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

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.

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.

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.

Comparative diagnosis of the alveolar antral artery canal in the lateral maxillary sinus wall in corresponding panoramic radiography and cone-beam computed tomography

PURPOSE

Sinus lift operations are a tried and tested means of providing adequate implant prosthetics to patients with compromised jawbones. Knowledge of the arterial supply of the maxillary sinus region is essential for surgical treatment in this area. The aim of the present comparative study was to determine whether alveolar antral artery (AAA) canal can be diagnosed both in corresponding panoramic radiography (PR) and cone-beam computed tomography (CBCT).

METHODS

A total of 335 patients with 635 sites and corresponding maxillary sinus in both PR and CBCT were selected and examined for AAA canal visibility.

RESULTS

The visibility of the AAA canal was significantly higher in CBCT than in PR. A total of 154 (46.0%) AAA canals could be identified in the maxillary sinus on the right. However, only four (1.2%) of these were also visible in PR. The detected values of the AAA canals in the maxillary sinus on the left in the PR and CBCT images were similar to those of the right. While 164 AAA canals (49%) were observed in CBCT images, only 1 (0.3%) was identifiable in PR.

CONCLUSIONS

The results show that CBCT can be recommended for visualising the AAA canal when surgically planning sinus augmentation procedures.

Anatomic evaluation of the posterior superior alveolar artery using cone-beam computed tomography: A systematic review and meta-analysis

Purpose

This systematic review examined the detection of the posterior superior alveolar artery, along with various anatomic characteristics, on cone-beam computed tomography images.

Materials and Methods

Studies were identified electronically through the Web of Science, MEDLINE, Scopus, and Embase databases. The quality of the included studies was evaluated using a 5-item binary scale. The detection rate, location, and classified diameter of the posterior superior alveolar artery were estimated as prevalence values. The diameter of this artery, as well as the distances from the artery to the alveolar crest and sinus floor, were estimated as means with associated 95% confidence intervals.

Results

Thirty-seven studies were enrolled, with 34 of these included in the meta-analysis. The mean detection rate was 79% (range: 72%-84%), and the mean diameter was 1.06±0.05 mm (range: 0.96-1.16 mm). The posterior superior alveolar artery was located intraosseously in 64% of cases. The mean distance of the artery from the alveolar crest was 16.71±0.49 mm (range: 15.75-17.68 mm), while the mean distance from the artery to the sinus floor was 8.85±0.4 mm (range: 8.05-9.64 mm).

Conclusion

According to the findings of this meta-analysis regarding various anatomic characteristics of the posterior superior alveolar artery, severe hemorrhage after damage to this artery during sinus augmentation procedures is not a substantial clinical problem.

Evaluation of the posterior superior alveolar artery location and diameter with a newly defined stable plane

The aim of this study was to analyse the vertical location of the posterior superior alveolar artery (PSAA) using a reliable new reference plane regardless of tooth and alveolar bone, and to measure the diameter in each posterior tooth region, which is of relevance to lateral sinus floor elevation surgery. A total of 270 sinuses in 139 patients were examined in this study. The A-plane was defined by A-point and the bilateral jugal points on reconstructed three-dimensional images. The distance from the PSAA to the defined plane was measured in four regions: first premolar (P1), second premolar (P2), first molar (M1), and second molar (M2). The average distance of the PSAA above the plane in the P1, P2, M1, and M2 regions was determined to be 10.24mm, 7.35mm, 5.47mm, and 7.23mm, respectively. The PSAA was found to run above the plane in 97.4% of sinuses, below the plane in 1.1%, and on the plane in 1.5%. In conclusion, the new plane is useful for intraoperative location of the PSAA. According to the study findings, the area below the reference plane can be considered safe for lateral approach sinus surgery in terms of preserving the integrity of the PSAA.

Modified transcrestal sinus floor elevation with concomitant implant placement in edentulous posterior maxillae with residual bone height of 5 mm or less: a non-controlled prospective study

The aim of this study was to describe a modified transcrestal sinus floor elevation (mTSFE) technique and to evaluate its clinical effectiveness and reliability when residual bone height is severely reduced. Forty-three maxillary edentulous patients who met the inclusion criteria were enrolled. All patients underwent the mTSFE technique; 66 dental implants were inserted simultaneously. Patient-reported outcomes were assessed 2 weeks after surgery. Prosthetic crowns were placed 6 months after surgery. Radiographic analyses and clinical analyses were conducted to assess the clinical effectiveness and feasibility of mTSFE during a follow-up period of 2-8 years. The mean vertical bone increase after surgery was 8.09 mm, and it decreased to 6.56 mm at 6 months after surgery. Two cases of membrane perforation occurred during surgery and one implant was lost in the third year after surgery; the survival rate at the implant level was 98.48%. No severe postoperative complication was reported and the subjective feeling of patients was acceptable. This mTSFE technique could simplify the operative procedure and might be helpful to reduce intraoperative trauma, as well as to alleviate postoperative discomfort.

Evaluation of alveolar antral anastomosis in south Indian population using cone beam computed tomography: a prospective study

OBJECTIVES

The posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA), both of which are ultimate branches of the maxillary artery, are connected by a horizontal anastomosis. PSAA anastomoses intraosseously and extraosseously with IOA. Profuse bleeding from the lateral wall while performing the direct sinus augmentation is a significant intraoperative complication.Thus the present study focused to assess the location of an alveolar antral anastomosis (AAA) in relation to the crest of the alveolar bone using cone beam computed tomography (CBCT).

METHODS

A total of 200 CBCT scans of patients who were indicated for implant surgery were chosen and assessed. Group 1 includes 100 dentate patients and Group 2 includes 100 partially edentulous patients. The location of anastomosis along the lateral wall of the maxillary sinus was evaluated in association with alveolar bone height with respect to three posterior maxillary teeth: first premolar, second premolar, and first molar.

RESULTS

The mean distance for P1, P2, and M1 was 21.94 ± 1.02 mm, 19.41 ± 0.40 mm, and 17.36 ± 0.51 mm, respectively, in the dentate group, whereas in the edentulous group, it was 20.07 ± 0.46 mm, 18.95 ± 0.32 mm, and 16.08 ± 0.16 mm. In 80% of participants, the distance of an AAA from the alveolar crest was between 16 and 23 mm, whereas in 12% of the participants the distance of an AAA from the alveolar crest was less than 16 mm.

CONCLUSION

The present study concludes that the first premolar region is safe for preparing the lateral window but for the second premolar and first molar additional care should be taken prior to surgery.

Use of a Lateral Sinus Bony Window as an Intraoral Donor Site for Guided Bone Regeneration in Wide Post-Extraction Defects

Maxillary sinus augmentation (MSA) and guided bone regeneration (GBR) have shown successful clinical, radiological, and histological outcomes for implant-related bone reconstruction and have been used to augment bony defects of various shapes and sizes. This study demonstrated that the lateral sinus bony window obtained during MSA can be used as an autogenous block bone graft for the augmentation of wide post-extraction defects. During the uncovering procedure performed 6 months after surgery, the grafted lateral bony window was well integrated with the adjacent native bone, and complete bone filling was observed in all bony defects around the implants. All of the implants survived. Within the limitations of this study, autogenous block bone obtained from lateral window sites can be used as novel donors for the resolution of wide bony defects around implants.

Anatomical variations and accessory structures in the maxilla in relation to implantological procedures: an observational retrospective study of 212 cases using cone-bean computed tomography

PURPOSE

This study used cone-beam computed tomography (CBCT) to analyze the prevalence of several maxillary anatomical/accessory structures, as well as variations within each type, assessing how accurate diagnosis can minimize the risk of intraoperative complications during implantological procedures in the oral cavity.

METHODS

212 CBCT scans of the maxilla were analyzed, captured over a period of 18 months for surgical planning purposes. The prevalence of posterior superior alveolar arteries (PSAA), maxillary sinus septa (MSS), and branches of the canalis sinuosus (CS) were evaluated, as were the diameter and location of each anatomical structure in horizontal and vertical planes. P < 0.05 was considered statistically significant.

RESULTS

PSAAs were observed in 99.1% of cases, the intrasinus type being the most frequent; MSS were noted in 15.6% of the sample, mainly in the posterior region with sagittal orientation; CS branches were observed in 50% of patients, mainly in relation to the incisors and significantly more prevalent among males.

CONCLUSIONS

The use of CBCT significantly increases the possibility of clearly identifying these anatomical structures. The differences found between patients highlight the importance of carrying out an exhaustive radiological study of the individual to prevent complications, such as Schneiderian membrane perforation, neurovascular damage or bleeding during surgery.

The Use of CBCT in Evaluating the Health and Pathology of the Maxillary Sinus

The use of cone-beam computed tomography (CBCT) has been increasing in dental practice. This narrative review summarized the relevance and utilizations of CBCT to visualize anatomical structures of the maxillary sinus and common pathologies found in the maxillary sinus. The detection/visualization rate, the location and the morphometric characteristics were described. For sinus anatomy, the reviewed features included the posterior superior alveolar artery, sinus pneumatization, sinus hypoplasia, sinus septa, and primary and accessory sinus ostia. For pathology, the following items were reviewed: membrane thickening associated with periapical lesions/periodontal lesions, mucous retention cyst, and antrolith. The visualization and assessment of the maxillary sinus is very important prior to procedures that take place in close proximity with the sinus floor, such as tooth extraction, implant insertion, and sinus floor elevation. Some sinus pathologies may be associated with odontogenic lesions, such as periapical diseases and periodontal bone loss.

Detection of posterior superior alveolar artery using multi-detector row CT: a retrospective study focused on age-related changes

PURPOSE

The posterior superior alveolar artery (PSAA) is a branch of the maxillary artery that supplies the lateral sinus wall and overlying membrane. This artery is one among several arteries in which arterial damage during surgery can cause massive and fatal bleeding. The purpose of this study was to detect the PSAA using multi-detector row computed tomography (MDCT) by age.

MATERIALS AND METHODS

The present study was approved by our university ethics committee (EC19-010). The study included 230 patients (110 males, 120 females; ages 5-91 years, average age 42.5 years) who underwent MDCT of the jaw. The subjects were divided into two groups, one group in which the PSAA was observable and another in which the PSAA was not observable, to perform the Mann-Whitney U test. To perform the Tukey-Kramer multiple comparison test, the subjects were divided into the following ten groups depending on their age: 5-9 years, 10-19 years, 20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, 80-89 years, and 90-91 years.

RESULTS

The PSAA was identified in 74.5% (5-91 years) of the maxillary sinuses. The average age of subjects in whom the PSAA was observable was 33.4 years, and the average age of subjects in whom the PSAA was not observable was 11.3 years, indicating a significant difference between these two groups (p < 0.01). A comparison by age group showed a significant difference (p < 0.05).

CONCLUSIONS

The detection ratio for the PSAA using MDCT increased with increasing age of the subject, reaching a high detection ratio of 94% in adults. This study has shown that MDCT is a very useful tool to observe the PSAA.

Cleft lip and palate cause large variations in size and location of the posterior superior alveolar canal

OBJECTIVE

The aim of this study was to evaluate the posterior superior alveolar canal (PSAC) in patients with cleft lip and palate (CLP) as compared to patients with no cleft lip and palate (NC) using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This was a retrospective multicenter study based on two steps: (1) evaluating intra- and inter-calibration and (2) detecting the presence or absence of PSAC and its location, diameter, and anastomosis with anterior superior alveolar canal.

RESULTS

A total of 300 patients were selected for the study, out of which 150 were categorized as CLP (75 men, 75 women; mean age: 29.8 years) and 150 were categorized as NC (75 men, 75 women; mean age: 40.3 years). PSAC in patients with CLP and NC was visible in 100% of the cases, in men and women, bilaterally. PSAC location in CLP was middle and upper third of the maxillary sinus as compared to NC (lower third) (chi-squared < 0.001). PSAC mean diameter in CLP was 1.12 mm. It was larger compared to 0.6 mm in NC (t-test < 0.0001).

CONCLUSION

PSAC location in patients with CLP was predominantly in the middle and upper third of the maxillary sinus, compared with NC. PSAC mean diameter in CLP was 1.12 mm. It was larger compared to that of 0.6 mm in NC.

CLINICAL RELEVANCE

These anatomical variations in CLP are important and should be acknowledged by surgeons for the following reasons: (1) to perform pre-surgical planning, (2) to avoid bleeding, and (3) to avoid neurosensory alterations.

Sinus membrane elevation and implant placement

Sinus Schneiderian membrane elevation surgery is widely performed for dental implant placement in the maxillary posterior region. With regard to sinus elevation surgery, various complications can occur and lead to implant failure. For successful implants in the maxillary posterior region, the clinician must be well acquainted with sinus anatomy and pathology, a variety of bone graft materials, the principles of sinus elevation surgery, and prevention and management of complications.

Evaluation of the Posterior Superior Alveolar Artery Prior to Sinus Floor Elevation via Lateral Window Technique: A Cone-Beam Computed Tomography Study

Aim:

To evaluate the prevalence, diameter, localization of the posterior superior alveolar artery (PSAA) and the relationship between PSAA and the floor of the maxillary sinus and the thickness of the maxillary sinus lateral wall using cone-beam computed tomography (CBCT).

Material and Methods:

In this retrospective study, more than 500 CBCT images were retrieved. Out of them 156 CBCT images were related to the sinus floor elevation, among which 120 CBCT images were enrolled in the study based on the inclusion criteria, and 36 CBCT images were excluded. A total of 120 CBCT images of the PSSA from 60 patients comprising 32 (53.3%) men and 28 (46.7%) women were analyzed. Statistical data were analyzed using SPSS for Windows version 22. Descriptive statistics (mean, standard deviation, frequency) were used for the analyses.

Results:

The ages of the participants ranged between 26 and 76 years and the mean age was 54.48 ± 10.92 years. The PSAA was detected on the right side in 95% of the CBCT scans and on the left side in 85% of the maxillary sinuses. At the first detection point (FDP) and last detection point (LDP), the mean values of the distance between the inferior border of the PSAA and the floor of the maxillary sinus were 9.54 ± 4.27 mm and 7.91 ± 4.75 mm, respectively. The mean diameters of the PSAA at the FDP and LDP were 1.36 ± 0.46 mm and 1.12 ± 0.35 mm, respectively.

Conclusion:

Detection of the characteristics of the PSAA by using CBCT is crucial for handling the sinus floor elevation procedures uneventfully.

Anatomical Considerations and Study of the Fractal Dimension around the Posterior Superior Alveolar Artery

The Posterior Superior Alveolar Artery (PSAA) provides vascular support to molars, gingiva, and maxillary sinus. A tear of the PSAA may cause profuse hemorrhages which may lead to complications at a surgical level. As such, it becomes crucial to anatomically analyse several features regarding the PSAA as well as the area surrounding it. In this paper, we are particularly interested in the study of the complexity of the periodontal tissue structure which appears close to the location of the PSAA. A total amount of 400 cone beam computed tomography (CBCT) scans (two per subject) were performed to explore the presence of the PSAA, the thickness of the Schneider’s membrane, and the existence of septa. Several parameters were evaluated including the location of the artery in the maxillary sinus, the distance from the PSAA to the alveolar ridge, the thickness of the membrane, the diameter of the cavities produced by the septa, and the fractal dimension of the trabecular tissue that surrounds the PSAA. They were found strong linear relationships between Distal and Central Measures (a Pearson’s R 2 = 0.9952 ), Mesial and Central Measures ( R 2 = 0.9950 ), and Distal and Mesial Measure ( R 2 = 0.997 ). We hypothesised that the loss of dental pieces would imply a distinct complexity of the trabecular tissue structure surrounding the PSAA. In this way, a p-value equal to 0.001 was provided by the Mann-Whitney test, which supports our hypothesis. Furthermore, the mean of the fractal dimensions of the group of edentulous patients (equal to 1.56 ) was found to be lower than the one of the group of non-edentulous patients (equal to 1.61 ) with small standard deviations in both cases. Our study suggests that accurate calculations of the fractal dimension combined with the use of CBCT do provide valuable information regarding the area that surrounds the PSAA.

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.

The maxillary sinus: physiology, development and imaging anatomy

OBJECTIVES

The maxillary sinus is of paramount importance for otolaryngologists, rhinologists, oral and maxillofacial surgeons, head and neck and dental and maxillofacial radiologists. A comprehensive review article concerning the physiology, development and imaging anatomy was undertaken.

METHODS

Relevant literature pertaining to the physiology of the sinonasal cavity, development of the paranasal sinuses and imaging anatomy of the maxilla and maxillary sinus from 2000 to 2019 was reviewed. Emphasis was placed on literature from the last 5 years.

RESULTS

Extensive recent research using imaging has provided new insights into the development of the maxillary sinus, the other paranasal sinuses and the midface. The fundamental physiological concept of mucociliary clearance and its role in sinus health is emphasized. The paranasal sinuses are an integral part of a common mucosal organ formed by the upper and lower airway.An in-depth understanding of the soft-tissue and neurovascular relationships of the maxillary sinus to the deep fascial spaces and branches of the trigeminal nerve and external carotid artery respectively is required to evaluate and report imaging involving the maxillary sinus.Sinusitis of rhinogenic, rather than odontogenic origin, originates from nasal inflammation followed by anterior ethmoid disease and secondary obstruction of the ostiomeatal unit. The role of anatomical variants that predispose to this pattern of disease is discussed in detail with illustrative examples.The maxillary sinus is intimately related to the roots of the posterior maxillary teeth; the high frequency of mucosal disease and sinusitis of odontogenic aetiology is now well recognized. In addition, an understanding of the anatomy of the alveolar process, morphology of the alveolar recess of the maxillary sinus and neurovascular supply are essential both for deliberate surgical intervention of the sinus and complications related to oral surgical procedures.

CONCLUSIONS

An understanding of the fundamental principles of the development, physiology, anatomy and relationships of the maxillary sinus as depicted by multi-modality imaging is essential for radiologists reporting imaging involving the paranasal sinuses and midface.

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.

Anatomical analyses for maxillary sinus floor augmentation with a lateral approach: A cone beam computed tomography study

BACKGROUND

Various anatomical references and structures should be analyzed prior approaching a surgery in the maxillary sinus. The objective of the present study was to evaluate the anatomical structures and references involved in sinus floor elevation with a lateral approach.

MATERIALS AND METHODS

Seventy-five patients planned for sinus floor elevation were included in the study. Eighty-eight maxillary sinuses were evaluated using cone beam computed tomographies (CBCTs). The nasal floor was used as main reference (X) and sinus mucosa width, bone crest height, palatal-nasal recess angle (PNR), sinus width at the level of the nasal floor, distance from the nasal floor to the base of the sinus (X-F), position of the posterior superior alveolar artery (PSAA height) and diameter (PSAA diameter), lateral bone wall width at 3mm (LW 3mm) and 9mm (LW 9mm) from the base of the sinus (F), patency of the ostium (OP), and presence and position of septa have been evaluated.

RESULTS

The mean dimensions and standard deviations were the following: mucosa thickness was 2.0±1.4mm, bone crest height 2.8±1.4mm, distance X-F 8.3±1.9mm, PNR angle 135.5±23.1, sinus width 12.6±4.2mm, X-F 8.3±1.9mm, PSAA height 14.4±2.9mm, PSAA diameter 1.1±0.4mm, LW 3mm 1.5±1.2, LW 9mm 1.3±0.6mm, OP 1.9±0.4mm. Septa were present in 19.3% of the sinuses evaluated and were located mostly in the molar region.

CONCLUSIONS

In conclusion, the analysis of the CBCT before sinus floor elevation allows the identification of anatomical structures and references that might be used for the planning of the surgical approach, aiming to improve the outcome of the treatment and to avoid possible 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.

Anatomic Variation of Posterior Superior Alveolar Artery: Review of Literature and Case Introduction

The objective of this article is to review topography of posterior superior alveolar artery (PSAA), and to present a case with visualization of a rare anatomic variation of PSAA. An electronic search was undertaken to identify articles about topography of PSAA in Medline, Embase, and Google Scholar databases, published between January 1977 and December 2017. Two animal studies, 8 cadaver studies, 18 cone-beam computerized tomography (CBCT) studies, and 2 review articles were found. The animal studies, cadaver studies, and review articles were excluded because they were not about topography of PSAA. Only CBCT studies were included in this review. Accurate knowledge of vital structures in the surgical area is critical during surgical procedures. PSAA should be analyzed during planning sinus lifting with lateral approach. In the present case, a detailed evaluation of patient by CBCT provided the opportunity to find out a rare variation of PSAA with multiple vessels.

Devitalization of adjacent teeth following maxillary sinus floor augmentation: A retrospective radiographic study

BACKGROUND

Elevation of the schneiderian membrane, during maxillary sinus floor augmentation (MSFA) may theoretically result in devitalization of adjacent teeth, which are in a close spatial relationship to the sinus floor.

PURPOSE

To assess retrospectively the probability of devitalization of teeth adjacent to the osteotomy site after MSFA in a relatively large number of patients.

MATERIALS AND METHODS

All MSFA procedures, performed at a university oral surgery clinic within a time period of 10 years, were assessed on the following eligibility criteria: (1) presence of vital teeth (ie, not root canal treated and no periapical radiolucency on a panoramic radiograph taken just after MSFA), (2) presence of a 3 to 12 months postoperative radiograph of the teeth adjacent to the osteotomy site displaying the root apices, and (3) complete medical records up to at least 12 months postoperatively. The radiographs of the different time points were compared and any changes in the radiographic status of the adjacent teeth (eg, development of a periapical lesion, root canal treatment, etc.) were recorded and the spatial relationship of the adjacent teeth to the maxillary sinus classified.

RESULTS

Out of 684 MSFAs, 257 fulfilled the inclusion criteria and involved 357 adjacent teeth, of which 221 presented close to and/or intimate relationship to the sinus. In only a single case, tooth vitality might have been lost due to the procedure. Thus, the probability for tooth devitalization for teeth with close to and/or intimate spatial relationship to the sinus floor ranged from 0.45% to 0.7%.

CONCLUSIONS

Even for teeth with apices very close to and/or intimately related to the sinus tooth devitalization after MSFA is an extremely rare complication; that is, the probability of tooth devitalization after MSFA is ≤0.7%.

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.

Evaluation of the Anastomosis Canal in Lateral Maxillary Sinus Wall With Cone Beam Computerized Tomography: A Clinical Study

This clinical study used cone beam computerized tomography (CBCT) to locate the position of the anastomosis canal in lateral wall of maxillary sinuses, and to evaluate the thickness of lateral sinus wall and the distance from the lower border of the canal to the sinus floor, which could provide surgeon with information about this anastomosis. Two hundred and forty-two (242) volumes of CBCT scans were included in this study. The distances from the lower border of the anastomosis canal to the sinus floor and from the maxillary alveolar crest to the sinus floor were evaluated in transversal plane, and the thickness of the lateral sinus wall was measured at the distance of 3, 6, 9 mm from the sinus floor and at the level of the lower border of the canal at the same plane. The canal was identified in 87.6% (424/484) of the sinus. Most canals were intraosseous, or beneath the sinus membrane. The mean distance was 9.2 ± 3.5 mm from the lower border of the canal to the sinus floor, and 10.8 ± 4.0 mm from the alveolar crest to the sinus floor. The thickness of the lateral sinus wall was 2.4 ± 0.9 mm, 1.8 ± 0.8 mm, 1.7 ± 0.7 mm, 1.8 ± 0.8 mm at the distance of 3, 6, 9 mm from the sinus floor and at the level of the lower border of the canal. The location of the anastomosis canals varied from each patient, but the distance from the sinus floor was similar in different teeth sites. The sinus floor could be an anatomic landmark of sinus floor augmentation. In order not to interrupt this canal, great care must be taken by the implant surgeon to identify this canal.

Evaluation of symptomatic maxillary sinus pathologies using panoramic radiography and cone beam computed tomography-influence of professional training

Background

A comparison of panoramic radiography (PAN) alone and PAN together with small field of view cone beam computed tomography (sFOV-CBCT) for diagnosis of symptomatic pathologies of the maxillary sinus was carried out by clinicians of different experience.

Methods

Corresponding radiographic images (PAN/sFOV-CBCT) of 28 patients with symptomatic maxillary sinus pathologies were chosen and analyzed by two general practitioners (GP), two junior maxillofacial surgeons (MS1), and three senior maxillofacial surgeons (MS2) via questionnaire.

Results

Visibility of maxillary pathologies in PAN was significantly different between the groups (GP 39%, MS1 48%, MS2 61%; p < 0.05). The number of incidental findings varied within examiner groups in PAN with a significant increase in MS2 (p = 0.027). The majority of examiners rated an additional sFOV-CBCT as “reasonable”/“required” with a significant influence of the examining groups (GP 98.2%, MS1 94.6%, MS2 80.9%; p = 0.008). In 58% of cases, an additional sFOV-CBCT was seen as “affecting therapy” with significant differences between the groups (GP 68%, MS1 50%, MS2 55%; p < 0.001).

Conclusions

PAN alone is not sufficient for the evaluation of pathologies of the maxillary sinus. But, depending on the examiners’ clinical experience, it remains a useful diagnostic tool. Along with the observers’ training, significant benefits of an additional sFOV-CBCT for evaluation of symptomatic maxillary sinus pathologies were detected.

Diameter of alveolar antral artery in the lateral sinus wall: study of related factors

To identify the variables that influence the diameter of the artery in the lateral sinus wall, we studied 240 sinuses, focusing on sex, pattern of tooth loss, type of residual crest, thickness of the lateral wall, height and width of the ridge, and width of the sinus.

Distance of the alveolar antral artery from the alveolar crest. Related factors and surgical considerations in sinus floor elevation

Background

In a variable proportion of maxillary sinuses alveolar antral artery is located close to the residual ridge, increasing the chances for haemorrhagic complications during sinus floor elevation procedures.

Material and Methods

Retrospective observational study of CBCT explorations performed for implant-treatment planning. The upper first molar area was selected for this study. The relative uncertainty (standard deviation of the measurement divided by its mean and expressed as a percentage from 0% to 100%) was chosen for determining the observational errors. For modeling the chances of AAA detection, the generalized additive models (GAM) approach was chosen.

Results

A total of 240 maxillary sinuses were studied (46.25% males) whose median median age was 58 years old (IQR: 52-66). Univariate models showed that the chances for an AAA-alvelar crest distance ≤15mm increase in wider sinuses with lower, subsinusally edentulous crests. When distance is considered as a continuous variable, the best mutivariate model showed an explained deviance of 67% and included AAA diameter, distance AAA-sinus floor, sinus width, and shape, height and width of the residual ridge. Thinner AAAs are found closer to the crest (within the ≤15mm safe distance).

Conclusions

Bearing in mind the inclusion criteria and the limitations of this investigation, it is concluded that there is a high proportion of maxillary sinuses where AAA describes a course close to the alveolar crest (≤15mm), which was classically considered a safe distance for SFE. This position is related to the presence of atrophic crests (depressed ridge form) and wide maxillary sinuses where the distance of the vessel to the floor of the sinus is small. This information may permit a better surgical planning of SFE procedures.

Key words:Cone-beam computed tomography, blood vessels, sinus floor augmentation, intraoperative complications.

Three-dimensional cone beam computed tomography analysis of maxillary sinus and alveolar bone anatomy in the restorative axis of dental implants using radiopaque drill guides

The objectives were to assess the sinus anatomy and alveolar ridge dimensions and to identify clinical factors and morphological relationships that may predict the characteristics of the sinus anatomy. A total 336 edentulous molar and 168 edentulous premolar regions were analyzed. The mediolateral maxillary sinus (5mm and 10mm above alveolar bone), lateral maxillary sinus wall, ostium height, and alveolar ridges were measured. Measurement regions were defined by radiopaque simulation of the restoration goal. Mean molar mediolateral dimensions were >10mm: first molar, 11.8mm (range 3.8-21.1mm); second molar, 12.2mm (range 7.9-20.1mm). The extent of the sinus differed significantly between premolars and molars (P<0.001). The first molar region had the highest mean value for the lateral sinus wall (2.4mm, range 0.2-7.9mm) and the greatest distance between the alveolar crest and simulated restorative goal (8.1mm, range 1.1-16.3mm). Septum prevalence was 46% in the molar region and 27% in the premolar region. A lower alveolar ridge height was associated with a wider transverse extent of maxillary sinus and consequently longer distances between the crest and restorative goal. Systematic three-dimensional analysis of the maxillary sinus yields precise preoperative information about sinus configurations. There were significant variations and relationships among characteristics of the maxillary sinus, ridge, and the restorative goal.