Arterial blood architecture of the maxillary sinus in dentate specimens

Automatic detection of posterior superior alveolar artery in dental cone-beam CT images using a deeply supervised multi-scale 3D network

OBJECTIVES

This study aimed to develop a robust and accurate deep learning network for detecting the posterior superior alveolar artery (PSAA) in dental cone-beam CT (CBCT) images, focusing on the precise localization of the centre pixel as a critical centreline pixel.

METHODS

PSAA locations were manually labelled on dental CBCT data from 150 subjects. The left maxillary sinus images were horizontally flipped. In total, 300 datasets were created. Six different deep learning networks were trained, including 3D U-Net, deeply supervised 3D U-Net (3D U-Net DS), multi-scale deeply supervised 3D U-Net (3D U-Net MSDS), 3D Attention U-Net, 3D V-Net, and 3D Dense U-Net. The performance evaluation involved predicting the centre pixel of the PSAA. This was assessed using mean absolute error (MAE), mean radial error (MRE), and successful detection rate (SDR).

RESULTS

The 3D U-Net MSDS achieved the best prediction performance among the tested networks, with an MAE measurement of 0.696 ± 1.552 mm and MRE of 1.101 ± 2.270 mm. In comparison, the 3D U-Net showed the lowest performance. The 3D U-Net MSDS demonstrated a SDR of 95% within a 2 mm MAE. This was a significantly higher result than other networks that achieved a detection rate of over 80%.

CONCLUSIONS

This study presents a robust deep learning network for accurate PSAA detection in dental CBCT images, emphasizing precise centre pixel localization. The method achieves high accuracy in locating small vessels, such as the PSAA, and has the potential to enhance detection accuracy and efficiency, thus impacting oral and maxillofacial surgery planning and decision-making.

Assessment of neurovascular channels in lateral maxillary sinus wall using cone-beam computed tomography: An imperative clinicians guide for implant placements

Background

The aim of this study is to evaluate the location and radio morphometric features of the posterior superior alveolar artery (PSAA) in patients undergoing rehabilitation of posterior maxilla and other sinus augmentation surgical procedures by cone-beam computed tomography (CBCT).

Materials and Methods

A total of 816 CBCT scans were included. Various radio morphometric measurements were done to assess the PSAA location, diameter, and distances to the sinus floor and alveolar crest.

Results

The PSAA was mostly intraosseous in the maximum in the age group 31-51 years (56%), in males (53.4%), and in dentate patients (57.4%). The artery tends to be wider in older patients. Distances to the sinus floor or the alveolar crest tend to be shorter in women.

Conclusions

This study suggests that CBCT is a valuable pre-surgical tool and the evaluation of the PSAA on CBCT images could reduce the likelihood of excess bleeding during surgery in the maxillary posterior region.

Morphometric Assessment of Alveolar Antral Artery Using Medical Computed Tomography

This study aimed to investigate the prevalence, diameter, and position of the alveolar antral artery (AAA) in paranasal sinus computed tomography (CT) images and to correlate the location of the AAA with tooth position, the presence of teeth, and residual alveolar bone height (ABH). A retrospective study was conducted at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from November 2016 to October 2021. CT images of 100 maxillary sinuses from 50 patients managed for modified endoscopic sinus surgery and sinus lifting by a single surgeon were selected and obtained from the Infinitt picture archiving and communication system radiology system (Infinitt Healthcare Co., Seoul, Korea). The location of the AAA in the lateral wall of the maxillary sinus was evaluated in correlation with the area of the first and second molars (M1 and M2), the presence of teeth, and the residual ABH. In this study, we found that the intraosseous type is the most common type of AAA. Furthermore, the location and distance of the AAA are significantly affected by tooth position, an edentulous state in the case of the first molar, and residual ABH. Pre-evaluation of the diameter, position, and distance to the AAA using CT images is essential to help prevent hemorrhage. The existence and wide range of the AAA distances based on the tooth position, edentulous state, and residual ABH should be considered even if CT imaging cannot locate the AAA.

Maxillary Sinus Lift Procedures: An Overview of Current Techniques, Presurgical Evaluation, and Complications

A maxillary sinus lift procedure is indicated if a dental implant needs to be placed in the posterior maxilla with limited bone available to accommodate a dental implant. Both open and closed sinus lifting procedures are reliable approaches for increasing the bone volume needed to support proper implant positioning. However, these methods can lead to several complications. In addition to the general complications commonly linked to oral surgery, such as swelling or hematoma, the primary complication in open sinus lifting is typically the perforation of the Schneiderian membrane during osteotomy. Detailed and extensive presurgical evaluation is crucial to minimize such complications. The objective of this study was to delineate contemporary trends in sinus lift surgery, with a specific emphasis on different techniques of sinus lift procedure, anatomical and surgical factors, presurgical evaluation, bone grafting, and the practical implications of these factors in implant dentistry cases involving a deficient posterior maxilla. In conclusion, while both osteotome and lateral window techniques can assist clinicians in addressing the complexities of implant placement in a deficient posterior maxilla, bone height before implantation remains a critical factor in determining the success and longevity of implants.

Anatomy of the Posterior Superior Alveolar Artery: a Cone-Beam Computed Tomographic Study

Introduction

Posterior superior alveolar artery (PSAA) is a major part of the circulation of the sinus floor. This study aimed to analyze the anatomy of PSAA in an Iranian population for the first time.

Methods

This study was performed on coronal CBCT slices of 400 hemimaxillae (1598 slices through premolar and molar areas), to evaluate the PSAA's prevalence, diameter, and its vertical distances from the sinus floor and the alveolar ridge. Potential associations between anatomical properties with age, gender, and maxilla sides were assessed statistically (α = 0.05, 0.0125).

Results

The PSAA was detected in 73.2% of all slices (58.5%, 79.6%, 71.5%, and 83.0%, in P1-M2 areas, respectively). The mean PSAA diameter was 0.83 ± 0.33 mm (95% CI 0.81-0.85; 0.96, 0.85, 0.80, and 0.74 mm, in P1-M2 areas, respectively). Canals > 2 mm in diameter were seen only in M1 (0.4%) and M2 (0.9%) areas.

Conclusions

PSAA diameters were smaller in this population than all others, with very few large canals available. Although the average diameter increased in the anterior regions, large canals were not present in these regions. Males tended to have larger PSAAs. Age might not change canal parameters. Gender might affect canal diameter. Right/left sides are similar.

Position of posterior superior alveolar artery in relation to the maxillary sinus using cone beam computed tomography in Indian sub-population

Purpose: To assess the location of posterior superior alveolar artery (PSAA) using CBCT in relevance to sinus lift procedure for implant placement. Patients and Methods: A retrospective study was conducted using the CBCT data of 500 patients (n = 500). Linear measurements were carried out to localize the medio-lateral and vertical position of posterior superior alveolar artery in postero-lateral wall of maxillary sinus and its proximity to the floor of maxillary sinus using CS 3D imaging 3.7.0 software program. The relative position of PSAA was determined as; (a) intra-osseous, (b) below the membrane and (c) outer-cortex of lateral sinus wall. The location of PSAA was assessed in molar region bilaterally by using following radiographic measurement; (1) distance between the lower border of posterior superior alveolar artery and alveolar crest, (2) height from the floor of maxillary sinus to alveolar crest and (3) distance from the posterior superior alveolar artery to medial wall of maxillary sinus. Results: The prevalence of the artery was observed in 99.4% of the sinuses and was mostly intraosseous (84.2%).The mean distance between the lower border of the artery and alveolar crest is significantly higher in males compared to females (P < 0.01). The distribution of artery location did not differ significantly across various age groups (P > 0.05). Discussion/Conclusion: The most common variant of PSAA was identified in the intra-osseous region and the mean distance of the vessel to crest of the residual ridge differs significantly with gender and not with age.

Evaluation of anatomical references for locating the course of the posterior superior alveolar artery for dental implant surgery

This retrospective cohort study aimed to identify the best anatomical reference for predicting the posterior superior alveolar artery (PSAA) location. Computed tomographic images of 90 maxillary sinuses were evaluated. We studied five references, including the alveolar crest, maxillary sinus floor, zygomatoalveolar crest, hard palate and soft palate, and measured the distances between them and the PSAA. Variations in the distance were evaluated by the standard deviation and coefficient of variation (CV). The zygomatoalveolar crest was an unstable reference, owing to its high standard deviation and CV. The smallest CV was for the distance between the alveolar crest and PSAA, although the distance was smaller in edentulous jaws than dentulous jaws. The distance between the sinus floor and PSAA was larger in male and edentulous patients. The PSAA was detected in 40.0%, 44.4%, 54.4% and 56.7% of the sinus walls at the first and second premolar and the first and second molar positions, respectively. At these tooth positions, the respective heights above the hard palate were 11.2 ± 4.9, 8.2 ± 4.9, 6.2 ± 2.8 and 8.1 ± 2.9 mm. The hard palate was the most stable reference for predicting the location of the PSAA, irrespective of sex, age and dentition.

Evaluation of length and location of the maxillary sinus intraosseous artery using computerized tomography

BACKGROUND

The intraosseous artery is a branch of the posterior superior alveolar artery that supplies the lateral wall of the maxillary sinus. The present study seeks to analyze the location of the intraosseous artery and its site of termination.

METHODS

Cone beam computed tomography was used to evaluate 200 patients making up 400 maxillary sinuses. The following criteria were measured: (1) the distance of the lower border of the intraosseous artery to the floor of the sinus, (2) the average length of the artery, (3) the diameter of the artery, (4) the site at which the artery terminates at, and (5) the distance of the artery from the first premolar, second premolar, first molar, second molar, and third molar.

RESULTS

The intraosseous artery was identified in 336 (84.0%) quadrants. The most common site of termination was at the mesial of the second molar (22%), regardless of dental status and right or left quadrant. Its overall mean diameter was 0.91 ± 0.56 mm, with no difference within the dental status. Its overall mean length was 7.40 ± 3.39 mm, with a statistically significant difference between dentate and edentulous quadrants (P < 0.001). Its overall mean distance from the floor was 6.95 ± 6.49 mm, with no difference within the dental status. All parameters showed no difference between right or left quadrants.

CONCLUSIONS

The chances of encountering the intraosseous artery at the premolar area is <21% during a lateral window sinus floor elevation. The most common (22%) site of termination of the intraosseous artery is at the mesial of the second molar. Understanding of the course, location, and termination of the artery enhances the precision of a clinician when it comes to pre-operative treatment planning.

Preserving the Neurovascular Bundle in Targeted Endodontic Microsurgery: A Case Series

Endodontic microsurgery encompasses the use of microscopy, specialized instruments, and advanced imaging with cone-beam computed tomographic (CBCT) imaging. This treatment modality results in high clinical success rates and facilitates the enucleation of osteolytic lesions, the resection of apical root canal complexities harboring persistent bacterial biofilms, and the evaluation of possible root defects and fractures. However, there is the risk of injury to important anatomic structures, particularly when treating posterior teeth. Neurovascular bundles are among these structures at risk for injury. Fortunately, high-resolution CBCT scans can be used to detect these structures that are known to have a high anatomic variability. In addition, CBCT information can be combined with high-resolution intraoral scans to plan, design, and fabricate surgical guides to be used in a targeted endodontic microsurgery (TEMS) approach. We report 3 cases with previous endodontic treatment having persistent apical periodontitis that were treated with TEMS to avoid damage to the neurovascular bundles at risk of injury. In the first case, the palatal root of tooth #14 was adjacent to the greater palatine artery. In the second case, the mental nerve exited through 2 separate foramina close to the predictive osteotomy site for the mesial root of tooth #19. In the third case, the posterior superior alveolar artery was in close proximity to the mesiobuccal root of tooth #14. Collectively, these cases illustrate the diagnostic value of CBCT imaging for detecting neurovascular bundles and the use of TEMS to mitigate the risk of injury to these important structures. Thus, the combination of CBCT imaging and TEMS can potentially minimize the risk of intraoperative complications and postoperative sequelae while increasing the predictability of endodontic microsurgeries in complex cases.

Selective Retreatment and Sinus Lift: An Alternative Approach to Surgically Manage the Palatal Roots of Maxillary Molars

Endodontic microsurgery on the palatal root of maxillary molars presents a clinical challenge because of the root position and approximation from the maxillary sinus floor. Attempting a buccal or a palatal approach to address the root is associated with limited accessibility and visibility as well as the risk of injury to the maxillary sinus membrane and/or the greater palatine nerves and vessels. If all the maxillary molar roots require surgical intervention, two flaps may even be needed, which can make the procedure technically more difficult and lengthier. This case report presents 2 clinical cases in which apicoectomy was needed on the palatal roots of maxillary molars. The treatment includes selective nonsurgical retreatment of the palatal root and obturation using a root repair material followed by a surgical intervention from a buccal approach to treat the buccal roots, sinus lift using piezosurgery, and root resection of the palatal root. The approach was successful in both cases without any untoward events. We monitored the radiographic changes using cone-beam computed tomographic imaging immediately after the surgery and at multiple follow-up appointments. The cone-beam computed tomographic images revealed healing of the periapical disease around all the roots up to 14 and 24 months and apical repositioning of the maxillary sinus floor.

[Surgical anatomy of the maxillary sinus]

BACKGROUND

Improved understanding of the microanatomy of the paranasal sinuses, including its individual variations, makes a substantial contribution to current progress in endonasal endoscopic microsurgery. Microanatomy of the sinuses is an active field of present scientific investitations.

MATERIALS AND METHODS

A comprehensive review on microanatomy of the maxillary sinus is presented from the perspective of contemporary endonasal endoscopic microsurgery.

RESULTS

The range of variation of the individual microanatomy of all sections of the maxillary sinus is presented, in particular to minimize secondary sugical tissue trauma, to avoid complications (e.g. on orbital tissues) and as a basis for the prelacrimal access to the maxillary sinus.

CONCLUSION

Improved understanding of the range of microanatomical variations reduced the burden on the patient while opimizing the effectiveness of the necessary surgical manipulations.

Prevalence and morphometric analysis of the alveolar antral artery in a group of Thai population by cone beam computed tomography

OBJECTIVE

To investigate the prevalence, diameter, and position of the alveolar antral artery (AAA) canals and measure the distances from the canal to the maxillary sinus floor and to the edentulous alveolar crest in each posterior maxillary tooth locations by cone beam computed tomography (CBCT).

METHODS

CBCT images of the posterior maxillary region from 280 patients were investigated. The prevalence and diameter of the AAA canal were evaluated. The perpendicular distances from the canal to the maxillary sinus floor and to the edentulous alveolar crest of each tooth locations were measured. The mediolateral positions and routes of the canals were observed with novel classification. Statistical analyses were carried out to determine any significant differences in mean distances between the tooth locations along with mean distances of tooth location by age, gender, and dentate status.

RESULTS

The AAA canal was found in 94.6% with a mean diameter ± SD of 1.05 ± 0.34 mm. The mean ± SD perpendicular distance from AAA canal to the edentulous alveolar crest at the first (16.02 ± 3.94 mm) and the second molars (16.74 ± 3.51 mm) were significantly shorter than the second premolar region. The intrasinus mediolateral position of the canal (72.5%) was the most common in concordance with the all-in type mediolateral route (50.9%).

CONCLUSION

The intrasinus mediolateral position of the AAA canal is a common structure in the lateral wall of maxillary sinus, which could be detected with CBCT images. The all-in type is the most prevalent mediolateral route among a novel 7-type classification system of AAA routes. Owing to the short distance between the AAA canal and the alveolar crest in the first and second molar locations, CBCT images should be taken to investigate the AAA position and route before sinus lift procedure to prevent the risk of hemorrhage.

[The alveolar antral artery prevalence and topography according to literature review]

INTRODUCTION

The lack of the available bone in the posterior maxilla is determined by the range of anatomical and topographical factors. Lateral sinus floor elevation is the procedure for vertical augmentation in this region. Several complications may occur while performing a lateral sinus lift and bleeding due to alveolar antral artery (AAA) damage is one of them.

The aim of the study is to analysis the different literature on AAA topographical features on cadaver species and on radiographic methods.

MATERIALS AND METHODS

A search of the English language literature was performed by three independent readers in the PubMed electronic database. Articles published between 2013 and 2018 on cadaver and radiographic studies were included.

RESULTS

The analysis included 9 articles. AAA prevalence in cadavers was 100% but AAA bone signs in CBCT studies varied between 32% and 93%. The diameter varied from 0.91 mm to 3.6 mm, and the distances from AAA to the sinus floor and to the alveolar ridge crest were 7.38-9.97 and 14.6-18.66 mm respectively.

CONCLUSION

Our literature analysis showed the difference between AAA prevalence in cadavers and in CBCT scans. The results show that even proper pre-operative planning of the lateral sinus lift with CBCT cannot guarantee avoiding AAA damage while performing the surgery.

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.

Quantitative and qualitative assessments of intraosseous neurovascular canals in dentate and posteriorly edentulous individuals in lateral maxillary sinus wall

Objective

Knowledge and evaluation of the blood supply within the maxillary sinus before sinus augmentation are vital to avoid surgical complications. The lateral maxilla is supplied by branches of the posterior superior alveolar artery and infraorbital artery forming intraosseous anastomoses (IA) within the bony lateral antral wall. This study was undertaken to (i) measure mean diameter of IA and its distance from the alveolar ridge within dentate and posteriorly edentulous subjects and, (ii) qualitatively display the relationship of IA throughout its course within the lateral maxillary sinus in cone beam computed tomography (CBCT).

Method

Maxillary CBCT images of two-hundred-and-fifty-seven consecutive patients (163 men, 94 women, mean age 42 years) were analyzed. Samples were later divided into dentate (n = 142) and posteriorly edentulous (n = 115) jaws. Using both alveolar ridge and tooth location as reference points, the distance and diameter of IA were assessed.

Result

The IA was seen in 63.7% of all sinuses with 68.2% in dentate and 62.4% in edentulous. Mean distance and diameter of IA across the posterior tooth locations were 17.9 ± 3.0 mm and 1.4 ± 0.5 mm (dentate) and 15.1 ± 3.0 mm and 1.0 ± 0.5 mm (posteriorly edentulous), respectively. In each sample, there were no significant differences in distance-alveolar ridge and no significant correlations in diameter-tooth location. A statistically significant Pearson coefficient correlation between diameter and distance in dentate state was observed (r = −0.6).

Conclusion

This study reveals that dentate maxillary jaws present larger diameters as compared to posteriorly edentulous jaws, although the IA course remains the same. As these canal structures contain neurovascular bundles with diameters that may be large enough to cause clinically substantial complications, a thorough pre-surgical planning is therefore highly advisable.

Clinical anatomy of the maxillary sinus: application to sinus floor augmentation

The anatomy of the maxillary sinus, especially its vascular anatomy, and its relationships with the teeth and alveolar processes have been well documented. The development of cone-beam computed tomography has resulted in dentists being more familiar with maxillary sinus floor augmentation procedures. This paper aims to revisit the classic anatomy of the maxillary sinus and review the newly published literature in order to help dentists diagnose in more detail and perform safer surgery of the maxillary sinus.

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 ± 1 mm, and the mean distance of PSAA from the crest was 15 ± 1.6 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.

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.

Evaluation of the position of the posterior superior alveolar artery in relation to the maxillary sinus using the Cone-Beam computed tomography scans

Background

The aim of the present study was to evaluate the diameter, relationship and position of the posterior superior alveolar artery and its relationship with the alveolar ridge, the medial wall of the maxillary sinus, the prevalence of pathologic conditions and the maxillary sinus septa on CBCT images.

Material and Methods

A total of 200 CBCT images (400 maxillary sinuses) of patients over 20 years of age were evaluated. The distances between the lower border of the artery and the alveolar crest and between the artery and the medial wall of the sinus and the diameter of the artery were measured. The position of the artery, the presence of pathologic conditions and septa were recorded in the posterior region in: a) males edentulous in the posterior region; b) males having teeth in the posterior region; c) females edentulous in the posterior region; and d) females having teeth in the posterior region.

Results

The mean distance between the artery and the alveolar crest, irrespective of groupings, was 16.17±1.63 mm, with significant differences between the groups (P<0.05). The mean distance between the artery and the medial wall of the sinus was 11.65±1.21 mm, with no significant differences between the groups (P=0.796). The mean diameter of the canal was 1.37±0.44 mm, with no significant differences between the 4 groups (P=0.570). The position of the artery was intraosseous in 73.2%, beneath the sinus membrane in 21.7% and external to the lateral wall of the sinus in 4.9% of the cases. The overall prevalence rates of pathologic conditions and septa in the maxillary sinus were 45.7% and 26%, respectively.

Conclusions

CBCT technique is useful for such evaluations and for possible variations in maxillary sinuses and presence of septa and pathologic entities in maxillary sinuses.

Key words:Maxillary sinus, maxillary artery, Cone-Beam computed tomography.

A comprehensive clinical review of maxillary sinus floor elevation: anatomy, techniques, biomaterials and complications

Several systematic reviews have shown that maxillary sinus augmentation is a predictable and effective procedure for augmentation of an atrophic posterior maxilla. However, we know of no reviews that have covered all the clinical aspects. We searched the PubMed, EMBASE, Cinhal, and Cochrane databases up to January 2015 to select relevant studies that cover the different objectives of this review, including the anatomy of the maxillary sinus, surgical techniques, biomaterials used in the sinus augmentation, and potential complications.

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.

The Relationships of the Maxillary Sinus With the Superior Alveolar Nerves and Vessels as Demonstrated by Cone-Beam CT Combined With μ-CT and Histological Analyses

There are no available detailed data on the three-dimensional courses of the human superior alveolar nerves and vessels. This study aimed to clarify the relationships of the maxillary sinus with the superior alveolar nerves and vessels using cone-beam computed tomography (CT) combined with μ-CT and histological analyses. Digital imaging and communication in medicine data obtained from the scanned heads/maxillae of cadavers used for undergraduate/postgraduate dissection practice and skulls using cone-beam CT were reconstructed into three-dimensional (3D) images using software. The 3D images were compared with μ-CT images and histological sections. Cone-beam CT clarified the relationships of the maxillary sinus with the superior alveolar canals/grooves. The main anterior superior alveolar canal/groove ran anteriorly through the upper part of the sinus and terminated at the bottom of the nasal cavity near the piriform aperture. The main middle alveolar canal ran downward from the upper part of the sinus to ultimately join the anterior one. The main posterior alveolar canal ran through the lateral lower part of the sinus and communicated with the anterior one. Histological analyses demonstrated the existence of nerves and vessels in these canals/grooves, and the quantities of these structures varied across each canal/groove. Furthermore, the superior dental nerve plexus exhibited a network that was located horizontally to the occlusal plane, although these nerve plexuses appeared to be the vertical network that is described in most textbooks. In conclusion, cone-beam CT is suggested to be a useful method for clarifying the superior alveolar canals/grooves including the nerves and vessels.

Detection of the posterior superior alveolar artery in the lateral sinus wall using computed tomography/cone beam computed tomography: a prevalence meta-analysis study and systematic review

A systematic search of MEDLINE, Embase, and Proceedings Web of Science was undertaken to assess the prevalence of the posterior superior alveolar artery (PSAA) in the lateral sinus wall in sinus lift patients, as identified using computed tomography (CT)/cone beam computed tomography (CBCT). For inclusion, the article had to report PSAA detection in the bony wall using CT and/or CBCT in patients with subsinus edentulism. Studies on post-mortem findings, mixed samples (living and cadaveric), those presenting pooled results only, or studies performed for a sinus pathology were excluded. Heterogeneity was checked using an adapted version of the DerSimonian and Laird Q test, and quantified by calculating the proportion of the total variance due to between-study variance (Ri statistic). Eight hundred and eleven single papers were reviewed and filtered according to the inclusion/exclusion criteria. Ten studies were selected (1647 patients and 2740 maxillary sinuses (study unit)). The pooled prevalence of PSAA was 62.02 (95% confidence interval (CI) 46.33-77.71). CBCT studies detected PSAA more frequently (78.12, 95% CI 61.25-94.98) than CT studies (51.19, 95% CI 42.33-60.05). Conventional CT revealed thicker arteries than CBCT. It is concluded that PSAA detection is more frequent when CBCT explorations are used. Additional comparative studies controlling for potential confounding factors are needed to ascertain the actual diagnostic value of radiographic explorations for assessing the PSAA prior to sinus floor elevation procedures.

Anatomical Considerations on the Alveolar Antral Artery as Related to the Sinus Augmentation Surgical Procedure

BACKGROUND

The alveolar antral artery (AAA) is a vascular structure that often passes through the area of lateral window opening during sinus augmentation and can reach dimensions that, if the vessel is severed, can represent a serious complication of the surgical procedure.

PURPOSE

With this narrative review, we aimed at summarizing the results obtained from all the studies that analyzed the variability in anatomical position and dimension of the AAA in order to give the clinician a reference when planning for a sinus augmentation surgery.

MATERIALS AND METHODS

A search of available literature was conducted using electronic databases (PubMed and Medline) and manual searching.

RESULTS

Detection rate of AAA on cone beam computerized tomography (CBCT) is variable and may depend upon the experience of the clinician. The course of the vessel is most frequently intraosseous, and its diameter, despite being smaller than 1 mm in most of the cases, can have a high incidence of diameters between 1 mm and 2 mm. Mean distances of the AAA from alveolar crest and sinus floor range from 11.25 mm to 26.90 mm and 5.80 mm to 10.40 mm.

CONCLUSIONS

Anatomical variants of the AAA that may increase the risk of severe intraoperatory bleeding are frequent and must be detected by the clinician implementing the use of the CBCT.