Presentation about the imaging of the oral cavity from anatomy, imaging modalities used to the most common neoplastic lesions met during clinical practice.

1. ByBy
Dr; Sameh Abdel Raouf M.DDr; Sameh Abdel Raouf M.D
Assistant Prof of RadiodiagnosisAssistant Prof of Radiodiagnosis
Ain shams universityAin shams university

2. By the end of this session you should be able
to:
 Identify the normal anatomy of the oral cavity.Identify the normal anatomy of the oral cavity.
 Cross sectional anatomy of the oral cavity .Cross sectional anatomy of the oral cavity .
 Nodal level system.Nodal level system.
 When to perform??……(Indications)When to perform??……(Indications)
 Imaging techniques and their application in different ageImaging techniques and their application in different age
groups and variable pathological processes.groups and variable pathological processes.
 Imaging features of some of oral cavity malignant lesions .Imaging features of some of oral cavity malignant lesions .

3. Anatomy
 Predominantly, oral cavity lesions are clinicallyPredominantly, oral cavity lesions are clinically
apparent.apparent.
 cross-sectional imaging provides the clinician withcross-sectional imaging provides the clinician with
the crucial pretherapeutic information on deepthe crucial pretherapeutic information on deep
tumor infiltration.tumor infiltration.
 It also gives important information on theIt also gives important information on the
differential diagnosis i.e. many pathologicaldifferential diagnosis i.e. many pathological
processes have main diagnostic feature (shortprocesses have main diagnostic feature (short
cut)cut)

4. Anatomy
 The oral cavity is the mostThe oral cavity is the most
anterior part of the aeroanterior part of the aero
digestive tract.digestive tract.
 Its borders are:Its borders are:
 The lips ventrally.The lips ventrally.
 The mylohyoid muscle caudally.The mylohyoid muscle caudally.
 The gingivobuccal regionsThe gingivobuccal regions
laterally.laterally.
 The circumvallate papillae andThe circumvallate papillae and
the anterior tonsillar pillarthe anterior tonsillar pillar
dorsally.dorsally.
 The hard palate cranially.The hard palate cranially.
 The center of the oral cavity isThe center of the oral cavity is
filled out by the tongue.filled out by the tongue.

5. Anatomy
The Floor of the Mouth:
 The floor of the mouth is considered the spaceThe floor of the mouth is considered the space
between the mylohyoid muscle and the caudalbetween the mylohyoid muscle and the caudal
mucosa of the oral cavity.mucosa of the oral cavity.
 The mylohyoid muscle has the form of aThe mylohyoid muscle has the form of a
hammock which is attached to the mandiblehammock which is attached to the mandible
ventrally and laterally on both sides but with aventrally and laterally on both sides but with a
free dorsal margin.free dorsal margin.

6. Anatomy
The Tongue:
 The two anterior thirds of the tongue belong to theThe two anterior thirds of the tongue belong to the
oral cavity.oral cavity.
 the posterior third of the tongue is part of thethe posterior third of the tongue is part of the
oropharynx.oropharynx.
 The tongue contains a complex mixture of variousThe tongue contains a complex mixture of various
intrinsic and extrinsic muscles.intrinsic and extrinsic muscles.

7. Anatomy (Tongue Cont;)
Intrinsic musclesIntrinsic muscles are made up by 4 pairs whichare made up by 4 pairs which
are superior and inferior longitudinal, transverse,are superior and inferior longitudinal, transverse,
vertical, and oblique fibers which are notvertical, and oblique fibers which are not
connected with any structure outside the tongue.connected with any structure outside the tongue.
The extrinsic muscles :The extrinsic muscles :
Also four pairs whichAlso four pairs which have their origin external to thehave their origin external to the
tongue:tongue:
 The genioglossus (chin).The genioglossus (chin).
 Hyoglossus (hyoid bone).Hyoglossus (hyoid bone).
 Styloglossus (styloid process) muscles.Styloglossus (styloid process) muscles.
 Palatoglossus.Palatoglossus.

8. Anatomy (Tongue Cont;)

9. The sublingual spaceThe sublingual space
These are situatedThese are situated
lateral to the pairedlateral to the paired
genioglossusgenioglossus
muscle andmuscle and
superomedial to thesuperomedial to the
mylohyoid musclemylohyoid muscle

10. The retromolar trigoneThe retromolar trigone
It is a triangular region
bordered by:
AnteriorlyAnteriorly by theby the
posterior surface of theposterior surface of the
last mandibular molarlast mandibular molar
tooth.tooth.
posteromediallyposteromedially by theby the
anterior tonsillar pillar,anterior tonsillar pillar,
 laterallylaterally by the buccalby the buccal
mucosa.mucosa.

11. The retromolar trigoneThe retromolar trigone
 Its apexIts apex superiorlysuperiorly is attachedis attached
to theto the pterygoid hamulus.pterygoid hamulus.
 TheThe pterygomandibular raphepterygomandibular raphe isis
a band of connective tissuea band of connective tissue
situated beneath the mucosalsituated beneath the mucosal
surface of the retromolarsurface of the retromolar
trigone.trigone.
 It attaches superiorly at theIt attaches superiorly at the
medial pterygoid plate andmedial pterygoid plate and
inferiorly to the posterior aspectinferiorly to the posterior aspect
of the mylohyoid line of theof the mylohyoid line of the
mandible.mandible.

12. The palatine tonsils

13. The palatine tonsils

14. Cross sectional Anatomy
Axial CT (a) and MRI (b) of the
foor of the mouth:
1. geniohyoid muscle;
2. mylohyoid muscle.
3.fatty lingual septum.
4. submandibular gland.
5. Base of the tongue.
6. mandible;.
7.hyoglossus muscle.
Arrows, sublingual (fat)
space with lingual artery
and vein

15. Cross sectional Anatomy
 Axial CT (a) and MRI (b) at
the level of the tongue:
1. Tongue with fatty lingual1. Tongue with fatty lingual
septum.septum.
2. (lower) lip.2. (lower) lip.
3.Palatopharyngeal3.Palatopharyngeal muscles andmuscles and
palatopharyngeal arch.palatopharyngeal arch.
4.Intrinsic lingual muscles fibers.4.Intrinsic lingual muscles fibers.
5.parapharyngeal fat space.5.parapharyngeal fat space.
6.Medial pterygoid6.Medial pterygoid muscle.muscle.
7.Masseter muscle.7.Masseter muscle.
8.Mandible8.Mandible

16. Cross sectional Anatomy
Axial CT (a) and MRI (b) at theAxial CT (a) and MRI (b) at the
level of the maxilla:level of the maxilla:
1. Maxilla.1. Maxilla.
2. Mandible.2. Mandible.
3. Lateral pterygoid muscle.3. Lateral pterygoid muscle.
4. Soft palate.4. Soft palate.
5.Tongue.5.Tongue.
6.Parapharyngeal fat space.6.Parapharyngeal fat space.
7. Masseter muscle.7. Masseter muscle.
8. Buccinator muscle.8. Buccinator muscle.
9.Area of the retromolar trigone9.Area of the retromolar trigone
(with bony pterygoid process(with bony pterygoid process
on CT).on CT).
Arrows, (Stensen’s) parotid ductArrows, (Stensen’s) parotid duct

17. Cross sectional Anatomy
Coronal CT (a) and MRI (b) at moreCoronal CT (a) and MRI (b) at more
anterior aspects of the oral cavity.:anterior aspects of the oral cavity.:
1.Mandible.1.Mandible.
2. Hard palate2. Hard palate
3. Mylohyoid muscle.3. Mylohyoid muscle.
4. Anterior belly of digastric4. Anterior belly of digastric
muscle.muscle.
5.geniohyoid muscle.5.geniohyoid muscle.
6. genioglossus muscle.6. genioglossus muscle.
7.Intrinsic lingual muscles.7.Intrinsic lingual muscles.
8.Submandibular fat space;8.Submandibular fat space;
arrows, sublingual fat spacearrows, sublingual fat space
with lingual artery and vein.with lingual artery and vein.

19. Significant Nodal Groups
Deep lateral cervical.
Submental-submandibular.
Parotid.
Retropharyngeal.
Anterior cervical.

21. Level system of lymph node classification
• Nomenclature dividing the palpable cervical lymph nodes into 7 regionsNomenclature dividing the palpable cervical lymph nodes into 7 regions
or 'levels‘.or 'levels‘.
• some lymph nodes are not part of any of these levels, and are describedsome lymph nodes are not part of any of these levels, and are described
by their anatomical location.by their anatomical location.
• Although this classification was devised using surgical landmarks,Although this classification was devised using surgical landmarks,
translation into an imaging-based nodal classification is feasible .translation into an imaging-based nodal classification is feasible .
• A precise as possible application of this classification on CT or MRA precise as possible application of this classification on CT or MR
studies considerably enhances the communication with the clinician onstudies considerably enhances the communication with the clinician on
neck nodal disease.neck nodal disease.

22. Simplified Nodal Classification
Level 1Level 1: Submandibular, submental.: Submandibular, submental.
Level 2Level 2: Internal jugular from skull base to carotid bifurcation.: Internal jugular from skull base to carotid bifurcation.
Level 3Level 3: Internal jugular below carotid bifurcation to omohyoid.: Internal jugular below carotid bifurcation to omohyoid.
Level 4Level 4: Internal jugular below omohyoid.: Internal jugular below omohyoid.
Level 5Level 5: Posterior triangle.: Posterior triangle.
Level 6Level 6: Adjacent to thyroid.: Adjacent to thyroid.
Level 7Level 7: Tracheal esophageal groove and superior mediastinum.: Tracheal esophageal groove and superior mediastinum.

23. level of the hyoid
Bifurcation of common caroitd Level of C4
Posterior triangle of the neck
Sternocleidomastoid
Trapezius.
Clavicle.
The level of the bottom of
the cricoid arch.
Omohyoid
N.B Level VII
Superior mediastinal nodes, between the carotid arteries below the level of the top

24. Detailed leveling of cervical lymph nodes
Level I Submental and submandibular nodes.
Level I A Submental nodes, between the medial margins of the anterior bellies of the digastric muscles.
Level I B
Submandibular nodes, lateral to level I A nodes and anterior to the back of the submandibular salivary
gland.
Level II
Upper internal jugular nodes, posterior to the back of the submandibular salivary gland, anterior to the
back of the sternocleidomastoid muscle and above the level of the bottom of the body of the hyoid bone.
Level III
Middle jugular nodes, between the level of the bottom of the body of the hyoid bone and the level of the
bottom of the cricoid arch, anterior to the back of the sternocleidomastoid muscle.
Level IV
Low jugular nodes, between the level of the bottom of the cricoid arch and the level of the clavicle,
anterior to a line connecting the back of the sternocleidomastoid muscle and the posterolateral margin
of the anterior scalene muscles; they are lateral to the carotid arteries.

25. Level VLevel V
Posterior triangle nodes, posterior to the back of the sternocleidomastoid muscle, and posterior to the linePosterior triangle nodes, posterior to the back of the sternocleidomastoid muscle, and posterior to the line
described in level IV.described in level IV.
Level V ALevel V A Above the level of the bottom of the cricoid arch.Above the level of the bottom of the cricoid arch.
Level V BLevel V B Between the level of the bottom of the cricoid arch and the level of the clavicle.Between the level of the bottom of the cricoid arch and the level of the clavicle.
Level VILevel VI
Upper visceral nodes, between the carotid arteries from the level of the bottom of the body of the hyoid boneUpper visceral nodes, between the carotid arteries from the level of the bottom of the body of the hyoid bone
to the level of the top of the manubrium.to the level of the top of the manubrium.
Level VIILevel VII
Superior mediastinal nodes, between the carotid arteries below the level of the top of the manubrium andSuperior mediastinal nodes, between the carotid arteries below the level of the top of the manubrium and
above the innominate vein.above the innominate vein.
Supraclavi-Supraclavi-
cular nodescular nodes
Nodes at, or caudal to, the level of the clavicle and lateral to the carotid artery.Nodes at, or caudal to, the level of the clavicle and lateral to the carotid artery.
RetropharyngeRetropharynge
al nodesal nodes
Nodes behind the pharynx, medial to the internal carotid artery, from the skull base down to the level of theNodes behind the pharynx, medial to the internal carotid artery, from the skull base down to the level of the
hyoid bonehyoid bone

26. Lymphatic Drainage
The lips predominantly drain to the submental and/ or
submandibular (level 1) lymph nodes.
The major lymphatic drainage of the floor of the mouth
is to the submental, submandibular, and/or internal
jugular nodes (levels 1 and 2).
The oral tongue drains mainly to the submandibular
and internal jugular nodes (levels 1 and 2), often with
bilateral involvement in case of a carcinoma of the
tongue.

27. Imaging techniques
Ultrasound.Ultrasound.
 What are the indicationsWhat are the indications
(stones,infection,vascular lesion congenital(stones,infection,vascular lesion congenital
abnormalities.)abnormalities.)
CT.CT.
MRI.MRI.

28. Ultrasound.

29. Ultrasound.

30. Imaging techniquesImaging techniques
In children, due to radiation exposure,In children, due to radiation exposure,
ultrasound and MRI are the methods of firstultrasound and MRI are the methods of first
choice.choice.
Contrast-enhanced MRI offers severalContrast-enhanced MRI offers several
diagnostic advantages over ultrasound; itdiagnostic advantages over ultrasound; it
allowsallows covering of the entire oral cavitycovering of the entire oral cavity andand
has ahas a higher diagnostic accuracyhigher diagnostic accuracy , especially, especially
regardingregarding the exact evaluation of thethe exact evaluation of the
extension and differential diagnosis of aextension and differential diagnosis of a

31. Imaging techniques
In adults, CT and MRI are the mostIn adults, CT and MRI are the most
frequentlyfrequently
used imaging modalities.used imaging modalities.
The administration of intravenous contrastThe administration of intravenous contrast
agent is a rule.agent is a rule.
NON contrast study…….when ?NON contrast study…….when ?

32. Malignant lesions
 Squamous cell carcinomaSquamous cell carcinoma
(major sites in descending(major sites in descending
frequency)frequency)
 Lips.Lips.
 Floor of the mouth.Floor of the mouth.
 Retromolar trigone.Retromolar trigone.
 Tongue.Tongue.
 Adenoid cysticAdenoid cystic
 Lymphoma.Lymphoma.
 Non-Hodgkin lymphoma.Non-Hodgkin lymphoma.
 Burkitt lymphoma.Burkitt lymphoma.
 Sarcoma (rhabdomyoma,Sarcoma (rhabdomyoma,
lipoma,lipoma, fibroma-fibroma-, angioma,, angioma,
leiomyoma).leiomyoma).
 Adenocarcinoma.Adenocarcinoma.
 Malignant schwannoma.Malignant schwannoma.


33. Squamous Cell Cancer
 Most lesions in the oral cavity sent for imaging areMost lesions in the oral cavity sent for imaging are malignant.malignant.
 The most frequent question to answer is whether there is deepThe most frequent question to answer is whether there is deep
infiltration in already clinically detected and biopsied oral cancer.infiltration in already clinically detected and biopsied oral cancer.
 It affects men between 50–70 years of age.It affects men between 50–70 years of age.
 The risk factors are a long history of tobacco and/or alcoholThe risk factors are a long history of tobacco and/or alcohol
abuse, local chronic illness,EBV,HPV,leukoplakia, andabuse, local chronic illness,EBV,HPV,leukoplakia, and
eryrthroplakiaeryrthroplakia
 Oral SCC originate from the mucosa and, therefore, allow easyOral SCC originate from the mucosa and, therefore, allow easy
access to clinical detection biopsy.access to clinical detection biopsy.

34. Squamous Cell Cancer
Furthermore, local extension of a tumor of the lipFurthermore, local extension of a tumor of the lip
can usually be sufficiently determined clinically socan usually be sufficiently determined clinically so
that cross-sectional imaging is only needed inthat cross-sectional imaging is only needed in
very large tumors (e.g. to exclude mandibularvery large tumors (e.g. to exclude mandibular
infiltration).infiltration).
Three specific intraoral sites are predominantlyThree specific intraoral sites are predominantly
affected, in descending frequency:affected, in descending frequency:
1.1. The floor of the mouth.The floor of the mouth.
2.2. The retromolar trigone.The retromolar trigone.
3.3. The ventrolateral tongue.The ventrolateral tongue.

35. Squamous Cell Cancer
 Small superficial T1 tumors(less than 2 cm)Small superficial T1 tumors(less than 2 cm) are oftenare often
not visible on both CT and MR images.not visible on both CT and MR images.
 With increasing size, SCC infiltrate deeper submucosalWith increasing size, SCC infiltrate deeper submucosal
structures.structures.
 As a result, CT and MRI show a tumor mass and allowAs a result, CT and MRI show a tumor mass and allow
for an accurate evaluation of deep tumor infiltration.for an accurate evaluation of deep tumor infiltration.
 This results in the possibility of staging SCC of theThis results in the possibility of staging SCC of the
oral cavity according to the TNM system (UICC 2002)oral cavity according to the TNM system (UICC 2002)

36. TNM system (UICC 2002)TNM system (UICC 2002)

37. TNM systemTNM system

38. Carcinoma of the lip
Carcinoma of the
mucous membrane of
the vermillion area of
the lip is the most
common malignant
neoplasm of the oral
cavity.
95 % at lower lip.
If in the lower lip it will
be more aggressive.

39. Carcinoma of the lip
 Three morphological types of squamous cellThree morphological types of squamous cell
carcinomas are seen: exophytic, ulcerative, andcarcinomas are seen: exophytic, ulcerative, and
verrucous.verrucous.
 Many of the labial carcinomas arise in areas of clinicalMany of the labial carcinomas arise in areas of clinical
leukoplakia and may present as exophytic outgrowthsleukoplakia and may present as exophytic outgrowths
or begin as small ulcers.or begin as small ulcers.
 In general, metastases to lymph nodes are late andIn general, metastases to lymph nodes are late and
relatively infrequent(less than 10% in lower liprelatively infrequent(less than 10% in lower lip
cancers). as compared to squamous cell cancers ofcancers). as compared to squamous cell cancers of
other regions.other regions.

40. Extensive carcinoma of the lip

41. Squamous Cell Cancer

42. Carcinoma of the Floor of the Mouth
 It arises from the mucosaIt arises from the mucosa
covering the U-shaped areacovering the U-shaped area
between the lower gumbetween the lower gum
(inner surface of the lower(inner surface of the lower
alveolar ridge) and thealveolar ridge) and the
undersurface of theundersurface of the
anterior two-thirds of theanterior two-thirds of the
tongue.tongue.
 It accounts forIt accounts for
approximately 10-15%of allapproximately 10-15%of all
oral carcinomasoral carcinomas

43. Carcinoma of the Floor of the Mouth

44. Floor of the Mouth Cancer

45. Squamous cell carcinoma of theSquamous cell carcinoma of the
tonguetongue

46. Anterolateral tongue cancer

47. Tongue base cancer

48. SCC of the tongue

49. SCC of the tongue

50. Patterns of tumor spread in
carcinoma of the oral tongue

51. Hard Palate, Gingival and Buccal Cancer

52. Hard Palate, Gingival and Buccal
Cancer(patterns of spread)

53. Retro molar cacer

54. Adenoid cystic carcinoma

55. Adenoid cystic carcinoma

56. Abnormal (malignant) NodesAbnormal (malignant) Nodes
Size:Size:
Greater than 1.5Greater than 1.5 centimeters incentimeters in
juglodigastric area (level 1, 2, and 3).juglodigastric area (level 1, 2, and 3).
Greater than 1Greater than 1 centimeter elsewhere.centimeter elsewhere.
NecrosisNecrosis: Regardless of size.: Regardless of size.
Extracapsular spread:Extracapsular spread: Regardless of sizeRegardless of size

57. Cervical lymph node metastases
 They occur inThey occur in
approximately 50% of theapproximately 50% of the
patients with SCC of thepatients with SCC of the
oral cavity.oral cavity.
 In tumors crossing theIn tumors crossing the
median (midline) there ismedian (midline) there is
often bilateral lymph nodeoften bilateral lymph node
involvement.involvement.
 This holds especiallyThis holds especially
true for tumors of thetrue for tumors of the
tongue.tongue.

58. Recurrent cancer

59. Post irradiation consequences