Squamous cell carcinomas amount to more than 90% of malignant tumours of the oral cavity and oropharynx. As in other parts of the upper aero digestive tract, there is a strong and synergistic association with tobacco smoking and alcohol abuse. In some regions, particularly the Indian subcontinent, oral cancer is among the most frequent malignancies, largely due to tobacco chewing. The WHO Working Group has made an attempt to unify the terminology used to define the histological features of precursor lesions throughout the head and neck region. Although there has been considerable progress in the understanding of the genetic and molecular events underlying the progression of precancerous lesions to invasive carcinomas, this has yet to be translated into novel therapeutic strategies.

Oral Medicine is the discipline of dentistry concerned with the oral health care of medically complex patients-including the diagnosis and management of medical conditions that affect the oral and maxillofacial region. Oral medicine is concerned with clinical diagnosis and non-surgical management of non-dental pathologies affecting the orofacial region (the mouth and the lower face). Many systemic diseases have signs or symptoms that manifest in the orofacial region. Pathologically, the mouth may be afflicted by many cutaneous and gastrointestinal conditions. There is also the unique situation of hard tissues penetrating the epithelial continuity (hair and nails are intra-epithelial tissues). The biofilm that covers teeth therefore causes unique pathologic entities known as plaque-induced diseases.

Oral-Maxillofacial Surgery is a surgical specialty which involves the diagnosis, surgery and adjunctive treatment of diseases, injuries and defects involving both the functional and aesthetic aspects of the hard and soft tissues of the oral and maxillofacial region. More simply put, the oral and maxillofacial surgeon is the orthopedic surgeon of the facial region. He or she is an individual who addresses problems ranging from the removal of impacted teeth to the repair of facial trauma.

Dental emergencies are identified symptoms that need more immediate treatments. Dental emergencies can have many causes, including accidents, sports-related injuries, tooth decay and infection. Some of the dental emergencies are as like: a traumatic injury to your mouth, jaw or teeth, severe pain that you cannot control with over-the-counter pain medication, uncontrolled bleeding and severe swelling in mouth, face or neck.

Oral pathology refers to the diseases of the mouth, jaws and related structures such as salivary glands, temporomandibular joints, facial muscles and perioral skin (the skin around the mouth). The mouth is an important organ with many different functions. It is also prone to a variety of medical and dental disorders. The specialty oral pathology is concerned with diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial region. It is sometimes considered to be a specialty of dentistry and pathology. Sometimes the term head and neck pathology is used instead, but this might imply that the pathologist deals with otorhinolaryngologic disorders (i.e. ear, nose and throat) in addition to maxillofacial disorders. In this role there is some overlap between the expertise of head and neck pathologists and that of endocrine pathologists.

According to World Health Organization, Dental health as a state of being free from mouth and facial pain, oral and throat cancer, oral infection and sores, periodontal disease, tooth decay, tooth loss, and other diseases and disorders that limit an individual’s capacity in biting, chewing, smiling, speaking, and psychosocial wellbeing. It includes healthy gums, hard and soft palate, linings of the mouth and throat, tongue, lips, salivary glands, chewing muscles, and upper and lower jaws. Good dental health enables us to speak, smile, kiss, breathe, whistle, smell, taste, drink, eat, bite, chew, swallow and express feelings. The oral cavity plays a central role for intake of basic nutrition and protection against microbial infections.

Nanorobots which are considered as the most useful gift of nanotechnology to medical sciences, having size of few nanometers (10-9)meters are produced by a modern technology called nanorobotics. These micron sized devices aid in précised interaction with objects of nanoscale and manipulate with high power resolution. The advents of nanotechnology involve the application of nanorobots in various aspects of dentistry like, Local Anesthesia, Dentition Renaturalization, and permanent Hypersensitivity cure, complete Orthodontic Realignments during single office visit, and continuous oral health maintenance using mechanical dentifrobots. It is envisoned that Dental Nanorobots could be constructed to destroy caries-causing bacteria or to repair tooth blemishes. Eventhough research work and clinical trials on Nano robots are in the early stage, researchers are quite optimistic regarding the use these microrobots in dentistry.

Every interaction between dental practice and a patient is a component of dental marketing. In some cases, this will encompass concrete details like the way office staff answers the phone or the list of offered services. In other cases, it will rely on more diffuse elements like the way logo looks or the branding of dental materials. But in subtle yet powerful ways, all of these cues establish an image of practice in the minds of patients. Dental management is the backbone of the dental practice. Dental management includes appropriate, timely assessments, which provide diagnosis of mandatory and adjunctive services. A systematic approach to reactivating overdue hygiene patients must be in place. Effective communication for treatment planning and explaining the importance of frequent preventive care appointments is imperative.

Endodontics encompasses the study and practice of the basic and clinical sciences of the biology of the normal dental pulp and the etiology, diagnosis, prevention and treatment of diseases and injuries of the dental pulp along with associated per radicular conditions. Endodontics has evolved tremendously in the past decade and its applications have immensely improved the quality of dental treatment. Endodontists perform a variety of procedures including endodontic therapy (commonly known as "root canal therapy"), endodontic retreatment, surgery, treating cracked teeth, and treating dental trauma. Root canal therapy is one of the most common procedures. If the dental pulp (containing nerves, arterioles, venules, lymphatic tissue, and fibrous tissue) becomes diseased or injured, endodontic treatment is required to save the tooth. Endodontics is recognized as a specialty by many national dental organizations including the British General Dental Council, American Dental Association, Royal College of Dentists of Canada, Indian Dental Association, and Royal Australasian College of Dental Surgeons.

Paediatric dentistry is the branch of dentistry dealing with children from birth through adolescence. The specialty of paediatric dentistry is recognized by the American Dental Association, Royal College of Dentists of Canada, and Royal Australasian College of Dental Surgeons. Paediatric dentists promote the dental health of children as well as serve as educational resources for parents. It is recommended by the American Academy of Paediatric Dentistry (AAPD) and the American Academy of Paediatrics (AAP) that a dental visit should occur within six months after the presence of the first tooth or by a child's first birthday. The AAPD has said that it is important to establish a comprehensive and accessible ongoing relationship between the dentist and patient – referring to this as the patient's "dental home". This is because early oral examination aids in the detection of the early stages of tooth decay. Early detection is essential to maintain oral health, modify aberrant habits, and treat as needed and as simply as possible. Additionally, parents are given a program of preventative home care (brushing/flossing/fluorides), a caries risk assessment, information on finger, thumb, and pacifier habits, advice on preventing injuries to the mouth and teeth of children, diet counseling, and information on growth and development.

Dental sleep is a sleep related breathing disorders, such as snoring and OSA, and the impact of sleep disorders on society. A comprehensive evaluation is described that includes upper airway examination and imaging with a focus on areas of pathophysiology in OSA. The essentials of dental sleep medicine course is a logical way to incorporate OAT into your practice. The course includes a review of sleep related breathing disorders, such as snoring and OSA, and the impact of sleep disorders on society. A final portion of the treatment is case-based and provides clinical examples of the evaluation and treatment of sleep disorders in a dental practice.

Periodontology or periodontics is the specialty of dentistry that studies supporting structures of teeth, as well as diseases and conditions that affect them. The supporting tissues are known as the periodontium, which includes the gingiva (gums), alveolar bone, cementum, and the periodontal ligament. Periodontal diseases take on many different forms but are usually a result of a coalescence of bacterial plaque biofilm accumulation of the red complex bacteria (e.g., P. gingivalis, T. forsythia, and T. denticola) of the gingiva and teeth, combined with host immuno-inflammatory mechanisms and other risk factors which lead to destruction of the supporting bone around natural teeth. Untreated, these diseases lead to alveolar bone loss and tooth loss and, to date, continue to be the leading cause of tooth loss in adults.

Oral implantology is the study of surgical component that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, facial prosthesis or to act as an orthodontic anchor. The basis for modern dental implants is a biologic process called osseointegration where materials, such as titanium, form an intimate bond to bone. The implant fixture is first placed, so that it is likely to osseointegrate, then a dental prosthetic is added. A variable amount of healing time is required for osseointegration before either the dental prosthetic (a tooth, bridge or denture) is attached to the implant or an abutment is placed which will hold a dental prosthetic. Success or failure of implants depends on the health of the person receiving it, drugs which affect the chances of osseointegration and the health of the tissues in the mouth. The amount of stress that will be put on the implant and fixture during normal function is also evaluated. Planning the position and number of implants is key to the long-term health of the prosthetic since biomechanical forces created during chewing can be significant. The position of implants is determined by the position and angle of adjacent teeth, lab simulations or by using computed tomography with CAD/CAM simulations and surgical guides called stents. The prerequisites to long-term success of osseointegrated dental implants are healthy bone and gingiva. Since both can atrophy after tooth extraction, pre-prosthetic procedures such as sinus lifts or gingival grafts are sometimes required to recreate ideal bone and gingiva. The final prosthetic can be either fixed, where a person cannot remove the denture or teeth from their mouth, or removable, where they can remove the prosthetic. In each case an abutment is attached to the implant fixture. Where the prosthetic is fixed, the crown, bridge or denture is fixed to the abutment with either lag screws or dental cement. Where the prosthetic is removable, a corresponding adapter is placed in the prosthetic so that the two pieces can be secured together.

A dental laser is a type of laser designed specifically for use in oral surgery or dentistry. Lasers can be used as a safe and effective treatment for a wide range of dental procedures and are often used in conjunction with other dental instruments. Dental lasers can be used to: reduce the discomfort of canker and cold sores, expose partially erupted wisdom teeth, remove muscle attachments that limit proper movement, manage gum tissue during impressions for crowns or other procedures, remove overgrown tissues caused by certain medications, perform biopsy procedures, remove inflamed gum tissues and aid in the treatment of gum disease, remove or reshape gum and bone tissues during crown lengthening procedures, help treat infections in root canals and speed up tooth whitening procedures. There are several advantages. Dentists may not need to use a drill or administer anesthesia in some procedures, allowing the patient to enjoy a more relaxed dental experience. Laser procedures can be more precise. Also, lasers can reduce symptoms and healing times associated with traditional therapies; reduce the amount of bacteria in both diseased gum tissue and in tooth cavities; and control bleeding during surgery.

Orthodontics is the branch of dentistry that corrects teeth and jaws that are positioned improperly. Crooked teeth and teeth that do not fit together correctly are harder to keep clean, are at risk of being lost early due to tooth decay and periodontal disease, and cause extra stress on the chewing muscles that can lead to headaches, TMJ syndrome and neck, shoulder and back pain. Teeth that are crooked or not in the right place can also detract from one's appearance. The benefits of orthodontic treatment include a healthier mouth, a more pleasing appearance, and teeth that are more likely to last a lifetime.

Dental Ergonomics is the study to define work related musculoskeletal disorders, risk factors and stressful individual behaviours in dentistry which lead to injures and implementing preventive strategies. These problems can be avoided by increasing awareness of the postures used during the work, redesigning the work station to promote neutral positions, examining the impact of instrument use on upper extremity pain, and following healthy work practices to reduce the stress of dental work on the practitioner’s body.

Hypnodontics is the art and science of using hypnosis to induce comfortable and pain free dental visits. Hypnosis is used to reduce stress and induce anesthesia so that less medication is used. Hard to manage patients often present the majority of problems the dentist encounters in their daily routine. They take extra time and require special consideration by the dentist and the staff. Hard to manage patients often put off going to the dentist until the pain or dental problem can no longer be ignored. There are numerous reasons why these patients are fearful, tense, nervous and anxious before, during, and even after the dental visit. These patients will complain of extreme anxiety prior to a simple check-up and repeatedly request tranquilizers to help them cope. Hypnosis can easily alleviate the tension, nervousness and unreasonable fear of pain often exhibited by these patients. The hypnotherapist should meet with this type of dental patient two or three days prior to the scheduled dental appointment. One of the most troublesome problems that a patient may bring to the dentist is that of gagging as soon as anything is inserted into the mouth. Ordinarily this gagging response will occur only if the object is inserted deep into the mouth and into the throat. It is a natural reflex governed by the vagus nerve (cranial nerve 11) to protect against choking. The trigger lies so deep that the reflex does not normally affect the person who is having dental work. For some people, this trigger has moved forward through conditioning to the lips, or the tongue, or some other area touched in the dental examinations. Unless controlled, the gagging can make dental procedures difficult or impossible. Control can be achieved in many cases by direct suggestion or properly developed imagery, but sometimes more complex methods are required. Waking hypnosis is a very effective means to completely eliminate the gag reflex.

In the year 2000, the term and may be the field of nanodentistry were born. As nanomedicine advanced, dentistry also started evolving in the field of Nanotechnology. It is envisaged that nanotechnology will affect the fields of diagnosis, materials,restorative dentistry, and surgery. These exciting new branches namely nanorobotics, nanodiagnosis, nanomaterials, and nanosurgery and nanodrugs would profoundly impact clinical dentistry in the not-so-distant future. Various nanomaterials can be used for restoration of decayed, carious, missing, and fractured teeth. Recent advances in nanomaterials have brought nanocomposites,nanoimpression, and nanoceramic into the domain of clinical dentistry. Nanocomposite artificial teeth are also a new development in this field. Nanoinorganic fillers are diffused in the matrix of composite. These are more durable as well as highly resistant to abrasion with superior color.

Restorative Dentistry is the study, diagnosis and integrated management of diseases of the oral cavity, the teeth and supporting structures. It includes the rehabilitation of the teeth and the oral cavity to functional, psychological and aesthetic requirements of the individual patient, including the co-ordination of multi-professional working to achieve these objectives. Restorative dentistry encompasses the dental specialties of Endodontics, Periodontics and Prosthodontics (fixed and removable) and its foundation is based upon the interaction of these specialties in cases requiring complex, multi-faceted care. Restorative Dentistry is often aptly called ‘Oral Rehabilitation’ due to the increasing need for multidisciplinary and integrated care within and out with the speciality including Orthodontics, Oral and Maxillofacial Surgery, Paediatric Dentistry and Dental and Maxillofacial Radiology, due to the increasing complexity of oral health problems as people live longer. The focus of the Restorative Dentistry speciality is to work with other dental, medical and surgical specialists and other clinical colleagues, to provide and support the integrated management and oral rehabilitation of patients with complex treatment needs.

Craniofacial surgery is a surgical subspecialty of plastic surgery, oral and maxillofacial surgery and otolaryngology-head & neck surgery that deals with congenital and acquired deformities of the head, skull, face, Neck, jaws and associated structures. Although craniofacial treatment often involves manipulation of bone, craniofacial surgery is not tissue-specific, i.e., craniofacial surgeons deal with bone, skin, nerve, muscle, teeth, etc. Defects typically treated by craniofacial surgeons include craniosynostosis (isolated and syndromic), rare craniofacial clefts, acute and chronic sequellae of facial fractures, cleft lip and palate, micrognathia, Treacher Collins Syndrome, Apert's Syndrome, Crouzon's Syndrome, hemifacial microsomia and many others.

Cosmetic dentistry is generally used to refer to any dental work that improves the appearance (though not necessarily the function) of a person's teeth, gums and/or bite. It primarily focuses on improvement dental aesthetics in color, position, shape, size, alignment and overall smile appearance.