Oral cancer ; Important facts

There are several type of oral cancers and the most common type is oral squamous cell carcinoma which is a malignant neoplasm which arises from the oral epithelium. It may affect the lips as well as intraoral sites.

oral cancer

Important facts about oral squamous cell carcinoma (SCC) 

oral carcinoma

• There are 4400 new cases of oral cancer every year in the UK (Cancer Research UK).
• Men are affected more than women but the incidence in women is rising.
• The most commonly affected sites are the lateral border of the tongue, floor of mouth and the retromolar region and about 80% of cancers in the Western world occur in these sites.

• This is related to alcohol consumption and smoking, two important risk factors in the development of oral cancer. It is thought that the carcinogens (chemicals that cause cancer) which are present in tobacco dissolve in saliva and pool in these regions of the mouth.

• Alcohol itself is not carcinogenic (i.e. it does not contain carcinogens) but it potentiates the effects of carcinogens by increasing the permeability of the oral mucosa.

lip cancer

• Cancer on the lower lip is caused by sunlight and is prevalent in fair-skinned individuals with outdoor occupations or lifestyles.

• A diet low in fresh fruit and vegetables is a risk factor for the development of oral cancer.

• The percentage of people who survive 5 years after diagnosis of oral cancer (all sites) is in the region of 50%.
• In South-East Asia many cases of oral cancer are caused by betel quid chewing and occur on the cheeks adjacent to where the quid is placed. Studies have shown that immigrant populations from South-East Asia in the UK continue this habit and have a higher risk of developing oral cancer (Farrand et al., 2001;Warnakulasuriya, 2002).

• Almost all patients with cancer of the lip survive 5 years.

• The percentage of people who survive 5 years with cancer of the posterior parts of the mouth is very low.
• The majority of new cases occur in individuals over the age of 40 years with a peak incidence between 60 and 70 years.
• The incidence is rising in younger individuals. It is thought this is due to changes in alcohol consumption rather than an increase in tobacco consumption (Hindle et al., 2000) but one study has shown that a significant proportion of young patients have no risk factors (Llewellyn et al., 2003).

Pathology of oral cancer

In health the oral epithelium forms a continuous layer on the surface of the mucosa but in oral cancer the epithelium proliferates excessively due to genetic changes and eventually the epithelial cells grow down into the underlying connective tissue. This is known as invasion and is a characteristic feature of malignancy . The tumour cells continue to divide and invade and will spread into and destroy the underlying tissues which will then feel hard and not function properly. Tissues affected in this way may include skeletal muscle, salivary glands and bone. Tumour cells will also invade lymphatic vessels and spread to the cervical lymph nodes in the neck. This process is called metastasis.

Once in the node, the tumour cells continue to proliferate and they destroy the node and sometimes spread out into the tissues of the neck. Nodes which contain tumour feel very hard and are usually painless. If the tumour has spread into the neck, the node will not be mobile, as is usual, but will be attached (fixed) to the surrounding tissues. In a small proportion of cases the cancer spreads beyond the lymph nodes, enters the blood stream and grows in other organs, but this is rare.

Clinical features of oral cancer

• Recognition of oral cancer is important and early detection,particularly before the cancer has spread to the lymph nodes in the neck, may save lives. 

Important features of oral cancers

• Some oral cancers arise in pre-existing leukoplakia; lesions which have a raised nodular surface and show variations in colour with speckled red–white areas are particularly suspicious.
• Some cancers present as erythroplakia. These are velvety red patches which may be raised above the surrounding tissues .
• Long-standing ulceration is also a common presentation and typically the ulcers have raised, rolled margins.
• Some cancers fungate (grow out) into the oral cavity as well as invade into the underlying tissues.
• The site of the lesion is important; high-risk sites are the lateral border of tongue, the floor of mouth and the retromolar area.
• Tissues affected by oral cancer are firm or hard to touch and there may be destruction leading to loss of function.
• Lesions are usually painless in the early stages and many patients are unaware of the lesions until they are quite large.
• If the cancer has spread to the cervical lymph nodes these will feel rock hard and painless and may be enlarged.
• In advanced stage disease the patient may appear very thin and pale (cachexic).

Treatment

• The diagnosis of oral cancer is made by biopsy and histopathological examination. Once the diagnosis is made it is important for the clinician to determine the extent of the disease and whether it has spread to the lymph nodes in the neck. 
• Oral cancer is treated by surgery and/or radiotherapy, and the decision as to which is appropriate is taken at multi-disciplinary team meetings attended by all who are involved in patient care.

Tips on Dental Caries

What are dental caries ?

Dental caries is a disease that cause demineralization of  dental hard tissues by acids, produced by bacteria from acting on fermentable carbohydrates.

Important Features of dental caries 

1. Fermentation of carbohydrate to organic acids by micro-organisms in plaque on the tooth surface.
2. Rapid acid formation, which lowers the pH at the enamel surface below the level (the critical pH) at which enamel will dissolve.
3. When carbohydrate is no longer available to the plaque micro-organisms, the pH within plaque will rise due to the outward diffusion of acids and their metabolism and neutralization in plaque, so that remineralization of enamel can occur.
4. Dental caries progresses only when demineralization is greater than remineralization. The realization that demineralization and remineralization is an equilibrium is key to understanding the dynamics of the carious lesion and its prevention.

How Dental caries Progress?

• An early carious lesion of the enamel is subsurface; that is, most of the mineral loss occurs beneath a relatively intact enamel surface.

• This contrasts strongly with the histological appearance of enamel after a clean tooth surface has been exposed to acid, where the surface is etched and there is no subsurface lesion. This dissolution of the surface of enamel, or etching, is a feature of enamel erosion caused, among other things, by dietary acids. 
• The explanation for the intact surface layer in enamel caries seems to lie in diffusion dynamics: the layer of dental plaque on the tooth surface acting as a partial barrier to diffusion. Further erosion occurs at much lower pHs than caries.
• Dental plaque forms on uncleaned tooth surfaces and is readily apparent if toothbrushing is stopped for 2-3 days. Contrary to popular opinion, plaque does not consist of food debris, but comprises 70% micro-organismsabout 100 million organisms per milligram of plaque.
• Diet influences the composition of the plaque flora considerably, with mutans streptococci much more numerous when the diet is rich in sugar and other carbohydrates, and these organisms are particularly good at metabolizing sugars to acids.
• Within 2-3 min of eating sugar or rinsing with a sugar solution, plaque pH falls from an average of about 6.8 to near pH 5, taking about 40 min to return to its original value. Below pH 5.5 demineralization of the enamel occurs, this is known as the critical pH.
• The clinical appearance of these early lesions is now well recognized. They appear as a white area that coincides with the distribution of plaque. This might be around the gingival margin, or between the teeth
• If the process of dental caries continues, support for the surface layer will become so weak that it will crumble like an eggshell, creating a cavity. 
• Once a cavity is formed, the process of dental caries continues in a more sheltered environment and the protein matrix of enamel and then dentine is removed by proteolytic enzymes produced by plaque organisms.

Can Dental Caries be Healed?

• The ability of early carious lesions ('precavitation carious lesions') to remineralize is now well understood; periods of demineralization are interspersed with periods of remineralization, and the outcome health or diseaseis the result of a push in one direction or the other on this dynamic equilibrium. 
• The shorter the time during which plaque-covered teeth are exposed to acid attack and the longer the time remineralization can occur, the greater is the opportunity for a carious lesion to heal. 
• Satisfactory healing of the carious lesion can only occur if the surface layer is unbroken, and this is why the 'precavitation'stage in the process of dental caries is so relevant to preventive dentistry. 
• Once the surface has been broken and a cavity has formed, it is usually necessary to restore the tooth surface with a filling. The carious process is driven by the plaque on the surface and therefore it is possible to arrest the caries by effective removal of plaque even after cavitation has occurred. However, the lost tissue cannot be replaced.

How Do dental caries First occur ?

• The first stage of dental caries to be visible is the 'white spot' precavitation lesion stage. 
• This can occur within a few weeks if conditions are favourable to its development. In the general population, though, it commonly takes 2-4 years for caries to progress through enamel into dentine at approximal sites.

Natural Defense Against dental caries ? 

• The most important of the natural defences against dental caries is saliva. If salivary flow is impaired, dental caries can progress very rapidly. Saliva has many functions. 
• The presence of food in the mouth is a powerful stimulus to salivation, with strong-tasting acid foods being the best stimulants. Saliva not only physically removes dietary substrates and acids produced by plaque from the mouth,but it has a most important role in buffering the pH in saliva and within plaque. 
• Fast-flowing saliva is alkaline reaching pH values of 7.5-8.0and is vitally important in raising the pH of dental plaque previously lowered by exposure to sugar and carbohydrates. 
• Because teeth consist largely of calcium and phosphate, the concentration of calcium and phosphate in saliva and plaque is thought to be important in determining the progression or regression of caries.
• well known that fluoride aids the remineralization process. Although it may seem sensible to try to maximize the availability of calcium, phosphate, and fluoride in the environs of the tooth, in practice, fluoride is much the most important.

Tips on tooth brushing techniques

What is the correct technique for tooth brushing ?

Researches have done various studies on effective tooth brushing and they have suggested different techniques for effective brushing.
It is advisable for a person who doesn't have a extensive periodontal condition to use Bass method for daily brushing.
Parents can introduce brushing to their kids with horizontal scrubbing method which have simple movement where the child find it easy to coordinate. When the child become mature enough to follow complex movements Bass method can be introduced.

The main indications of Bass method  are

1. For all patients for dental bio film removal adjacent to and directly beneath the gingival margin.
2. For open interproximal areas, cervical areas beneath the height of contour of the enamel, and exposed root surfaces.
3. For the patient who has had periodontal surgery.
4. For adaptation to abutment teeth, under the gingival border of a fixed partial denture and orthodontic appliances.

The stillman's method is the other commonly used method which have the following indications.

1. Dental bio-film removal from cervical areas belowthe height of contour of the crown and from exposed proximal surfaces.
2. General application for cleaning tooth surfaces.
3. Recommended for cleaning in areas with progressing gingival recession and root exposure.

Why is it important to follow a proper brushing technique?

• As we all know damage to a tooth is irreversible and last for the rest of the life time. The main causes of teeth damage are caries and periodontal diseases which are preventable with proper oral hygiene practice.
• Nowadays the cost of dental treatments are quite high as well as the time you have to spent in clinics are longer. These difficulties would not appear if you have a perfect oral hygiene practice.

Brushing techniques in detail ...........

Tips on use of Chlorhexidine mouthwash

Chlorhexidine Mouthwash

Chlorhexdine is one of most commonly used mouthwashes in worldwide. 0.2% or 0.12%  is the normal concentration of regular Chlorhexdine mouthwash and also available in higher concentrations.
Why Chlorhexidine is useful as a mouthwash?

• Having high antiplaque activity.
• Used as antiseptic.
• More active against gram positive bacteria.
• Absorbed by teeth and oral tissues and slowly released to the oral environment
• Bactericidal (kills bacteria) in high concentrations and bacteriostatic (limit bacterial growth) in low concentrations.
• Primary root of excretion is via faeces and not absorbed from bowel, and therefor safe to use.

What are the side effects of Chlorhexidine mouthwash?

Staining due to Chlorhexidine Mouthwash It may cause staining of teeth, restorations and your tongue usually if used more than 10 days. Not everyone will experience this. This stain can be removed by having your teeth professional cleaned. Lingering after taste that may change taste perception. You will adjust to time to this effect with no permanent change to your taste perception. May cause Irritation in salivary ductal areas rarely parotid salivary gland swelling may present. Increase in calculus formation above the gumline may develop.  Can Chlorhexidine mouthwash  be used if I am pregnant or a nursing mother? Pregnancy Teratogenic Effects Pregnancy category B. Reproduction studies have been performed in rats and rabbits at Chlorhexidine gluconate doses up to 300 mg/kg/day and 40 mg/kg/day, respectively, and have not revealed evidence of harm to the fetus. However, adequate and well-controlled studies in pregnant women have not been done. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Chlorhexidine gluconate oral rinse is administered to nursing women. In parturition and lactation studies with rats, no evidence of impaired parturition or of toxic effects to suckling pups was observed when Chlorhexidine gluconate was administered to dams at doses that were over 100 times greater than that which would result from a person's ingesting 30 ml (2 capfuls) of Chlorhexidine gluconate oral rinse per day. Pediatric Use Clinical effectiveness and safety of Chlorhexidine gluconate oral rinse have not been established in children under the age of 18. How to use Chlorhexidine Mouthwashes? Have to use as an adjunct. chlorhexidine alone cannot eliminate dental plaque proper brushig have to be done. Do not use before or immediately after tooth brushing. Use after at least 1hour  from brushing. Why ? Anionic surfactants in toothpastes cause low effective delivery of Chlorhexidine 0.2% mouthwash 10 ml twice daily. maximum period of use 2-3 weeks. keep in the mouth for 1 minute. do not swallow.

Why Teeth Erupt Late?

Delayed tooth eruption

• Eruption is the axial movement of a tooth from its nonfunctional position in the bone to functional occlusion. 
• Eruption is often used to indicate the moment of emergence of the tooth into the oral cavity. 
• The normal eruption of deciduous and permanent teeth into the oral cavity occurs over a broad chronological age range. Racial, ethnic, sexual, and individual factors can influence eruption and are usually considered in determining the standards of normal eruption.
• True and significant deviations from accepted norms of eruption time are often observed in clinical practice. Premature eruption has been noted,but delayed tooth eruption (DTE) is the most commonly encountered deviation from normal eruption time.

Other words Used in delayed teeth eruption

• Delayed eruption
• Impacted teeth
• Primary retention
• Embedded teeth
• Pseudoanodontia
• Late eruption
• Retarded eruption
• Arrested eruption
• Primary failure of eruption
• Misplaced teeth
• Displaced teeth
• Impaired eruption
• Depressed eruption
• Noneruption
• Submerged teeth
• Reinclusion/inclusion of teeth

What are the normal ages of teeth eruption?

What are the Causes of Delayed tooth eruption?

Treatment for Delayed Erupting teeth (DE)

Delayed eruption presents a challenge for orthodontic treatment planning. A number of techniques have been suggested for treating. The main considerations for teeth affected by DE are

• the decision to remove or retain the tooth or teeth affected by DE, 
• the use of surgery to remove obstructions, 
• surgical exposure of teeth affected by DE, 
• the application of orthodontic traction, 
• the need for space creation and maintenance, and 
• diagnosis and treatment of systemic disease that causes DE.

Teeth Sensitivity

What Is teeth sensitivity / dentin sensitivity?

Teeth sensitivity

Teeth sensitivity is characterized by short, sharp pain arising from exposed dentin in response to stimuli typically thermal, evaporative, tactile, osmotic, or chemical that cannot be attributed to any other dental defect or pathology.
Dentin get exposed due to wearing off of overlying enamel of the tooth by mechanical and chemical means. Common examples are vigorous tooth brushing, frequent consumption of acidic beverages.

dentin sensitivity mechanism

What are the special features of tooth sensitivity?

sensitive teeth

• A short duration pain 
• sharp pain
• pain arising from exposed dentin in response to 
• Thermal (while taking hot or cold drinks) 
• Evaporative
• Tactile (while brushing) 
• Osmotic stimuli (while eating sweets)
• There is no evidence of caries

• wearing off of the enamel may not always visible.

What causes tooth sensitivity?

• Abnormal thickness or structure of enamel- most of the time may be present from birth. Ex. Amelogenesis imperfecta, enamel hypoplasia.
• Vigorous tooth brushing and other brushing related causes leading to enamel wear-off.
• Frequent consumption of acidic and carbonated drinks.
• Gastric acid regurgitation (frequent vomiting)
• Dentin exposure by enamel cracks or fractures.
• Aging
• Root exposure due to periodontal diseases.
• After tooth bleaching.

What are the preventive methods of tooth sensitivity?

reasons for tooth sensitivity

1. Use of Proper tooth brushing technique
1. Use a tooth brush with soft bristles.
2. Do not brush soon after meals. wait for about at least one hour.
3. Do not apply excessive pressure on the brush while brushing
4. Pregnant mothers should not brush there teeth soon after vomiting 
2. Do not drink acidic or carbonated drinks, fruit juices frequently
3. Protect your gums from periodontal diseases which lead to root exposure

What are the Treatment available for sensitive teeth?

Treatment Strategies

• Plug the dentinal tubules preventing fluid flow
• Desensitize the nerve making it less responsive to stimulation

Plug the dentinal tubules preventing fluid flow

• Composite or GIC restoration 
• Crown placement 
• Periodontal surgery to cover the exposed roots

 plug the inside of the dentinal tubules

Ions or salts: stannous fluoride, sodium fluoride, potassium oxalate, etc
Precipitates: glutaraldehyde 

Resin: dentin sealers

• Potassium nitrate containing product/toothpaste  should be used 2×day for at least 2 week

Desensitize the nerve making it less responsive to stimulation

Potassium Nitrate is the only one approved by FDA and ADA. 

KNO3 penetrates through the dentinal tubules to the nerve; K+ may depolarize the nerve and prevent it from repolarizing; Thereby, Preventing it from sending pain signals to the brain.

What could be done to eliminate Post bleaching sensitivity?

Active methods

Use of either fluoride,potassium nitrate, or both in combination. Traditionally,fluoride has been used
as a method of reducing sensitivity. The primary mechanism for action is to occlude dentinal tubules or
increase the hardness of enamel, which impedes the flow of materials to the pulp.

Passive approach

The passive approach for treating sensitivity was first used. This involved a reduction in wear

time, or in frequency of application.Cessation of treatment results in no lingering sensitivity.

Tips for Teeth Whitening

Tips  for Teeth Whitening

What cause staining of teeth?

Whitishness of the teeth can be lost due to two main types of stains. They are

EXTRINSIC stains (stains on teeth due to external factors).

The causes for extrinsic stains are

• plaque and tartar
• restorations (fillings).
• Beverages ( drinks such as coffee, tea, carbonated drinks etc. which leave behind ugly stains).
• Eating habits (tobacco, aricanut etc.)
• Drugs (iron tablets)

INTRINSIC stains (stains on teeth due to internal factors)

• Hereditary disorders.(amelogenesis imperfecta)
• Medications (Tetracycline).
• Flourosis (excessive exposure to fluoride can cause unaesthetic white patches on the surface of teeth).
• Trauma to the teeth causing bleeding in to the pulp

What are methods used to make the teeth white?

teeth whitening

There are several method available for teeth whitening depending on the type of discolouration. Every type of method do not suitable for any type of discolouration. That is the first thing that you should keep in mind. Common methods of treating discolouration can be divided into two main types.

teeth bleaching

• Professional methods (That you should need a dentists help)
• Home used methods

Collectively they can be simply listed as below

1. Removal of surface stains through Scaling and brushing
2. Bleaching (Teeth whitening)
3. Microabrasion,
4. Macroabrasion,
5. Veneers 
6. Crowns

What I want to know about teeth whitening bleaching?

• various substances used
• Best work for  extrinsic staining
• Commonly used agents are 

• Hydrogen peroxide (3-35%)
• Carbamide peroxide (10%)
• Usually low concentrations used in home bleaching systems.
• The outcome of the procedure is usually unpredictable.
• gross intrinsic staining may require other types of treatment modalities 
• Office bleaching is usually more effective than over the counter products.
• As darker the stain it takes longer period to eliminate that (tetracycline stain takes about 6 months to improve)

How do i know whether I am a suitable candidate to undergo dental bleaching?

• Most important thing is that you should not have high expectations about the outcome.
• You also should not have
• Sever periodontitis 
• Extremely large pulps 
• Exposed Root surfaces 
• Severe loss of Enamel (enamel ware off )  
• Extensive large non-ceramic restorations 
• Peroxide Allergy
• You should not be Pregnant and a Nursing mother

How do peroxides make white my teeth?

mechanism of dental bleaching

Free radicals liberated from carbamide peroxide breaks down large chromogenic particles to smaller colourless molecules.

What are the adverse effects of teeth bleaching?

• Teeth Sensitivity
• Gingival irritation
• Shade regression
• Cervical resorption mainly due to heat
• Decrease the hardness of the enamel

What are the products available in the market for teeth bleaching?

 

A few years ago if you wanted to achieve a beautiful bright and white set of teeth, you had to take out of your pocket quite a hefty fee at the dentist’s. The situation has changed by now, because there are plenty of different types of teeth whitening kits available, which are quite affordable, and you can apply the treatment at home.

Certainly there are high quality kits that give exceptional results, but there are also several teeth whitening devices that only advertise they are good, but they ultimately fail to offer any results at all. Therefore, you need to be careful when purchasing such teeth whitening kits, and make sure you invest into a device that is of high quality and which is recommended by health specialists.

Teeth Whitening Toothpastes

Firstly, there are the so called “brush-on” teeth whitening systems. In this category, you will find the different toothpastes that contain whitening agents, so you will basically get cleaner and whiter teeth with every brushing.

However, the whitening toothpastes are not to be used as a main whitening solution, especially if your teeth are extremely stained. This whitening method s relatively cheap and it will help you get teeth that are one shade whiter than your natural set of teeth.


Teeth Whitening Strips

Then, there are the teeth whitening strips available, which have a whitening gel coating and which must be worn for quite an extended time until you see the desired results. Most often, the gel that can be found on these strips is similar to that used in the whitening tray devices. One downside of using these strips is that if you are not careful, and the strips move, you will get an uneven whitening result.

Teeth Whitening Trays

The teeth whitening trays are extremely popular because they are quite affordable and they are also effective. The trays usually contain a special teeth whitening gel, and the trays must be worn for at least half an hour every day.

According to statistics, people who use this method can obtain teeth that are up to 10 or 11 shades whiter than their natural set of teeth. You must make sure that the trays that you use are a perfect fit for your mouth, so that you will get the best results.

laser whitening