Dr, Kathirvel Gopalakrishnan M.D.S (OMFS) Presentation on Anterior triangles of neck which helps for a quick refresh. Applied aspects described well and all slides will be informative with lot of image based examples

1. ANTERIOR TRIANGLES OF
NECK
Presented by
Dr.Kathirvel.G
MDS (OMFS)

2. Contents:
• Triangles of the neck
Anterior triangle of Neck
• Submental triangle
• Submandibular triangle
• Carotid triangle
• Muscular triangle
• Journal Club discussion

3. TRIANGLES OF NECK:
Anterolaterally, neck is quadrilateral in shape
Boundaries:
Anteriorly : Midline of neck
Posteriorly : Anterior border of trapezius
Superiorly : Inferior border of mandible
Inferiorly : Clavicle

4. Sternocleidomastoid muscle:
Passes obliquely upwards and backwards
Origin : Clavicle and sternum
Insertion : Mastoid process and occipital
bone
Sternocleidomastoid muscle divides the
quadrilateral area into two triangle
• Anterior triangle
• Posterior triangle

5. ANTERIOR TRIANGLES OF NECK:
Boundaries:
• Anteriorly : The midline of the neck
• Posteriorly : The anterior border of the sternocleidomastoid muscle
• Superiorly/ Base : The inferior border of the mandible
B.D.Chaurasia – Human anatomy – Fifth edition – Volume 3

6. Divisions:
3 paired and 1 unpaired.
Unpaired triangle:
• Submental triangle
Paired triangles:
• Submandibular triangle
• Carotid triangle
• Muscular triangle
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

7. SUBMENTAL TRIANGLE:
Boundaries:
Anteriorly : Midline of neck
Posteriorly : Anterior belly of digastric
Base / Inferiorly : Body of the hyoid bone
Floor : Mylohyoid muscle
B.D.Chaurasia – Human anatomy – Fifth edition – Volume 3

8. Contents:
• Submental lymph nodes
• Small veins anastomose to form the anterior
jugular vein.
• As the anterior belly of the digastric muscle
can present with variable anatomy or even be
absent, the submental triangle can be distorted
or absent.
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

9. • Two accessory bellies
originated anteriorly to the
intermediate tendon of the
digastric muscles
• Appeared fused along the
midline and inserted on the
medial surface of mandible

10. Applied aspects:
• Any odontogenic infection in anterior teeth,
usually appear as an abscess or fistula on the
skin in the chin area.
• Occasionally, they can spread out into the
submental space and form an abscess.
• The risk of the incision is low because structures
within the triangle are sparse and include no
arteries.
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

11. Submandibular triangle:
Area between body of the mandible and hyoid
bone
Boundaries:
Anteriorly : Anterior belly of digastric muscle
Posteriorly : Posterior belly of digastric muscle
Superiorly : Inferior border of the mandible
Floor : Mylohyoid muscle
B.D.Chaurasia – Human anatomy – Fifth edition – Volume 3

12. Contents:
Nerves:
• Marginal mandibular branch of
the facial nerve
• Nerve to the mylohyoid
• Hypoglossal nerve
Arteries and veins:
The facial and lingual arteries and
veins
Others:
• Submandibular gland
• Lower pole of the parotid gland
• Lymph nodes.
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019
Marginal mandibular
nerve
Mylohyoid
nerve
Hypoglossal
nerve
Facial artery and vein
Submandibular
gland
Parotid gland

13. Layers:
Superficial structure:
• Platysma
• Facial vein
• Marginal mandibular
branch of facial nerve
After removal of superficial
layer
• Submandibular gland

14. Remaining structure
• Facial artery
• Lingual nerve
• Lingual artery
• Hypoglossal nerve

15. Applied aspects:
The attachment of the mylohyoid muscle onto the
mandible is more inferiorly in the anterior region and
more superiorly in the posterior region of the triangle.
Infection from lower molar tooth could easily spread
below the mylohyoid muscle into the submandibular
space.
Submandibular lymph nodes are clinically very
important because of its wide range of drainage.
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

16. Applied aspects:
The submandibular incision to access to this
triangle should be inferior to the MMB.
An incision two fingers-breadth below the
inferior border of the mandible would provide
safer access to the submandibular triangle than
the 2 cm line below the inferior border of the
mandible in order to avoid injury to the MMB.
Davies et al; Evaluation of Clinically Relevant Landmarks of the Marginal Mandibular Branch of the Facial Nerve;
Clinical anatomy; 2016

17. Two small triangles are included :
• Lesser’s triangle
• Pirogov’s triangle
Tubbs Et al; Three nearly forgotten anatomical triangles of the neck: triangles of Beclard, Lesser and Pirogoff and their potential
applications in surgical dissection of the neck. Surgery Radiology anatomy; 2011

18. Lesser’s triangle:
Named after the German surgeon Leon Lesser
Also called the lingual triangle.
Boundaries:
Anteriorly : Anterior belly of digastric muscle
Posteriorly : Posterior belly of the digastric muscle
Superiorly : Hypoglossal nerve
Floor : Hyoglossus muscle
Lingual artery is found beneath it

19. Applied aspects:
• Tubbs et al. reported that Lesser's triangle was present in 30 out of 34 .
• When it was absent, the hypoglossal nerve coursed inferior to the digastric muscle.
• It is an ideal location for accessing the lingual artery.
Tubbs et al; Three nearly forgotten anatomical triangles of the neck: triangles of Beclard, Lesser and Pirogoff and their potential
applications in surgical dissection of the neck; Surgery radiology anatomy; 2011

20. Pirogov’s triangle:
Named after Russian surgeon Nikolai I. Pirogov
This triangle is the posterior part of Lesser's triangle.
Boundaries:
Superiorly :
Hypoglossal nerve
Inferoposteriorly :
Intermediate tendon of the digastric muscle
Anteriorly :
Posterior border of the mylohyoid muscle
Van et al; Pirogoff’s Triangle revisited: an alternative site for microvascular anastomosis to the lingual artery; International
journal of Oral and maxillofacial surgery; 2000

21. Applied aspects:
• Tubbs et al reported that Pirogov's triangle was found in 30/34 sides
• When it was absent, the hypoglossal nerve coursed below the digastric
muscle, as with Lesser's triangle.
• This triangle constantly included the lingual artery deep to the
hyoglossus muscle.
Tubbs et al; Three nearly forgotten anatomical triangles of the neck: triangles of Beclard, Lesser and Pirogoff and their potential
applications in surgical dissection of the neck; Surgery radiology anatomy; 2011

22. CAROTID TRIANGLE:
Boundaries:
Superiorly : Posterior belly of the digastric muscle
Anteriorly : Superior belly of the omohyoid muscle
Posteriorly : Anterior border of the SCM.
Floor : Hyoglossus
Thyrohyoid membrane
Inferior and middle pharyngeal constrictor muscles.
B.D.Chaurasia – Human anatomy – Fifth edition – Volume 3

23. Contents :
Artery :
Common carotid artery
Internal External
carotid artery (ICA) carotid artery (ECA)
Superior thyroid
Lingual
Facial
Occipital
Ascending pharyngeal artery
The anterior triangle of the neck; Harold Ellis, Vishy Mahadevan; Surgery 32:52; 2013

24. Variation in levels of bifurcation of the common carotid artery, related
to the cervical vertebrae
SURGERY 32:52; 2013

25. Superior Thyroid Artery
Origin :
Common carotid artery - 19 cases (47.5%)
External carotid artery - 12 cases (30%)
Carotid bifurcation - 9 cases (22.5%)
When it arise from the external carotid artery, the
distance of origin from the bifurcation ranged
from 2 to 10.5 mm.
The distance of origin from the common carotid
artery to the bifurcation ranged from 2 to 10.7
mm.

26. Lingual Artery
The distance of origin from the bifurcation
ranged from 5 to 40 mm.
In 8 cases the lingual artery shared a common
trunk with the facial artery.
Facial Artery
The distance of origin from the carotid
bifurcation ranged from 8 to 50 mm.

27. Veins:
• Superior thyroid
• Lingual
• Facial
• Ascending pharyngeal
• Occipital
Nerve:
• Hypoglossal nerve
• External and internal
branches of the superior
laryngeal nerve
The anterior triangle of the neck; Harold Ellis, Vishy Mahadevan; Surgery 32:52; 2013

28. Carotid body:
• Small cluster of
chemoreceptors near the
bifurcation of common carotid
artery
• Detects changes in
composition of blood passing
through it, mainly Po2
• It is also sensitive to changes
in Ph and temperature

29. Carotid sinus
• Localized dilation at the origin of
internal carotid artery
• Contains numerous Baroreceptors for
maintaining blood pressure
• It is innervated by sinus nerve of
hering, which is a branch of
glossopharyngeal nerve

30. Beclards triangle:
Named after the French anatomist
Pierre A. Beclard
Boundaries:
Superiorly : Posterior belly of the digastric muscle
Floor : Posterior border of the hyoglossus muscle
Inferiorly : Greater horn of the hyoid bone

31. Applied aspects:
• Tubbs et al examined Beclard's triangle and found it in 28/34 sides (84%)
• With absent, the reasons were that the posterior belly of the digastric muscle did not
attach to the hyoid bone, or directly located just above the greater horn of the hyoid
bone.
• Beclard's triangle constantly included both the lingual artery and hypoglossal nerve.
• Convenient landmark for identifying both anatomical structures.
Tubbs et al; Three nearly forgotten anatomical triangles of the neck: triangles of Beclard, Lesser and Pirogoff and their potential
applications in surgical dissection of the neck; Surgery radiology anatomy; 2011

32. Farabeuf's Triangle
Named for the French surgeon Louis-
Hubert Farabeuf
Boundaries:
Posteriorly : Internal Jugular Vein
Anteroinferiorly : Common facial vein
Anterosuperiorly : Hypoglossal nerve
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

33. Applied aspects:
• Tubbs et al. reported that Farabeuf's triangle was present in 75% (15/20 sides).
• This triangle was constantly located within the carotid triangle and included at
least one of the branches of the common carotid artery on 14 out of 15 sides.
• Campbell et al., also mentioned that “this triangle is a helpful landmark in
extensive dissections of the neck, especially in locating the IJV, the safety of
which is best conserved by promptly exposing it.”
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

34. MUSCULAR TRIANGLE:
Boundaries:
Anteriorly : Midline of the neck
Superiorly: Hyoid bone
Inferiorly : Sternum
Inferoposteriorly : Anterior margin of the
Sternoclediomastoid
Posterosuperiorly :Superior belly of the
omohyoid muscle
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

35. Contents:
Muscles - Sternohyoid
Sternothyroid
Omohyoid
Thyrohyoid
Artery - Superior thyroid artery
Veins - Anterior jugular
Inferior thyroid
Nerve - Ansa cervicalis
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

36. Contents:
Lymph nodes - Anterior cervical
Infrahyoid
Prelaryngeal
Thyroid
Pretracheal
Paratracheal
Other - Esophagus
Trachea
Thyroid gland
Lower part of the larynx
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

37. Applied aspects:
• Tracheostomy and thyroidectomy are invasive
surgeries that access this triangle.
• Skin incision should be made parallel to
Langer’s line to avoid scar
• During thyroidectomy, Injury of the superior
thyroid artery can result in bleeding during
surgery.
Kikuta Et al; Triangles of the neck: a review with clinical/surgical applications; Anatomy and Cell biology; 2019

38. THANK YOU