incidence of membrane perforation during the sinus elevation procedure. Understanding the sinus membrane thickness is essential for prevention of this specific surgical complication. Therefore, the aim of this retrospective study was to investigate the impact of sex, age, and season on the membrane thickness. MATERIALS AND METHODS: The charts of 144 healthy patients were included in the study. Cone beam computed tomography (CBCT) images from these patients were analyzed to determine the sinus membrane thickness in the coronal and sagittal views. Sex, age, and season were correlated with the membrane thickness. RESULTS: The mean thickness of the sinus membrane was 1.81 ± 1.66 mm (range: 0.47 to 9.49 mm). In 22.12% of the CBCT images, the sinus membrane was not visible. Membrane thickness of less than 2 mm was found in 70.8% of the cases. Age was found to be strongly correlated (P < .05) with sinus membrane thickness but not sex or season. CONCLUSION: Based on CBCT assessment, age was found to be a factor influencing sinus membrane thickness but not sex or season.

Relation between periapical lesions and sinus membrane thickening assessed by Cone Beam Computed Tomography.

The aim of this study was to evaluate thickening of the Schneiderian membrane and to determine its association with periapical pathologies, using computerized cone beam tomography. An observational, analytical, cross-sectional retrospective study was conducted. A total 179 maxillary sinuses were evaluated using CBCT. The presence of sinus membrane thickening and its association with unhealthy teeth was analyzed. Results are shown as percentages with 95% confidence intervals (95%CI); Chi square test was used with a significance level of 5%.Sinus membrane thickening was detected in 70 cases (39%; 95%CI=32% to 46%) and no sinus membrane thickening was observed in 109 (61%; 95%CI = 54% to 68%) (p<0.05). The 70 cases showing sinus membrane thickening included 46 of odontogenic origin (66%; 95%CI = 54% to 76%) and 24 (34%; 95%CI = 24% to 46%) of non odontogenic origin (p<0.05). The frequency of odontogenic causes followed a heterogeneous distribution (p<0.05): penetrating caries, failing endodontic therapy, root remnants, deep restorations, implants, periodontal pathology. The main cause was caries (46%; 95%CI=32% to 60%) followed by failing endodontic therapy (26%, 95% CI=16% to 40%). The frequency distribution of involved teeth was uneven (p<0.05), with tooth 16 (33%; 95%CI=21% to 47%) being the most frequently involved, followed by tooth 26 (30%; 95%CI=19% to 45%).The high incidence of sinus pathology of odontogenic origin shows the need for interdisciplinary work involving dentists and ear-nose-throat specialists. Caries, inadequate restorations, periodontal lesions, implants, and the presence of root remnants are the main causes of Schneiderian membrane thickening. The use of CBCT for diagnosis and treatment planning allows detecting maxillary sinus membrane thickening and determining its association with an odontogenic etiology.

El objetivo del presente trabajo fue evaluar el engrosamiento de la membrana de Schneider y determinar su asociación con patologías periapicales, mediante tomografía computarizada cone beam (CBCT). Se realizó un estudio observacional, analítico, retrospectivo y transversal. Un total de 179 senos maxilares fueron evaluados utilizando CBCT. Se analizó la presencia de engrosamiento de la membrana sinusal y su asociación con piezas dentarias sin vitalidad pulpar. Los resultados se muestran como porcentajes con intervalos de confianza del 95% (IC del 95%). Se utilizó la prueba de Chi cuadrado con un nivel de significación del 5%. Se detectó engrosamiento de la membrana sinusal en 70 casos (39%; IC del 95% = 32% a 46%) y no se observó engrosamiento de la membrana sinusal en 109 (61%; IC del 95% = 54% a 68%) (p < 0.05). Los 70 casos que mostraron engrosamiento de la membrana sinusal incluyeron 46 de origen odontogénico (66%; IC del 95% = 54% a 76%) y 24 (34%; IC del 95% = 24% a 46%) de origen no odontogénico (p <0,05). La frecuencia de las causas odontogénicas siguió una distribución heterogénea (p <0.05): caries penetrantes, tratamiento endodóntico deficiente, restos radiculares, restauraciones profundas, implantes, patología periodontal. La principal causa fue la caries (46%; IC 95% = 32% a 60%), seguida por endodoncia deficiente (26%, IC 95% = 16% a 40%). La frecuencia se distribuyó en forma heterogénea entre las distintas piezas (p<0,05). Las piezas más afectadas fueron la 16 (33%; IC95=21% a 47%) y la 26 (30%; IC95=19% a 45%). La alta incidencia de patología sinusal de origen odontogénico implica la necesidad del trabajo interdisciplinario entre odontólogos y otorrinolaringólogos. Caries, restauraciones inadecuadas, lesiones periodontales, implantes y la presencia de restos radiculares son las principales causas del engrosamiento de la membrana de Schneider. El uso de CBCT para el diagnóstico y la planificación del tratamiento permite detectar el engrosamiento de la membrana del seno maxilar y determinar su asociación con una etiología odontogénica.

Histological evaluation of effectiveness of platelet-rich fibrin on healing of sinus membrane perforations: A preclinical animal study.

The aim of this study was to evaluate the effectiveness of platelet-rich fibrin (PRF) in repairing of Schneiderian membrane perforations in rabbit maxillary sinus. A total of 42 female New Zealand rabbits were randomly divided into two groups. Symmetrical bony defects were created 1 cm in diameter and the sinus membranes were exposed. The Schneiderian membranes were elevated in both sinuses and each membrane was perforated with a 1 cm incision. No treatment was applied to the right perforations in both groups. Left-sided perforations were closed with collagen membrane in the first group and PRF membrane in the other group. Seven animals randomly selected from each group were sacrificed at weeks 1, 2 and 4 in order to be able to examine the amounts of lymphocytes, fibroblasts, veins, and collagen fibers in the area where the membranes were applied. Histological analyses showed that there were no statistically significant differences between the collagen membrane and the PRF membrane in the healing of sinus perforation area. PRF may be considered as an alternative application to collagen membrane in sinus membrane perforations.