Physical And Chemical Injuries Of The Oral Cavity Question And Answers

Physical And Chemical Injuries Of The Oral Cavity

Question.1. Write notes on osteoradionecrosis.
Or
Write short note on osteoradionecrosis.

Answer. Osteoradionecrosis is a radiation-induced pathologic process characterized by the chronic and painful infection and necrosis is accompanied by the late sequestration and sometimes permanent deformity.

This is one of the most serious complications of radiation to head and neck seen frequently today because of bettr treatment modalities and prevention.

Factors leading to osteoradionecrosis

• Irradiation of an area of previous surgery before adequate healing had taken place.
• Irradiation of lesion in close proximity to bone.
• Prolong oral hygiene and continued use of irritants.
• Poor patient’s corporation in managing irradiated tissues.
• Surgery in irradiated area.
• Failure to prevent trauma to irradiated bony areas.

Read And Learn More: Oral Pathology Question And Answers

Clinical Features

• Osteoradionecrosis is the result of nonhealing dead bone.
• Mandible is affcted more commonly than maxilla.

Histology

• There is destruction of osteocytes, absence of osteoblasts and lack of new bone or osteoid formation.
• Walls of regional blood vessels are thickened by fibrous connective tissue.
• Radiation causes proliferation of intima of blood vessels leading to thrombosis of arteries which results in nonvital bone.

Treatment

• Debridement of necrotic tissue should be done along with removal of sequestrum.
• Administration of intravenous antibiotics and hyperbaric oxygen therapy are essential
• Maintenance of oral hygiene is necessary.

 

Question.2. Write short note on lead poisoning.

Answer. Lead poisoning leads to plumbism.

Etiology

• Paints consisting of lead: Workers and children are most commonly affected.
• Illicit alcohol consisting of lead can cause lead poisoning.
• Gasolining consisting of lead.
• Lead from automobile smoke can lead to occupational exposure.

Clinical Features

• Due to lead poisoning, there is axon degeneration and demyelination.
• In more severe cases there is presence of encephalopathy, seizures, mental retardation, and cerebral palsy.
• Patient often complains of nausea, vomiting, and constipation.
• Due to lead poisoning bone deposition and resorption is disturbed.

Oral Manifestations

• There is presence of excessive salivation, metallic taste, and dysphagia.
• Burtonian line is seen in cases of lead poisoning with poor oral hygiene. A gray-black line is seen along marginal gingiva which is known as burtonian line.
• Characteristic signs are pale lips, Ashen colored face,muscle tone is poor.
• Bilateral parotid gland hypertrophy is evident.

Treatment

Chelating agents such as EDTA should be given to treat the patient.

 

Question.3. Write short note on chemical injuries of oral cavity.

Answer. Oral cavity manifests serious reaction to the wide variety of drugs and chemicals.

• Tissue injury can be due to local response to a severe irritant or due to administration of systemic drugs.
• Aspirin, sodium perborate, hydrogen peroxide, gasoline, turpentine, rubbing alcohol and battery acid is the examples.
• Various patients many children under psychiatric care hold medication under their mouth rather swallowing them. Such medications are potentially caustic when held in mouth for long duration.
• Following are the materials in detail which lead to chemical injuries of oral cavity:

Chemical injuries by materials used locally in Dentistry
Aspirin

• Aspirin tablets or powder are mainly used mistakenly in oral cavity by patients as local obtundent mainly for relief of toothache.
• Initially, there is burning sensation present in oral mucosa.
• Affected surface appears blanched as well as white in appearance.
• Epithelial separation and sloughing of epithelium along with frequent bleeding is seen.
• Healing take place under 1 to 2 weeks.

Endodontic Materials

• Some of endodontic materials lead to soft tissue damage causing deep spread of inflammation and necrosis.
• Paraformaldehyde is used to devitalize inflmed pulp. It can leak from pulp chamber in surrounding tissue and lead to necrosis of gingiva and bone.
• Sodium hypochlorite produces same effect as paraformaldehyde when it leaks in surrounding supporting tissue or injected beyond the apex.
• Sodium hypochlorite when come in contact with vital tissue it leads to hemolysis and ulceration.
• Microscopically sodium hypochlorite inhibits neutrophil
  migration and damage endothelial and firoblast cells.

Hydrogen Peroxide

• This is a caustic agent.
• As it comes under the contact with tissues it lead to burning of tissues and release toxic free radicals, per hydroxyl ion or both.
• 30 to 35% of hydrogen peroxide is used with heat for bleaching teeth. This thermocatalytic process damages the tooth by causing irritation to cementum and periodontal ligament which also causes cervical root resorption.

Phenol

• It is cavity sterilizing and cauterizing agent.
• This is used in treatment of aphthous ulcers.
• As extensive necrosis is seen from medicaments consisting of 0.5% phenol, this product should be used with atmost care.

Silver Nitrate

• It is useful for treatment of aphthous ulcers as chemical cautery leads to pain relief by destroying the nerve endings.
• Its over usage leads to the painful burn of oral cavity.

Histopathology Of Locally Acting Agents Leading To
Chemical injuries

• White slough removed from mucosal chemical burns shows coagulative necrosis of epithelium. Outline of epithelial cells and nuclei is visible.
• Necrosis starts over the surface and moves basally.
• Underlying connective tissue consists of mixture of acute and chronic inflmmatory cells.

Chemical injuries by materials used systemically in Dentistry

Lead

• Lead poisoning or plumbism is an occupational hazard.
• Lead line or Burtonians line is a grey or blue black line of sulphide pigmentation present on gingiva.
• Ulcerative stomatitis is seen.
• Excessive salivation and metallic taste are commonly present.

Mercury

• Mercury poisoning occur when it is used therapeutically.
• In this tongue and salivary glands are swollen.
• Metallic taste in mouth is present.
• Salivary flow is increased.
• Ulcerations are present on gingiva, palate and tongue.
• Exfoliation of teeth is also present.
• Acrodynia occurs due to chronic mercury exposure in infants and children.

Silver

• Subepithelial deposition of silver in mucus membrane
  leads to diffuse grayish discoloration.
• A blue silver line occurs at gingival margin due to secondary deposition of metallic silver.
• Amalgam tattoo is the most common finding. In this particles enter via lacerations which occur during removal of old amalgam restorations. It appears as raised blue, black or grey lesion.

Bismuth

• It is used by oral surgeons in surgical packs.
• Pigmentation of bismuth is seen in gingiva and buccal mucosa.
• Bismuth line, i.e. blue black line is present at marginal gingiva.

Tetracycline

• It lead to the discoloration of permanent or deciduous teeth due to deposition of tetracycline during prophylactic or therapeutic regimens in pregnant female or postpartum in infant.
• Affected teeth are yellowish or show brown-gray discoloration.
• Dentine is more stained than enamel.