Folia Morphol.

Vol. 83, No. 1, pp. 66–71

DOI: 10.5603/FM.a2023.0024
ORIGINAL ARTICLE Copyright © 2024 Via Medica
ISSN 0015–5659
eISSN 1644–3284
journals.viamedica.pl

The relationship between the auriculotemporal

nerve and middle meningeal artery in a sample
of the South African population
Sherelle Moodley1 , Sundika Ishwarkumar2, Pamela Pillay1
1
University of KwaZulu-Natal, Durban, South Africa
2
University of Johannesburg, Johannesburg, South Africa

[Received: 23 February 2023; Accepted: 6 March 2023; Early publication date: 3 April 2023]

Background: The interaction between the auriculotemporal nerve and the middle
meningeal artery within the infratemporal fossa is vital in the spread of perineural
tumours. Knowledge of their morphological and morphometric variations is critical
to surgeons approaching the infratemporal fossa. There is a paucity of literature on
the relationship between the auriculotemporal nerve and middle meningeal artery
in a South African population. Hence, the aim of this study was to document the
morphology and morphometry of the auriculotemporal nerve and its relationship
to the middle meningeal artery within a South African cohort.
Materials and methods: The infratemporal fossae of 32 cadaveric specimens
were dissected and the auriculotemporal nerves and middle meningeal arteries
were analysed, together with their variations.
Results: Nine out of 32 specimens displayed one-root, 14/32 two-root, 7/32
three-root, and 2/32 four-root auriculotemporal nerves. Eighteen auriculotempo-
ral nerves originated from the mandibular nerve, while the rest had at least one
communication to the inferior alveolar nerve. The mean distance between the
first and second roots of the auriculotemporal nerve was 4.69 mm. There were
V-shaped formations found in 23 auriculotemporal nerves. However, the middle
meningeal artery only passed through 13/23 V-shapes. The maxillary artery was of
a deep course in relation to the lateral pterygoid muscle in 19/32 and superficial in
13/32 of the sample. There were 15 accessory middle meningeal arteries present
in 14/32 specimens. The accessory middle meningeal arteries often arose from
the middle meningeal artery (46.67%).
Conclusions: The results of this study show a high possibility of variations of
the auriculotemporal nerve and middle meningeal artery in the South African
population. The variations and interactions should be considered during surgical
procedures. (Folia Morphol 2024; 83, 1: 66–71)

Keywords: infratemporal fossa, mandibular nerve, maxillary artery,

meningeal arteries, neoplasms

Address for correspondence: Dr. Pamela Pillay, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of
KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa, e-mail: soobramoneypa@ukzn.ac.za
This article is available in open access under Creative Common Attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license, allowing to download
articles and share them with others as long as they credit the authors and the publisher, but without permission to change them in any way or use them commercially.

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 Sherelle Moodley et al., Relationship between the auriculotemporal nerve and middle meningeal artery

INTRODUCTION MATERIALS AND METHODS

The auriculotemporal nerve (ATN) may be involved The study used 16 formalin-fixed South African
in parotid gland cancers and the resultant perineural cadavers dissected bilaterally (n = 32) at the De-
tumour spread along the nerve may extend cranially partment of Clinical Anatomy, University of KwaZu-
to the foramen ovale, through which the mandibular lu-Natal. The Biomedical Research Ethics Committee
branch of the trigeminal nerve passes [5, 19]. The pro- at the University of KwaZulu-Natal granted ethical
gression of a tumour along the ATN can compromise permission for this study (BREC/00002919/2021). The
tissues in the infratemporal fossa, cause trigeminal dissection procedures followed those of Dias et al. [7],
nerve palsy, and displace or obliterate vascular struc- Komarnitki et al. [13], and Loukas et al. [14].
tures [17, 21]. The interaction between nerves and This study used all available adult cadavers with no
vessels is critical in the spread of perineural tumours, visible injury to the mandibular ramus or contents of
and the close association between the ATN and the the infratemporal fossa. The cadavers were placed in
middle meningeal artery [22] may cause additional a supine position and dissected to expose the in-
complications [17]. As a result, medical practitioners fratemporal fossa and its contents. The skin and su-
must understand the morphology of the ATN and its perficial tissue overlying the zygomatic arch, parotid
relationship to the middle meningeal artery (MMA), gland and duct, and mandibular ramus was removed.
as well as the anatomy of the infratemporal fossa, Thereafter, the zygomatic arch and mandibular ramus
to appropriately identify the neurovasculature and was cleaned and dissected using a bone saw to ex-
limit the risk of complications during procedures to pose the contents of the infratemporal fossa [13]. The
the infratemporal fossa. However, the relationship lateral and medial pterygoid muscles were dissected
between the ATN and MMA has not been investigated to reveal the deep contents of the infratemporal fos-
in a South African population. sa, viz. the mandibular nerve and the MMA. Tracing
The auriculotemporal, inferior alveolar, and lingual the inferior alveolar nerve superiorly to the foramen
nerves are the cutaneous branches of the posterior ovale assisted in identifying the trunk of the mandibu-
division of the mandibular nerve [8, 18]. The ATN lar nerve [14]. The roots of the ATN were cleaned and
has been reported to arise as two roots within the traced from the most inferior root to facilitate proper
infratemporal fossa, forming a buttonhole to encircle identification of the ATN’s variations. The MMA was
the MMA before re-joining to form its main trunk [8, also cleaned and traced from its origin to the foramen
18]. Some aural structures, the temporomandibular ovale. The maxillary artery was identified, and the
joint, the posterior portion of the temple, and the part from which the MMA originated was recorded.
parotid gland, are innervated by the ATN [8, 10, 18]. Variations in the ATN’s roots and its relationship with
The MMA is the maxillary artery’s largest branch, the MMA were documented, as well as the presence
and originates within the infratemporal fossa as the of the accessory middle meningeal artery (aMMA).
third branch from the first segment of the maxillary The distance between the roots of the ATN was meas-
artery [11, 18]. The MMA coursed cranially through ured three times for accuracy using a digital vernier
the buttonhole of the ATN and entered the cranium calliper. The descriptions and data were entered on
via foramen spinosum, supplying the dura mater a Microsoft Excel 2016 spreadsheet for analysis.
[11, 18]. The infratemporal fossa may contain an The data were statistically analysed using the R
accessory MMA, which arises from either the MMA Project for Statistical Computing software (version
or the maxillary artery, depending on the anatomical 3.6.3 of the R Core Team). Data were analysed using
relationship between the maxillary artery and the descriptive statistics, and parameters were found to
lateral pterygoid muscle [1, 4, 11, 18]. be statistically significant with p-values less than 0.05.
While standard anatomical text stipulates the
usual morphology of the ATN and its relationship to RESULTS
the MMA, many authors have discovered variations The results of this study is shown in Table 1.
in this regard [3, 5, 7, 9, 13, 20]. Hence, the present
study aimed to document the morphological and Demographics
morphometrical anatomy of the ATN, the relation- The specimens used in the study were of South
ship between the MMA and the ATN, as well as their African White (87.50%) and Black (12.50%) descent.
variations (if any) in a South African sample. The cadavers were of an older cohort (72.4 ± 11.9

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Table 1. Quantity and description of ATN, MMA, and aMMA discovered in the bilateral dissection of infratemporal fossae in a South
African population (n = 32)
One-root Two-root Three-root Four-root Buttonhole V-shape aMMA Maxillary artery Maxillary artery
ATN (%) ATN (%) ATN (%) ATN (%) formations (%) formations (%) present (%) deep to LPM superficial to
(%) LPM (%)
9 (28.13%) 14 (43.75%) 7 (21.88%) 2 (6.25%) 1 (3.13%) 22 (68.75%) 14 (43.75%) 19 (59.38%) 13 (40.63%)
aMMA — accessory middle meningeal artery; ATN — auriculotemporal nerve; LPM — lateral pterygoid muscle

inferior roots from the inferior alveolar nerve. All

specimens had a V-shape formation; however, the
MMA only passed through four.
Four-root ATN. Only two specimens displayed
four-root ATN with their first root from the man-
dibular nerve, and their third and fourth roots orig-
inating from the inferior alveolar nerve. However, in
one specimen, the second root originated from the
mandibular nerve, while another originated from
the inferior alveolar nerve. Both specimens exhibited
V-shaped formations, but only one had the MMA
passing through.

Morphometry of the ATN

Figure 1. A two-root auriculotemporal nerve (ATN) and middle me- The mean distances measured between the roots
ningeal artery (MMA) within the infratemporal fossa. The first root of the ATN are shown in Table 2. The mean distance
of the nerve joins with the second root, forming a V shape (black between the first and second roots of the ATN was
dashed line). The MMA coursed through the V shape; 1 — first
root of ATN, 2 — second root of ATN; CNV3 — mandibular nerve; found to be the largest, while the distances between
LN — lingual nerve; IAN — inferior alveolar nerve. the third and fourth roots were the smallest.

Relationship between the ATN’s roots

years) and there was equal distribution regarding the and the MMA or maxillary artery
sex of the specimens. The observations of the relationship between the
ATN and MMA are depicted in Table 3. However, it is
Morphology of the ATN noted that particular specimens were also related to
One-root ATN. Eight of the nine one-root ATN the maxillary artery.
specimens originated from the mandibular nerve, In a two-root specimen, the second root of the
while the remaining one originated from the inferior ATN was superficial to both the MMA and maxillary
alveolar nerve. artery. Two specimens had their second roots deep
Two-root ATN. Seven of the 14 two-root speci- to the maxillary artery and were, therefore, unrelated
mens displayed both roots originating from the man- to the MMA. The second root of another specimen,
dibular nerve. The remaining specimens showed the which originated from the mandibular nerve, split
first root originating from the mandibular nerve and into a buttonhole but did not contain any vasculature.
the second from the inferior alveolar nerve. All spec- The second root in a three-root specimen was
imens with a two-root ATN had a V-shape formation, superficial to the maxillary artery and anterior to the
but the MMA was only found to pass through eight MMA. Furthermore, the second root of the ATN in
(Fig. 1). two specimens was closely related to the maxillary
Three-root ATN. Seven specimens had three-root artery — one was deep to the maxillary artery, and
ATN (Table 1). However, only three specimens were another was inferior. The third roots of four specimens
discovered with all roots originating from mandibular were also closely related to the maxillary artery — two
nerve. The first root of the remaining four specimens were superficial, one was deep, and one inferior to
originated from the mandibular nerve and the two the maxillary artery.

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 Sherelle Moodley et al., Relationship between the auriculotemporal nerve and middle meningeal artery

Table 2. Mean distances measured between the first and second, second and third, and third and fourth roots of the auriculotemporal
nerve (ATN) [mm]
One-root ATN Two-root ATN Three-root ATN Four-root ATN Total
First root First Second First Second Third First Second Third Fourth
root root root root root root root root root
Superficial to MMA 9 13 1 6 2 – 2 – – – 33
Deep to MMA – 1 10 – 1 3 – 2 2 1 20
Anterior to MMA – – 1 1 1 1 – – – 1 5
MMA — middle meningeal artery

Table 3. Relationship between roots of the one-, two-, three-, trifurcated (Fig. 2). Hence, 15 aMMA was encountered
and four-root auriculotemporal nerve and the middle meningeal in this study.
artery in dissected infratemporal fossae
Measurement [mm] DISCUSSION
Mean ± SD
The ATN has been described to originate as two
Distance between the first and second roots 4.69 ± 5.24
roots from the mandibular nerve, forming a button-
Distance between the second and third roots 3.63 ± 3.89
hole to enclose the MMA [8, 18]. However, many
Distance between the third and fourth roots 2.67 ± 2.06
studies have discovered that the ATN can arise from
SD — standard deviation as few as one to as many as five roots [12, 16]. The
two-root ATN is the most prevalent in the Ameri-
can, Turkish, Polish, New Zealand, Indian, and Thai
populations [2, 6, 7, 9, 12, 16]. This correlated with
the present study, as a prevalence of 43.75% was
documented. Furthermore, the ATN can originate
from the inferior alveolar and mandibular nerves [6,
7, 12], which was shown to be true in the present
study. This study demonstrated that the first root of
the ATN originated from the mandibular nerve and
the inferior roots from the inferior alveolar nerve.
This corroborated with Komarnitki et al. [12], Dias et
al. [7], and Chanasong et al. [6] who found that the
Figure 2. Schematic representation of the three-root auriculotem- inferior alveolar nerve contributes to the main trunk
poral nerve (ATN) variant. The second root bifurcated — upper part of the ATN. Although, Quadros et al. [16] discovered
joined first root and lower part joined third root. Middle meningeal
artery (MMA) passed through V-shape created between the first that the inferior alveolar nerve was a point of origin
and second roots; MA — maxillary artery; aMMA — accessory of all the ATN in their population. The inferior alve-
middle meningeal artery; CNV3 — mandibular nerve; IAN — inferi- olar nerve’s contribution to the ATN could explain
or alveolar nerve; LN — lingual nerve.
unexpected ATN neuralgia resulting from an inferior
alveolar nerve block [15].
Course of the maxillary artery The morphometric distance measured between
The maxillary artery often coursed deep to the lat- the roots of the auriculotemporal nerve suggested
eral pterygoid muscle in the studied sample (Table 1). that the distance between the inferior roots is smaller
Of the 19 deep course specimens, the maxillary ar- than that of the superior roots. The mean distance
teries coursed through a loop formed in the inferior between all the roots of the ATN was 4.42 mm in the
alveolar nerve in six specimens. present study, while Baumel et al. [2] and Gulekon
et al. [9] found that the distance between the roots
Presence of the aMMA of the auriculotemporal nerve was 3.92 mm and
The aMMA was present in 14 (43.75%) specimens 4.12, respectively. The difference in measurements
(Table 1). A double aMMA was found in one specimen, amongst the various populations may suggest that
which coursed superiorly, superficial to the ATN, and morphometric distances may be affected by ethnicity.

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Previous research has described the relationship CONCLUSIONS

between the roots of the ATN and the MMA as either This study examined the relationship between
superficial or deep to the artery [2, 7, 9, 16]. The the MMA and the ATN in a South African population
present study further included a description of the and added pivotal information on the contents of
roots being anterior to the artery. However, this study the infratemporal fossa in a South African population
also demonstrated that the superior roots are usually which may be beneficial to anatomists and surgeons.
superficial to the MMA, whereas the inferior roots are The findings of this study indicated several variations
deep. These results corroborated with Baumel et al. in the morphology of the ATN and its relationship to
[2] and Gulekon et al. [9]. Furthermore, the anatom- the MMA, which are similar to those found in pop-
ical relationship of the three-root ATN to the MMA ulation groups previously studied. The results of this
in a South African population is similar to that of the study further highlighted that the variations of the
American population — the superior two roots are ATN and the MMA are not concisely documented in
superficial to the MMA, and the inferior root is deep standard anatomical literature.
[2]. Contrarily, the first root in the Turkish population
was superficial to the MMA, while the lower two Limitations and recommendations
were deep [9], while the Indian population showed Due to the limited sample size, no significant
one root being deep and two superficial to the MMA differences could be found between the individuals’
[16]. As a result, there is a great deal of variation in sexes, sides, and ethnicities. However, the findings
the relationship between the ATN roots and the MMA. of this study may aid future research in discovering
In agreement with previous literary reports, the ethnic differences. Hence, the recommendation made
typical buttonhole formation was not discovered in for future studies is to utilise a bigger sample size
the present South African population [2, 7, 12]. The to determine if there are significant differences in
most common interval formed by the roots of the laterality, age, sex, and population groups. Due to
ATN in this study was a V-shape, as found in previous the paucity of literature on the ATN and MMA, ethnic
studies [2, 7, 12]. Although the V-shape was found differences have not been previously established. This
in 22/32 of the selected sample, the MMA was only study, therefore, adds to the existing literature by
enclosed in 14 (63.64%). Dias et al. [7] and Chanasong discovering the morphology of the ATN and MMA
et al. [6] found the MMA enclosed in 52.00% and in a South African population which may be useful
69.86% of their specimens, respectively. The findings for future studies examining population differences.
of this study support previous research stating that
the buttonhole is seldom present and that the MMA Ethical approval
does not always pass through the ATN [2, 7, 12]. This study was performed in line with the prin-
Although Baumel and Beard [1] concluded that ciples of the Declaration of Helsinki. The Biomedical
the aMMA is commonly present, it was only found in Research Ethics Committee of the University of Kwa-
43.75% in the present study. Similarly, Chanasong et Zulu-Natal (BREC/00002919/2021) granted ethical
al. [6] discovered an aMMA in 21.91% of their sample. approval for this study.
The aMMA may also arise in equal parts from the MMA
and the maxillary artery [1]. However, Chanasong et al. Acknowledgements
[6] discovered that the aMMA arose more frequently Acknowledging donor cadavers: The authors sin-
from the MMA (75.00%). This study also found the cerely thank those who donated their bodies to sci-
aMMA frequently originating from the MMA (53.33%) ence and their families for their selfless sacrifice so
in the South African population. Baumel and Beard that anatomical research could be performed.
[1] suggested that the course of the maxillary artery
in relation to the lateral pterygoid muscle determined Conflict of interest: None declared
the origin of the aMMA. When the maxillary artery was
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