Anatomy of Maxillary Sinus: Focus on Vascularization and Underwood Septa via 3D Imaging.

The study of the maxillary sinus anatomy should consider the presence of two features of clinical importance. The arterial supply course and the presence of the so-called Underwood septa are two important factors to consider when planning surgical treatment to reduce the risk of surgical complications such as excessive bleeding and Schneiderian membrane perforations. This study aimed to investigate the above-mentioned anatomical structures to improve the management of eventual vascular and surgical complications in this area. This study included a total of 200 cone-beam computed topographies (CBCTs) divided into two groups of 100 CBCTs to evaluate the arterial supply (AAa) course through the lateral sinus wall and Underwood's septa, respectively. The main parameters considered on 3D imaging were the presence of the AAa in the antral wall, the length of the arterial pathway, the height of the maxillary bone crest, the branch sizes of the artery in the first group, and the position of the septa, the length of the septa, and their gender associations in the second group. The CBCT analysis showed the presence of the arterial supply through the bone wall in 100% of the examined patients, with an average size of 1.07 mm. With regard to the septa, 19% of patients presented variations, and no gender difference was found to be statistically significant. The findings add to the current understanding of the clinical structure of the maxillary sinus, equipping medical professionals with vital details for surgical preparation and prevention of possible complications.

Frequency, location, and diameter of the anastomosis between the posterior superior alveolar artery and the infraorbital artery in imaging studies: systematic review and meta-analysis.

The anastomosis between the posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA) courses along half of the lateral wall of the maxillary sinus. Risk of injury to the anastomosis between PSAA and IOA during surgical procedures has been reported. The aim of the present study was to carry out a systematic review and meta-analysis to determine the frequency, location, and diameter of the anastomosis between PSAA and IOA in imaging studies (cone-beam computed tomography, spiral cone-beam computed tomography, and computed tomography). A search was carried out in the PubMed, EMBASE, and LILACS. Original works were included reporting imaging studies to analyze the frequency, location, and diameter of the anastomosis in humans. The risks of bias were analyzed using the AQUA tool. Generalized linear mixed models were used to estimate the frequency and the 95% CI in the meta-analysis. The variance in prevalence estimates was stabilized by logit transformation. The qualitative analysis included 49 studies with 10,837 patients. The frequency of the anastomosis between PSAA and IOA was 74% (prediction interval 0.20-0.97%). The anastomosis was most frequently located in the intraosseous region (60.0%), followed by the submembranous region (33.0%), and least frequently in an extraosseous location (5.0%). Arteries with diameter of 1.0-1.9 mm were most frequent (32.0%), followed by arteries with diameter less than 1 mm (23.0%); a small number with diameter greater than 2 mm was recorded (4.0%). These data can be used as a reference to help surgeons when planning interventions in the lateral wall of the maxillary sinus. Registration number: INPLASY, number 202120071.

[Topographic assessment of the vascular anastomosis in the maxillary sinus wall using cone-beam computed tomography]. / Topografiya sosudistogo anastomoza v stenke verkhnechelyustnoi pazukhi po dannym konusno-luchevoi komp'yuternoi tomografii.

OBJECTIVE: The aim of the study was to establish the prevalence, diameter and topography of the intraosseous vascular canal of the maxillary sinus lateral wall. MATERIAL AND METHODS: The data of cone-beam computed tomography of 150 dental patients (294 maxillary sinuses) were analyzed. RESULTS: Intraosseus anastomosis of the branches of the posterior superior alveolar artery and infraorbital artery was detected in 87.8% of cases (258 of 294 sinuses). Anastomosis was found inside the wall of the sinus in every tooth location in 9.5% of sinuses; in other cases, the anastomosis was partially or fully embedded in the thickness of the lateral wall of the maxillary sinus in different tooth site. The mean diameter of the vascular anastomosis was 0.95±0.3 mm (range 0.3-2.18 mm). The average distance from the anastomosis to the sinus floor was 8.91±3.39 mm (range 1.68-21.83mm). In most cases, at locations of molars and premolars, the distance from the vascular anastomosis to the alveolar crest was greater than 15 mm (from 75.5% at the location of the first molar to 99.2% at the location of the first premolar). CONCLUSION: Detection of the topography of the vascular anastomosis by using cone-beam computed tomography is essential when planning the position of the antrostomy for the lateral sinus lift procedure in order to minimize iatrogenic complications.

Study of factors influencing preoperative detection of alveolar antral artery by CBCT in sinus floor elevation.

This study aimed at assessing the prevalence of alveolar antral artery (AAA) detection by CBCT, its related variables, and at describing explanatory models useful in surgical planning, by retrospective evaluation of CBCT explorations. The modelling of the probability for detecting AAA was undertaken using logistic generalized additive models (GAM). The capacity for discriminating detection/no detection was assessed by receiver operating characteristic curves. A total of 466 sinuses were studied. Univariate models showed detection probability was linked to sinus width and thickness of the lateral bony wall, together with the shape and height of the osseous crest. AAA detection probability increased steadily until the thickness of the bony wall reached 6 mm. Multivariate models resulted good discriminators for AAA detection, particularly for females, showing an area under the curve (AUC) of 0.85. Models considering patients altogether, and those including only males offered slightly lower values (AUC = 0.79). The probability of AAA detection by CBCT was influenced by gender (higher in males and for narrow sinuses) and increases with the thickness of the sinus lateral bony wall and the height of the residual alveolar ridge. Besides, and particularly for women, the thickness of the ridge at the basal level seems to improve the explanatory model for AAA detection.

Important anatomical variations of the superior posterior alveolar artery: Studied by cone beam computed tomography.

The knowledge of anatomical variations of the posterior superior alveolar artery (PSAA) is very important in surgeries for maxillary sinus (MS) elevation and subsequent insertion of dental implants, avoiding common and serious surgical complications. The main objective of this study was to analyse important anatomical variations of the PSAA by means of cone beam computed tomography (CBCT) examinations. 180 tomographic CBCT were analysed, and MS was divided into three equal regions: (I) anterior, (II) intermediate and (III) posterior. Variables evaluated were the visualisation of the artery, distance from the artery to the ridge crest, distance from the artery to the sinus floor, alveolar ridge height and arterial diameter. The PSAA visualisation was more prevalent in males and region III (76.7%). The distance from the artery to the sinus floor presented no significant difference between regions II and III, with both regions showing significantly lower values than region I. A significant difference was observed in the diameter of the arteries with higher prevalence of diameters >1.0 mm in males and <1.0 mm in females. The PSAA can be well visualised frequently with a CBCT, and differences in artery diameter were observed in relation to gender (males > females). Additional care is recommended when it is necessary to extend surgeries to the posterior MS region, avoiding haemorrhages that are associated with failures in these procedures.

Canalis sinuosus: anatomical variation or structure?

PURPOSE: The main goal of the present study was to verify the presence, spatial location, the end of the canalis sinuosus (CS) trajectory and size of CS using cone beam computed tomography (CBCT) to characterise it as either a structure or an anatomical variation. METHODS: A trained examiner specialist in dental radiology and imagenology selected 200 CBCT images of the maxilla from 107 (53.5%) female and 93 (46.5%) male individuals aged between 18 and 85 years. RESULTS: A total of 133 (66.5%) patients had CS, being 61 (45.86%) unilateral and 72 (54.14%) bilateral. A higher frequency of CS was observed in males (P < 0.05) and no relationship was found between its presence and age. The end of the CS trajectory was more frequent in the regions of central incisor (n = 91; 44.39%), followed by lateral incisor (n = 45; 21.95%) and canine (n = 29; 14.15%). In our sample, the majority of these canals had a diameter of up to 1 mm (n = 198/205; 96.6%). No statistically significant relationship between diameter and the end of the CS trajectory, with location (i.e. bilateral or unilateral) was found. Gender and age had no influence on diameter, spatial location and the end of the CS trajectory (P > 0.05%). CONCLUSION: As CS was frequently found in our sample, it can be considered an anatomical structure, and as such, it is fundamental that the dentist requests a CBCT examination before performing any invasive procedure in the maxillary region to preserve this important structure.

Relationship Between the Posterior Superior Alveolar Artery and Maxillary Sinus Pathology: A Cone-Beam Computed Tomography Study.

PURPOSE: The purpose of the present study was to assess the relationship between the posterior superior alveolar artery (PSAA), which plays an important role in the maxillary sinus blood supply, and maxillary sinus pathologic entities using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: The CBCT data from 325 patients (650 sinuses), aged 18 to 55 years, who had been referred to the Department of Dentomaxillofacial Radiology from 2015 to 2017 were evaluated retrospectively. For the PSAA examination, the axial, coronal, and sagittal CBCT images were evaluated for detection of an osseous canal in the lateral wall of the maxillary sinus and the prevalence, position, and location of the canal. In addition, the presence of maxillary sinus pathologic features was analyzed, and the relationship with the PSAA was investigated. The relationship among the categorical variables was tested using the χ2 test. RESULTS: The study group consisted of 325 patients, including 155 men (47.7%) and 170 women (52.3%). The PSAA was observed in 80.6% of the patients. Of the detected PSAAs, 79.0% were bilateral and 21.0% were unilateral and 56.3% were intraosseous and 40.7% were submembranous. A significant positive correlation was detected between the presence of a PSAA and patient age (P < .05). The prevalence of sinus pathologic entities was 73.2% of all patients. The most common sinus pathologic finding was localized mucosal thickening (53.5%). A significant relationship was found between the presence of PSAA and maxillary sinus pathologic entities (P < .001). CONCLUSIONS: The presence of a PSAA might be a predisposing factor that increases the susceptibility to maxillary sinus pathologic entities. CBCT is an effective imaging method in the evaluation of the maxillary sinuses.

The potential clinical relevance of anatomical structures and variations of the maxillary sinus for planned sinus floor elevation procedures: A retrospective cone beam computed tomography study.

BACKGROUND: Complications arising from sinus floor elevation (SFE) with lateral approach surgery can be avoided by means of maxillary sinus examination in the preoperative period. PURPOSE: To investigate anatomical variations in the maxillary sinus by making use of cone beam computed tomography (CBCT) in terms of SFE with a lateral approach. MATERIALS AND METHODS: Two hundred twenty eight maxillary sinuses in 114 patients were included. Parameters such as the position and diameter of the posterior superior alveolar artery (PSAA) canal, the frequency and localization of the septa or accessory maxillary ostium (AMO), and lateral wall thickness values were subjected to statistical analysis. RESULTS: Septa were observed in 35.1% of sinuses. The majority of septa were determined in the middle region (48.8%). Additionally, 71.1% of PSAA canals were intraosseous, generally exceeding 1 mm in diameter (68.9%). The shortest mean perpendicular distance between the sinus floor and the PSAA canal was determined in the first molar region (9.22 ± 5.66 mm). Similarly, the highest mean sinus lateral wall thickness was determined in the first molar region, in the area 3 mm distant from the sinus floor (2.42 mm ± 0.88 mm). AMO was detected in 40.8% of sinuses. CONCLUSION: CBCT-guided treatment planning may be beneficial prior to SFE procedures in order to avoid surgical complications.

Cone Beam Computed Tomography Evaluation of the Artery in the Lateral Wall of the Maxillary Sinus: Retrospective Analysis of 602 Sinuses.

PURPOSE: This retrospective study evaluates the location of the arteries in the maxillary sinus, particularly in the middle portion, using cone beam computed tomography (CBCT) scans that can detect the lateral arteries with high reliability. METHODS: In this retrospective study, 2 experienced independent examiners evaluated 602 sinuses on CBCT scans. DISCUSSION: No significant correlation was found between the location of arteries and the patient's age, sex, or dentition. In 92.0% (P ≤ 0.001) of the sinuses, at least 1 arterial branch was detectable. CONCLUSION: Based on the CBCT scans, we found that a very high proportion of patients have the maxillary artery in their lateral sinus wall, which is important information for sinus augmentation or sinus surgery.

Vascular Precautions Before Sinus Lift Procedure.

The aim of the study was to evaluate the benefit of cone beam computed tomography (CBCT) and how to minimize injury to the posterior superior alveolar artery (PSAA) before sinus lift procedure. Cone beam computed tomography scans of 30 maxillary sinuses (15 patients) assessed to determine the location of PSAA presinus lift procedure. The data collected were used to extend the existed literature. The most common location of the PSAA was intraosseous (66.7%), the subantral distance mean was 5 ±â€Š1 mm, and the mean distance of PSAA from the crest was 15 ±â€Š1.6 mm. Cone beam computed tomography is valuable before the sinus lift procedure to exclude the presence of any lesion and to detect the location of the PSAA. The study recommends not to extend the upper border of the window beyond 16 mm from the residual crest during the lateral sinus approach.

[Detection and management of the vascular paths in the lateral sinus wall using cone beam computed tomography].

OBJECTIVE: To detect the vascular paths in the lateral wall of maxillary sinus using cone beam computer tomography (CBCT), and to retrospect the surgical managements of avoiding bleeding complication during the lateral approach maxillary sinus elevation. METHODS: The documents of 71 consecutive patients with 81 sides maxillary sinus elevation surgery were collected. The vascular paths in the lateral wall of maxillary sinus were detected by the preoperative CBCT, and the messages about the vascular in surgical records were analyzed. RESULTS: The paths of the vascular could be detected in 77 (95.1%) sides maxillary sinus in the reconstruction panoramic images of CBCT. At the position of the first molar, the paths of the vascular of the lateral maxillary sinus walls could be detected in 54 sides (66.7%) in the reconstruction coronal images of CBCT, and the other 27 sides (33.3%) could not be detected. Two approximately parallel paths of the vascular were found in 3 sides (3.7%) of the lateral maxillary sinus walls. The different diagnoses occurred in 6 sinuses between two observers. The kappa of diagnostic consistency of the two observers was 0.842 (P<0.001). The mean distance between the lower border of the vascular path to the plane of the alveolar crest of 54 sides maxillary sinuses was about (13.0±4.7) mm. The mean distance between lower border of vascular path to the plane of the floor of the sinus was (9.3±4.8) mm. The vascular path was located in the floor wall in 1 sinus. During the lateral approach maxillary sinus elevation operation, intraosseous vessels were dissected in 4 sides sinus lateral wall, the vascular path was avoided consciously in 3 sides, and the sinus elevation surgery had to be given up in 1 side for the vessel was torn and bleeding. There were no vascular related messages in 73 sides of the lateral approach maxillary sinus elevation operation records. CONCLUSION: The vascular paths of maxillary sinus wall could be detected by CBCT in most cases. Preoperative CBCT examination was proved to be reliable. The vascular paths of maxillary sinus wall should be examined carefully. It was helpful to make the surgical design perfectible and reduce the risk of tearing the vessel in operation.

Sinus presurgical evaluation: a literature review and a new classification proposal.

INTRODUCTION: Presurgical evaluation with cone beam computed tomography (CBCT) or computed tomography (CT) has become an essential tool for diagnosis and surgical planning, including maxillary sinus floor elevation. Before performing a sinus lift, the clinician's attention should not be only directed to the patency of the ostium through CBCT or CT, because many anatomical features could influence the surgical approach of sinus floor elevation. The goal of this article was to facilitate the communication between clinicians regarding the type of maxillary sinus, encourage in-depth analysis prior to surgery and reduce the risk of complications due to possible underestimation of important parameters. EVIDENCE ACQUISITION: An electronic search was conducted in Pubmed, Embase, Medline and Scopus, matching the following keywords: "sinus lift", "CBCT", "CT", "presurgical" and "evaluation". Clinical Oral Implant Research, Implant Dentistry, International Journal of Periodontics and Restorative Dentistry and Journal of Oral Implantology were hand-searched. The bibliographies of review articles were checked and personal references were also searched. EVIDENCE SYNTHESIS: Eleven parameters, that clinicians must check every time through CBCT or CT, were evaluated from different studies. At the end of the literature review for every single feature, the Authors established a favorable, a normal and an unfavorable situation, in order to provide a new classification. CONCLUSIONS: The grade of the described classification may be useful for clinicians to understand what probably the risk level of the sinus lift surgery could be and it may encourage the surgeon to have a careful pre-operative evaluation through CBCT or CT.

Vascular Structures of the Lateral Wall of the Maxillary Sinus: A Vascular Labeling Technique.

PURPOSE: Sinus floor augmentation is a common procedure in implant dentistry. However, several intraoperative complications can occur during this procedure, such as bleeding from the lateral wall of the maxillary sinus. The aim of this study was to describe the vascular structures of the lateral wall of the maxillary sinus using a vascular labeling technique. MATERIALS AND METHODS: Ten cadaveric specimens were prepared by the vascular labeling technique. Liquid latex was injected into the large vessels of the head, and the lateral wall of the maxillary sinus was exposed by dissection. The diameter of the vessels and their distance from the alveolar ridge (AR) were recorded. RESULTS: Blood vessels could be observed in all the dissected specimens (100%). The mean distance from the lower edge of the blood vessels to the AR was 18.5 mm (SD 3.31 mm). CONCLUSIONS: The vascular labeling technique detects maxillary sinus vessels in a predictable and effective way. These structures are clinically relevant because they are located in the area where the lateral window is usually created in sinus augmentation procedures and can cause profuse bleeding.

Radiographic Evaluation of Maxillary Sinus Lateral Wall and Posterior Superior Alveolar Artery Anatomy: A Cone-Beam Computed Tomographic Study.

OBJECTIVE: The purpose of the current study is to assess the thickness of the maxillary sinus lateral wall in dentate and edentulous patients using cone beam computed tomography (CBCT). This study also provides information about the diameter, prevalence, and course of the posterior superior alveolar artery (PSAA), and its relation to the maxillary sinus floor. MATERIALS AND METHODS: Four hundred and thirty CBCT scans of the maxillofacial complex (860 maxillary sinuses) were reviewed. Measurements of the lateral wall of the maxillary sinus and PSAA were performed on the CBCT images. RESULTS: Statistical analysis showed that dental status (edentulous, non-edentulous) of the patients had no significant effect on the lateral wall thickness. The mean thickness of the lateral wall of the maxillary sinus was 1.21 ± 1.07 mm at the second molar (M2), 1.98 ± 1.87 mm at the first molar (M1), 2.02 ± 1.53 mm at the second premolar (P2) and 2.16 ± 1.25 mm at the first premolar (P1). There was statistically significant difference between the left and right sides of the maxillary sinus only at P2 (p =.043). Detection rate of the PSAA on CBCT was reported as 60.58%. The mean diameter of the artery was 1.17 mm (range 0.4-2.8 mm). There was no significant correlation between age and the size of the PSAA. The most frequent path of the PSAA was intraosseous (69.6%), followed by intrasinusal (24.3%) and superficial (6.1%). The overall mean distance of the PSAA from the floor of the maxillary sinus is 8.16 mm. CONCLUSIONS: The results from this study suggest that using CBCT prior to the surgery provides valuable diagnostic information. However, undetected intraosseous canal in CBCT does not exclude its existence. Alteration in the lateral window design and the use of piezoelectric instruments are recommended if intraoperative complications are expected.

Histological and radiographic study of human edentulous and dentulous maxilla.

Data on the bone trabecular structure and density of the edentulous regions of the first upper molars are important for designing successful dental treatments, especially dental implants. However, no detailed defined morphometric properties on the human maxilla are available at the immunohistochemical and radiographic levels. Cone-beam computed tomography analysis and immunohistochemical observation were applied to the maxillary first molar region of 91 cadavers (46 males and 45 females). The edentulous maxilla can be classified into the following three forms: fully edentulous (FE), partially edentulous (PE), and immediately edentulous (IE). Compared with the first molar dentulous (FMD) specimens, significant differences in cortical bone structure and bone density exist among IE, PE, and FE in maxilla (P < 0.001). According to histochemical observations, the positive CD31 reaction clearly described a large vessel of the PE and small vessels of FMD and IE in maxillary sinus connective tissue. These structural issues were clearly related to tooth extraction. These morphological and radiographic data describing the edentulous region of the maxillary first molar might be useful for improving dental treatments.

[The anatomy of maxillary sinus in single maxillary posterior edentulous area based on cone-beam CT].

OBJECTIVE: To compare the anatomy of maxillary sinus in single maxillary posterior edentulous area and the contralateral side without loss of tooth, and to investigate the effect of tooth loss on the anatomy of maxillary sinus by cone-beam CT(CBCT). METHODS: A total of 128 patients with single unilateral single maxillary tooth loss were included in the study. CBCT was taken in these patients and the thickness of the maxillary lateral wall, mucosa thickness of sinus floor and sinus septa of the maxillary sinus were recorded and compared with the contralateral side. The bone height from the sinus floor to the ridge crest and the distance between maxillary sinus floor and the vascular anastomosis of maxillary lateral wall were analyzed. RESULTS: The thickness of maxillary sinus lateral wall and maxillary sinus mucosa were 1.59 (1.22), 1.61(1.95) mm in the maxillary posterior edentulous area and significantly less than those of the contralateral side(1.76[1.10], 1.91[2.23] mm)(P<0.05), and the data was demonstrated using median(quartile range). The difference of the mean number of maxillary sinus septa between the two sides was not statistically significant(P>0.05). There was a negative correlation between the bone height from the sinus floor to the ridge crest and the distance between maxillary sinus floor and the vascular anastomosis of maxillary lateral wall (r= -0.343, P<0.01). CONCLUSIONS: The changes of the thickness of lateral wall of maxillary sinus and maxillary sinus mucosa are closely related to tooth loss. The change of the number of maxillary sinus septa is not related to tooth loss. There is a negative correlation between the bone height from the sinus floor to the ridge crest and the distance between maxillary sinus floor and the vascular anastomosis of maxillary lateral wall.

Location of the extraosseous and intraosseous arterial anastomosis of the maxillary sinus in edentulous specimens.

OBJECTIVES: The aim of this anatomical study was to measure the distance from the intraosseous and extraosseous arterial anastomoses of the maxillary sinus to the alveolar ridge in edentulous specimens dissected from human cadavers. MATERIALS AND METHODS: Forty edentulous maxillary specimens were dissected, anatomically prepared, and injected for a better visualization of the maxillary sinus artery. RESULTS: This study showed that the mean distance from the alveolar ridge to the extraosseous anastomosis was 16 mm for the second maxillary molar, 12 mm for the first maxillary molar, and 13 mm for the second maxillary premolar. For the intraosseous anastomosis to the alveolar ridge, the mean distance was 17 mm for the second maxillary molar, 13 mm for the first maxillary molar, and 14 mm for the second maxillary premolar. CONCLUSIONS: Under the conditions of this study, we found that the mean distance from the alveolar crest to the extraosseous anastomosis and intraosseous anastomosis was shortest for the first maxillary molar and second maxillary premolar and greatest for the second maxillary molar. CLINICAL RELEVANCE: These findings provide data whose relevance for clinical dentistry is that they can be applied to minimize the risk of damage to the arterial network of the maxillary sinus during surgical procedures in this region.

Location of Posterosuperior Alveolar Artery and Correlation with Maxillary Sinus Anatomy.

The blood supply to both the lateral wall of the maxillary sinus and the overlying membrane originates from the posterosuperior alveolar artery (PSAA) and the infraorbital artery. The purpose of the present study was to evaluate the anatomic characteristics of the PSAA in a large number of subjects of the Lebanese population. Images of 696 sinuses were analyzed using cone beam computed tomography (CT). Coronal, axial, and sagittal CT images were evaluated for the presence of an osseous canal in the lateral wall of the sinus, and the prevalence, position, and location of the canal were studied and presented.

Preoperative 3D imaging in maxillary sinus: brief review of the literature and case report.

OBJECTIVE: The purpose of the present case report is to document the removal of a radix in antro without a hemorrhagic complication in presence of a posterior superior alveolar artery (PSAA) with a 2.8 mm diameter following a radiographic 3D planning by cone beam computed tomography (CBCT) scan. Furthermore, a brief literature overview on studies describing the existence and the variance of the PSAA is provided. METHOD AND MATERIALS: A foreign body removal in the right maxillary sinus was performed on a 33-year-old healthy man by using the lateral window osteotomy. The preoperative CBCT scan showed three arteries in the lateral maxillary sinus wall at a distance of 24.6 mm, 19.5 mm, and 13.5 mm to the alveolar crest. RESULTS: By removing a foreign body out of the maxillary sinus a vessel with a diameter of nearly 3 mm was exposed. Due to CBCT scan planning and the use of piezosurgery it was possible to avoid any damage to the vessel during the operation. The postoperative healing was uneventful and no complications occurred. CONCLUSION: Although laceration of vessels with a large diameter during lateral window osteotomy is not life-threatening it may compromise visualization and reduces the surgical outcome. Therefore, 3D imaging is recommended for the minimization of intra- and postoperative complications and for the localization of any foreign body in relation to other anatomical structures. This is of special interest in case of anatomical variances of blood vessels.