Floor of the mouth - Vital Structures.

1. FLOOR OF THE MOUTH.
Dr Nida Sumra

2.  The floor of the mouth is a small horseshoe-shaped region
situated beneath the movable part of the tongue and above
the muscular diaphragm formed by the mylohyoid muscles
and above this diaphragm is the genohyoid muscle.

3.  Sublingual gland
and its duct.
 The deep part of
the submandibular
gland and its duct.
 Lingual frenum
 Deep lingual
artery and veins.
 Lingual nerve.

4. SKELETALASPECT.

5. Inner surface of the mandible.
 Superior and
inferior genial
tubercles.
 Mylohyoid line.
 Sublingual fossa.
 Submandibular
fossa.

6. Hyoid bone.
 A body.
 Two larger greater horns
(greater cornu.)
 Two conical lesser horns
(lesser cornu.)
 Hyoid bone connects floor of
the mouth with the pharynx
behind and the larynx below.

7. Inferior surface of the tongue.
 The inferior surface of the tongue is covered with a thin
transparent mucous membrane through which one can see the
underlying veins
 A sublingual caruncle (papilla) - opening of the submandibular
duct
1- frenulum,
2- lingual vein,
dashed-circle- sublingual gland.
Arrow- Wharton's duct opening,

8. Lingual frenum.
 The inferior surface of the tongue is connected to the floor of
the mouth by a midline fold called the frenulum of the tongue.
 The frenulum allows the anterior part of the tongue to move
freely.

9. Ankyloglossia.
 Tongue tie.
 Commonly congenital in origin due to abnormally short and
thick lingual frenulum .
 It restricts tongue movements.
 Treatment is frenulectomy.

10. Frenulectomy.

11. Diagram of the human head at
the level of the first molars,
depicting the most important
structures in relation to
periodontal surgery.

12. MUSCLES.

13. Mylohyoid. Geniohyoid.
 ORIGIN - Mylohyoid line of
the mandible.
 INSERTION – Median
fibrous raphe and adjacent
part of hyoid body.
 ORIGIN - Inferior mental
spines of mandible.
 INSERTION - Body of the
hyoid bone.
.

14. Functions.
 Contributes structural
support to the floor of the
oral cavity.
 Participates in elevating and
pulling forward the hyoid
bone.
 When the hyoid bone is in
fixed position depress the
mandible and open the
mouth.
 Mainly pulls the hyoid
bone.
 When the hyoid bone is
fixed they can act with the
mylohyoid muscle to
depress the mandible.
MYLOHYOID GENIOHYOID

15. Vascular supply.
 sublingual branch of the
lingual artery,
 The maxillary artery, via the
mylohyoid branch of the
inferior alveolar artery,
 The submental branch of the
facial artery.
 lingual artery (sublingual
branch).
MYLOHYOID GENIOHYOID.

16. Innervation.
 Geinohyoid - C1 via the
hypoglossal nerve.
 Mylohyoid - Nerve to the
mylohyoid from the inferior
alveolar branch of the
mandibular nerve.

17. Gateway into the floor of
the mouth.

18.  The free posterior border of the mylohyoid muscle on each side forms
one of the three margins of a larger triangular aperture - a major route
by which structures in the upper neck and infra temporal fossa of the
head pass to and from structures in the floor of the oral cavity.
 Structures that pass through the aperture - includes muscles
(hyoglossus , styloglossus ) ,vessels (lingual artery and vein) ,
nerves (lingual , hypoglossal , glossopharyngeal) and lymphatics.
 The submandibular gland.

19. VASCUALTURE.

20. Arteries. Veins.
 The major artery that
supplies the oral mucosa of
the floor of the mouth is the
Lingual artery.
 Deep lingual veins
 Dorsal lingual vein.

21. Lingual nerve.
 Originates in the infra
temporal fossa and
passes anteriorly into
the floor of the oral
cavity.

22. Lymphatics.
 Submental nodes.
 Submandibular
nodes.
 Drainage from the
above two into the
deep cervical
nodes.

23. GLANDS.

24. Submandibular gland.
 Hook shaped.
 Divided into deeper and
superficial part by the
mylohyoid muscle.
 Submandibular duct
emerges from the deep part
and lies on the summit of
the sublingual papilla
besides the frenulum of the
tongue.

25. Sublingual gland.
 Almond shaped.
 Lies against the medial
surface of the mandible where
it forms the sublingual fossa.
 Drains via numerous small
ducts.

26. Chorda tympani.
 Presynaptic parasympathetic secretomotor fibres
conveyed from the facial nerve to the lingual nerve by
the chorda tympani nerve which synapse with post
synaptic neurons in the submandibular ganglion.

27. SUBLINGUAL SPACE.

28. Boundaries.
 Anteriorly – lingual surface of the
mandible.
 Posteriorly – body of the hyoid bone.
 Superiorly – oral mucosa.
 Inferiorly – mylohyoid muscle.
 Medially – muscles of the tongue.
 Laterally – lingual surface of the
mandible.
CONTENTS.
 Sublingual gland
 Whartons duct
 Sublingual artery and nerve
 Lingual nerve

29. Source of infection
and neighbouring
spaces.
Schematic diagram of the relationship of the tooth roots to
the sublingual, submandibular, and buccal spaces. Infection
extending through the lingual cortex from premolar and molar
teeth will involve the sublingual space, whereas infection
from molar teeth will involve the submandibular space.
(Courtesy of Indiana University School of Medicine Office of Visual Media, Indianapolis, IN; with
permission.)

30. Clinically.
 Swelling is seen on the anterior part of the floor of
the oral cavity.
 Interferes with swallowing and is extremely
painful.
 Infections might pass anteromedially across the
genial muscles into the sublingual space on the
other side.
 Infections can also spread to submental and
submandibular spaces and lead to ludwigs angina.
 Sublingual space also communicates with the
parapharyngeal space at the posterior border of the
mylohyoid muscle lateral to the hyoid bone.

31. CLINICAL
IMPLICATIONS.

32. Haemorrhage.
 The floor of the mouth is richly
vascularised by a number of
branches of submental and
sublingual arteries.
 During a dental implant
procedure in the anterior zone
of the mandible perforation of
the lingual cortex may invade
the floor of the mouth and
hence damage structures within
the sublingual space.

33. Sublingual haematoma.
 Sublingual haematoma also known as pseudo ludwigs
phenomenon is an entity commonly described in patients on
anticoagulant therapy.
 Spontaneous sublingual haematoma is a rare subtype. It is
thought to be due to aneursymal changes in facial or lingual
arteries occurring mostly in elderly hypertensive patients

34. Exotosis.
 Found along the body of the
mandible and most commonly in the
region of canines and premolars
above the mylohyoid muscle medial
to molar roots.
 Large tori can interfere with flap
placement or correction of infrabony
defects through osseous
recontouring.
 Tissue overlying tori can be very thin
and can be easily torn during flap
reflection

35. Haematomas.
 Floor of the mouth haematomas with
periodontal surgery with torus and exotoses
reduction is a common occurrence
 The haematoma occurring as a result of
extensive bone reduction on the lingual
surface of mandible is worrisome because
of the anatomic site and the potential for
serious infection through loose aerolar
facial planes.
 Vascular injury can lead to serious
morbidity and potential mortality as a result
of airway obstruction due to immense
enlargement of sublingual haematoma
View of the hematoma on the
morning after periodontal
surgery( torus reduction) on the
mandibular left quadrant. Note
the edema
and erythema of the floor of the
mouth
(journal of contemporary dental practice
Vol 8 num-3 march 1 2007)

36. Treatment.
 Administration if antibiotics
preoperatively
 NSAID regimen
 Application of pressure on
surgical site
Seven days after periodontal
surgery. Note the dramatic
improvement

37. Significant soft
tissue oedema of
the neck.
Seen here is the large expanding
haematoma in the floor of the mouth
resulting in
elevation and protrusion of the
tongue.
Bony window
resolution of the
anterior mandible that
demonstrates the site of
perforation lingual to
site number 25
Int. J. Oral Maxillofac. Surg. 2006; 35: 961–964
47-year-old female presented to her dentist for extraction of
her remaining mandibular teeth (#s 21–28) and placement
of 4 immediate endosseous implants

38. Arteriovenous malformation.
 Arteriovenous malformations (AVMs) is a vascular
abnormality resulting in an abnormal connection between an
artery and a vein without capillary connections.
 An AVM in the floor of the mouth has been reported in an
elderly male supplied by multiple vessels and it caused
difficulty in speaking and swallowing.
(J Craniofac Surg. 2012 Mar;23(2):e86-8.)

39. PATHOLOGIES.

40. Sialolith.
 Salivary calculi or stones may
obstruct salivary flow.
 Usually occurs in the
submandibular gland because of
the tortuous course of the duct and
because of the viscosity of the
secretions.
 Acute symptoms occur during
mealtime.
 Secondary infection may occur.

41. Dermoid cyst.
 Painless dome shaped dome
shaped mass.
 Dough like consistency and
tongue is slightly elevated.
 Slow growth and treatment is
surgical enuleation.
 Epidermoid cyst is the same
but without skin appendages.

42. Ranula.
 Mucocele arising in the floor of the
mouth.
 Unilateral , dome shaped, fluctuant and
painless.
 Plunging or cervical ranula extend
beyond the mylohyoid muscle beyond
the sublingual space and involves the
submandibular space and adjacent
structures.

43. Conclusion.
 Consideration of the surgical anatomy serves as a basis for
surgical procedures involving periodontal tissues and implants.
 Damage to nerves, such as the mental nerve, the mandibular nerve
and the lingual nerve can be avoided with proper technique.
 Treatment planning should include three-dimensional radiographs
when these structures are likely to be within the vicinity of
surgical approaches.
 Inadvertent surgical incision of major blood vessels can be
avoided by knowledge of their anatomic positioning.

44. REFERENCES-
 GRAYS ANATOMY
 BD CHAURASIA 4TH
EDITION
 CLINICALLY ORIENTED ANATOMY – MOORE DALLEY
 SHAFERS FIFTH EDITION
 J Craniofac Surg. 2012 Mar;23(2):e86-8.)
 journal of contemporary dental practice Vol 8 num-3 march 1 2007
 Int. J. Oral Maxillofac. Surg. 2006; 35: 961–964