• Adenomatoid odontogenic tumor (AOT), generally considered to be an uncommon tumor
• Occurs mostly in association with an unerupted maxillary cuspid.
• Some investigators consider it as a benign neoplasm, while others have categorized it as a hamartomatous malformation due to the limited size and to the lack of recurrence of most cases (attributed perhaps to its minimal growth potential).
• The AOT represents 3% to 7% of all odontogenic tumors.

• Although this lesion was formerly considered to be a variant of the ameloblastoma and was designated as “adenoma glioblastoma,” its clinical features and biologic behavior indicate that it is a separate entity.

PATHOPHYSIOLOGY:
• There is evidence that the tumor cells are derived from enamel organ epithelium.
• Investigators have also suggested that the lesion arises from remnants of dental lamina.
• The specific stimulus that triggers proliferation of the progenitor cells of AOT is unknown.
• Various hypotheses for the pathogenesis of AOT have been proposed. It could theoretically arise from the:

1. Enamel organ
2. The Epithelial lining of dentigerous cyst.
3. Epithelial rests of Malassez of the deciduous or permanent tooth
4. Remnants of the dental lamina.

CLINICAL FEATURES:
• The mean age of these patients was approximately 18 years, with a range of 5-53 years.
• However, 73% of the patient were under 20 years of age.
• Marked predilection: in females 64%: males 36%.
• Occurrence: greater in the maxilla (65%) than in the mandible (35%).
• In contrast to the ameloblastoma, this tumor occurs more frequently in the anterior part of the jaws with 76% developing anterior to the cuspid in the maxilla and mandible.
• Only very rarely does the lesion occur distal to the premolar area.
• It is of some interest that in at least 74% of the cases, the tumors were associated with an unerupted tooth, and in over two-thirds of the cases, this tooth was the maxillary or mandibular cuspid.
• Most tumors are relatively small, seldom exceed 3 cm in greatest diameter.
• Although a few large lesions have been reported.
• Peripheral (extraosseous) forms of the tumor are also encountered but are rare.
• These usually appear as small, sessile masses on the facial gingiva of the maxilla.
• Clinically, these lesions cannot be differentiated from the common gingival fibrous lesions.

***It is known as two-third tumour:
As it is seen :
• 2/3rd in females.
• 2/3rd in Anterior teeth region.
• 2/3rd in impacted tooth region.
• 2/3rd in cuspid region.

RADIOGRAPHIC FEATURES:
• They are frequently asymptomatic , are discovered during the course of a routine radiographic examination or when films are made to determine why a tooth has not erupted.
• Larger lesions cause a painless expansion of the bones.
• In about 75% of cases, the tumor appears as a circumscribed, unilocular radiolucency that involves the crown of an unerupted tooth, most often a canine.
• Follicular type of AOT may be impossible to differentiate radiographically from the dentigerous cyst.
• Radiolucency associated with the follicular type of AOT sometimes extends apically along the root past the cementoenamel junction.
• This feature may help to distinguish an AOT from a dentigerous cyst.
• Less often the AOT is a well-delineated unilocular radiolucency that is not related to an unerupted tooth, but rather is located between the roots of erupted teeth (extrafollicular type)
• The lesion may appear completely radiolucent: often, however, it contains fine (snowflake) calcifications.
• Rare, multilocular cases have been reported and a scalloped border is observed occasionally.
• Most cases are between 1 and 3 cm in greatest diameter. About 65% of reported cases also demonstrate faintly detectable radiopaque foci within the radiolucent lesion.
• Occasionally, a more obvious intralesional radiopacity may be identified, usually eccentrically positioned within the lesion.
• Divergence of roots and displacement of teeth occurs more frequently than root resorption.
• Orbital and maxillary sinus encroachment have been reported.
• Gingival lesions may cause slight erosion of the underlying alveolar bone cortex.

HISTOLOGICAL FEATURES:
• AOT is a well-defined lesion that is usually surrounded by thick capsule.
• When the lesion is bisected the central portion of the tumor may be essentially solid or may show varying degrees of cystic change.
• Microscopically , the tumour composes of spindle shaped epithelial cells that form sheets, strand, or whorled masses of cells in a scant fibrous stroma
• The epithelial cells may form rosette like structures about a central space, which may be empty or contain small amounts of eosinophilic material.
• This material may stain for amyloid.
• The tubular or duct like structures, which are the characteristic feature of the AOT, may be prominent, scanty, or even absent in a given lesion.
• Lesion may consist of a central space surrounded by a layer of columnar or cuboidal epithelial cells.
• The nuclei of these cells tend to be polarized away from the central space.
• Small foci of calcification may also be scattered throughout the tumor.
• These have been interpreted as abortive enamel formation.
• Some tumours may contain larger areas of matrix material or calcification.
• This material has been interpreted as dentinoid or cementum.
• Some lesions also have another pattern, particularly at the periphery of the tumor adjacent to the capsule.
• This consists of narrow, often anastomosing cords of epithelium in an eosinophilic, loosely arranged matrix.

TREATMENT & PROGNOSIS:
• AOT is completely benign: because of its capsule, it enucleated easily from the bonc
• Aggressive behavior has not been documented.
• Recurrence after enucleation seldom, if ever, occurs.

REFERENCES:
• Shafer’s Textbook of Oral Pathology (6th Edition).
• Textbook of Oral Pathology, Neville (3rd Edition).
• Manual of Oral Histology & Oral Pathology, Maji Jose.

• Hackdentistry/youtube.com

Written by : Dr.Urusa I Inamdar

Diagnosis

• Specimen collection and processing
• Imaging techniques

Management

• prevention of the odontogenic infection is the golden standard.
• complex odontogenic infection may require an incision and drainage.
• mild odontogenic infection can be easily treated with simple antibiotic.
• Complicated odontogenic infection require patient admission and hospitalization.
• any odontogenic infection should be treated promptly and should not be underestimated.
• Determine the severity of infection.
• evaluate the host defence.

Severity of infection

• Rate of progression.
• Potential of airway compromise or affecting vital organs.
• Anatomic location of infection.

Incision and drainage

• Incise in healthy skin.
• Incise in gravity dependent aesthetic area – if possible.
• Explore entire abscess cavity.
• Non – absorbable drains.

Principles in the use of drains

• Drained wounds should be cleansed frequently.
• Bacteria can migrate into a wound along the drain surface.
• Latex Penrose drains are best used unmodified.

Empiric therapy of odontogenic infections

• penicillin
• penicillin + metronidazole
• allergic to penicillin give clindamycin

Management

• Determine severity- assess history of onset and progression perform physical examination of area:

1. Determine character and size of the swelling
2. Establish presence of trismus

• Evaluate host defense- evaluate:

1. Diseases that compromise the host
2. Medications that compromise the host

• Perform surgery- remove the cause of infection , drain pus , relieve pressure.
• Select antibiotic- Determine

1. Most likely causative organisms based on history
2. Host defense status
3. Allergy history
4. Previous drug history

• Follow up- confirm treatment response, evaluate for side effects and secondary infections.

Follow up

• out patient should return for f/u in 2-3 days.
• Patient should have decreased swelling, discharge, airway edema, malaise in 2-3 days.
• If no improvement consider:

1. Re- culture
2. Re- image
3. Repeat incision and drainage

References

• slideshare – odontogenic infection
• Shafer’s – Textbook of Oral Pathology (7th edition)

Written by - Dr.Urusa I Inamdar

An odontogenic infection is an infection of the alveolus,jaws, or face that originates from a tooth or from its supporting structures and is one of the most frequently encountered infections.

Causes

• dental caries
• deep fillings
• failed root canal treatment
• periodontal disease
• pericoronitis

Localised and spreading of odontogenic infection

infections have the potential to spread to other areas of the maxillofacial region and beyond through tissue planes and bloodstream.

A spreading odontogenic infection presents with varying degrees of facial swelling , trismus and pain , and can be life threatening.

Signs and symptoms

• pain in the oral cavity and jaws
• Swelling
• mobile tooth
• tenderness on biting or tapping on the affected tooth
• Pain on Palpation of the surrounding gum
• spontaneous drainage of pus

Red Flag suggestive of

• Difficulty in speaking , swallowing and breathing
• Dehydration
• Trismus
• Pyrexia
• Raised tongue and floor of the mouth , drooling
• Tachycardia and tachypnoae
• Hypotension
• Increased white blood cell count
• Lymphadenopathy
• Periorbital cellulitis

Clinical presentation

• Dentoalveolar infection– swelling of the alveolar ridge with periodontal, periapical and subperiosteal abscess.
• Submental space infection– firm midline swelling beneath the chin, caused by infection from the mandibular incisor.
• Submandibular space infection– swelling of the Submandibular triangle of the neck around the angle of the mandible, caused by mandibular molars infection.
• Sublingual space infection– swelling of the floor of the mouth with possible elevation of the tongue and dysphagia.
• Retro pharyngeal space infection– stiff neck, sore throat, dysphagia and raspy voice, caused by the infections of the molars. It has high potential to spread to the mediastinum.
• Buccal space infection– swelling of the cheek caused by infection of premolars and molars.
• Masticator space infection– swelling on either side of the mandibular ramus, caused by infection of the mandibular third molars. Trismus is present.
• Canine space infection– swelling of the anterior cheek with loss of the nasolabial fold and possible extension to the infraorbital region.

Complications of odontogenic Infections

• respirtory obstruction
• Sepsis
• Endocarditis
• Pericarditis
• Necrotising fascitis
• descending mediastinitis
• spondylitis
• brain abscess
• cavernous sinus thrombosis
• thoracic empyema
• pleuropulmonary suppuration
• aspiration pneumonia
• pneumothorax
• mandibular or Cervical osteomyelitis
• abscess of the carotid sheath and jugular thrombophlebitis
• hematogenous dissemination to distant organs and coagulation abnormalities.

References

• Ogle OE . Odontogenic Infections. Dent Clin North Am.
• gskpro.com ( Understanding Odontogenic Infections and its complications )
• Shafer’s Textbook of Oral Pathology ( 7th edition )