Prevalence and location of posterior superior alveolar artery in Lebanese population. A retrospective tomography study

Abstract

The position of the posterior superior alveolar artery (PSAA) relative to the maxillary sinus walls is crucial. This study aims to investigate the prevalence and positioning of the PSAA in the Lebanese population using Cone Beam Computer Tomography (CBCT). A series of 282 CBCT scans of the maxillary sinus belonging to adult patients of Lebanese ethnicity were enrolled in this study. None of the included patients had sinus pathologies. Radiographic records were inspected for the presence or absence of the PSAA, its relation to the anterolateral wall of the sinus, its diameter, and its distance from sinus floor. Furthermore, three-dimensional segmentation was conducted for better visualization of the course of the artery. The PSAA was detected in 85.8% of 282 sinuses. The artery followed an intraosseous course in 50%, submucosal in 48.7, and an external path in 1.3% of the records. The mean diameter was 1.07 ± 0.47 mm, and the mean vertical distance from the sinus floor was 9.52 ± 4.14 mm. A statistically significant correlation was found between the artery’s position and both its diameter and distance from the sinus floor. The PSAA was present in the majority of cases, with significant anatomical variation in its position, diameter, and distance from the sinus floor. These findings highlight the necessity of preoperative CBCT assessment to reduce the risk of vascular complications during sinus-related surgical procedures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44445-026-00119-1.

Introduction

The largest paranasal sinus is the maxillary sinus of Highmore. Paranasal sinuses are responsible for pressure regulation, olfaction, reducing skull weight, voice resonance, shock absorption, and facial growth facilitation, particularly during secondary dentition eruption (Iwanaga et al. 2019; De Haven 2014; Somayaji et al. 2023). Maxillary sinus Pneumatization is a natural age-related process, accelerated by tooth loss, which in severe cases can lead to inadequate alveolar bone stock in the posterior maxilla zone (Somayaji et al. 2023). Sinus augmentation is proposed to restore proper bone height in preparation for endosseous implant and dental rehabilitation (Bathla et al. 2018). Based on diverse parameters, the Sinus lift procedure is commonly performed through an external lateral frame in the sinus anterolateral face (Bathla et al. 2018).

Maxillary sinus augmentation procedure owes a plethora of intraoperative complications which could be attributed to either procedural variations or the various anatomical variations in the maxillary sinus morphology (Stern and Green 2012; Ardekian et al. 2006; Kim and Jang 2019). One of these anatomical variations is the position of the arteries providing the sinus vascular supply (Flanagan 2005).

The maxillary artery gives the arterial supply to the Highmore sinus through intraosseous and extraosseous anastomosis and arterial architecture with vast anatomical variation. The 3 main branches are the Infraorbital, Sphenopalatine, and Posterior Superior Alveolar (PSAA) arteries (Lyu et al. 2023). Traumatic or iatrogenic injuries to the PSAA can cause significant bleeding and may obstruct vision or damage the Schneiderian membrane during augmentation (Alves et al. 2023; Kim et al. 2011).

Apart from the three-dimensional alveolar bone evaluation, Cone Beam Computed Tomography (CBCT) offers valuable appraisal and precise mapping of critical anatomical features, such as the accurate location of the PSAA (Anamali et al. 2015). Although there are many reports that evaluated the radiographic location of the PSAA in relation to the sinus anterolateral wall, there are limited studies that targeted PSAA radiographic prevalence in the Lebanese population.

Thus, the study intentions is to answer this gap by examining this variable in a cohort of Lebanese individuals using CBCT imaging. The employed null hypothesis asserts that there is statistically insignificant variance in the prevalence and spatial distribution of the PSAA among individuals within the Lebanese population. This implies that any detected differences in the occurrence and localization of the PSAA are attributed solely to random fluctuations and do not signify systematic dissimilarities linked to demographic parameters or anatomical disparities within the examined cohort.

Materials and methods

Study design

The study was conducted as an observational cross-sectional retrospective design. In order to ensure transparency and rigor in the design, conduct, and reporting of the research, the study was handled in accordance with the STROBE guidelines (strobe-statement.org) (Fig. 1). Ethical approval was obtained from the relevant local review boards at Beirut Arab University (IRB code: 2025-H-0163-D-M-0705), and patient confidentiality was strictly maintained throughout the study. Sample size was estimated based on the following assumptions: 95% confidence level and 5% margin of error. According to the previous studies (Anamali et al. 2015; Ilgüy et al. 2013; Apostolakis and Bissoon 2014; Menhall et al. 2022), the prevalence of the main artery ranged from 82 to 94%. The prevalence was set at 82% to ensure the largest sample size; therefore, the minimum required sample size will be 225 Cone Beam Computed Tomography scans (CBCT) (Gpower 3.1.9.7) (Faul et al. 2007).

Fig. 1.

Descriptive flow of the study participants (n = 282)

Study setting and recruitment

The research cohort was obtained from the outpatient clinic's digital database of the Faculty of Dentistry clinics of Beirut Arab University, Beirut, Lebanon. CBCT scans of the maxillary sinuses from January 2015 to December 2024 were included in the study. The scans of the maxillary sinuses were performed for various clinical indications, including but not limited to pre-operative planning for dental implant surgeries, post-operative assessments, as well as evaluations related to orthodontic treatments.

All of the CBCT images were captured by a Carestream Dental CBCT machine, with the clinical resolution of 0.3-mm Voxel, 8.9 s, and 6*6-cm FOV (Carestream Dental LLCCS,9600 CBCT scanner). Each scan was reviewed, and only those that met the study's inclusion criteria were selected.

To ensure accuracy and consistency, all measurements related to the anatomical features of the maxillary sinuses, including the Posterior Superior Alveolar Artery (PSAA), were performed using the built-in measurement tools of the CBCT software (CS Imaging version 8). These software tools allow for the precise calculation of distances, diameters, and topographic anatomical relationships, which were assessed in the axial, cross-sectional, sagittal, and panoramic aspects.

Eligibility criteria and participant selection

Evaluation of the anatomical features and the spatial relationships within the maxillary sinus was performed for all of the enrolled records based on the following inclusion criteria:

• Only those of the Lebanese ethnicity were included.

• CBCT records of individuals who are 18 years old and older.

• Posterior edentulous maxillary CBCT, with healthy maxillary sinuses.

Invalid CBCTs, scans not involving the maxillary sinus, or those showing one maxillary sinus, were excluded from the study. CBCTs with signs of acute sinusitis, presence of sinus pathology (cyst, pseudocysts, or mucous plugs), or those with a history of previous sinus surgery were further excluded from the study as they do not allow further measurements and proper analysis.

Definition and measurement

PSAA radiographic detection

The presence or absence of the PSAA was determined and reported within the coronal cut of the radiographic record. The artery's presence was confirmed if it was identifiable in at least one coronal slice, and its visibility was noted. If the PSAA was absent, this was explicitly documented.

PSAA distance from sinus floor

For the assessment of the PSAA proximity to the sinus floor, the vertical distance from the lowest point of the maxillary sinus floor to the inferior margin of the PSAA was measured in the cross-sectional view of the CBCT scan.

PSAA diameter

For the establishment of the PSAA size, the diameter of the PSAA was measured at its widest point in the cross-sectional view of the topographic record.

PSAA position

The specific anatomical features and the spatial relationship of the PSAA to the lateral wall of the maxillary sinus were also analyzed. The location of the PSAA according to its anatomical relationship to the lateral wall of the maxillary sinus was categorized into:

• Intraosseous Position: The PSAA is located entirely within the bone of the maxillary posterior region, without any part of it being located outside the bone or in the sinus cavity (Fig. 2).

• Sub-membranous Position: The PSAA lies beneath the mucosal membrane of the maxillary sinus, not entering the sinus cavity but still closely related to the sinus mucosa (Fig. 3).

• Extra-membranous (External) Position: The PSAA is situated on the external cortex of the lateral wall of the maxillary sinus, visible outside the sinus membrane, typically in proximity to the alveolar ridge or external cortical bone (Fig. 4).

Fig. 2.

Intra-osseous PSAA anatomical position

Fig. 3.

Sub-membranous PSAA anatomical position

Fig. 4.

Extra-membranous PSAA anatomical position

All of the enrolled records were independently evaluated by two observers, an experienced oral and maxillofacial specialist (H.A), and a proficient radiologist (G.S).

PSAA three-dimensional visualization

For better conceiving of the course of the PSAA through the anterolateral sinus wall, segmentation of the course of the PSAA along the anterolateral wall of the sinus was performed (Mimics, Materialise, Leuven, Belgium) (Figs. 2, 3 and 4).

Statistical analysis

The IBM-SPSS V.23 was used for the statistical analysis of the data (Armonk, NY: IBM Corp, released 2011). The detection and anatomical position of the PSAA were treated as categorical variables, while diameter and distance from the sinus membrane were treated as continuous variables. The normality of continuous variables was assessed using the Kolmogorov–Smirnov test. All tests were two-tailed, and the significance level was set at p < 0.05.

Reliability analysis

The cohort of the included scans was observed by another assessor for only the detection of the PSAA (Y.E.). The other assessor is also an experienced oral and maxillofacial specialist with experience in CBCT analysis and reading. The interrater reliability of the collected data was checked using Cohen’s kappa test, based on duplicate evaluations of a subset of the CBCT scans (McHugh 2012).

Results

In all together a cohort of 282 sinuses from CBCT records were enrolled and evaluated. The collected sample included 135 males (47.9%) and 147 females (52.1%), with a male-to-female ratio of 0.92:1. The PSAA was identified in 242 sinuses (85.8%), while it wasn’t distinguished in 40 cases (14.2%). The artery was observed on the right side in 128 cases (45.6%) and on the left side in 154 cases (54.6%) (Table 1). A non-parametric tests were utilized for statistics analysis owing to the lack of data normality. The outcome of the study reported a statistically insignificant association concerning the presence of the PSAA and the gender of the enrolled scan (P = 0.282), which was assessed using the Chi-square test (Table 2).

Table 1.

Descriptive data of the study (n = 282)

n = 282	Frequency (%)
Presence of PSAA
Present (+)	242 (85.8)
Absent (-)	40 (14.2)
Gender
Male (♂)	135 (47.9)
Female (♀)	147 (52.1)
Side
Right (R)	128 (45.6)
Left (L)	154 (54.6)

N number, PSAA Posterior Superior Alveolar Artery

Table 2.

Association of the PSAA occurrence with the gender in the included cohort

n = 242	PSAA-	PSAA +	Total	P
Male	16	119	135	0.282
Female	24	123	147
Total	40	242	282

N number, PSAA + Posterior Superior Alveolar Artery Present, PSAA - Posterior Superior Alveolar Artery Abscent

The mean PSAA diameter was 1.07 ± 0.47 mm, ranging from 0.3 to 2.1 mm, while the mean PSAA-sinus floor distance was 9.52 ± 4.14mm, ranging from 2.8 to 19.2mm. As for the PSAA anatomical location, intraosseous position was reported in 121 (50%) scans, followed by submucosal position in 118 scans (48.7%). The least occurring position was an external cortex artery position, reported in only 3 (1.3%) scans.

The relation between the artery diameter and its anatomical positions revealed a statistically significant difference (P < 0.001) using the Kruskal–Wallis test. The median diameter was smallest in intraosseous PSAA (0.8mm), followed by submucosal (1.4mm), and largest in the external cortex (1.7mm). Post-hoc analysis showed significant differences between intraosseous and submucosal, and between intraosseous and external cortex positions.

Furthermore, the relation between the artery diameter and its anatomical positions likewise revealed a statistically significant difference (P = 0.008) using the Kruskal–Wallis test. The greatest reported distance was noted in the external cortex group (median = 18.7mm), compared to submucosal (9.35mm) and intraosseous (9mm). Pairwise comparisons revealed significant differences between the external cortex position and both other groups (Table 3).

Table 3.

Relation between the anatomical location of the PSAA and the artery’s diameter and distance from the sinus floor

n = 242		Intraosseous Position	Submucosal Position	External cortex Position	KW p
PSAA Diameter	Mean ± SD	0.81 ± 0.29	1.33 ± 0.46	1.7 ± 0	< 0.001*
	95%-CI	[0.77, 0.85]	[1.27, 1.39]	[1.7, 1.7]
	Median (IQR)	0.8a (0.6–1)	1.4b (1–1.7)	1.7b (1.7–1.7)
PSAA Distance from Sinus Floor	Mean ± SD	9.07 ± 3.92	9.74 ± 4.13	18.7 ± 0	0.008*
	95%-CI	[8.57, 9.57]	[9.22, 10.26]	[8.7, 18.7]
	Median (IQR)	9a (5.9–12.1)	9.35a (6.5–12.7)	18.7b (18.7–18.7)

PSAA PSAA, Posterior Superior Alveolar Artery, SD Standard deviation, CI Confidance interval, IQR Interquartile range, KW Kruskal–Wallis test with post-hoc analysis; *Statistically significant difference at P-value < 0.05. ^(a,b)Different letters denote significant differences between different groups

The Cohen’s kappa inter-rater reliability demonstrated almost perfect agreement (K = 0.942), indicating high consistency between evaluators in identifying the presence of the PSAA.

Discussion

The current study intends to evaluate the prevalence, anatomical positioning, diameter, and vertical distance of the PSAA in a Lebanese population using CBCT. A total of 282 maxillary sinuses tomographic scans were enrolled and analyzed. PSAA visualization was evident in 85.8% of cases, with the artery taking an intraosseous course in half of these records. Submucosal and external positions were detected in 48.7% and 1.3% respectively. The average gauged PSAA diameter was 1.07mm, while the mean vertical distance from the PSAA to the sinus floor was 9.52mm. An insignificant correlation was found between artery presence and either age or gender. However, the anatomical location was significantly associated with both PSAA diameter and vertical distance from the sinus floor. The consistency of the measurements was supported by the high inter-observer reliability outcome (K = 0.942).

The observed PSAA prevalence in this Lebanese cohort aligns closely with findings from other CBCT-based investigations. Menhall et al.(Menhall et al. 2022) documented 87% PSAA prevalence in a Lebanese hospital without specifying the ethnicity. Ilgüy et al. reported an 89.3% prevalence in a Turkish institute (Ilgüy et al. 2013). On the other hand, Tassoker observed prevalence rates around 85% in a selected Turkish ethnicity sample (Tassoker 2022). Conversely, lower detection rates have been described by Kim et al. reporting a 52% detection rate in a South Korean cohort (Kim et al. 2011), and Danesh-Sani et al. reporting 60.6% in a USA/Iran cohort (Danesh-Sani et al. 2017). Godil et al. found an exceptionally elevated prevalence of 99.4% in an Indian legion (Godil et al. 2021).

These variations likely reflect differences in CBCT imaging resolution and voxel size, which affect the visualization of smaller-caliber vessels. Additionally, inconsistencies in defining the artery’s presence, particularly regarding accessory branches, could be attributed to demographic and ethnic craniofacial differences, sinus pneumatization patterns, and alveolar bone resorption.

Operator experience and interobserver calibration also play critical roles, especially when identifying vessels with small lumens or partial calcification. Despite these disparities, the majority of CBCT studies confirm the frequent presence of the PSAA, underscoring the importance of its identification during preoperative assessments.

Concerning gender differences in PSAA prevalence, Kim et al. found a significantly superior male prevalence (64%) compared to females (40%), suggesting possible anatomical variation (Kim et al. 2011). However, other reports did not detect statistically significant gender effects on artery presence (Ilgüy et al. 2013; Menhall et al. 2022). In this report, an insignificant gender difference was reported, aligning with the literature trend. This could denote that gender is not a strong determinant of PSAA prevalence. Variations among studies may reflect differences in sample size, ethnicity, or imaging protocols.

Regarding anatomical location, a nearly equal distribution between intraosseous (50%) and submucosal (48.7%) courses, with external cortical positioning being rare (1.3%), was reported in this report. In comparison, Ilgüy et al. reported a higher proportion of intraosseous position (71%) and a slightly elevated rate of external cortical positions (5.2%) (Ilgüy et al. 2013). Tassoker documented similar intraosseous predominance (Tassoker 2022), while Danesh-Sani et al. and Fayek et al. found intraosseous routes in 69% and 82% of their respective populations (Danesh-Sani et al. 2017; Fayek et al. 2021). Godil et al. observed an even greater predominance of intraosseous location (84%) in their Indian cohort (Godil et al. 2021). These findings collectively suggest that the intraosseous course is the dominant anatomical configuration.

The mean arterial diameter of 1.07 mm was reported in this study, which is consistent with those reported by Apostolakis and Bissoon (1.1mm), Ilgüy et al. (0.94mm), and Fayek et al. (1.05 mm) (Ilgüy et al. 2013; Apostolakis and Bissoon 2014; Fayek et al. 2021). Slightly larger diameters were observed in Kim et al. (1.52mm) and Danesh-Sani et al. (1.17mm) (Kim et al. 2011; Danesh-Sani et al. 2017). Menhall et al. did not report mean diameters but noted that arteries ≥ 2 mm were uncommon (Menhall et al. 2022). The observed moderate vessel caliber emphasizes the clinical relevance of PSAA identification to minimize hemorrhagic risk during sinus lift procedures.

For PSAA vertical orientation, the average reported the artery-to-sinus floor distance was 9.52mm, which aligns closely with those reported by Apostolakis and Bissoon (7.5 mm) and Fayek et al. (Apostolakis and Bissoon 2014; Danesh-Sani et al. 2017; Fayek et al. 2021). However, Kim et al. and Menhall et al. declared a substantially greater distances (19mm and 16.4mm respectively), likely due to measuring from the alveolar crest rather than the sinus floor (Kim et al. 2011; Menhall et al. 2022). Godil et al. reported gender differences in the artery-to-alveolar crest distance (Godil et al. 2021). This was also declared by Fayek et al. (8.2mm in males and 7.3mm in females), which could imply potential sexual dimorphism in vascular anatomy. On the other hand, Godil et al. found an insignificant age-related variation (Godil et al. 2021).

These discrepancies underscore how measurement reference points and population-specific craniofacial anatomy influence reported values. Choosing the window position and size in the lateral sinus lifting procedure is influenced by a plethora of factors; however, the patient's anatomical features and position of the PSAA are usually unacknowledged during planning of the external sinus lifting procedure.

Multiple studies, including the present one, confirm significant associations between the artery’s anatomical course, its diameter, and vertical extent from the sinus floor. Specifically, arteries following an intraosseous course exhibited the smallest median diameter (0.8mm), while submucosal and external cortical arteries were larger (1.4 mm and 1.7 mm, respectively). This size trend was mirrored in vertical distances, with external arteries positioned furthest from floor of the sinus. Ilgüy et al. Danesh-Sani et al. and Fayek et al. similarly reported that intraosseous arteries tend to be smaller and closer to the sinus floor (Ilgüy et al. 2013; Danesh-Sani et al. 2017; Fayek et al. 2021). Tassoker and other high-prevalence studies reinforced the predictive value of arterial location for morphometric parameters, emphasizing that the risk of vascular injury may increase as the artery courses more externally (Tassoker 2022; Laovoravit et al. 2021).

Despite its contributions, this study has limitations. The retrospective design restricts control over confounding factors such as systemic health status, prior dental trauma, or surgical interventions that may influence sinus anatomy. Although CBCT offers high-resolution imaging, its soft tissue contrast is limited, possibly missing smaller or compressed vessels. The sample was drawn from a single institution, potentially limiting broader applicability within the Lebanese population. Measurements were performed on static images rather than dynamic vascular imaging, which may affect the functional interpretation of vessel size. Finally, although inter-observer reliability was high, some degree of operator-dependent variability in artery identification cannot be fully excluded. From what we understand, this is the first report to apply the segmentation tools for better visualization of the course of PSAA along its course in the anterolateral sinus wall. This contemporary tool could offer a valuable contribution in preoperative planning, along with educational purposes for proper visualization.

Conclusion

This report examined the prevalence of the PSAA in a Lebanese population using CBCT imaging. The artery was present in 85.8% of cases, with intraosseous and submucosal positions being the most common. The null hypothesis, which proposed no significant anatomical variation in the PSAA, was rejected. Significant associations were found between the artery’s anatomical location and both vertical distance from the sinus floor and diameter. These variations highlight the imminent possibility for the occurrence of surgical complications during sinus lift procedures. Therefore, preoperative tomographic imaging is essential for identifying the PSAA and minimizing intraoperative risks. Understanding these anatomical differences can guide safer and more precise surgical planning.

Supplementary Information

Below is the link to the electronic supplementary material.

Authors contributions

All authors critically revised the manuscript, did the final revision, and gave permission for submission. All authors are accountable for all aspects of work, ensuring integrity and accuracy.

- M.R.: Conceptualization, study design, data collection, data analysis, drafting of the manuscript.

- Y.A: Methodology, data interpretation, critical revision of the manuscript.

- M.H: Data collection, image analysis, literature review, critical revision.

- Y.M: Supervision, image analysis, drafting of specific sections, critical revision, final approval.

- M.A: Statistical analysis, data interpretation, critical revision, final approval.

- H.A: Supervision, project administration, critical revision, correspondence with the journal, and final approval.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

All of the analyzed data in this study are available upon reasonable request.

Declarations

Ethical approval

Ethical approval was obtained from the relevant local review boards at Beirut Arab University (IRB code: 2025-H-0163-D-M-0705).

Consent for publication

All of the enrolled subjects have given a full written informed consent for study participation and the utilization of their radiographic data for publication.

Competing interests

The authors declare that they have no competing interests.