Clinical Relevance of the Variability of the Infraorbital Arterial Anatomy Evaluated by Three-Dimensional Computed Tomography.

BACKGROUND: Knowledge of the anatomy of the infraorbital artery (IOA) is crucial for the rejuvenation of the anterior medial aspect of the midface; however, studies adequately describing the anatomy of the IOA branches are lacking, and their connection with the ophthalmic artery branches remains unclear. OBJECTIVES: This study aims to elucidate the anatomical characteristics of the IOA in its deployment within the lower eyelid using three-dimensional (3D) technology, thereby offering an anatomical foundation for clinical surgical procedures. METHODS: An analysis was conducted on computed tomography scans of 132 cadaveric head sides post-contrast injection, utilizing the Mimics software for reconstruction. The study focused on examining the anastomosis of the IOA, its principal branches, and the branches emanating from the ophthalmic artery. RESULTS: The prevalence of type I IOA was observed at 38.6% (51/132), while Type II IOA was found in 61.4% (81/132) of cases. A 7.6% incidence (10/132) of IOA directly anastomosing with the angular artery was noted. The presence of palpebral branches (PIOA) was identified in 57.6% (76/132) of instances. In the lower eyelid, four distinct distribution patterns of IOA were discerned: The likelihood of Type I PIOA was 5.3%, whereas for Types IIA, IIB, and IIC PIOA, the probabilities were 8.3%, 32.6%, and 11.4%, respectively. The occurrence of the orbital branch of IOA was recorded at 41.7% (55/132). CONCLUSIONS: 3D technology can map IOA variants and identify the deployment patterns of IOA branches in the lower eyelid vascular vesicles at high resolution as a guide in clinical practice. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Peroneal artery injury potential due to different syndesmosis screw placement options: a simulation study with lower extremity computed tomography angiography.

INTRODUCTION: The aim of this study is to assess the risk of peroneal artery injury of hardware placement at the fixation of syndesmotic injuries. MATERIALS AND METHODS: The lower extremity computed tomography angiography was used to design the study. The syndesmosis screw placement range was simulated every 0.5 cm, from 0.5 to 5 cm proximal to the ankle joint. The screw axes were drawn as 20°, 30° or individual angle according to the femoral epicondylar axis. The proximity between the screw axis and the peroneal artery was measured in millimeters. Potential peroneal artery injury was noted if the distance between the peroneal artery to the axis of the simulated screw was within the outer shaft radius of the simulated screw. The Pearson chi-square test was used and a p-value < 0.05 was considered significant. RESULTS: The potential for injury to the peroneal artery increased as the syndesmosis screw level rose proximally from the ankle joint level or as the diameter of the syndesmosis screw increasds. In terms of syndesmosis screw trajection, the lowest risk of injury was observed with the syndesmosis screw angle of 20°. Simulations with a screw diameter of 3.5 mm exhibited the least potential for peroneal artery injury. CONCLUSION: Thanks to this radiological anatomy simulation study, we believe that we have increased the awareness of the peroneal artery potential in syndesmosis screw application. Each syndesmosis screw placement option may have different potential for injury to the peroneal artery. To decrease the peroneal artery injury potential, we recommend the followings. If individual syndesmosis screw angle trajection can be measured, place the screw 1.5 cm proximal to the ankle joint using a 3.5 mm screw shaft. If not, fix it with 30° trajection regardless of the screw diameter at the same level. If the most important issue is the peroneal artery circulation, use the screw level up to 1 cm proximal to the ankle joint regardless of the screw angle trajection and screw diameter.

Arterial vascularization of the mandible and soft tissues. Anatomic study.

PURPOSE: The literature has for too long described the arterial supply of the mandible as coming from a single artery, the inferior alveolar artery, and being of the terminal type. Rather, it appears to come from an extensive and complex arterial network dependent on the lingual, facial, and maxillary arteries and their collateral branches. Our study aims to confirm and demonstrate the arterial vascular richness of the mandible and to establish arterial mapping. METHODS: The arterial vascularization of the mandible was revealed in six anatomic specimens after performing selective injections of the lingual, facial, and maxillary arteries with different dyes. A specimen was injected intra-arterially with colored latex at the level of the maxillary artery for a morphometric study. RESULTS: Eighteen selective arterial injections were performed on six anatomic specimens. The mucocutaneous, musculoperiosteal, and intramedullary vascularizations were analyzed. Each of the arteries has a defined and delimited cutaneo-mucous vascular territory. The facial and maxillary arteries supply the musculoperiosteal vascularization of the mandible from the condyle to the symphysis. The lingual artery supplies only the inner cortex of the parasymphyseal and symphyseal regions. The facial and maxillary arteries provide intramedullary vascularization from the angle of the mandible to the parasymphysis. The vascularization of the symphysis depends on the facial artery. No staining was found in the condyle region. Neoprene latex injection was performed on an anatomic specimen, revealing a permeable anastomosis between the inferior alveolar and facial arteries. CONCLUSION: The arterial vascularization of the mandible is dependent on the maxillary, facial, and lingual arteries. This is a network vasculature. This study makes it possible to establish an arterial map of the mandible. The presence of an anastomosis between the inferior alveolar artery and the facial artery confirms the existence of dynamic and borrowed vascularization. Knowledge of this arterial system makes it possible to adapt maxillofacial surgical care and to anticipate possible intraoperative complications.

The dominance of dorsal scapular artery as the blood supply to muscles of the back in the absence of two primary vessels: a cadaveric case report.

PURPOSE: Understanding of rare or unknown anatomical variations of the vasculature of the neck is critical to reduce the risk of complications during surgeries and other invasive procedures in the neck and shoulder regions. METHODS: Bilateral dissection of the neck and muscles of the back of an 87-year-old Caucasian male donor was performed to demonstrate the origin, course and termination of the arteries that arise in the neck. RESULTS: Several anatomical variations were noted on the right side of the neck of the donor body - (i) only inferior thyroid and ascending cervical arteries originated from the thyrocervical trunk (TCT), from the first part of the subclavian artery (SA), whereas the transverse cervical (TCA) and suprascapular (SSA) arteries were entirely absent, (ii) Dorsal scapular artery (DSA) emerged normally from the third part of the SA. However, after supplying the rhomboids and levator scapulae muscles, DSA provided two additional branches to the trapezius muscle and a branch to the supraspinatus muscle. Interestingly, the branches to the trapezius muscle from the DSA were the only sources of blood supply to the muscle. CONCLUSION: We report a unique anatomical variation involving the absence of the TCA and SSA from the TCT. The unilateral absence of these major vessels and the branches of DSA supplying the trapezius and supraspinatus muscles have not been reported previously in the literature in a single case report. This case study may provide useful information for head and neck reconstruction and shoulder repair surgeries.

Superior laryngeal artery originating from the lingual artery.

In most cases, the superior laryngeal artery (SLA) branches from the superior thyroid artery, which, in turn, leaves the external carotid artery. Few dissection studies found previously that the SLA could originate from the lingual artery. We report here probably the first evidence of such a rare anatomical variation found unilaterally in a retrospectively evaluated by computed tomography angiography adult male case. The left SLA left a suprahyoid coil of the lingual artery and continued over the greater hyoid horn to enter the larynx through the thyrohyoid membrane. On both sides, thyroid foramina were found, but only the right one used for the entry of the right SLA. Therefore, the rare SLA origin from the lingual artery can be documented on computed tomography angiograms, which could help during preoperative evaluations and prevent unwanted surgical complications.

Course and Relation of the Facial Vessels-An Anatomical Study.

Background and Objectives: Facial vascular anatomy plays a pivotal role in both physiological context and in surgical intervention. While data exist on the individual course of the facial artery and vein, to date, the spatial relationship of the vasculature has been ill studied. The aim of this study was to assess the course of facial arteries, veins and branches one relative to another. Materials and Methods: In a total of 90 halved viscerocrania, the facial vessels were injected with colored latex. Dissection was carried out, the relation of the facial vessels was studied, and the distance at the lower margin of the mandible was measured. Furthermore, branches including the labial and angular vessels were assessed. Results: At the base of the mandible, the facial artery was located anterior to the facial vein in all cases at a mean distance of 6.2 mm (range 0-15 mm), with three cases of both vessels adjacent. An angular vein was present in all cases, while an angular artery was only present in 34.4% of cases. Conclusions: The main trunk of the facial artery and vein yields a rather independent course, with the facial artery always located anterior to the vein, while their branches, especially the labial vessels, demonstrate a closer relationship.

Clinical Anatomy of the Chin Evaluated by 3-Dimensional Tomography and Cadaveric Dissection: Implications for Safety and Optimal Injection Techniques in Chinese.

BACKGROUND: Soft tissue fillers have been widely used for the correction of chin volume loss because of congenital conditions and aging. OBJECTIVE: This study aimed to discuss anatomical concerns for chin filler injections, which may help to reduce the incidence of severe intravascular embolization complications and improve patient satisfaction. METHODS AND MATERIALS: We scanned 40 cadaveric heads with a contrast agent using a 64-row spiral computed tomography scanner. The scan was visualized by a Philips IntelliSpace workstation and analyzed by Materialise's interactive m image control system software to measure and quantify the arterial data. Twenty of 40 cadavers were dissected to define the layers of tissue. RESULTS: In total, 221 arteries passed through the sagittal plane of 40 specimens. The number of superficial arteries (163 of 221) was much greater than the number of deep arteries (58 of 221). The number of arteries gradually decreased with distance from the lower lip vermilion border plane, which formed the lower third of the face. CONCLUSION: This study introduces a safe and effective technique for administering chin filler injections that minimizes risks and improves patient satisfaction.

Anatomical variations of the superior thyroid artery: A systematic review.

BACKGROUND: The superior thyroid artery (STA) is one of the main arteries that provide blood supply to the thyroid gland. It has a plethora of anatomical variations, and knowledge of its anatomy is necessary in procedures in this area. The aim of this review is to summarize and describe human studies (cadaveric and angiographic) that investigate the anatomical variations related to the STA. MATERIAL AND METHODS: A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A literature search in PubMed, and Embase databases was carried out. Original studies that investigated the origin of the STA and reported data on the variant arterial anatomy were considered, including only cadaveric and angiographic studies. RESULTS: A total of 34 studies (4048 heminecks in total; heminecks in each study: min: 25-max: 1280) were finally included. All studies provide details about sex [men/women ratio median (IQR): 2(1-5)] but none about age and 10 (29%) about nationality. STA morphological characteristics described in the included studies are origin, length, number of branches, distance from the carotid bifurcation and the vessel's diameter. CONCLUSIONS: The STA's anatomical features are subject to a non-negligible degree of variability. Our results should improve the awareness of anatomical variations of the STA, and eventually have an impact on the interventions regarding the visceral compartment of the neck in clinical practice.

Hierarchical semantic composition of biosimulation models using bond graphs.

Simulating complex biological and physiological systems and predicting their behaviours under different conditions remains challenging. Breaking systems into smaller and more manageable modules can address this challenge, assisting both model development and simulation. Nevertheless, existing computational models in biology and physiology are often not modular and therefore difficult to assemble into larger models. Even when this is possible, the resulting model may not be useful due to inconsistencies either with the laws of physics or the physiological behaviour of the system. Here, we propose a general methodology for composing models, combining the energy-based bond graph approach with semantics-based annotations. This approach improves model composition and ensures that a composite model is physically plausible. As an example, we demonstrate this approach to automated model composition using a model of human arterial circulation. The major benefit is that modellers can spend more time on understanding the behaviour of complex biological and physiological systems and less time wrangling with model composition.

Anatomic study of the profunda artery perforators by multidetector CT scanner and clinical use of the banana-shaped flap design for breast reconstruction.

BACKGROUND: The profunda artery perforator (PAP) flap is a well-known free flap for breast reconstruction. However, a reproducible perforator mapping system has yet to be developed. METHODS: The PAP perforators were localized by CTA using a novel X-Y axis system. Flap dimensions were based on the CTA images and localized PAP-perforators. Perioperative findings and postoperative outcomes were analyzed. RESULTS: A total of 70 lower limbs and 180 PAP perforators were evaluated. An average of 2.78 ± 1.22 and 2.22 ± 0.96 perforators were seen, in the right and left legs, respectively, and were divided in five clusters (PAP1-PAP5) based on their location on the Y-axis. The course of the perforators was noted as well as the average diameter at the origin. The overall average diameter was 1.99 ± 0.86 mm. A banana-shaped PAP-flap was harvested in 10 patients. The mean operative time was 278 min, pedicle length 76 ± 12 mm, and mean flap weight 247 g. No major complications were seen. CONCLUSION: The PAP flap can be mapped by CTA in a reproducible way. The X and Y axes are based on fixed anatomic landmarks and may form the basis for a banana-shaped flap design of the PAP-flap.

Avoiding the Intercostal Arteries in Percutaneous Thoracic Interventions.

The purpose of this study was to define relevant intercostal artery (ICA) anatomy potentially impacting the safety of thoracic percutaneous interventional procedures. An ICA abutting the upper rib and running in the subcostal groove was defined as the lowest risk zone for interventions requiring a supracostal needle puncture. A theoretical high-risk zone was defined by the ICA coursing in the lower half of the intercostal space (ICS), and a theoretical moderate-risk zone was defined by the ICA coursing below the subcostal groove but in the upper half of the ICS. Arterial phase computed tomography data from 250 patients were analyzed, revealing demographic variability, with high-risk zones extending more laterally with advancing age and with more cranial ribs. Overall, within the 97.5th percentile, an ICS puncture >7-cm lateral to the spinous process incurs moderate risk and >10-cm lateral incurs the lowest risk.

Variations ignored in routine wrist MRI reports: prevalence of the median nerve anatomical variations and persistent median artery.

BACKGROUND: It is vital to know the anatomical variations of the wrist to avoid iatrogenic injuries during carpal tunnel (CT) surgery. PURPOSE: To determine the anatomical variations of the median nerve (MN) and the prevalence of persistent median artery (PMA) on wrist magnetic resonance imaging (MRI). MATERIAL AND METHODS: A total of 300 wrists evaluated by MRI during 2013-2015 were retrospectively identified. While branching of the MN distal to the CT is accepted as the normal anatomy, proximal to the tunnel and within the tunnel were considered as variations. The prevalence of PMA was also evaluated. The patients were assigned to groups according to age, gender, and wrist side and compared to determine whether there was any significant difference in terms of these variations. All evaluations were assessed with the shared decision of a musculoskeletal radiologist and a radiology resident. RESULTS: Of the 300 wrists, 38 (12.7%) and 34 (11.3%) had a bifid MN proximal to the CT and within the CT, respectively. Only one nerve trifurcation was seen within the CT. The MN exhibited branching distal to the CT in 227 (76%) patients. PMA was observed in 44 (14.7%) patients. Of the 44 PMA cases, 28 (63.6%) also had a coexisting MN variation. There was no significant difference in the prevalence of MN variations and PMA in the subgroups (P > 0.05). CONCLUSION: Nearly one in four patients (24.4%) have MN variations and 14.8% had PMA. Preoperative evaluation of these common anatomical variations with MRI will be protective against postoperative complications of CT surgery.

Trapezius Perforator Flaps Based on Superficial Cervical Artery and Dorsal Scapular Artery: An Anatomical Study and a Systematic Review of Their Clinical Application.

BACKGROUND: The flaps in the trapezius region are routinely elevated as musculocutaneous flaps. The anatomy of trapezius perforators and their clinical application are unclear. METHODS: The number and distribution of superficial cervical artery perforators (SCAPs) and dorsal scapular artery perforators (DSAPs) were studied on 8 cadavers. The clinical usage of SCAP and DSAP flaps was investigated through a systematic literature review. RESULTS: A total of 27 SCAPs and 28 DSAPs were found in the 16 hemibacks. The mean calibers of SCAP and DSAP were 0.9 ± 0.2 and 0.8 ± 0.2 mm, respectively. The vascular length to the takeoff of the source artery was 7.3 ± 2.0 cm (range, 4.7-9.7 cm) for SCAPs and was 8.1 ± 2.8 cm (range, 3.2-13.6 cm) for DSAPs. Contour and density heat maps showed that the SCAPs were clustered within approximately 3 to 5 cm above the horizontal line through the medial point of the scapular spine (x-axis) and 5 to 8 cm from the midline (y-axis, P = 0.001) and clustered DSAPs located in approximately 4 to 9 cm below the x-axis and 4 to 10 cm from the y-axis ( P = 0.002). Four SCAP and 19 DSAP flaps were found in literature. The mean sizes of SCAP flaps and DSAP flaps were 18.5 × 7.8 and 16.5 × 8.7 cm, respectively. CONCLUSIONS: Both SCAP and DSAP flaps can be elevated with a relatively long pedicle. The anatomical knowledge of the location of major clusters of perforators contributes to the application of these flaps.

Clinical Anatomy of Feeding Artery of the Submandibular Gland.

ABSTRACT: The purpose of this study was to investigate the clinical anatomy of the feeding artery of the submandibular gland (SMG). A total of 199 SMG removals were performed in extraoral or intraoral approach with/without endoscopic assistance by a single surgeon. The feeding artery of the SMG was always identified intraoperatively and recorded in the operation record. The clinical anatomy of the feeding artery of the SMG was investigated based on the intraoperative findings. The facial artery was ligated and transected for the involvement of tumor or severe inflammation in 16 (8.0%) procedures. The feeding artery was investigated in the remaining 183 procedures. The mean number of the glandular branch was 1.5. There were 1 branch in 98 procedures (53.6%), 2 branches in 80 procedures (43.7%), and 3 branches in 5 procedures (2.7%). Detailed anatomical knowledge of the feeding artery of the SMG is useful for proper dissection of the SMG and preservation of the facial artery.

Descriptive Study on Vascular Anatomy of the Upper Lip.

INTRODUCTION: The superior labial artery (SLA) is a facial artery (FA) that drains into the peri-oral region (dangerous area of face). Owing to the recent rise in the demand for reconstructive procedures and filler injections in this region, it is important to understand its arterial topography. This paper aims to study the embranchment pattern of the labial arteries in the eastern Indian population. METHOD: An observational study using conventional dissection and dry dye injection methods was conducted to visualize the facial and superior labial arteries in 56 hemifaces. The origin, morphometry (length and diameter), branching pattern, and termination of the arteries were recorded and compared with the existing data. RESULTS: Two hemifaces were excluded from analysis (vessels damaged in dissection); in the remaining 54, a single SLA was present in all samples originating at a mean distance of 1.29 ± 0.32 cm from oral commissure (68.51% originating above). Lee type II (independent SLA giving off alar branch) was the predominant pattern (56.2%), followed by type I (independent SLA and alar branches, 33%) and type III (FA terminating as SLA, 10.8%). The average length of SLA was 4.75 ± 1.28 cm and 4.56 ± 0.78 cm on the right and left sides, respectively. CONCLUSION: The SLA is highly variable in occurrence, course, and depth, sometimes even occurring unilaterally; therefore, any intervention in this region should be done with caution. Since the SLA was not found subcutaneously at the vermillion border, the intradermal and the subcutaneous injections used here are relatively safer. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Circumflex arterial sulcus of the scapula (sulcus arteriae circumflexae scapulae): its anatomy and clinical relevance.

INTRODUCTION: The circumflex scapular artery (CSA) has been described in detail in the literature, but the groove, i.e., the circumflex sulcus (CFS), formed by the artery on the lateral pillar of the scapula has been completely neglected. The aim of the present study was to describe the variability and anatomy of the CFS. MATERIALS AND METHODS: The study was based on the examination of 103 pairs of dry bone specimens of adult scapulae, i.e., 206 specimens, including 92 (46 pairs) male and 114 (57 pairs) female specimens. In the first step, quantitative criteria were defined for assessment of the CFS presence and type. Subsequently, statistical analysis of the obtained data was performed. RESULTS: The study revealed considerable variability of the arterial groove, which was well developed in 33% (type A), shallow in 40% (type B), and absent in 27% (type C) of cases. The mean distance between CFS and the infraglenoid tubercle was 3.3 cm CI0.95 (3.1-3.3), which corresponds to the proximal third of the lateral border of the scapula. CONCLUSION: The study has confirmed variability of the arterial groove (CFS) and its localization in relation to the inferior glenoid rim. The findings are clinically important, particularly in relation to the Judet approach to scapular fractures (localization of the CSA course).

Arteries of the Lower Limb-Embryology, Variations, and Clinical Significance.

OBJECTIVES: The purpose of this article is to review the embryology of the lower limb arterial anatomy along with common variants and their clinical relevance. DESIGN: Embryologic variations of the lower limb arterial system may be explained by i.) persistence of primordial arterial segments, ii.) abnormal fusion, iii.) segmental hypoplasia/absence, or a combination of both. Persistent sciatic artery, corona mortis, and popliteal entrapment syndrome will also be discussed with associated symptoms, and potential complications. CONCLUSION: Knowledge of these variations is essential for surgical and endovascular management as failure to recognize them can result in complications.

Facial Arterial Variations in Asians: A Study on Computed Tomographic Angiography.

BACKGROUND: A consensus on facial artery anatomy has not been established due to the discrepancies in previous studies. OBJECTIVES: The authors sought to assess the branches, course, and location of the facial artery in Asians by utilizing computed tomographic angiography. METHODS: The computed tomographic angiography images of 300 facial arteries from 150 Asian patients were evaluated. The FA was classified as follows: type 1, facial artery terminates superior labial or inferior labial artery; type 2, facial artery terminates lateral nasal or inferior alar artery; type 3, facial artery terminates medial canthal artery; or type 4, facial artery is divided into duplex branches with dominant medial canthal artery laterally. The relationship between nasolabial fold and FA was evaluated, and the distances from anatomical landmarks to FA were measured to position the course. RESULTS: Seventy (23.3%), 163 (54.3%), 49 (16.3%), and the other 18 arteries (6.0%) were classified as type 1, 2, 3, and 4, respectively. A total 72.3% of facial arteries were located medially to the nasolabial fold, and only 14.7% of arteries were lateral to the nasolabial fold. The vertical distance between the facial artery and the inner canthus or the midpoint of the inferior orbital rim decreased from type 1 to type 4 facial artery (P < 0.0001). The 4 types did not significantly differ in distance between the mandibular angle (P = 0.1226) or oral commissure (P = 0.1030) and the facial artery at inferior of mandible. CONCLUSIONS: Detailed findings of the facial artery will provide a valuable reference for filler injection in cosmetic procedures and flap design in reconstructive surgery.

The Layered Anatomy of the Nose: An Ultrasound-Based Investigation.

BACKGROUND: An increasing number of soft tissue filler procedures in the nasal region has been reported. Concomitant with demand, the number of complications has risen due to the difficulty in administering filler in a region where soft tissue layering is complex. OBJECTIVES: The authors sought to describe the layered soft tissue arrangement of the nose as it relates to the underlying arterial vasculature and to define safer zones for nasal filler enhancement. METHODS: A total of 60 (28 males and 32 females) study participants were investigated with respect to their layered anatomy in the midline of the nose utilizing ultrasound imaging. The presence and extent of the layered arrangement was examined as well as the depth of the arterial vasculature. RESULTS: In the mid-nasal dorsum, a 5-layer arrangement was observed in 100% (n = 60) of all investigated cases, whereas it was found to be absent in the nasal radix and tip. The 5-layer arrangement showed an average extent of 26.7% to 67.5% in relation to nasal length. The nasal arteries coursed superficially in 91.7% of all cases in the nasal radix, in 80% in the mid-nasal dorsum, and in 98.3% in the nasal tip. CONCLUSIONS: Soft tissue filler administration in the nose carries the highest risk for irreversible vision loss compared with any other facial region. The safety of soft tissue filler rhinoplasty procedures is enhanced by knowledge of the layered anatomy of the nose, the location and depth of the major nasal vasculature, and employment of maneuvers to decrease the risk of blindness.

Domestic pig head and neck arteries from the viewpoint of imaging methods and experimental surgery

The aim of this paper is to summarize the current knowledge of the anatomy of domestic pig head and neck arteries for the needs of experimental surgery and imaging methods in biomedical research and translational medicine. The potential of this large animal model seems to be valuable also for the xenotransplantation of certain organs. Demands for the knowledge of morphological differences between analogous human structures and particular breeds are growing also in connection with the need for more precise planning of experiments or interpretation of the results. Deepening anatomical knowledge is allowed also by the development of imaging methods. The search was performed using the keywords "domestic pig" and "arteries of the head and neck" in the MEDLINE database, PubMed interface.