Fissural cysts arise along lines of fusion between embryonic processes. Nasopalatine duct cysts are the most common non-odontogenic cyst, arising from epithelial remnants of the nasopalatine duct. Median palatal cysts occur in the midline of the hard palate from entrapped epithelium. Dermoid and epidermoid cysts contain skin elements and arise from implantation of epithelium during embryonic development. These cysts are examined clinically and radiographically and often surgically removed.

1. FISSURAL CYSTS
PRESENTED BY
N.NARMATHA
II YEAR PG

2. CYST- DEFINTION:
Kramer(1974) - cyst as a pathological cavity having fluid, semifluid
or gaseous contents and which is not created by accumulation of pus.
Most cysts but not all are lined by epithelium.
CLASSIFICATION OF CYSTS
Cysts of the jaws
Odontogenic Non-odontogenic

3. Epithelial cysts
Classification of the World Health Organization (WHO) 1998
Developmental cysts Inflammatory cysts
Odontogenic cysts Non Odontogenic cysts
•Newborn gingival cyst
•Odontogenic keratocyst
•Dentigerous or follicular
cyst
•- Eruptional cyst
•- Lateral periodontal
•- Gingival cyst of adult
•- Sialo-odontogenic cyst
•- Nasopalatine duct cyst
•- Naso-alveolar and
naso-labial cyst
•Radicular cyst-
•Apical
•Lateral
•Residual
•Periodontal cyst-
Inflammatoty
• collateral
•Infected vestibular
mandibular

4. Examination of cysts
Inspection:
• Dermoid cyst – tuft of hairs emanating from midline nasal
depression or nodule
- Unilateral upper eyelid swelling – first sign
• Epidermal inclusion cyst – prominent punctum
- Foul smell – cheesy like material discharge
• Thyroglossal cyst – midline of the neck

5. Palpation:
Mobility :
• Freely mobile - Epidermal inclusion cyst , Dermoid cyst
• Elevates when the patient protrudes the tongue - Thyroglossal
cyst
Extent:
Border: Border of firm dermoid cyst can be readily demonstrated

6. Consistency:
• Soft
• If under tension – rubbery
• Infected – firm
• Dermoid cyst – cheesy
Fluctuancy:
Fluctuant , painless, non emptiable

7. Aspiration:
• Yellowish ,cheesy substance – dermoid cyst
• Thick, yellow –white , granular fluid – epidermoid cyst
• Thick, homogeneous yellow to gray – sebaceous cyst
• Dark, amber coloured fluid – Thyroglossal cyst.

9. Fissural (inclusion, developmental) cysts of oral region:
• Arise along the lines of fusion of various bones or embryonic
process .
• True cysts – lined by epithelium – derived from epithelial cells
entrapped between embryonic process of bones at union lines.

10. Fissural cysts
• Median anterior maxillary cyst
• Median palatal cyst
• Globulomaxillary cyst
• Median mandibular cysts

11. Developmental cysts derived from embryologic structures or faults
which involve the oral or adjacent soft tissue structures.
• Nasoalveolar cyst
• Palatal cysts of neonate
• Thyroglossal tract cyst
• Benign cervical lympho epithelial cyst
• Epidermoid cyst
• Dermoid cyst
• Heterotrophic oral gastrointestinal cyst.

12. NASOPALATINE DUCT CYST:
• Most common of the non-odontogenic cyst
• It is developmental, non neoplastic in nature
• Location is peculiar and specific
• Affects the midline anterior maxilla

13. PATHOGENESIS
Nasopalatine ducts
Progressive degeneration
Persistence of epithelial remnants
Trauma/infection/mucous retention
spontaneous proliferation
Nasopalatine duct cyst
• Mucous glands- secrete mucin – secondary cyst formation

14. CLINICAL DIFFERENTIAL DIAGNOSIS

15. CLINICAL DIFFERENTIAL DIAGNOSIS

16. Radiographic features:
Location:
• Nasopalatine foramen or canal.
• If it extend posteriorly – median palatal cyst.
• Anteriorly between central incisors – median anterior
maxillary cysts
Periphery and shape:
• Well defined and corticated
• Circular or oval in shape
• Heart shape – shadow of nasal spine superimposed on the
cyst.

17. Internal structure:
• Radiolucent
• Effects on surrounding structures:
• Divergence of roots
• Root resorption
• Expansion of labial /buccal cortex
• Floor of nasal fossa may be displace in superior direction.

19. Standard occlusal view

21. POST OPERATIVE CT AXIAL AND CORONAL

22. CYSTS OF THE INCISIVE PAPILLA
NPDC form within incisive canal – cyst of incisive papilla
Etiology: Unknown
• Trauma, infection, mucous retention
• Spontaneous cystic degeneration of ductal epithelium
Clinical features:
• Males commonly affected
• 40-60 years
• Smaller cysts – asymptomatic
• Larger cysts – swelling, discharge, pain, salty taste

23. • Devitalization ,Bony expansion
• Translucent/blue in colour,dome shaped
• Slow and progressive growth > 60 mm in diameter.
H/F:
On aspiration:
A clear or straw coloured fluid

24. Radiographic Differential diagnosis:
• Large incisive foramen >6 mm
• Radicular cyst
Treatment:
Enucleation

25. MEDIAN PALATAL CYSTS
Epithelium entrapped
Line of fusion of palatal process of maxilla
Median palatal cyst
C/F:
• Location – midline of hard palate
• Clinically visible palatal swelling
Etiology: unknown

26. Two main criteria for diagnosis of a median palatine cyst are;
• Location in the median fissure of the palate behind the incisive
canal
• Presence of epithelium lined sac.
Additional criteria
• Asymptomatic swelling of the midline hard palate,
• No association with a nonvital tooth,
• Ovoid, pear or circular shape.
CLINICAL DIFFERENTIAL DIAGNOSIS

27. • Globulomaxillary cysts
Nasoalveolar cysts lateral to the midline.
• Nasopalatine duct cysts
Incisive canal cysts midline, derived from the incisive
duct.
• Median alveolar cyst is also midline - related to the median
fissure - appears anterior to the incisive canal, posterior to the
maxillary incisors

28. R/G :
• Well circumscribed radiolucent area -
opposite to bicuspid and molar area
• Sclerotic bordered
Differential diagnosis:
• Nasopalatine duct cyst - does not show
palatal enlargement
H/F

29. TREATMENT:
• Surgical removal - local anesthesia by infraorbital block
injection - Crevicular incision - palatal flap elevated - cystic
lining and contents were removed - completely enucleated
• Curettage -additional removal of surrounding bone to -
complete removal - with a sharp curette or a round diamond
bur with copious cool irrigation to remove 1 to 2 mm of bone
and any pathology remnants

30. GLOBULOMAXILLARY CYST:
Embryology:
• Found at the junction of globular portion of medial nasal process
and the maxillary process of the globulomaxillary fissure ,between
lateral incisor and cuspid teeth.
• Suture between premaxilla and maxilla, incisive suture –
premaxilla-maxillary cyst

31. C/F
• Asymptomatic
• Vitality is preserved
Differential diagnosis:
• Keratotic odontogenic cyst
• Radicular cyst
• Lateral periodontal cyst
R/G:
• Inverted, pear shaped radiolucent area between roots of lateral
incisor and cuspid
• Divergence of roots

33. Christ - globulomaxillary cyst are odontogenic rather than fissural
in origin.
H/F:
Treatment:
Surgically removed.

34. MEDIAN MANDIBULAR CYST: Rare
C/F:
• Asymptomatic
• Vitality is preserved
• Bony expansion
• Divergence of roots
R/F:
• Unilocular, well circumscribed radiolucency
• Multilocular

35. Differential diagnosis:
• Traumatic cyst
• Sublingual salivary gland
depression
• Apical cysts and granulomas
• Radicular cyst
Treatment :
Surgical excision

36. NASOALVEOLAR CYST:(NASOLABIAL CYST,KLESTADT
CYST)
• Rare
Embroyolgy :
• Proliferation of entrapped epithelium along the fusion line
• Arise at junction of globular process,lateral nasal process,
maxillary process

37. C/F:
• Swelling in nasolabial fold, floor of the nose
• Superficial erosion of outer surface of maxilla
• Not visible on radiographs
H/F:
Differential diagnosis:
Treatment: surgical excision
• Acute dentoalveolar abscess.
• Large mucous extravasation cyst or a cystic
salivary adenoma

38. PALATAL AND ALVEOLAR CYSTS OF NEWBORN:
(Epstein pearls , bohn’s nodules, gingival cysts of new born)
Embryology:
Arises from epithelial remnants of deeply budding dental lamina
during tooth development – after fourth month in utero – gingival
cyst

39. PALATAL CYST OF NEW BORN:
• Posterior midline of hard palate
Embryology:
Epithelial remnants in the stroma after fusion of the palatal process
which meet medially to form palate.
Epstein pearls:
Cysts along the median raphe of palate.
Bohn’s nodules : originates from palatal gland structure

41. C/F:
Palatal cysts: multiple,1-4 mm, yellow – white sessile mucosal
papules
Hard palate , anterior soft palate
Treatment : No treatment .

42. THYROGLOSSAL DUCTAL CYST:
• Rare
• Location: midline of the neck
Dilatation of or remnant at site where primitive thyroid
descended from its origin
Failure of subsequent closure and obliteration of this tract
Thyroglossal ductal cyst

43. C/F:
• Palpable asymptomatic midline neck mass
• Neck pain, throat pain, dysphagia
• Infection – cyst dilatation
Histology

44. Treatment:
• Antibiotics - Neosporin, polysporin – 3.5 gm
twice daily for 5 days
• Surgical management – Sistrunk procedure

45. EPIDERMAL INCLUSION CYST: (Epidermal cyst, epidermoid
cyst, epithelial cyst, keratin cyst, sebaceous cyst)
Implantation of epithelial remnants
Cystic transformation
• Milia – miniature epidermoid cysts

46. ETIOLOGY :
• Sequestration and implantation of epidermal rests during
embryonal period
• Occlusion of pilo sebaceous unit
• Iatrogenic or surgical implantation of epithelium
• HPV infection and eccrine duct occlusion
• Proliferation of epidermal cells within dermis

47. C/F:
• Indolent ,asymptomatic
• Common in third/fourth decades
• Discharge of foul smelling cheese like material
• Once infected – pain
• Firm ,round, mobile, flesh coloured to yellow or white
subcutaneous nodules

48. • Pigmented
• Sites: face, trunk, neck , extremities ,scalp
• Ocular ,oral mucosa ,palpebral conjuctiva ,on the lips ,buccal
mucosa ,tongue, uvula
• Anterior fontanelle

49. Hereditary syndromes associated with epidermoid cysts
• Gardner syndrome
• Basal cell nevus syndrome
• Panchynochia congenita
Treatment : surgical removal

50. DERMOID CYST:
Contain sebaceous glands, skin adnesia – nails, dental cartilage
like and bone like structures, fatty tissues
Origin:
Sequestration of skin
Implantation along the lines of embryonic closure

51. C/F:
• Face, neck, scalp
• Can be intracranial, intraspinal,perispinal
• Common – floor of mouth
• Congenital
• Localised on the neck (midline)
• 1-4 cm

52. Keratin filled lumen
Keratinized stratified squamous lining

53. RADIOGRAPHIC FEATURES
• Best accomplished by CT or MRI.
• Well defined by more radiopaque soft tissue
• Radiolucent on conventional radiographs.
• However, a CT scan of the area may reveal a soft tissue
multilocular appearance

55. Congenital mouth cysts
• Epidermoid (simple)cysts
• Dermoid (complex) cysts
• Teratoid cyst(complex)
Differential Diagnosis
• Ranula (unilateral or bilateral blockage of wharton ’s
ducts),
• Thyroglossal duct cysts,
• Cystic hygromas,
• Branchial cleft cysts,
• Cellulitis,
• Tumors (lipoma and liposarcoma), and
• Normal fat masses in the submental areas
Treatment: surgical exicision

56. HETEROTROPHIC ORAL GASTROINTESTINAL CYST:
C/F:
• Infants or young children
• Male predominance
• Small nodule present within the body of tongue,posterior or
anterior floor of mouth,
• Difficulty in eating or speaking
Treatment: Surgical exicision

57. References :
1.Oral radiology,principles,interpretation – white and
pharoah
2.Elliott KA , Franzese CB , Pitman KT : Diagnosis and
surgical management of nasopalatine duct cysts ,
Laryngoscope 114 : 1336 - 1340 , 2004 .
3.Mraiwa RJ , Jacobs R , Van Cleynenbreugel J et al : The
nasopalatine duct cyst revisited using 2D and 3D CT imaging
, Dentomaxillofac Radiol 33 : 396 - 402 , 2004 .
4.Swanson KS , Kaugars GE , Gunsolley JC : Nasopalatine
duct cyst: an analysis of 334 cases , J Oral Maxillofac Surg 49 :
268 - 271 , 1991 .