Introduction

The classic idea of the blood supply to the masseter is based on the topography of the masseter branch (a. masseterica), known in anatomical terminology as arteria masseterica (TA2, 4439), from the basin of the maxillary artery, which in turn is filled from the external carotid artery [1].

The masseter muscle primarily gets its vascular supply from the masseteric artery, a branch of the maxillary artery (formerly the internal maxillary artery). The maxillary artery comes off the external carotid artery behind the neck of the mandible. The maxillary artery divides into the mandibular, pterygoid, and pterygopalatine portions. The pterygoid portion (muscular portion, the second portion) has four main branches including the masseteric artery, pterygoid branches, deep temporal arteries, and the buccal artery. The masseteric artery is a small branch that passes through the mandibular notch of the mandible into the deep surface of the masseter muscle. The masseteric artery anastomoses with branches of the facial artery (formerly the external maxillary artery) and the transverse facial artery [2].

The issue of blood supply to the masticatory muscle in different animals is of interest. In turn, it is known about the constant growth of teeth in rabbits and other rodents, which puts the masticatory muscles under regular stress due to maintaining the height of the animal’s bite. Moreover, the facial artery, according to [3], emits a developed cranial masseteric artery and other masseteric branches, and the transverse artery — well developed and emits many masseteric branches in correlation with the development of the masseter muscle at this specie [4].

According to [5], raccoons have facial artery bent inferolaterally and passed laterally giving off the pterygoid and the inferior masseteric branches. The mainstream of the artery ran anterosuperiorly at about 40 degrees to the horizontal plane along the anterior margin of the masseter muscle, since the notch was located on a projected level posterior to the middle of the zygomatic arch, giving rise route to the anterior masseteric. In a study of the masticatory apparatus [6], Lvov received information that the facial artery gave rise to the mandibular glandular branch posterosuperiorly immediately after its origin and passed forwards medial to the insertion of the masseter along the superior margin of the digastricus and bent anteroinferiorly giving off the sublingual glandular branch after the divergence of a thick, masseteric branch. The facial artery passed anterosuperiorly along the anterior margin of the masseter muscle, giving off the buccal, the cutaneous and the mandibular marginal branches, up to a position posterior to the oral angle.

The general type of nutrition and load on the chewing area can be traced in canines in [7]: facial artery was found to arise from the external carotid between the points of origin of the lingual and posterior auricular arteries. The artery continued anterolaterally giving off the digastric, the inferior masseteric and the cutaneous branches. In the face, the facial artery gave rise to the mandibular marginal, the anterior masseteric and others.

In primates, there is a similar tendency to supply blood to the lateral part of the face and the masticatory apparatus: in the Common Marmoset facial region, the facial artery passed anterosuperiorly along the anterior margin of the masseter muscle on 12 sides and away from it forwards on 2 sides, giving off the premasseteric branch in one of these 2 sides. It gave rise to the cutaneous, the buccal and the buccinator branches, the inferior labial artery and the communicating branch with the zygomatic artery [8]. In turn, in rhesus monkeys it has been shown [9] that large massetric artery passes forward along the lateral side of the subcondylar portion of the ramus of the mandible to enter the deep head of the masseter muscle. It most supplies of this muscle and anastomoses along the frontedge of the ramus with other branches from the maxillary artery. Near the angle, this artery joins with branches of the facial artery which also supply the inferior part of the masseter muscle. In the same study, it is obvious that Near the origin of the posterior deep temporal artery, small masseteric and capsular arteries arise which pass downward and posteriorly to their area of supply.

Summarizing the data on the blood supply to the masseter of large animals, it can be noted that the masseter muscle, as one of the most powerful representatives of the group of the same name, requires sufficient blood flow at different levels of origin and insertion. The fact of multiple arteries, originating both in the masticatory itself and in the transverse and facial arteries, is clearly confirmed. Anatomical studies of primates show the division of the masseter muscle into two portions, superficial and deep, which in turn requires an isolated blood supply either through its own branches or through an anastomotic network.

Today it is obvious that the masseter muscle has two parts, superficial and deep: the superficial masseter muscle has a quadrangular shape appearance on gross examination due to its origins and insertions. The deep portion of the masseter muscle originates from the entire surface of the zygomatic arch. The fibers run inferiorly and insert along the mandibular ramus superior to the masseter muscle’s superior portion. Anteriorly, the deep portion is covered by the superior portion of the masseter, while posteriorly, the parotid gland covers the deep portion [2, 10], which is reflected in the international anatomical terminology TA2 [1]. Thus, item 2105, the masseter muscle, is continued in 2106 and 2107, corresponding to the superficial and deep parts of the masseter.

There is information in the literature about the isolation of the so-called coronoid part [11], running from the medial surface of the zygomatic process of the temporal bone to the root and posterior margin of the coronoid process. However, one cannot agree with the authors’ statements about the first mention, because historically there is evidence rooted in research of the 17th and 18th centuries [12]. Modern studies of the second half of the 20th and beginning of the 21st centuries only emphasize the isolation of deep portions of the muscle [13—15]. Additional research on muscle segmentation [16] clearly demonstrates the parts separated from each other, which determines the function of helping in retracting the mandible due to its oblique angulation [17].

According to the literature, it is not obvious whether the above segmentation of the masticatory muscle is a separation of parts through the fascial covering, just as there is no evidence that each part receives an independent blood supply. In this regard, the results of the study [18] open a current discussion about dangerous places for medical interventions around the angle of the mandible. Thus, according to the author, the blood supply to the masticatory muscle is carried out by seven branches from the external carotid artery, incl. from deep temporal. This division is indirectly confirmed by studying the speed of blood flow in different parts of the muscle [19].

Despite studies conducted in compliance with the principles of evidence-based medicine, proving the existence of additional arteries supplying blood to the masticatory muscle, in educational resources, such as Complete Anatomy or Pirogov Anatomy, the masticatory muscle is represented by two layers, but is supplied with blood by the masticatory artery (Fig. 1).

Fig. 1. Topography of the masticatory muscle and blood vessels in the Complete anatomy (a) and Pirogov anatomy (b) systems. The bony structures of the zygomatic arch are hidden, showing the external carotid artery, facial artery, masseter artery and masseter muscle, consisting of two parts.

The purpose of this review is to systematize information about the blood supply to the massetert muscle and to offer terminological options for solving missing names.

Materials and methods

The literature review was carried out using the keywords “premasseter”, “premasseterica”, “masseter”, “postmasseter”, “blood supply”, “digital anatomy”, “dissection”, “injection”, “complication”, “facial artery”, “ external carotid artery”. The search period was limited in time from 1900 to 2024 and was carried out using such databases as PubMed, eLibrary, CyberLeninka, Scopus in Russian, English, German, Czech, Polish. Methodology for selecting works for review, the original version was taken from the website: https://www.prisma-statement.org/): identification ->screening->included. A total of 52 works were selected. Materials (19) without open access to abstracts and/or the entire text, as well as articles in the languages of the Far East, Iranian and Afroasiatic groups, and Sino-Tibetan languages were excluded from the review due to the complexity of translation and the specifics of professional vocabulary.

Discussion

In the professional literature, you can find a new term that describes the premasseteric branch, ramus premasseterica [20], which originates from the facial artery. The emphasis of doctors in this area is to prevent bleeding during surgical tactics [21]. Despite the increased interest of medical specialists in the premasticatory region, the earliest attempt to systematize knowledge about the blood supply was made in 1925 by Adachi [22]. On the other hand, of interest is a single report [23] about another source of pre-masticatory blood supply, namely from the infraorbital artery and providing potential compensation for the facial artery’s shortness.

Further studies described the variability of blood vessels [24, 25], their connection with the vessels of the deep region of the face [26], topography relative to the duct of the parotid salivary gland [27] and other types of structural relationships. In general, we can distinguish the main options for blood supply to the masseter muscle (Table. 1).

Table 1. Chronology of terminological solutions to the question of blood supply to the human masseter muscle

Despite the absence of masticatory (or pre-masticatory) branches of the facial artery and vein in anatomical terminology, they are present in some interactive educational platforms. So, for example, on the anatomylearning.com platform, in addition to the masseter artery, which classically arises from the maxillary, there are, in the order of a graphical representation without detail, the masticatory branches of the facial artery (Fig. 2).

Fig. 2. Masseteric branches of the facial artery in the anatomical atlas anatomy learning.

Conclusion

Using the example of the latest educational resource, it is obvious that this leads to confusion and distortion of the meaning of the terminological order. Therefore, it is now important to systematize the available information and propose a variable range for the terminology of the arterial blood supply to the masseter muscle (Table 2). In terms borrowed from TA2, the original number is preserved.

Table 2. Terminological solution to the issue of blood supply to the masseter

Defects in the representation of anatomical structures can lead to clinical errors, because can mislead the doctor about dangerous and safe zones if we are talking about invasive techniques. In our next work, we will present the results of an anatomical and angiographic study that systematizes information on the superficial and deep blood supply to the masseter muscle, depending on the human constitution and the shape of the skull.

Participation of authors:

Concept and design of the study — Yu.L. Vasil’ev

Investigation — Podder B., Tatarkin V.V., Velichko E.V.

Resources — Shakirov E.Yu., Shakirova L.R., Saleev N.R.

Data collection and processing — B. Podder, A.V. Glinskii, V.V. Tatarkin

Text writing — Yu.L. Vasil’ev, E.V. Velichko

Editing — S.S. Dydykin