A Odontogenic cyst developing from the stellate reticulum which is formed in place of a tooth.

Etiology:

1. Develops through liquefaction and cystic degeneration of stellate reticulum of enamel organ before any calcified enamel or dentine is formed.
2. Usually it may develop from a normal tooth germ, which may be clinically missing from the arch or a supernumerary tooth germ or from dental lamina

Clinical features:

1. Accounts to 5-10 % of the Jaw Cysts
2. It is seen in place of a tooth in an Edentulous area
3. Location: Mandibular third molar region, Ramus region, Pre molar region, incisor region
4. May occur early in life but usually discovered later
5. Usually a tooth is missing
6. Varies in size
7. May expand bone and displace teeth

Radiographic Features:

1. Well demarcated , round or oval radiolucency with sclerotic or reactive border
2. Unilocular or multilocular
3. Seen below or between roots or near to the alveolar ridge
4. More in relation to third molars

Histopathology:

Based on Histology it is of 2 types:

• Keratinized type (more common)
• Non-Keratinized type (less common)

1. Connective tissue capsule shows parallel arrangement of collagen bundles, with varying compactness.
2. Epithelial lining is of stratified squamous – intact or interrupted.
3. Epithelium may also be sometimes non keratinized, with a prominent spinous layer and long and confluent rete ridges and with less conspicuous basal layer.
4. Sometimes the epithelium may be ortho keratinized with a thin to moderate spinous layer and a thin or flattened basal layer.
5. Sometimes the epithelium may also be para keratinized and corrugated in some areas or may also be uniform 6 – 10 cells thick, with a prominent basal layer – with the cells arranged in a PICKET FENCE pattern or TOMB STONE pattern
6. Rete ridge formation is not seen (cf. : odontgenic kerato cyst)
7. Inflammatory infiltrate may be variable.

Treatment:

Radical surgery – Curretage of Bone

Recurrence: Highly recurrent.

How to Select Dental Articulators for Fabrication of Complete Denture

1. If occlusal contacts are to be perfected in centric occlusion only, a simple sturdy hinge type articulator without provision for lateral or protrusive movements can be selected.
2. This type of instrument as been called one dimensional because only one interocclusal record is necessary for its adjustment and use.
3. If denture teeth are to have a cross arch and cross tooth balanced occlusion, the minimum requirement is a semi adjustable articulator.
4. This may be an instrument with individually adjustable condylar guidance’s in both horizontal and vertical plane. Example: hanau university series, whip mix articulator, dentatus articulator.
5. If more control of occlusion is desired a completely adjustable three dimensional articulator is used.
6. It requires a centric relation record , some means for controlling the height and inclinations of cusps.
7. The means for their adjustment may be interocclusal records or three dimensional graphic tracing made by kinematic face bow.

Uses of Dental Articulators:

1. To hold opposing casts in a predetermined fixed relationship.
2. To open and close
3. To produce border intraborder diagnostic sliding motions
4. To diagnose dental occlusal conditions in both natural and artificial dentition’s
5. To plan dental procedures that involve positions ,contours and relationships of both natural and artificial teeth as they relate to each other.
6. To aid fabrication of dental restoration and the lost dental parts.
7. To correct and modify completed dental restorations.
8. Helpful in teaching and studying of occlusion and mandibular movements.

Ideal Requirements of Dental Articulators:

1. It should hold casts in correct horizontal and vertical relationships.
2. It should provide a positive anterior vertical stop (incisal pin).
3. It should accept a face bow transfer record.
4. It should open and close in a hinge movement.
5. It should allow protrusive and lateral motion.
6. The moving parts should move freely and be accurately machined.
7. The non-moving parts should be a rigid construction.

Additional Requirements of Dental Articulators:

1. Adjustable horizontal and lateral condylar guide elements.
2. The condylar elements as a part of lower frame and condylar guides as a part of upper frame.
3. A mechanism to accept a third reference point from a face bow transfer record.
4. A terminal hinge motion locking device.
5. Removable mounting plates that can be repositioned accurately.
6. An adjustable incisal guide table.
7. Adjustable intercondylar width of condylar elements, when graphic tracing to be used to set and / or select condylar guidance.

Advantages of Dental Articulators:

1. Properly mounted casts allow the operator to visualize the patients occlusion especially from lingual view.
2. Patient co-operation is not a factor when using an articulator once the appropriate interocclusal records are obtained from patient.
3. The refinement of complete denture occlusion in mouth is extremely difficult because of shifting denture bases and resiliency of supporting tissues .This difficulty is eliminated when articulators are used.
4. Reduced chair time ,patients appointment time.
5. The patients saliva , tongue and cheeks are not factors when using an articulator.

Limitations of Dental Articulators:

1. An articulator may be made of metal or plastic. Metal articulators show errors in tooling (manufacture) or errors resulting from metal fatigue.
2. The articulator may not exactly simulate intraborder and functional movements of mandible
3. Errors in jaw relation procedures are reproduced as errors in denture occlusion. Articulators do not have any provision to indicate or correct these errors.

Odontogenic cysts

Mentioned here are the various classifications given by scientists for Cysts of Jaw:

1. WHO Classification
2. Shears Classification
3. Shafers Classification

WHO Classification is divided into 2 Types:

1. Developmental
2. Inflamatory

DEVELOPMENTAL:
I. Odontogenic:

1. Primordial ( Kerato ) cyst.
2. Gingival cyst.
3. Eruption cyst.
4. Dentigerous ( Follicular ) cyst.

II. Non Odontogenic:

1. Naso palatine duct ( Incisive canal ) cyst.
2. Globulomaxillary cyst.
3. Naso labial ( naso alveolar ) cyst.

INFLAMMATORY:

1. Radicular cyst.

Shear’s Classification

It is divided into 3 types:

1. Cysts of Jaw
2. Cysts associated with Maxillary Antrum
3. Cysts of the soft tissues of the Face, Neck and Mouth

Cysts Of Jaw:

EPITHELIAL CYSTS OF JAWS:

I. ODONTOGENIC:

a. Developmental:

1. Primordial (Kerato) cyst .
2. Gingival cyst of infants .
3. Gingival cyst of adults .
4. Lateral periodontal cyst .
5. Dentigerous cyst .
6. Eruption cyst .
7. Calcifying odontogenic cyst.

b. Inflammatory:

1. Radicular cyst .
2. Residual cyst .
3. Inflammatory collateral cyst.
4. Para dental cyst.

II. NON-ODONTOGENIC:

1. Nasopalatine duct cyst & Incisive canal cyst
2. Median palatine cyst
3. Median alveolar cyst
4. Median mandibular cyst
5. Globulomaxillary cyst
6. Naso labial (naso alveolar) cyst

a. Simple bone cyst:

1. Traumatic
2. Solitary
3. Hemorrhagic

b. Aneurysmal bone cyst.

Cysts Associated with the Maxillary Antrum

1.  Benign mucosal cyst .
2. Surgical ciliated cyst of maxilla.

Cysts of the Soft tissues of the Face, Neck and Mouth

1. Dermoid & Epidermoid cysts
2. Branchial cleft cyst (Lympho epithelial cyst)
3. Thyroglossal duct cyst
4. Anterior median lingual cyst
5. Oral cyst with gastro intestinal epithelium
6. Cystic hygroma
7. Cysts of the salivary glands
8. Parasitic cysts: Hydatid cyst, Cysticerous cellulosae

Shafers Classification

1. Primordial cyst .
2. Dentigerous cyst & Eruption cyst .
3. Periodontal cyst :
a. Apical periodontal cyst .
b. Lateral periodontal cyst .
4. Gingival cyst :
a. Gingival cyst of newborn(Dental lamina cyst)
b. Gingival cyst of adult .
5. Odontogenic kerato cyst .
(Jaw cyst , Basal cell nevus & Bifid rib syndrome)
6. Calcifying odontogenic cyst .

Synonyms: Fordyce Spots, Fordyce Disease

Etiology:

Inclusion of ectoderm having potentialities of skin in the oral cavity during development of maxilla & mandible- embryonic life

Differential Diagnosis:

• Sebaceous Hyperplasia
• Epidermoid cyst
• Dermoid cyst

Clinical Features:

Incidence:  80%
Age: Adults
Sex predilection :  M=F
Site or Location:

• Buccal mucosa (opposite molar teeth)
• Fordyce Lips
• Retromolar region

Clinical appearance:

• Bilaterally symmetrical
• Small yellow spots either discreetly separated or forming plaques
• Projecting slightly above the surface of the tissue

Histologic Features:

• Similar to sebaceous glands of skin –but not associated with hair follicles
• Usually superficial just beneath the overlying epithelium which often produce local elevation of the epithelium
• Consist of few or more lobules grouped around one or more ducts which open on the surface of the mucosa

Treatment of Fordyce spots or Granules:

• Treatment is not required.
• Inflamed glands can be treated by Clindamycin
• But in case of any effect to physical appearance due to Fordyce spots or Granules on Lips the mode of treatment is: Laser Treatment of Fordyce spots on Lips is done
• Neoplastic Transformation has been reported but very rare.

Recurrence:

• No Recurrence is seen