Prevalence, Location, and Variations of the Posterior Superior Alveolar Canal With Age and Gender in the Indian Population: A Cone Beam Computed Tomography (CBCT)-Based Retrospective Study.

BACKGROUND: Enhancing the availability of bone in the vertical dimension for implant insertion is thought to be possible through implant site preparation using direct or indirect sinus lift. The posterior superior alveolar (PSA) canal is extremely vulnerable to trauma during this procedure. The anatomy of this region should be thoroughly evaluated to prevent traumatizing this artery and eventual perioperative bleeding. Due to a lack of relevant knowledge and the clinical importance of this problem, the position, diameter, detectability, and proximity of this canal to the alveolar ridge were assessed on cone beam computed tomography (CBCT) scans which were the main objectives of this study. METHODOLOGY: A total of 240 CBCT scans were examined, and the position of the PSA canal, its diameter, the perpendicular distance from the inferior border of the PSA canal to the alveolar crest, and the perpendicular distance from the inferior border of the canal to the maxillary sinus floor was measured. RESULTS: Intraosseous PSA canals were the most prevalent, followed by intrasinusal and extraosseous canals. Males had larger canal diameters and greater distances between the maxillary sinus floor and alveolar crest and the canal (P < 0.05). CONCLUSION: CBCT was proven to be a useful method for assessing and localizing the PSA artery to prevent intraoperative bleeding and further complications.

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.

Maxillary sinuses, multiple aspects to consider prior to bone grafting procedure: a retrospective study in a sample of a Palestinian population.

OBJECTIVES: To analyze various anatomical aspects of the maxillary sinuses on CBCT volumes, mainly, the posterior superior alveolar artery (PSAA), and to compare its visibility on CBCT vs. panoramic radiographs. MATERIAL AND METHODS: A retrospective radiographic analysis was conducted on 120 patients (240 maxillary sinuses) using their CBCT coronal views (CCV) and panoramic radiographs (CP). On CCV, the PSAA's maximum dimension (MD), vertical distance (PVD) to the alveolar crest, and bone plate thickness (T1 and T2) buccally and inferiorly to the PSAA, respectively, were analyzed. Additionally, on CCV, the ostium vertical distance (OVD) and location were recorded, and the height of the remaining bone height inferior to the maxillary sinuses (MVD) was also measured. The PSAA's visibility was evaluated and compared between CCV and CP. All these variables were studied at the apical region of the second maxillary premolar (P2), first molar (M1), and second molar (M2). Age, gender, and face side (right vs. left) factors affecting the sinus dimensions and visibility were investigated. Several statistical tests were used to analyze these variables. RESULTS: PSAA was detected in 96.53% of the records on CCV, where it was significantly superior to CP in the detection of the PSAA structure (p value 0.000) at all sites analyzed. The PSAA's MD, PVD, T1 and T2 thicknesses, and MVD were on average 1.19 mm, 19.54 mm, 0.69 mm, 1.36 mm, and 10.25, respectively. OVD average was 31.04 mm where 42.9% of the ostia were within the mesiodistal extent of the second upper molar. No significant relation was found between different age groups, gender, and the visibility level of PSAA. CONCLUSION: Age, gender, and the side of the face investigated showed no discernible effects on the maxillary sinus's bone thickness, vertical dimensions, or PSAA diameter among the studied Palestinian sample. As CCV was superior to CP in the identification of PSSA, preoperative evaluation of PSSA using CBCT volumes is thus recommended.

Cone Beam Computed Tomography Analysis of Posterior-Superior Alveolar Canal from a Fixed Reference Point: Implications for Sinus Floor Elevation Procedure through Lateral Approach.

Objective: Sinus floor elevation is commonly done in the maxillary posterior region prior to dental implant placement. This study primarily aimed at assessing the location of the posterior superior alveolar artery (PSAA) canal on cone beam computed tomography (CBCT) scans and its relation to the alveolar ridge and maxillary sinus from a fixed reference point. Material and Methods: A total of 226 edentulous maxillary molar sites were included in this retrospective analysis. The distance from the PSAA to the sinus floor (SF), alveolar crest (AC) and a fixed reference point, that is, the roof of sinus (RS) were measured. The alveolar bone height (ABH), thickness of the crestal keratinized mucosa (CKM) and thickness of Schneiderian membrane (SM) were also evaluated. Results: 54 sites (23.89%) were excluded from the study. The SF, AC, RS and ABH values averaged at 11.91 mm ± 3.63 mm, 16.05 mm ± 3.96 mm, 25.32 mm ± 7.13 mm and 4.93 mm ± 4.27 mm respectively. SF and AC was higher in second molar than first molar region (p < 0.001), but RS did not show significant difference (p = 0.85). CKM and SM averaged at 2.02 mm ± 0.68 mm and 1.31 mm ± 0.81 mm respectively. Conclusion: The PSAA can be visualized in CBCT scans with a prevalence of 76.11% and may not be detected when adherent to the sinus membrane. This study stresses on the need for a CBCT, prior to sinus surgeries through lateral approach, to assess the PSAA.

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

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

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.

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.

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

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

The prevalence and location of the posterior superior alveolar artery in the maxillary sinus wall: A preliminary computed-cone beam study.

The lateral wall of the maxillary sinus is supplied by the posterior superior alveolar artery (PSAA). It may be affected by trauma, pathology, or surgery performed to access or correct any fracture involving the maxillary sinus. This study analysed the prevalence and distance of the PSAA from the floor of the maxillary sinus in selected Southeast Asian patients. Methods: This is a cross sectional study conducted using cone-beam computed tomographic images of 83 dentate patients with a mean age of 38.3 years. Results: One hundred sixty-six maxillary sinuses of 54 males and 29 females were evaluated, with PSAA observed in 91.6 % of sinuses. Of the PSAA identified (n = 152), 64.5 % were intraosseous (n = 98), 25.7 % were beneath the sinus membrane (n = 39), and the remaining 15 (9.9 %) were on the external cortex of the lateral sinus wall. The mean distance between PSAA and the lowest point of the sinus floor was 11.44 mm (SD, 3.36). Sixty-four maxillary sinus walls (38.6 %) presented with 2 PSAA branches. The inferior and superior branches were located 6.42 mm (SD, 2.68) and 8.48 mm (SD, 3.56) from the floor of the maxillary sinus, respectively. The mean difference between these 2 branches was 2.25 mm (SD, 1.90). Conclusion: This study confirms the different locations of the PSAA in relation to the lateral wall of the maxillary sinus with no gender influence. Branching of PSAA occurs, and should be highlighted to surgeons.

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.

Assessment of Pathway and Location of Posterior Superior Alveolar Artery: A Cone-Beam Computed Tomography Study.

Objective The current study evaluated the complicated pathway of the posterior superior alveolar artery (PSAA) and measured the prevalence, diameter, and length of PSAA to the alveolar crests of molars using cone-beam computed tomography (CBCT). The study compared findings between dentate and edentulous patients grouped by their age. In addition, the study researched the presence of the septa. Methods One hundred and fifty CBCT scans of patients with ages ranging from 20 to 80 years were analyzed for the study. The measurements of PSAA were obtained from CBCT scans. Results The PSAA was detected on CBCT scans of 87.3% of participants. The majority course of PSAA was intraosseous (right side 53.3%, left side 63.3%). The diameter of PSAA was 1.30±0.42 mm on the right side and 1.19±0.40 mm on the left side. The length of PSAA to the alveolar crest of the third molar (A1) was 17.16±2.72 mm on the right side and 17.82±3.2 mm on the left side, to the first molar (M1) was 11.6±2.66 mm on the right side and 11.65±2.37 mm on the left side, and to second molar (M2) was 12.51±1.96 mm on the right side and 12.44±2.72 mm on the left side. There was no significant difference noticed between dentate and edentulous participant groups. Six percent (6%) of the scans showed the septa in the maxillary sinus. Conclusions The study showed that CBCT scans and their analysis help the clinician to make a better radiographic diagnosis and clinical application while using surgical procedures, such as implant placement and sinus lift.

Anastomosis between the posterior superior alveolar artery and the infra-orbital artery: a review of current terminology / Anastomosis entre la arteria alveolar superior posterior y la arteria infra-orbital: una revisión de la terminología actual

SUMMARY: The posterior superior alveolar artery (PSAA) and the infra-orbital artery (IOA) present intraosseous and extraosseous rami which form an anastomosis in the lateral wall of the maxillary sinus. This anastomosis is always present, however it has not yet been included in anatomical terminology (AT), and different terms are used in scientific communication to refer to it. The aim of this study was to carry out a review of the different terms used to name this vascular structure. A literature review was carried out on the terms used to name the anastomosis between the PSAA and IOA in imaging studies and human cadavers that assessed the presence/frequency of this anatomical structure. The search was carried out in the Medline, EMBASE and LILACS databases, in Portuguese, Spanish and English, with no date restrictions. Qualitative analysis was applied to the studies selected, analysing the terminology used to refer to the anastomosis between the PSAA and IOA. Of the 2108 original articles found, 60 were selected as potentially relevant and 54 studies were finally included for qualitative analysis. Sixteen terms were found to refer to the anastomosis between the PSAA and IOA, the most frequent being Posterior Superior Alveolar Artery (PSAA), followed by Alveolar Antral Artery (AAA). Many terms are used in the medical literature to designate the anastomosis between the PSAA and IOA, the most frequent being PSAA and AAA. There is a need to unify the terms used to designate this vascular structure, and to incorporate the selected term into anatomical terminology, in order to avoid confusion in scientific communication.

RESUMEN: La arteria alveolar superior posterior (AASP) y la arteria infra-orbital (AIO) tienen ramas intra y extra óseas que forman una anastomosis en la pared lateral del seno maxilar. Esta anastomosis está siempre presente, sin embargo, aún no ha sido incluida en la terminología anatómica (TA), por lo que en la comunicación científica se utilizan diferentes términos para referirse a ella. El objetivo de este estudio fue realizar una revisión sobre los diferentes términos utilizados para nombrar esta estructura vascular. Se realizó una revisión de la literatura sobre los términos utilizados para nombrar la anastomosis entre AASP y AIO en estudios imagenológicos y en cadáveres humanos que evaluaron la presencia/frecuencia de esta estructura anatómica. La búsqueda fue realizada en las bases de datosMedline, EMBASE y LILACS, en los idiomas portugués, español e inglés, sin restricción de fecha. Los estudios seleccionados fueron evaluados de forma cualitativa, analizando la terminología empleada para referirse a la anastomosis entre AASP y AIO. Fueron encontrados 2108 artículos originales, siendo seleccionados 60 artículos potencialmente relevantes y finalmente fueron incluidos 54 estudios para análisis cualitativo. Fueron encontrados 16 términos para referirse a la anastomosis entre AASP y AIO, siendo AASP el más frecuente seguido de arteria alveolo-antral (AAA). Son muchos los términos utilizados en la literatura médica para designar la anastomosis entre AASP y AIO, siendo AASP y AAA los más usados. La unificación de los términos utilizados para designar esta estructura vascular y su incorporación en la Terminología Anatómica contribuiría a evitar equívocos en la comunicación científica.

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.

Influence of Anatomical Parameters on the Dimensions of the Subantral Space and Sinus Mucosa Thickening after Sinus Floor Elevation. A Retrospective Cone Beam Computed Tomography Study.

BACKGROUND: Various anatomical parameters might influence the surgical approach for maxillary sinus floor elevation. The objective of the present study was to retrospectively evaluate the influence of anatomical parameters on the dimensions of the subantral space and of the sinus mucosa thickening after sinus floor elevation. MATERIAL AND METHODS: Seventy-eight maxillary sinuses in sixty-five patients were evaluated on cone beam computed tomographies taken before surgery and after one week (t1w) and nine months (t9m). Several parameters such as the distance XF between an axis parallel to the base of the nose (X-axes) and the sinus floor (F) were correlated with the height gain (IF) at t1w and t9m and the post-surgical edema. RESULTS: A weak significant positive correlation was observed between height gain vs. sinus height of interest (XF), the balcony, and the sinus floor angle. The post-surgical edema was influenced by the initial mucosa thickness and the xenograft used. CONCLUSIONS: Various parameters might affect height gain and sinus mucosa thickening after sinus floor elevation. The height of interest, the balcony, and the sinus floor angle showed significant correlations with height gain. The initial thickness of the mucosa and the biomaterial used influenced the post-surgical edema.

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.

Three-dimensional visualization of the alveolar bone and posterior superior alveolar foramen in gender.

The present study applied a three-dimensional (3D) program to measure the distances from the maxillary sinus floor (MSF) to the lingual and buccal alveolar bone and also to the posterior superior alveolar foramen (PSAF), with the aim of determining differences according to gender. The study also attempted to verify the accuracy of measurements obtained from 3D images by performing comparisons with the results obtained in a preliminary study. The results showed that the alveolar bone length and the MAF-PSAF were generally larger in males than in females. It is also predicted that the accuracy of data obtained from a 3D program will be higher than that of data derived from conventional two-dimensional (2D) images. The accurate measurements obtained in this study are anticipated to prove useful in assessments related to dental implantation and anatomical structures. The fundamental data obtained in this study may also assist in setting the goals of future studies utilizing 3D programs.

Analysis of the presence, location and morphometry of the «alveolar antral artery¼ by cone-beam computed tomography in Chilean adults / Análisis de la presencia, ubicación y morfometría de la arteria alvéolo-antral por tomografía computarizada de haz cónico en adultos chilenos

SUMMARY: The posterior superior alveolar artery is responsible for the vascularisation of the mucous which covers the posterior wall of the maxillary sinus, pulp and the periodontal tissues of upper molars. The collateral rami of the infraorbital artery irrigate the mucous of the anterior and lateral walls of the maxillary sinus, as well as the pulp and periodontal tissue of the upper anterior teeth and upper premolars. Both these arteries present intraosseous and extraosseous rami which form an anastomosis in the anterior and lateral walls of the maxillary sinus, called the alveolar antral artery (AAA). The aim of this study was to analyse the presence, location and morphometry of the AAA in a Chilean population, considering sex, side and age, using Cone-Beam computed tomography (CBCT). Forty-two CBCT examinations of Chilean adults were evaluated to analyse the presence, location (extraosseous, intraosseous or subperiosteal) and diameter (<1mm, 1-2 mm, 2-3 mm, >3 mm) of the AAA and the distance from the AAA to the amelocemental limit of the upper second premolar (2PM), permanent upper first molar (1M) and permanent upper second molar (2M) by sex and age range. Pearson's chi-squared test, Student's t-test, ANOVA and Pearson's correlation coefficient were applied, using a significance threshold of 5 %. AAA was found in 75 sides (89.3 %), 38 on the right side (90.5 %) and 37 on the left (88.09 %); extraosseous location was most common. More than 80 % of the arteries presented a diameter between 1 and 2 mm, with no important differences between sexes or age ranges. In younger individuals, the artery was located closer to the vestibular amelocemental limit than in older individuals. Carrying out a proper treatment plan which includes imagenological analysis before surgical procedures is essential to avoid possible haemorrhagic events in the region.

RESUMEN: Arteria alveolar superior posterior es responsable de la vascularización de la mucosa que recubre la pared posterior del seno maxilar, la pulpa y el tejido peridontal en el que se insertan los molares superiores. Las ramas colaterales de la arteria infraorbitaria irrigan la mucosa de las paredes anterior y lateral del seno maxilar, así como la pulpa y el periodonto de los dientes anteriores superiores y los premolares superiores. Ambas arterias presentan ramas intraóseas y extraóseas que forman una anastomosis en las paredes anterior y lateral del seno maxilar, denominada arteria alvéolo antral (AAA). El objetivo de este estudio fue analizar la presencia, localización y morfometría del AAA en una población chilena, considerando sexo, lado y edad, mediante tomografía computarizada Cone-Beam (CBCT). Se evaluaron 42 exámenes CBCT de adultos chilenos para analizar la presencia, ubicación (extraósea, intraósea o subperióstica) y diámetro (<1 mm, 1-2 mm, 2-3 mm,> 3 mm) del AAA. y la distancia del AAA al límite amelocemental del segundo premolar superior (2PM), primer molar superior permanente (1M) y segundo molar superior permanente (2M) por sexo y rango de edad. Se aplicaron la prueba de chi-cuadrado de Pearson, la prueba t de Student, ANOVA y el coeficiente de correlación de Pearson, utilizando un umbral de significancia del 5 %. Se encontró AAA en 75 lados (89,3 %), 38 del lado derecho (90,5 %) y 37 del lado izquierdo (88,09 %); la localización extraósea fue la más común. Más del 80 % de las arterias presentaban un diámetro entre 1 y 2 mm, sin diferencias importantes entre sexos ni rangos de edad. En individuos más jóvenes, la arteria se ubicó más cerca del límite amelocemental vestibular que en individuos mayores. La realización de un adecuado plan de tratamiento que incluya análisis imagenológico antes de los procedimientos quirúrgicos es fundamental para evitar posibles eventos hemorrágicos en la región.

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.

Herniation of orbital fat through the inferior orbital fissure and into the infratemporal fossa: a cadaveric case report and review.

Orbital fat herniation is primarily in a subconjunctival location. However, herniation through the inferior orbital fissure (IOF) has been scantly reported. Here, we report a cadaveric case of herniation of orbital fat through the inferior orbital fissure and into the infratemporal fossa. The cadaver's orbital anatomy and orbital fat herniation were found during routine dissection. The details of this case are reported. We also discuss anatomical variations of the inferior orbital fissure as well as the related vascular and nervous system structures related to orbital fat herniation. This is a rare case of a cadaver with this anatomical abnormality.

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.