Minimally Anterior Medial Maxillary Approach (MAMMA): a novel technique for a wide access to the maxillary sinus.

PURPOSE: To describe a novel endoscopic technique to approach the maxillary sinus (MS), the Modified Anterior Medial Maxillary Approach (MAMMA), preserving the inferior turbinate (IT) and the nasolacrimal duct (NLD). To perform radiological measurements and describe a case series to study the feasibility and limits of MAMMA. METHODS: Computed tomography (CT) scans (n = 150 nasal cavities) were used to calculate areas of the MAMMA to define surgical limits and extensions. Measurement of distances to critical anatomy landmarks and total area for the MAMMA were calculated. An instructional case illustrating the surgical technique and outcome was also included. RESULTS: Radiological analysis showed a mean distance from the Piriform Aperture (PA) to the anterior limit of the NLD of 1.03 ± 0.18 cm (range 0.59-1.48) and a mean distance from de PA to the posterior limit of the NLD of 1.57 ± 0.22 cm (range 1.02-2.11). The mean distance from the nasal floor to the Hasner's valve was 1.61 ± 0.27 cm (range 1.06-2.52) and the distance from the nasal floor to the insertion of the IT was 2.20 ± 0.36 cm (range 1.70-3.69). Finally, the mean total area for the MAMMA was 4.04 ± 0.52 cm2 (range 3.17-5.53). No complications or recurrence of the pathology were observed in operated patients. CONCLUSION: The MAMMA provides a wide surgical field of the MS walls comparable to more aggressive techniques, with preservation of the sinonasal and lacrimal function. MAMMA is an effective alternative to treat different MS pathologies including benign recurrent maxillary sinus tumors.

Assessment of the prelacrimal recess in different maxillary sinus pneumatizations in relation to endoscopic prelacrimal recess approaches: a computed tomography study.

PURPOSE: To assist in planning before the endoscopic prelacrimal recess (PLR) approach, we aimed to investigate the relationship between morphometry and variations of PLR in maxillary sinus (MS) pneumatizations. METHODS: Retrospective analysis of the paranasal sinus computed tomography images of 150 patients was conducted to determine the pneumatization patterns of the MS, PLR variations, and the applicability of the PLR approach. The results were compared based on lateralization, gender, and age groups. RESULTS: The PLRwidth, the anteroposterior diameter of the nasolacrimal duct (NLD), the vertical and horizontal diameters of the MS were the highest in hyperplasic MS, and decreased significantly with increasing age (p = 0.005, p = 0.017, p = 0.000), respectively. Most of the morphometric measurements were higher in hyperplasic MS, while the medial wall thickness of PLR was higher in hypoplasic MS. The PLRwidth for feasibility of the PLR approach were Type I (48%) in hypoplasic MS and Type III (80%) in hyperplasic MS (p < 0.001), respectively. The PLR medial wall thickness was higher in Type I, while the piriform aperture angle (PAA), MS volume, length, and slope of the NLD were higher in Type III PLRwidth (p = 0.000), respectively. The highest anterior and separation-type variations of the PLR were observed in hyperplasic MS, whereas 31.0% of hypoplasic MS had no PLR (p < 0.001). CONCLUSION: This study revealed that PLRwidth and PAA were the highest in hyperplasic MS, which allows the endoscopic PLR approach to be performed more easily. For safer and uncomplicated surgery, surgeon should be aware of the PLR anatomy in different MS pneumatization patterns.

Relación entre el seno maxilar y ápices de dientes postero- superiores con tomografía computarizada de haz cónico / Relationship between the maxillary sinus and apices of posterior-superior teeth using cone beam computed tomography

El conocimiento de la relación entre el seno maxilar y los ápices de los dientes posterosuperiores es fundamental para evitar complicaciones frente a distintos tratamientos. Estudio descriptivo de corte transversal, con muestra por conveniencia de 383 imágenes de raíces de dientes posterosuperiores obtenidas por medio de tomografía computarizada de haz cónico (TCHC) de un centro radiológico en Viña del Mar, Chile. Cada raíz fue clasificada según su relación vertical con el seno en 4 categorías (0: ápice no se encuentra en contacto con contorno inferior del seno; 1: ápice en contacto con seno; 2: ápice lateralmente al seno; 3: ápice se protruye en seno). Además se midió su distancia en mm. Los datos fueron analizados con estadística descriptivas. El diente más lejano al seno maxilar fue el primer premolar superior (4.2 mm), seguido por el segundo premolar superior (1 mm). En el primer molar superior la raíz más lejana fue la mesio-vestibular (MV) 1mm, seguida por la raíz disto-vestibular (DV) 0.6mm y la raíz palatina (P) -1mm. En el segundo molar superior la raíz más lejana fue P 0.4mm, luego la DV 0.3mm, y MV -0,11mm. En cuanto a las categorías, se observó que la mayoría de las raíces se encuentran alejadas del seno siendo la raíz P del primer molar superior y la raíz MV del segundo molar superior las que se encuentran mayormente protruidas (42 % y 26 % respectivamente). El primer premolar es el diente posterosuperior que se encuentra más alejado del seno maxilar y a medida que se avanza hacia posterior hay tendencia a disminuir la distancia entre los ápices y el seno maxilar.

SUMMARY: Knowledge of the relationship between the maxillary sinus and the apices of the upper posterior teeth is crucial to avoid complications when considering different treatments. A descriptive cross-sectional study was carried out, with a convenience sample of 383 images of upper posterior teeth roots, obtained by means of cone beam computed tomography (CBCT) from a radiological center in Viña del Mar, Chile. Each root was classified according to its vertical relationship with the sinus into 4 categories (0: apex is not in contact with the lower contour of the sinus; 1: apex is in contact with the sinus; 2: apex laterally to the sinus; 3: apex protrudes in sinus). In addition, its distance was measured in mm. The data were analyzed with descriptive statistics. The tooth farthest from the maxillary sinus was the maxillary first premolar (4.2 mm), followed by the maxillary second premolar (1 mm). In the upper first molar, the most distant root was the mesiobuccal (MV) 1mm, followed by the distobuccal root (DV) 0.6mm and the palatal root (P) -1mm. In the upper second molar, the furthest root was P 0.4mm, then DV 0.3mm, and MV -0.11mm. In reference to the categories, it was observed that most of the roots are far from the sinus, with the P root of the first upper molar and the MV root of the second upper molar being the most protruding (42 % and 26 % respectively). The first premolar is the posterior maxillary tooth that is furthest from the maxillary sinus and as one advances posteriorly there is a tendency to decrease the distance between the apices and the maxillary sinus.

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.

The Use of 0° and 70° Endoscopes in Maxillary Antrostomy.

BACKGROUND AND OBJECTIVES: Performing an effective maxillary antrostomy is critical to improving chronic maxillary sinusitis symptomatology. Incomplete dissection of the uncinate process and failure to incorporate the natural drainage pathway may lead to recirculation and need for revision surgery. The purpose of this study is to determine if 70° endoscopes provide added value in determining incomplete dissection or residual disease. METHODS: Prospective study of 35 sinuses from 18 patients undergoing FESS for Chronic Rhinosinusitis (CRS) between 11/1/2020 and 4/30/2021. Two fellowship trained Rhinologists initially performed maxillary antrostomies exclusively using a 0° endoscope, then transitioned to a 70° endoscope. Surgeons completed a survey to assess completion of the antrostomy prior to use of 70° endoscope, sino-nasal anatomy, and difficulty of the operation. Intraoperative photographs before and after using a 70° endoscope were evaluated by a third party. Pre-operative CT scans were used to evaluate the sphenoid keel-caudal septum-nasolacrimal duct (SK-CS-NL) angle. RESULTS: Of 35 sinuses from 18 patients all 35 sinuses had CRS with 48.5% having nasal polyposis and 42.9% having active infection. There was residual inflammatory tissue in the anterior maxillary sinus, including polypoid tissue and uncinate process prior to using the 70° endoscope in 82.9% of sinuses. The natural drainage pathway was not incorporated into the dissection in 28.6% of sinuses before converting to 70° endoscope. Incomplete dissection with 0° endoscope was not associated with nasal polyposis (P = .086) or uncinate position (0.741). Narrow SK-CS-NL angles were associated with incomplete dissection of the anterior maxillary sinus with 0° endoscope (16.0° ± 3.0° vs 20.6° ± 3.2°; P = .013). CONCLUSION: Use of 70° endoscope in maxillary antrostomy may be beneficial in identifying and resecting disease within the anterior maxillary sinus that may otherwise be difficult to find using a 0° endoscope. This is especially true in patients with narrow nasolacrimal duct positioning.

Anatomical localization of posterior superior alveolar artery: A retrospective study by cone-beam computed tomography.

BACKGROUND: Familiarity with the anatomy of the arteries in the sinus wall is essential to prevent the perforation of the sinus membrane and bleeding during dental implant surgery. OBJECTIVES: The aim of the study was to evaluate the anatomical position of the posterior superior alveolar artery (PSAA), using cone-beam computed tomography (CBCT). MATERIAL AND METHODS: A total of 245 CBCT scans met the eligibility criteria for this cross-sectional study. The vertical distance from the lower border of the artery to the lower border of the sinus floor, the diameter of the artery, and the type of artery (intrasinusoidal, intraosseous or superficial) in the first and second premolar and molar regions were measured. The data was analyzed with the t tests, the one-way analysis of variance (ANOVA) and the χ2 tests. RESULTS: The maxillary PSAA was recognized in 187 (76.3%) scans. The mean distance between the artery and the floor of the sinus was 6.87 ±3.68 mm. The mean diameter of the artery was 1.37 ±0.61 mm. The greatest mean diameter of the artery was observed in the second premolar region, and the smallest in the first molar region. As many as 63.6% of the arteries were intraosseous, 28.9% intrasinusoidal, and 7.5% superficial. CONCLUSIONS: Due to the high prevalence of the intraosseous type, in most cases of sinus lift surgery there is an increased possibility of PSAA damage. As the largest diameter of the artery was observed in the second premolar region, the possibility of severe bleeding during sinus lift surgery in this area is increased. The average distance between the artery and the floor of the sinus was approx. 7 mm. Consequently, it is recommended that the lower border of the sinus access window should be as high as 7 mm to the floor of the sinus.

Analysis of the Prevalence, Location, and Morphology of Maxillary Sinus Septa in a Northern Chinese Population by Cone Beam Computed Tomography.

Purpose: The purpose of this study is to survey the prevalence and morphology of the maxillary sinus septum, which might increase the rate of maxillary sinus membrane perforation during maxillary sinus floor elevation surgery, among northern Chinese, and to further analyze the relationship between gender, age, edentulous type, and prevalence of maxillary sinus septa. Methods: The cross-sectional retrospective study was based on an analysis of Cone Beam Computed Tomography (CBCT) images of maxillary sinus which had been obtained from patients who visited radiology department of Beijing Stomatology Hospital of Capital Medical University (Beijing, China) during the period from January 2019 to December 2019. The data of demographic characteristic, prevalence, position, direction, and morphology of maxillary sinus septum were collected and further analyzed by SPSS version 25.0.1 and R version 3.5.1 software program. Results: 595 patients were included in this study, and 1190 maxillary sinuses were analyzed and the incidence rate of the sinus septum was 46.9%. 399 (33.5%) sinuses had one or more septa in 279 (46.9%) patients. In addition, maxillary sinus septa incidence showed no significant differences among gender, age, and edentulous type. The segment second molar had the highest incidence rate of septa. Conclusion: In this study, a higher incidence of the maxillary sinus septum was found in the northern Chinese, and its distribution varied with its position, morphology, and direction.

The pterygopalatine ganglion, palatine nerves and vessels: dissection and pathway / El ganglio pterigopalatino, nervios palatinos y vasos: disección y trayecto

SUMMARY: Background and Objectives: The palatine nerves and vessels cross the pterygopalatine fossa, the palatine canals, the palatine foramina and the submucosal space, at the level of the hard palate and the palatine recess of the maxillary sinus. Their trajectory is long, complicated and difficult to highlight on a single dissection piece. In the literature that we studied, we did not find clear images that fully highlight the real configuration of the pterygopalatine ganglion and nerves and of the palatine vessels. Our aim was to provide a clear and representative dissection of the pterygopalatine ganglion and of the palatine neurovascular bundle throughout its pathway in a simple, coherent and useful presentation for the practitioners interested in the regional pathology. We resected the posterior and inferomedial osseous walls of the maxillary sinus and highlighted the neurovascular structures in the pterygopalatine fossa and the wall of the maxillary sinus. We photographed the dissection fields and detailed the important relations. The images that we obtained are clear, simple and easy to interpret and use. We successfully highlighted the aspect and the main relations of the pterygopalatine ganglion and the pathway and distribution of the palatine nerves and vessels, from their origin to the terminal plexuses. There is a broad spectrum of clinical procedures or situations that require a proper knowledge and understanding of the anatomical pathway and relations of the palatine neurovascular elements. This includes the various types of regional anesthesia, tumor resection surgery, flaps of the palatine mucosa, the LeFort osteotomy etc. Demonstration of the pterygopalatine ganglion and its relations is useful in endoscopic interventions at the level of the pterygopalatine fossa.

RESUMEN: Los nervios y vasos palatinos atraviesan la fosa pterigopalatina, además de los canales palatinos, los forámenes palatinos y el espacio submucoso a nivel del paladar duro y el receso palatino del seno maxilar. Su trayectoria es larga, complicada y difícil de destacar en una sola pieza de disección. En la literatura que estudiamos, no encontramos imágenes claras que resalten completamente la configuración real del ganglio y los nervios pterigopalatinos y de los vasos palatinos. Nuestro objetivo fue proporcionar una disección clara y representativa del ganglio pterigopalatino y del haz neurovascular palatino a lo largo de su trayecto en una presentación simple, coherente y útil para los médicos interesados en la patología regional. Resecamos las paredes óseas posterior e inferomedial del seno maxilar y resaltamos las estructuras neurovasculares en la fosa pterigopalatina y la pared del seno maxilar. Fotografiamos los campos de disección y detallamos las relaciones importantes. Las imágenes que obtuvimos son claras, sencillas y de fácil interpretación. Resaltamos con éxito el aspecto y las principales relaciones del ganglio pterigopalatino y el trayecto y distribución de los nervios y vasos palatinos, desde su origen hasta los plexos terminales. En conclusion, existe un amplio espectro de procedimientos o situaciones clínicas que requieren un adecuado conocimiento y comprensión del trayecto anatómico y las relaciones de los elementos neurovasculares palatinos. Esto incluye los distintos tipos de anestesia regional, cirugía de resección tumoral, colgajos de mucosa palatina, osteotomía de LeFort, etc. La demostración del ganglio pterigopalatino y sus relaciones es útil en intervenciones endoscópicas a nivel de la fosa pterigopalatina.

Radioanatomic study of maxillary sinus palatal process pneumatization.

OBJECTIVES: To perform a detailed analysis of palatal process pneumatization (PPP) on cone beam computed tomography (CBCT) images. METHODS: This study consisted of 376 maxillary sinuses of 188 patients aged 22-88 years who had maxillary CBCT scans. The radioanatomy of the PPP was evaluated at distances 4, 8, 16, and 24 mm posterior to incisive foramen. The types of PPP were classified as follows: type I: maxillary sinus palatal process non-gasified; type II: palatal process gasification into the nasal floor, but not more than half of the width of the nasal floor; and type III: palatal process gasification into the nasal floor more than half of the width of nasal floor. Sinus opening angle (SOA), palatonasal recess angle (PNRA), palatal junction angle (PJA), and palatal depth measurement (PDM) were the evaluated parameters. RESULTS: Among the identified 1315 PPPs, type I PPP (880, 66.92%) was the most frequently observed, followed by type II (426, 32.4%), and the least observed was type III PPP (9, 0.68%). There was no significant difference between SOA and PJA according to the types of PPP (p > 0.05). The difference between PNRA and PDM of type I and type II PPP showed a statistically significant difference (p < 0.05). Type I PPP was the most encountered with the highest PDM, and PNRA was narrower in type III than in type II PPP. CONCLUSION: Physicians must be aware of these variations to prevent possible complications during surgery because 33.08% of the maxillary sinuses showed extensive pneumatization through the palatal process.

Anterior maxillary wall and lacrimal duct relationship in pediatric patients - CT analysis for the feasibility of the prelacrimal recess approach.

OBJECTIVE: The purpose of the current study is to determine the age-related feasibility rate of the intranasal endoscopic prelacrimal recess approach (PLRA) in pediatric patients. METHODS: Computed tomography (CT) images of 379 patients under 18 years old were analyzed retrospectively. The anteroposterior dimensions of the medial bony wall of the prelacrimal recess (PLR) were measured on 758 sides. The feasibility of the PLRA was evaluated according to the criteria of Simmen et al., for each age and three age groups based on trends in the change of the width of the PLR. RESULTS: Less than half (45.9%) of pediatric maxillary sinuses (MS) were found to have the favorable anatomy (width of PLR >3 mm) to perform the PLRA. The cut-off value for age regarding the feasibility of the PLRA was nine years old. Following an evaluation of the groups, the proportions of the MS with favorable anatomy for the PLRA were 5.7% in Group I (age 0-4 years), 33.3% in Group II (age 5-8 years), and 55.1% in Group III (age 9-17 years). In group III, the feasibility rate for the PLRA was greater in boys (62.1%) than in girls (48.3%). No difference in the feasibility rate was found between the right and left sides. CONCLUSION: The overall feasibility rate for the PLRA in pediatric patients under 18 years of age is 46%. In patients aged 9-17 years, the feasibility rate for the PLRA is >50%.

Surgical anatomy and nuances of the expanded transpterygoid approach to the pterygopalatine fossa and upper parapharyngeal space: a stepwise cadaveric dissection.

BACKGROUND: Superb knowledge of anatomy and techniques to remove the natural barriers preventing full access to the most lateral aspect of the skull base determines the ease of using the transpterygoid approach (ETPA) as the main gateway for all the coronal planes during endonasal surgeries. METHODS: Throughout stepwise image-guided cadaveric dissections, we describe the surgical anatomy and nuances of the ETPA to the pterygopalatine fossa (PPF) and upper parapharyngeal space (UPPS). CONCLUSION: The ETPA represents a lateral extension of the midline corridor and provides a valuable route to access the PPF/UPPS. Major landmarks for this EEA are the infraorbital canal, sphenopalatine foramen, and vidian nerve. It comprises the removal of the palatine bone, posterior wall of the maxillary sinus, and PPF transposition to drill the pterygoid process.

Neti pot irrigation volume filling simulation using anatomically accurate in-vivo nasal airway geometry.

Nasal saline irrigation is frequently utilised in rhinosinusitis management, and after nasal and sinus surgery. Nasal saline irrigation improves mucociliary transport and assists inflammatory mediator and post-surgical debris removal. The aim of this study was to assess the influence different head positions, irrigation inflow nostril, and the nasal cycle have on Neti pot nasal saline volume filling within the nasal passages and maxillary sinuses. Computational fluid dynamics modelling using anatomically correct nasal geometry found only minor difference in nasal cavity volume filling with inflow from either side of the nose however both head position and inflow direction were both found to have a major influence on maxillary sinus volume filling. Computational modelling flow velocity results at the nasopharynx were validated using particle image velocimetry. It was also found that directing irrigation inflow into the patent side of the nose while in the head-back position achieved the highest volume filling of both maxillary sinuses.

Three-dimensional CBCT based evaluation of the inferior part of the maxillary sinus: Retrospective Study.

The maxillary sinus is the largest of the four paranasal sinuses in humans, and its close proximity to the teeth means that caution is required during dental treatment. In particular, implant surgeries involving the maxillary posterior teeth should include evaluating the inferior part of the maxillary sinus. The purpose of this study is to evaluate the differences by comparing the inferior part of the maxillary sinus based on the nasal cavity floor (NCF) between patients (male 30, female 30) genders through the use of the three-dimensional (3-D) program that can facilitate 3-D visualizations. The present study results obtained from 3-D visualizations using cone beam computed tomography (CBCT) data showed that the inferior part of the maxillary sinus was mostly larger in males than in females. In addition, the utilization of 3-D visualization data was more likely to assure accuracy than when using data obtained by two-dimensional (2-D) imaging. Therefore, 3-D visualizations of the inferior part of the maxillary sinus will contribute to accurate analyses of its anatomical structure during implant surgery and other operations. Further studies utilizing 3-D visualization will yield useful fundamental data and guidelines for future research.

Anatomical variations of the maxillary sinus septa of an Iranian population using cone-beam computed tomography: a retrospective study / Variaciones anatómicas de los tabiques del seno maxilar de una población iraní mediante tomografía computarizada de haz cónico: estudio retrospectivo

This study sought to assess the internal anatomy of the maxillary sinuses and their septa using cone-beam computed tomography (CBCT) in an Iranian population. Materials and Methods: Resorption of alveolar bone decreases the height of the maxillary alveolar ridge. This height reduction may be so severe that it warrants ridge augmentation by a sinus lift. Manipulation of the maxillary sinuses, as in sinus lift surgery, requires adequate knowledge about the sinus anatomy.Results: Maxillary sinus septum, as an anatomical variation, may complicate the surgical procedures and increase the risk of complications such as sinus membrane perforation. In this retrospective study, 366 sinuses, 190 from females and 176 from males, aged between 10 and 65 years old presenting to the Oral and Maxillofacial Radiology Department of School of Dentistry at Hamadan University of Medical Sciences were evaluated by two oral radiologists. The extension of the maxillary sinuses, presence of septa, number of septa and their location were determined. Data were analyzed using the chi square test (level of significance p≤0.001). The coefficient of agreement between the two oral radiologists was calculated based on Cohen kappa. Septa were present in 40.5% of the maxillary sinuses, out of which, 31.6% had one, 7.9% had two and 1% had three or more septa; 38% of the septa were horizontal while 62% had an oblique orientation. In total, 184 septa were found in 183 patients; out of which, 91 septa were 2mm to 5mm long while 93 septa were longer than 5mm. Conclusions: Comprehensive knowledge about the three-dimensional internal anatomy of the maxillary sinuses acquired by CBCT priorto surgical procedures can greatly help to prevent postoperative complications.

Este estudio buscó evaluar la anatomía interna de los senos maxilares y sus septos mediante tomografía computarizada de haz cónico (CBCT) en una población Iraní. Materiales y Métodos: . La resorción del hueso alveolar disminuye la altura de la cresta alveolar maxilar. Esta reducción de altura puede ser tan severa que justifique el aumento de la cresta mediante una elevación de seno. La manipulación de los senos maxilares, como en la cirugía de elevación del seno, requiere un conocimiento adecuado sobre la anatomía del seno. Resultado: El tabique del seno maxilar, como una variación anatómica, puede complicar los procedimientos quirúrgicos y aumentar el riesgo de complicaciones como la perforación de la membrana sinusal. En este estudio retrospectivo, dos radiólogos orales evaluaron 366 senos, 190 de mujeres y 176 de hombres, con edades comprendidas entre 10 y 65 años que se presentaron en el Departamento de Radiología Oral y Maxilofacial de la Facultad de Odontología de Hamadan University of Medical Sciences. Se determinó la extensión de los senos maxilares, la presencia de septos, el número de septos y su ubicación. Los datos se analizaron mediante la prueba de chi cuadrado (nivel de significación p?0.001). El coeficiente de concordancia entre los dos radiólogos orales se calculó en base a Cohen kappa. Los septos estaban presentes en el 40.5% de los senos maxilares, de los cuales, el 31.6% tenía uno, el 7.9% tenía dos y el 1% tenía tres o más septos; El 38% de los septos eran horizontales, mientras que el 62% tenía una orientación oblicua. En total, se encontraron 184 septos en 183 pacientes; de los cuales, 91 septos tenían de 2mm a 5mm de largo, mientras que 93 septos tenían más de 5mm. Conclusion: El conocimiento exhaustivo sobre la anatomía interna tridimensional de los senos maxilares adquiridos por CBCT antes de los procedimientos quirúrgicos puede ayudar en gran medida a prevenir complicaciones postoperatorias.

Complications in sinus lift.

Prosthetic rehabilitation of atrophic maxillary implants often requires grafting owing to vertical and transversal bone deficiency. The use of this procedure in order to insert implants was introduced by Tatum and published as a clinical study by Boyne and James. It can be performed via a lateral or crestal approach. This surgery is now widespread, with good results in terms of bone augmentation and implant osseointegration. Nevertheless, there is a small proportion of patients who have infectious complications with an incidence ranging from 3.5% to 10.5%. We observe that maxillary sinus augmentation is a successful preprosthetic technique for augmentation of the edentulous posterior maxilla. Preoperative assessment of the anatomy of the sinus reduces the rate of complications considerably.

Estudio de la relación de los terceros molares superiores retenidos y el seno maxilar en radiografías panorámicas y tomografía (CBCT) / Study of the relationship of retained upper third molars and maxillary sinus in panoramic radiographs and tomography (CBCT)

Objetivo: Evaluar la eficacia de la radiografía panorámica para establecer la relación de los terceros molares superiores y la cortical inferior del seno maxilar, en comparación con la tomografía computarizada de haz cónico (CBCT). Material y métodos: El trabajo incluyó 72 pacientes, se estudiaron 34 terceros molares superiores retenidos izquierdos y 38 derechos. Se realizaron mediciones con el programa para establecer la distancia entre la cortical inferior del seno maxilar y el ápice del tercer molar superior a partir de la imagen de la radiografía panorámica en lo que se estableció como parámetros: «a distancia, en contacto y dentro del piso de seno maxilar¼. Luego, con los cortes oblicuos o paraaxiales de la tomografía computarizada (CBCT) se observó la verdadera ubicación en el plano bucopalatino. Resultados: Del total de los terceros molares superiores 34 fueron izquierdas (47.22%) y 38 derechas (52.78%). En la Rx. Panorámica, 18 casos (25%) se encontraron a distancia al seno maxilar, 12 en contacto (16.7%) y 42 por dentro (58.3%) del seno maxilar. En la tomografía se observaron 20 casos (27.8%) a distancia del conducto, 16 (22.2%) en contacto y 36 (50%) por dentro del seno maxilar. Se observaron diferencias estadísticamente significativas (p < 0.05) entre la Rx. panorámica y la tomografía (CBCT) de los terceros molares que se hallan por dentro del seno maxilar. Conclusión: A partir de los resultados obtenidos, podemos establecer que la radiografía panorámica no permite conocer la verdadera relación entre la cortical inferior del seno maxilar y los terceros molares superiores (AU)

Objective: To evaluate the effectiveness of panoramic radiography to establish the relationship of the upper third molars and the inferior cortical of the maxillary sinus, in comparison with the Cone Beam Computed Tomography (CBCT). Material and methods: The work included 72 patients, 34 upper left maxillary molars and 38 rights were studied. Measurements were made with the program to establish the distance between the lower cortex of the maxillary sinus and the apex of the upper third molar from the image of the panoramic radiograph in what was established as parameters: «at a distance, in contact and inside the floor of maxillary sinus¼. Then with the oblique or paraaxial slices of the computed tomography (CBCT) the true location in the bucco-palatal plane was observed. Results: Of the total upper third molars, 34 were left (47.22%) and 38 right (52.78%). In the panoramic X-ray 18 cases (25%) were found at distance to the maxillary sinus, 12 in contact (16.7%) and 42 inside (58.3%) of the maxillary sinus. The tomography showed 20 cases (27.8%) at a distance from the canal, 16 (22.2%) in contact and 36 (50%) inside the maxillary sinus. Statistically significant differences were observed (p < 0.05) between the Rx. panoramic and tomography (CBCT) of the third molars that are inside the maxillary sinus. Conclusion: From the results obtained, we can establish that the panoramic radiograph does not allow knowing the true relationship between the inferior cortical of the maxillary sinus and the upper third molars (AU)

Adjunctive techniques to improve access of the endoscopic prelacrimal recess approach.

OBJECTIVES: To determine whether adjunctive surgical techniques could improve access of instruments provided by the endoscopic prelacrimal recess approach to the anatomical boundaries of the maxillary sinus, and pterygopalatine and infratemporal fossa. METHODS: Ten fresh-frozen adult cadaver heads were utilized. The anatomical areas of interest were fixed, bony boundaries of the maxillary sinus, infratemporal fossa, and pterygopalatine fossa: alveolar recess (AR), zygomatic recess (ZR), perpendicular plate of the palatine bone (PB), ascending ramus of mandible (RM), floor of the orbit medial and lateral to infraorbital nerve (M-ION and L-ION, respectively). Access to the areas were compared using standard sinus surgery instruments (straight and 45° forceps) introduced via the prelacrimal recess approach, trans-septal window and canine fossa puncture. RESULTS: The prelacrimal recess approach successfully provided access to the PB and M-ION in >90% of dissections when using both the straight and 45° forceps. With the straight forceps, the ability to successfully access to the AR and ZR was the lowest at 50% and 35% respectively, although improving to 75% and 60% respectively with the 45° forceps. Access to the AR, ZR, and L-ION improved significantly when the 45° forceps was introduced through the trans-septal window. Frequency of access to the RM when either instruments when introduced through the canine fossa puncture was no greater than 60% of the dissections. CONCLUSIONS: The addition of a small trans-septal window for instruments significantly improved access of the prelacrimal recess approach especially to the orbital floor, lateral margins of the maxillary sinus, and retromaxillary space. LEVEL OF EVIDENCE: 4 Laryngoscope, 130: 1857-1863, 2020.

Endoscopic transnasal transmaxillary approach to the upper parapharyngeal space and the skull base.

PURPOSE: Treatment of tumors arising in the upper parapharyngeal space (PPS) or the floor of the middle cranial fossa is challenging. This study aims to present anatomical landmarks for a combined endoscopic transnasal and anterior transmaxillary approach to the upper PPS and the floor of the middle cranial fossa and to further evaluate their clinical application. METHODS: Dissection of the upper PPS using a combined endoscopic endonasal transpterygoid and anterior transmaxillary approach was performed in six cadaveric heads. Surgical landmarks associated with the approach were defined. The defined approach was applied in patients with tumors involving the upper PPS. RESULTS: The medial pterygoid muscle, tensor veli palatini muscle and levator veli palatini muscle were key landmarks of the approach into the upper PPS. The lateral pterygoid plate, foramen ovale and mandibular nerve were important anatomical landmarks for exposing the parapharyngeal segment of the internal carotid artery through a combined endoscopic transnasal and anterior transmaxillary approach. The combined approach provided a better view of the upper PPS and middle skull base, allowing for effective bimanual techniques and bleeding control. Application of the anterior transmaxillary approach also provided a better view of the inferior limits of the upper PPS and facilitated control of the internal carotid artery. CONCLUSIONS: Improving the knowledge of the endoscopic anatomy of the upper PPS allowed us to achieve an optimal approach to tumors arising in the upper PPS. The combined endoscopic transnasal and anterior transmaxillary approach is a minimally invasive alternative approach to the upper PPS.

Assessment of the prelacrimal recess in maxillary sinus in different sex and age groups using cone beam computed tomography (CBCT).

BACKGROUND: The intranasal endoscopic prelacrimal recess approach (PLRA) to the maxillary sinus (MS) has been reported to treat many MS and skull base diseases. However, previous studies revealed that the width of the prelacrimal recess (PLR) shows a large individual variation. The purpose of this study was to ascertain the prevalence of the PLR in MS according to gender and age. METHODS: A series of 701 maxillofacial cone beam computed tomography (CBCT) scans from adult patients were analyzed retrospectively. Patients were divided into five age groups (18-24 years, 25-34 years, 35-44 years, 45-54 years, and ≥ 55 years) and by sex. The frequencies of occurrence of the PLR in the MS were calculated and compared. RESULTS: According to the findings obtained from our study, PLR was present in 81.5% of maxillary sinuses. No differences were found when the data distributions of right and left sides were compared. For individuals, the right and left sides were not always symmetrical. The probability of PLR was lesser among women than among men, but this differences was not significant. Another finding of our study was that the percentage of PLR decreased with increasing age among patients aged < 55 years, however, increased again among patients aged ≥ 55 years. CONCLUSION: The anatomy of PLR varies among individuals. Careful analysis of individual anatomical structure characteristic is recommended when considering intranasal endoscopic PLRA to the MS. Besides, the age variation of PLR should be considered in order to avoid complications.

Assessment of maxillary premolar region in relation to maxillary sinus floor and buccal bone plate: a cone beam computed tomography study / Evaluación de la región premolar maxilar en relación con el piso del seno maxilar y la tabla osea vestibular: estudio de tomografía computarizada de haz cónico

The maxillary sinus floor location and the buccal bone plate are factors to be considered in the long-term success with implant treatments mainly in the premolar region. the aim of this study was to establish morphometric characteristics of the buccal cortical bone (BCB) thickness of maxillary premolars and its relation to maxillary sinus floor through CBCT. In this study 350 first and second maxillary premolars were analyzed from 110 CBCT images and the buccal cortical bone (BCB) was measured in a coronal view at the major axis level of each premolar. In addition, in 200 first and second maxillary premolars CBCT images were measured the distance from premolar apex to maxillary sinus floor (MSF) in both frontal and sagittal plane. The type of relationship between the apex and MSF was classified according to Ok et al. (2014). The second premolar was observed with higher values of BCB (p<0.001). In first premolar, higher values were observed in the male sex (p>0.05). In second premolar, only significantly higher values were observed in the male sex in MA-MB-MC (p>0.05). Regarding to MSF and its relation to premolar roots, it was observed that 10 % of the sample was classified as type I, 19 % as type II, 55.5 % as type III and 15.5 % as type IV. The BCB of the upper premolar region is thicker in the apical region and decreases toward the coronal region. Almost 50 % of apex of second premolars are closely and risky related MSF (Type I and II).

La localización del piso del seno maxilar (PSM) y la tabla ósea vestibular (TOV) son factores a considerar en el éxito a largo plazo de los tratamientos de implante dental en la región premolar. El objetivo de este estudio fue establecer características morfométricas del grosor de la TOV en los premolares maxilares y su relación con el PSM a través de CBCT. Se analizaron 350 primeros y segundos premolares en 110 CBCT y la TOV fue medida en vista coronal en el eje axial mayor de cada premolar. Además en 200 primeros y segundos premolares maxilares se midió la distancia desde el ápice del diente hasta el PSM en el plano sagital y frontal. El tipo de relación entre el ápice y el PSM se clasificó según Ok et al. (2014). El Segundo premolar obtuvo los mayores valores de grosor de TOV (p<0.001). En primeros premolares se observaron valores altos en el género masculino (p>0.05). En segundos premolares solo se encontraron valores significativamente altos en el género masculino en MA-MB-MC (p>0.05). En la relación con el PSM y ápices de raíces de premolares, el 10% de la muestra se clasificó como tipo I, el 19% como tipo II, el 55,5% como tipo III y el 15.5% como tipo IV. En conclusión la TOV de la región premolares superior es más grueso en la zona apical, decreciendo hacia la zona coronal. Alrededor del 50% de los ápices de raíces de premolares maxilares están cercanas y en relación de riesgo con el PSM (tipo I y II).