Oral Potentially Malignant Disorders

Courtesy : Guidelines for prevention and management of oral potentially malignant disorders Sri Lanka

Although oral cancer can arise denovo (without any precursor stage) very often it is preceded by the presence of some specific diseases involving the oral mucosa.

Terminology

·         Earlier OPMD were called as “pre cancerous lesions and pre cancerous conditions” , “Precursor lesions and conditions”.

·         Prefix “Pre” always denotes that these lesions and conditions will always transform into malignancy.

·         It is justifiable for the conditions like Proliferative verrucous leukoplakia which has a malignant transformation high as 70% and sublingual keratosis which has a malignant transformation of 35-45%.

·         But it is not for most of the Oral Potentially malignant lesions and condiditions (Eg:OLP which has a malignant transformation rate of less than 1%.

·         Most of them reverse to the healthy stage with the cessation of the causative agent or with the treatment.

·         Therefore, WHO workshop held in 2005 has introduced the term “Potentially” instead of “Pre”.

·         It conveys that not all lesions and conditions described under this term may transform to cancer.

Definition

Potentially Malignant Lesions

Area of morphologically altered clinical or histopathological oral mucosa, in which there is a higher risk of malignant transformation than other areas of the rest of the mucosa.

Potentially Malignant Condition

Generalized state of morphologically altered clinical or histopathological oral mucosa, in which there is a high risk of malignant transformation in any area.

Changes in terminology

In early working group of the WHO in 1978 proposed the the precancerous presentations in the oral cavity to be classified in to two broad catagories.

1.       Precancerous lesions

2.       Precancerous conditions

Definitions:

·         A precancerous lesion is a morphologically altered tissue in which oral cancer is more likely to occur than in its apparently normal counterpart.

·         A precancerous condition is a generalized state associated with a significantly increased risk of cancer’.

This classification is done because of

·         The previous studies shown that the areas of tissue with certain alterations in clinical appearances identified at the first assessment as “Precancerous” have undergone malignant changes.

·         Some if these alterations, particularly red and white patches, are seen to co-exist at the margins of overt oral squamous cell carcinomas.

·         A propotion of these oral premalignant lesion and conditions share morphological and cytological changes observed in epithelial malignancies, but without frank invasion.

·         Some chromosomal, genomic and moleculer alterations found in clearly incvasive oral cancers are detected in these presumptive “precancer” stage

These were classified purely based on clinical observation

Criteria used for diagnosing dysplasia

Architecture

·         Irregular epithelial stratification

·         Loss of polarity of basal cells

·         Drop-shaped rete ridges

·         Increased number of mitotic figures

·         Abnormal superficial mitoses

·         Premature keratinization in single cells (dyskeratosis)

·         Keratin pearls within rete pegs

Cytology

·         Abnormal variation in nuclear size (anisonucleosis)

·         Abnormal variation in nuclear shape (nuclear pleomorphism)

·         Abnormal variation in cell size (anisocytosis)

·         Abnormal variation in cell shape (cellular pleomorphism)

·         Increased nuclear-cytoplasmic ratio

·         Increased nuclear size

·         Atypical mitotic figures

·         Increased number and size of nucleoli

·         Hyperchromasia

·         This took account of worldwide experience that oral precancer’ has clinically diverse appearances. A range of precancerous lesions and conditions was recognized in that report.

·         At the time these terms were coined, it was considered that the origin of a malignancy in the mouth of a patient known to have a precancerous lesion would correspond with the site of precancer.

·         On the other hand, in precancerous conditions, cancer may arise in any anatomical site of the mouth or pharynx.

·         But in 2005 clinical assembly of WHO

·         It is now known that even the clinically normal’ appearing mucosa in a patient harbouring a precancerous lesion may have dysplasia on the contralateral anatomic site (3) or molecular aberrations in other oral mucosal sites suggestive of a pathway to malignant transformation, and that cancer could subsequently arise in apparently normal tissue (4).

·         The current Working Group, therefore, did not favour subdividing precancer to lesions and conditions and the consensus view was to refer to all clinical presentations that carry a risk of cancer under the term “Potentially malignant disorders” to reflect their widespread anatomical distribution.

Etiology

No single factor has been identified as the causative factor for potentially malignant disorders.

But a number of high risk factors has been put forwarded which has greater than normal risk of

malignancy at a future date.

A. Extrinsic Factors

1. Tobacco in any form (smoking or chewing) is the single most major extrinsic cause (people who smoke more than 80 cigarettes per day have 17-23 times greater risk).

2. Alcohol regardless of beverage type and drinking pattern – synergistic action along with tobacco (risk of smokers who are also heavy drinkers is 6-15 times than that of abstainers).

3. Virus infection – HPV, EBV, HBV, HIV, HSV.

4. Bacterial infection – Treponema pallidum.

5. Fungal infection – Candidiasis.

6. Electro-galvanic reaction between unlike restorative metals.

7. Ultraviolet radiation from sunlight – associated with lip lesions.

8. Chronic inflammation or irritation from sharp teeth or chronic cheek-bite (tissue modifiers rather than true carcinogens).

B. Intrinsic Factors

1. Genetic (5% are hereditary).

2. Immunosuppression – organ transplant,HIV.

3. Malnutrition

Epidemiology and Prevalence

·         Average age of population affected with PMD’s are 50-69 years

In the Indian subcontinent the prevalence of oral cancer is the highest among all cancers in men even though it is only the sixth most common cancer worldwide.

·         It’s estimated that more than one million new cases are being detected annually in the Indian subcontinent.

·         92-95% of all oral malignancies are oral squamous cell carcinomas (OSCC).

Five-year survival for cancer is directly related to the stage at which the initial diagnosis is made.

·         Surgical treatment of oral cancer is considered among the most debilitating and disfiguring of all cancers. It produces dysfunction and distortions in speech, difficulty in mastication and swallowing, and affects the patient's ability to interact socially.

Histopathological stages in epithelial precursor lesion

Squamous hyperplasia

This may be in the spinous layer (acanthosis) and/or in the basal/parabasal cell layers (basal cell hyperplasia); the architecture shows regular stratification without cellular atypia

Mild dysplasia

The architectural disturbance is limited to the lower third of the epithelium accompanied by cytological atypia

Moderate dysplasia

The architectural disturbance extends into the middle third of the epithelium; consideration of the degree of cytological atypia may require upgrading

Severe dysplasia

The architectural disturbance involves more than two thirds of the epithelium; architectural disturbance into the middle third of the epithelium with sufficient cytologic atypia is upgraded from moderate to severe dysplasia

Carcinoma in situ

Full thickness or almost full thickness architectural disturbance in the viable cell layers accompanied by pronounced cytological atypia

Classification

Potentially malignant lesions

1.       Leukoplakia

2.       Erythroplakia

3.       Actinic Keratosis

4.       Palatal Keratosis

Potentially malignant conditions

1.       Oral Lichen Planus

2.       Oral Submucous Fibrosis

3.       Siderophenic Dysphagia(Plummer-Vinson syndrome)

4.       Syphiliitic leukoplakia

5.       Discoid Lupus erythematosus

6.       Epidermolysis bullosa

7.       Xeroderma pigmentosum

8.       Dyskeratosis Congenita

9.       Bloom syndrome

1.   Fanconi Anaemia

Leukoplakia

Leukoplakia is generally defined as a predominantly white lesion of the oral mucosa that cannot be clinically (or histopathologically) characterized as any other definable lesion

WHO Definition

A white plaque of questionable risk having excluded other known disease or disorders that carry no increased risk for cancer.

Leukoplakia is the most common potentially malignant lesion of the oral mucosa. The term leukoplakia is a clinical descriptor only. (The terms keratosis and dyskeratosis are histological features and should not be used as clinical terms). On the basis of the following clinical features a provisional diagnosis of leukoplakia is made when the lesion cannot be clearly diagnosed as any other disease of the oral mucosa with a white appearance.

Aetiology

·         Smoking

·         Betel Chewing

·         Alcohol Consumption

·         Other tobacco related habits

Clinical features

·         Leukoplakia can be either solitary or multiple.

·         Leukoplakia may appear on any site of the oral cavity.

·         The most common sites for leukoplakia are

buccal mucosa

Ø  alveolar mucosa

Ø  floor of the mouth

Ø  tongue

Ø  lips

Ø  palate

·         Generally two clinical types of leukoplakia are recognised: homogeneous and non-homogeneous, which can co-exist .

Homogeneous leukoplakia is defined as a predominantly white lesion of uniform flat and thin appearance that may exhibit shallow cracks and that has a smooth, wrinkled or corrugated surface with a consistent texture throughout ³.

This type is usually asymptomatic.

1.       Flat

2.       Corrugated

3.       Wrinkled (Sublingual Keratosis)-Malignant transformation 35-45%

4.       Pumice like

Non-homogeneous leukoplakia has been defined as a predominantly  white-and-red lesion "erythroleukoplakia") 

Ø  that may be either irregularly flat, nodular ("speckled leukoplakia) or

Ø  exophytic ("exophytic or verrucous leukoplakia").

1.       Verrucous

2.       Nodular

3.       Ulcerated

4.       Speckled

These types of leukoplakia are often associated with mild complaints of localised pain or discomfort.

·         Proliferative verrucous leukoplakia is an aggressive type of leukoplakia that almost invariably develops into malignancy. This type is characterised by widespread and multifocal appearance, often in patients without known risk factors.

·         Malignant transformation of PVL considered to be above 70%

·         In general, non-homogeneous leukoplakia has a higher malignant transformation risk, but oral carcinoma may develop from any leukoplakia.

·         Leukoplakia malignant transformation rate varies  3% – 45%

Diagnosis

Clinical diagnosis of Leukoplakia has the following  approaches.

·         Provisional Clinical Diagnosis: It is based on clinical features stated above on a single visit, using inspection and palpation as the only diagnostic means .

·         Definitive Clinical Diagnosis: It is based on clinical evidence obtained by lack of changes after identifying and eliminating suspected aetiologic factors during a follow-up period of 2-4 weeks (In some cases the time may be longer) .

·         Histopathologically Proven Diagnosis: Definitive clinical diagnosis complemented by biopsy in which, histopathologically, no other definable lesion is observed.

Clinical differential diagnosis includes the following disorders. See Table for details of differential diagnosis:

·         lichen planus (especially the plaque type)or lichenoid reaction

·         discoid lupus erythematosus

·         leukoedema

·         acute pseudomembraneous candidosis

·         white sponge naevus

·         frictional keratosis

·         chronic cheek biting (chewing) lesions (morsicatio buccarum),

·         smoker’s palate (leukokeratosis nicotina palate)

·         chemical injury

·         skin graft

·         hairy leukoplakia

Disorder	Diagnostic  features	Investigations
Lichen planus (plaque type)	Other forms of lichen planus (reticular) found in association	Biopsy consistent with lichen planus
Lichenoid reaction	Drug history, e.g. close to an amalgam restoration	Biopsy consistent with lichen planus or lichenoid reaction
Discoid lupus erythematosus	Circumscribed lesion with central erythema, white lines radiating	Biopsy consistent with DLE supported by immunofloresence and other investigations
Leukoedema	Bilateral on buccal mucosa, could be made to disappear on stretching (retracting), racial	Not indicated
Acute pseudomembranous candidosis	The membrane can be scraped off leaving an erythematous⁄raw surface	Swab for culture
White sponge nevus	Noted in early life, family history, large areas involved, genital mucosa may be affected	Biopsy not indicated
Frictional keratosis	History of trauma, mostly along the occlusal plane, an etiological cause apparent, mostly reversible on removing the cause	Biopsy if persistent after elimination of cause particularly in a tobacco user
Morsicatio buccarum (Chronic cheek biting)	Habitual cheek – lip biting known, irregular whitish flakes with jagged out line	Biopsy not indicated
Leukokeratosis nicotina palate (smoker’s palate)	Smoking history, greyish white palate	Not indicated
Chemical injury	Known history, site of lesion corresponds to chemical injury, painful, resolves rapidly	Not indicated
Skin graft	Known history	Not indicated
Hairy leukoplakia	Bilateral tongue keratosis. Specific histopathology with koilocytosis	EBV demonstrable on in situ hybridization

Reported risk factors of statistical significance for malignant transformation of leukoplakia, listed in an at random order (not applicable in the individual patient)

1.       Female gender

2.       Long duration of leukoplakia

3.       Leukoplakia in non-smokers (idiopathic leukoplakia)

4.       Location on the tongue and/or floor of the mouth

5.       Size > 200 mm²

6.       Non-homogeneous type

7.    Presence of C. albican

8.       Presence of epithelial dysplasia

Erythroplakia

Oral erythroplakia (OE) is considered a rare potentially malignant disease of the oral mucosa and is classically defined as ‘‘fiery red patch of the oral mucosa that cannot be characterized clinically or pathologically as any other definable disease”.

It must be noted that in case of a mixture of red and white changes such lesion is usually categorized as non-homogeneous leukoplakia (‘‘erythroleukoplakia”). The natural history of OE is unknown. It is not clear whether OEs develop de novo or they develop from oral leukoplakia through several intermediate stages of white/red lesions.

Aetiology:

Tobacco and alcohol use are considered important aetiologic factors. The possible role of C. albicans is at present still unclear. The etiology of OE reveals a strong association with tobacco consumption and the use of alcohol.

Epidemiology:

Prevalence figures of erythroplakia are only available from studies performed in South- and Southeast Asia and vary between 0.02% and 0.83%.

A recent case control study of OE from India reported a prevalence of 0.2%. A range of prevalences between 0.02% and 0.83% from different geographical areas has been documented³. OE is predominantly seen in the middle aged and elderly.   There is no distinct gender preference. One study from India showed a female:male ratio of 1:1.04.

Clinical features:

Lesions of OE are typically less than 1.5 cm in diameter but lesions larger than 4mm in diameter have been reported. ⁵ The clinical appearance may be flat or with a smooth or granular surface². The surface of OE is often depressed

below the level of the surrounding mucosa.⁶.  Any site of the oral and oropharyngeal cavity may become involved, usually in a solitary fashion. This solitary presentation is often helpful in clinically distinguishing erythroplakia from several other erythematous lesions affecting the oral mucosa, since these lesions occur almost always in a bilateral, more or less symmetrical pattern.⁷    See Table 2.2.1 for differential diagnosis of OE. OE is soft to palpation and does not become indurated or hard until an invasive carcinoma develops in it.  The soft palate, the floor of the mouth and the buccal mucosa are most commonly affected by OE.⁸ The tongue is rarely affected.⁹

OE is a diagnosis by exclusion. The term OE does not carry a histopathologic connotation. As for Oral leukoplakia the principle of provisional diagnosis and definitive diagnosis is also suggested for OE. Provisional diagnosis was defined as: ‘‘A provisional diagnosis of OE is made when a lesion at clinical examination cannot be clearly diagnosed as any other disease of the oral mucosa with red appearance’’. Definitive diagnosis was defined as: ‘‘A definitive diagnosis of OE is made as a result of identification, and if possible elimination, of suspected aetiological factors and, in the case of persistent lesions, histopathological examination’’.  OE is seldom multicentric and rarely covers extensive areas of the mouth.⁷

Histopathologically, erythroplakia commonly shows at least some degree of dysplasia and often even carcinoma in situ or invasive carcinoma..

 Histopathologically, it has been documented that in OE of the homogenous type, 51% showed invasive carcinoma, 40% carcinoma in situ and 9% mild or moderate dysplasia. Transformation rates are considered to be the highest among all OPMDs. Surgical excision is the treatment of choice. 

Prognosis and treatment

 In general, OE needs to be treated because of its high risk of malignant transformation. Besides, most erythroplakias are symptomatic. Surgery, either by cold knife or by laser, is the recommended treatment modality. As for excision of leukoplakia, no guidelines are available with regard to the width of the surgical margins. There are no data from the literature about the recurrence rate after excision of erythroplakias.

Red lesions that need to be considered in the differential diagnosis of oral erythroplakia (adapted from Reichart and Philipsen and Warnakulasooriya et al )

Nature of lesion	Lesion/ condition	Diagnostic features
Inflammatory⁄ immune  disorders	Desquamative gingivitis	Associated mostly with erosive /atrophic lichen planus in other areas
	Erosive/atrophic lichen planus	Reticular lesion/striae may be seen in peripheral areas; multiple sites
	Discoid lupus erythematosus	Circumscribed lesion with central erythema, white lines radiating
	Pemphigus , Pemphigoids	History of bullous eruption and rupture, wider & multiple areas involved
	Hypersensitvity reactions	History of exposure to allergen; wider area affected
	Reiter’s disease	Non gonococcal urethritis, arthritis
Infections	Erythematous candidiasis including  denture induced stomatitis	Found on palate and under denture
	Histoplasmosis	Raised /ulcerated lesion
	Tuberculosis	Usually ulcerative stellate appearance
Hamartomas⁄ neoplasms	Haemangioma	Blanching on pressure
	Lingual varices	Ventral aspect of tongue,symmetrical
	Telangiectasia	Multiple sites and skin involvement
	Oral purpura	Bleeding diatheses present
	Kaposi’s sarcoma	Seen mostly in HIV infected people

Palatal Keratosis

·         The lesion is unknown in sri lankan patients

·         Reported in south India Andhra Pradesh where people practice unusual method of smoking

·         Which the lighted end of cigar is held inside the moth

·         Resultant keratosis on the palate

Actinic Keratosis

·         Mainly found among fair skinned populations in sunny habitats(bright sun light)

·         Keratosis is preceded by inflammatory reactions

·         Mainly on lower lip

·         Erythematous changes accompanied by oedema, Vesciculation and occasionally bleeding

·         Developmet of lower lip cancer.

Oral submucous fibrosis (OSF)

Oral submucous fibrosis (OSF) is a potentially malignant disorder associated with burning sensation in the oral mucosa from the early stages and with a significant risk for malignancy. It is a chronic, insidious disease with a progressive fibrosis in the submucosal tissues leading to restriction in opening the mouth with the advancement of the disease.

The fibrosis initially affects the lamina propria of the oral mucosa and as the condition worsens, extends to the submucosa and the deeper tissues including oral musculature.  Consequently the elasticity of the oral mucosa is progressively lost. Variable rates of malignant transformation ranging from 4.5 to 7.6 percent have been reported. ^3,4

 No such data is available for Sri Lanka

Aetiology

Conclusive evidence now exists that the disease is caused by the consumption of areca nut. The condition predominantly affects populations of the Indian subcontinent and South East Asia who chew areca nut in betel quid or in flavoured formulations of the nut. Although the disease mostly affects people older than 40 years of age, younger people are increasingly seen to be affected, particularly those who consume flavoured areca nut products alone.

Alkaloids in Arecanut responsible for OSMF

1.       Arecoline

2.       Arecodine

3.       Guacoline

4.       Guacine

Pathogenesis

Unlike the other OPMDs described here,  the pathogenesis of OSF has been well elucidated.  Although a detailed discussion of the pathogenesis of OSF is beyond the scope of these guidelines, an understanding of this aspect of OSF is important.  Fibrosis and hyalinization resulting from increased amount of collagen in the  extracellular matrix of  sub epithelial tissues contribute to the important clinical features seen in this condition. It has been shown that either an increased collagen synthesis or reduced degradation of collagen may be responsible for the development of OSF. Alkaloids in areca nut, importantly, arecoline, have been implicated in stimulation of fibroblast proliferation while tannins in the nut appear to stabilize collagen structure that resists degradation by collagenases. Increased secretion of fibrogenic cytokines such TGF beta and imbalance  between  matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMMS) are responsible to altered collagen metabolism leading to fibrosis. The disease is associated with certain genetic groups than in others.¹

Clinical features

The clinical features that are diagnostic include:

·         Burning sensation of the oral mucosa

·         blanching and stiffening of the oral mucosa leading to limitation in mouth opening.

·         Widespread pallor of the oral mucosa

·         palpable fibrous bands in cheeks, along the faucial pillars,  soft palate and lips

·         tightening of the lips with resultant lack of their stretchability

·    depapillation of the dorsum of the tongue with restricted mobility of the tongue including protrusion

·        depigmentation of the mucosa particularly noticeable on the vermilion border of the  lips in a significant proportion of patients

·         vesiculation of the oral mucosa is sometimes described but not often seen.

·         Other potentially malignant disorder such as leukoplakia may be seen in longstanding OSF.

 

Diagnosis of OSF

Diagnosis can be made easily in established OSF based on the above clinical features. In early stages, however,  the diagnosis may be difficult to establish purely on clinical grounds and a biopsy may be necessary for the diagnosis. Biopsy is also necessary in advanced stages to determine the presence of epithelial dysplasia if there are clinically suspicious features.  The condition may need to be distinguished from other diseases that may exhibit  fibrosis and may cause limitation in mouth opening such as epidermolysis bullosa,  post-irradiation fibrosis, cicatricial pemphigoid,  progressive systemic sclerosis  etc. 

Staging of OSF

Unlike other OPMDs, OSF is a disorder that is associated with a functional disability. Attempts have been made to stage OSF using mainly clinical / functional  criteria ^2,5

 A staging scheme proposed by Kerr et al²  is a useful one and is shown in table

  

Disease Grading  of Oral submucous fibrosis (Kerr et al²)

Grade	Clinical and functional features
Grade 1 – Mild	Any feature of the disease triad for OSF ((burning, depapillation, blanching or leathery mucosa) present + inter-incisal opening >35 mm
Grade 2 – Moderate	Above features of OSF + inter-incisal limitation of opening 20–35 mm
Grade 3 – Severe	Above features of OSF + inter-incisal opening <20 mm
Grade 4A	OSF + other potentially malignant disorder on clinical examination
Grade 4B	OSF with any grade of oral epithelial dysplasia on biopsy
Grade 5	OSF + oral squamous cell carcinoma (SCC)

Treatment of OSF

There is no single satisfactory and evidence-based treatment method for curing the disease.  Physical and medical treatments have all been tried with claims of varying rates of success. Physical methods such as stretching exercises aimed at increasing mouth opening and medical treatments such as intra-lesional injection of corticosteroids have been reported. Intra lesional steroid (for example methyl prednisolone) injection is the widely practised treatment⁶ in most centres, especially for symptomatic cases with developing limitation in mouth opening associated with burning sensation.   Surgical methods aimed at severing the fibrous bands in advanced           stages have also been attempted but are associated with relapse. None of these methods has satisfied all criteria for randomised controlled trials².   Education and habit control among patients has been found to arrest the progress of the disease in early stages although this has not been proven by any randomised controlled trial.  Many of the patients suffering from OSF may be affected by iron deficiency anaemia and other nutritional deficiencies². A full blood count is recommended for every patient when the diagnosis of OSF is made. When deficiencies are detected, treatment must be instituted to correct them.

Lichen Planus

Oral lichen planus is a common chronic inflammatory mucocutaneous disorder that typically affects the skin and/or mouth .Lichen planus can also affect other non-oral mucosal surfaces such as the genitals.

OLP, the mucosal counterpart of cutaneous lichen planus, which is a chronic inflammatory disorder based on immunologic T cell mediated process.

OLP is a relatively common condition which affects 1%-2% of the population. The possible malignant transformation of OLP is still a subject of an ongoing controversy.

However the reported malignant transformation potential varies from 0.4% to 5%. This is a case of OLP that can be considered on the verge of malignant transformation on the basis of presence of severe epithelial dysplasia.

•   Affects 1%-2% of the population.
•   OLP lesions are commonly seen in 5^th and 6^th decades of life.
•   OLP affects women more than men.
•   Female : Male  ratio -1.4 : 1

Oral lichenoid reactions (OLR)

Considered  a variant of OLP, may be regarded as a disease by itself or as an exacerbation of an existing OLP, by the presence of medications (Lichenoid drug reactions) or dental materials (contact hypersensitivity)

 Clinical features

·         OLP usually present as bilaterally symmetrical lesion or multiple lesions.

·         Typically affects the buccal mucosa, dorsum and ventral surfaces of the tongue and/or gingiva.

·         Other mucosal surfaces can be affected but palatal involvement is particularly rare.

·         Oral lichen planus is often asymptomatic^1,3 although when there are areas of erosion or ulceration, the patient may have variable amounts of discomfort, being particularly troublesome when eating spicy or acidic type foods.

·         The variable clinical presentations of oral lichen planus comprise white patches, erosions, ulcers and, very rarely, blisters^1,3. The clinical presentation of lichen planus can be classified as follows:

Asymptomatic

◦       Reticular

◦       Papular

◦       Plaque like

Symptomatic

◦       Erosive/ Ulcerative

◦       Atrophic

◦       Bullous

ü  Reticular oral lichen planus – this is the most common presentation, manifesting as a network of white striations. These lesions are often painless, although patients may complain of a slight roughness or dryness to the affected mucosal surfaces.

ü  Plaque-like oral lichen planus – this manifests as areas of homogenous whiteness. This typically arises on the buccal mucosa or dorsum of tongue and may be more prevalent amongst those who are smokers.

ü  Papular oral lichen planus – this manifests as small white raised areas approximately 1-2mm in diameter. These again typically arise on the buccal mucosa and dorsum of tongue, although may also present on other mucosal surfaces. Erosive oral lichen planus – this is sometimes termed atrophic oral lichen planus. In this form there are areas of redness within the aforementioned white patches. Patients with this type of disease often complain of oral soreness

ü  Ulcerative lichen planus – there are frank ulcers within the areas of whiteness. Patients complain of continued soreness, this being particularly severe with spicy or acidic foods.

ü  Bullous lichen planus – this rare presentation manifests as small vesicles or blisters (bullae) within the white patches.

Patients with disease involving the gingiva may have areas of white patches or striae superimposed upon redness of the gums. The latter is often termed desquamative gingivitis and can be extremely painful.

There is little predictability as regards the frequency of non-oral disease in patients with oral lichen planus. Likewise the oral features may precede, accompany or follow lichen planus affecting other sites.

Etiolopathogenesis of OLP and OLR

The precise aetiology of this condition is unknown.

Cell mediated immune dysregulation has been associated with the pathogenesis of OLP.

The data suggests that OLP is a T-cell mediated autoimmune disease in which autocytotoxic CD8+ T cells trigger the apoptosis of Oral epithelial cells.

The nature of antigen is still uncertain.

However, several predisposing factors have been implicated in the pathogenesis of OLP and OLR.

Drugs

◦       Anti-malarials

◦       Non-steroidal anti-inflammatory drugs

◦       Angiotensin converting enzyme inhibitors

◦       Diuretics

◦       Beta blockers

◦       Oral Hypoglycemics

◦       Gold Salts

◦       Penicillamine

◦       Anti-Retrovirals

Dental Materials

ü  Dental Amalgam

ü  Composite and resin based         materials

ü  Metals (Eg:Nickel)

Chronic liver disease and            

Hepatitis C virus

Stress

Genetics

Tobacco chewing

Graft versus Host Disease

Diagnosis

·         The diagnosis of oral lichen planus is initially based upon the clinical presentation of bilateral white patches with or without erosions, ulcers or blisters, typically affecting the buccal mucosa, dorsum of tongue and gingiva⁵.

·         Biopsy with subsequent histopathological examination of affected tissue is essential to exclude other disease that may mimic oral lichen planus – such as lupus erythematosus⁵.

·         In addition, it is advantageous to undertake a biopsy to identify possible areas of cellular atypia (dysplasia) within the involved tissue.

Siderophenic Dysphagia (Plummer Vinson Syndrome)

Manifestation of severe iron deficiency anaemia

Reported in middle aged female

Presents with

·         Angular chellitis

·         A lemon tinted pallor of the skin

·         A depapillated, erythematous and painful tongue

·         Dysphagia due to post cricoids oesophagial stricture

·         Koilonychias(Spoon shaped nails)

Syphilitic Leukoplakia

Complication of tertiary syphilis

Dorsum of the tongue is the usual site

Treponema pallidum is the responsible organism

Discoid Lupus Erythematosus

Occur in two forms

·         Mucocutaneous – DLE

·         Systemic type-multisystem autoimmune involevement-SLE

Both cause oral ulcers

Female predominantly affected

Central erythema ,white spots or papules, radiating white striae at margins and peripheral telengiectasia and it may ulcerate

In SLE ulcers are more severe than DLE

Epidermolysis Bullosa

·         Uncommon inherited mucocutaneous vesiculo-bullous condition

·         Several subtypes with varying patterns of inheritance

·         The subtypes that produce oral lesions are

o   autosomal recessive non scarring letalis type

o   autosomal recessive scarring dermolytic type

·         Vesicles for on oral mucosa and face in reaction to mild trauma

·         Scarring may cause microstomia and obliteration of buccal mucosa, tongue may become fixed

Xeroderma Pigmentosum

Rare

Inherited autosomal recessive trait in which there is an inability to repair damge DNA caused by UV light and by some chemicals

Skin cancer and SCC on Lower lip, tip of the tongue

Fanconi Anemia

Fanconi anemia (FA) is a genetic disease with an incidence of 1 per 350,000 births, with a higher frequency in Ashkenazi Jews and Afrikaners in South Africa.

Fanconi's anemia is due to an abnormal gene that damages cells, which keeps them from repairing damaged DNA.

Dyskeratosis congenita

(DKC), also called Zinsser-Cole-Engman syndrome, is a rare progressive congenital disorder that in some ways resembles premature aging (similar to progeria). The disease mainly affects the integumentary system (i.e, the skin, the organ system that protects the body from damage), with a major consequence being anomalies of the bone marrow.

Mucosal leukoplakia occurs in approximately 80% of patients and typically involves the buccal mucosa, tongue, and oropharynx. The leukoplakia may become verrucous, and ulceration may occur. Patients also may have an increased prevalence and severity of periodontal disease.

Other mucosal sites may be involved (e.g., esophagus, urethral meatus, glans penis, lacrimal duct, conjunctiva, vagina, anus). Constriction and stenosis can occur at these sites, with subsequent development of dysphagia, dysuria, phimosis, and epiphora.

Pulp therapy for primary teeth

Primary objective of pulp therapy is to maintain the integrity and health of the teeth and their supporting tissues by maintaining the vitality of the pulp of a tooth affected by caries, traumatic injury or any other cause damaging the liveliness of the pulp.

Indication and the type of the pulp therapy depends on the status of the pulp, whether it’s nonvital or vital and the type of the tooth whether its primary, young permanent or permanent. Status of the pulp would be determined by clinically with a proper history and a thorough clinical examination and by accurate special investigations such as vitality testing and radiographs. In this article I would mainly consider on the treatments to the pulp in primary teeth.

Vital pulp therapy for primary teeth diagnosed with a normal pulp or reversible pulpitis

Indirect pulp treatment

A procedure performed in a tooth with a deep carious lesion approximating the pulp but without signs and symptoms of pulp degeneration. The caries surrounding the pulp is left in place to avoid pulp exposure and is covered with a biocompatible material. A radiopaque liner such as a dentin bonding agent, resin modified glass ionomer, calcium hydroxide, zinc oxide-eugenol or glass ionomer cement is placed over the remaining carious dentin to stimulate healing and repair. Then the tooth is restored with a material that seals the tooth from micro leakage.

Direct pulp treatment

When a pinpoint mechanical exposure of the pulp is encountered during cavity preparation or following a traumatic injury a biocompatible radiopaque base such as mineral trioxide aggregate (MTA) or calcium hydroxide may be placed in contact with the exposed pulp tissue. Finally the tooth should always be restored with a material that seals the tooth from micro leakage.

Pulpotomy

A pulpotomy is performed in a primary tooth with extensive caries but without evidence of radicular pathology when caries removal results in a carious or mechanical pulp exposure. The coronal pulpotomy is amputated and the remaining vital radicular pulp tissue surface is treated with a medicament such as Buckley’s solution of formocresol. Gluteraldehyde and calcium hydroxide have been used but with less long term success. MTA is a more recent material with a high rate of success in pulpotomies. The coronal pulp chamber can be filled with zinc-oxide eugenol or other suitable base followed by acoronal restoration to avoid micro leakage and failure of the treatment. The most effective long term restoration has been shown to be a stainless steel crown although other alternatives such as composite resin and amalgam play a role when an adequate amount of enamel is intact.

Nonvital pulp therapy for primary teeth diagnosed with irreversible pulpitis or necrotic pulp

Pulpectomy

This involves the complete amputation of the pulpal tissue in a tooth that is reversibly infected or necrotic due to caries or trauma. The root canals are debrided mechanically with hand or rotary files and chemically with disinfectants such as sodium hypochlorite or chlorhexidine to ensure optimal bacterial decontamination of the canals. After proper drying of the canals a resorbable material such as non-reinforcedzinc oxide-eugenol, iodoform based paste or a combination paste of iodoform and calcium hydroxide is used to seal the canals.Then the tooth is restored with a material that seals the tooth from micro leakage.

The history of dentistry

A profession that is ignorant of its past experiences has lost a valuable asset because “it has missed its best guide to the future.” 

B.W. Weinberger Dentistry: An Illustrated History 

(Mosby, 1995)

Ancient  Dentistry

The Indus Valley Civilization has yielded evidence of dentistry being practised as far back as 7000 BC.

Earliest form of dentistry involved curing tooth related disorders with bow drills operated, perhaps, by skilled bead craftsmen.In what could be one of the earliest examples of dentistry.Scientists at the University of Missouri-Columbia in the United States have found tiny, perfectly rounded holes in teeth found in Mehrgarh in pre-historic Pakistan, which they suspect were drilled to repair tooth decay.Researcher Andrea Cucina, who first discovered the tiny holes, reveals that they didn't appear to be a funeral rite and the teeth were still in the jaw so they had not been drilled to make a necklace. He and his colleagues suspect the holes were a treatment for tooth decay and that plants or another substance had been inserted into the holes to prevent bacterial growth.

The earliest dental filling, made of beeswax, was discovered in Slovenia and dates from 6500 years ago.

The first and most enduring explanation for what causes tooth decay was the tooth worm, first noted by the Sumerians around 5000 BC. The hypothesis was that tooth decay was the result of a tooth worm boring into and decimating the teeth.The idea of the tooth worm has been found in the writings of the ancient Greek philosophers and poets, as well as those of the ancient Indian, Japanese, Egyptian, and Chinese cultures. It endured as late as the 1300s, when French surgeon Guy de Chauliac promoted it as the cause of tooth decay.

Examination of the remains of some ancient Egyptians and Greco-Romans reveals early attempts at dental prosthetics and surgery.Ancient Greek scholars Hippocrates and Aristotle wrote about dentistry, including the eruption pattern of teeth, treating decayed teeth and gum disease, extracting teeth with forceps, and using wires to stabilize loose teeth and fractured jaws. Some say the first use of dental appliances or bridges comes from the Etruscans from as early as 700 BC.

The ancient dentist

 The Egyptian,Hesi-Re was the earliest dentist whose name is known. He practiced in 3000 BC and was called “Chief of the Toothers.” Egyptian pharaohs were known to have suffered from periodontal disease. Radiographs of mummies confirm this fact.

Dental extractions

Historically, dental extractions have been used to treat a variety of illnesses. During the Middle Ages and throughout the 19th century, dentistry was not a profession in itself, and often dental procedures were performed by barbers or general physicians. Barbers usually limited their practice to extracting teeth which alleviated pain and associated chronic tooth infection.Before the 18th century, this often involved tying a string around the tooth; a drum might be played in the background to distract the patient, getting louder as the moment of extraction grew nearer. To advertise their services as ‘tooth-pullers’, many barber-surgeons hung rows of rotten teeth outside their shops.

The Armentariam

Dental Pelican

Dental Key

Instruments used for dental extractions date back several centuries. In the 14th century, Guy de Chauliac invented the dental pelican (resembling a pelican's beak) which was used to perform dental extractions up until the late 18th century. The pelican later gave way to the Dental Key which, in turn, was replaced by modern forceps in the 20th century.

The equipments

The first dental foot engine was built by John Greenwood in 1790 . It was made from an adapted foot-powered spinning wheel.

John Greenwood

1790 was a big year for dentistry, as this was also the year the first specialized dental chairwas invented. It was made from a wooden Windsor chair with a headrest attached.In 1871, George F. Green invented the first electrical dental engine and in 1957, John Borden invented the first high speed electric hand drill.

The father of modern dentistry

By 17th-century French physician Pierre Fauchard (1678 – 1761) started dentistry as it is known today, and he has been named "the father of modern dentistry".He is tremendously recognized for his book, Le chirurgiendentiste, "The Surgeon Dentist" 1728, where he described the basic oral anatomy and function, signs and symptoms of oral pathology, operative methods for removing decay and restoring teeth, periodontal disease, orthodontics, replacement of missing teeth, and tooth transplantation. His book is said to be the first complete scientific description of dentistry. Among many of his developments were the extensive use of dental prosthesis, the introduction of dental fillings as a treatment for dental caries and the statement that sugar derivative acids such as tartaric acid are responsible for dental decay.

Women in dentistry

Women in pre-20th century seems to play an unknown role in dentistry. In an early copper engraving by Lucas Van Leyden, a traveling dentist can be seen along with a woman acting as his assistant.  In 1852, AmaliaAssur became the first female dentist in Sweden. She was given special permission from the Royal Board of Health to practice independently as a dentist, despite the fact that the profession was not legally opened to women in Sweden until 1861. 

Emeline Roberts Jones became the first woman to practice dentistry in the United States in 1855.  She married the dentist Daniel Jones when she was a teenager, and became his assistant in 1855 and later on put up her own practice. Rosalie Fougelberg in 1866 became the first woman in Sweden to officially practice dentistry when profession was legally opened to females in 1861.

Dental schools throughout the world did not accept female students. Women such as Lucy B. Hobbs-Taylor and Nellie E. Pooler broke those barriers. In 1866 Lucy Hobbs Taylor became the first woman to graduate from a dental college which was the Ohio Dental College.

Dental education

Dr. John M. Harris started the world's first dental school in Bainbridge, Ohio, and influenced establishing dentistry as a health profession. It opened on 21 stFebruary 1828, and today is a dental museum. The first dental college, Baltimore College of Dental Surgery, opened in Baltimore, Maryland, USA in 1840.Chapin Harris and Horace Hayden founded the Baltimore College of Dental Surgery, the first school dedicated solely to dentistry. The college merged with the University of Maryland School of Dentistry in 1923, which still exists today.

History of the tooth brush

A recent researches reveals that the earliest use of toothbrushes may have occurred in India and Africa. It was discovered that a bristle toothbrush had been used there as early as 1600 BC. The first bristle toothbrush found was in China during the Tang Dynasty (619–907) and used hog bristle. In 1223, Japanese Zen master DōgenKigen recorded on Shōbōgenzō that he saw monks in China clean their teeth with brushes made of horse-tail hairs attached to an ox-bone handle. The bristle toothbrush spread to Europe, brought back from China to Europe by travellers. It was adopted in Europe during the 17th century. Many mass-produced toothbrushes, made with horse or boar bristle, were imported to England from China until the mid-20th century.The first patent for a toothbrush was by H. N. Wadsworth in 1857 in the United States, but mass production in the United States only started in 1885. During the 1900s, celluloid handles gradually replaced bone handles in toothbrushes. Natural animal bristles were also replaced by synthetic fibers, usually nylon, by DuPont in 1938. The first nylon bristle toothbrush, made with nylon yarn, went on sale on February 24, 1938. The first electric toothbrush, the Broxodent, was invented in Switzerland in 1954.

The first publication on dentistry

The first book focused solely on dentistry was the "ArtzneyBuchlein" in 1530 and the first dental textbook written in English was called "Operator for the Teeth" by Charles Allen in 1685.