The main types of dental abscess are:

- Periapical abscess: The result of a chronic, localized infection located at the tip, or apex, of the root of a tooth.

- Periodontal abscess: begins in a periodontal pocket (see: periodontal abscess)

- Gingival abscess: involving only the gum tissue, without affecting either the tooth or the periodontal ligament (see: periodontal abscess)

- Pericoronal abscess: involving the soft tissues surrounding the crown of a tooth (see: Pericoronitis)

- Combined periodontic-endodontic abscess: a situation in which a periapical abscess and a periodontal abscess have combined (see: Combined periodontic-endodontic lesions).

The pain is continuous and may be described as extreme, growing, sharp, shooting, or throbbing. Putting pressure or warmth on the tooth may induce extreme pain. The area may be sensitive to touch and possibly swollen as well. This swelling may be present at either the base of the tooth, the gum, and/or the cheek, and sometimes can be reduced by applying ice packs.

An acute abscess may be painless but still have a swelling present on the gum. It is important to get anything that presents like this checked by a dental professional as it may become chronic later.

In some cases, a tooth abscess may perforate bone and start draining into the surrounding tissues creating local facial swelling. In some cases, the lymph glands in the neck will become swollen and tender in response to the infection. It may even feel like a migraine as the pain can transfer from the infected area. The pain does not normally transfer across the face, only upwards or downwards as the nerves that serve each side of the face are separate.

Severe aching and discomfort on the side of the face where the tooth is infected is also fairly common, with the tooth itself becoming unbearable to touch due to extreme amounts of pain.

There are four types of abscesses that can involve the periodontal tissues:

1. Gingival abscess—a localized, purulent infection involves only the soft gum tissue near the marginal gingiva or the interdental papilla.

2. Periodontal abscess—a localized, purulent infection involving a greater dimension of the gum tissue, extending apically and adjacent to a periodontal pocket.

3. Pericoronal abscess—a localized, purulent infection within the gum tissue surrounding the crown of a partially or fully erupted tooth. Usually associated with an acute episode of pericoronitis around a partially erupted and impacted mandibular third molar (lower wisdom tooth).

4. combined periodontal/endodontic abscess

A periodontal abscess (also termed lateral abscess, or parietal abscess), is a localized collection of pus (i.e. an abscess) within the tissues of the periodontium. It is a type of dental abscess. A periodontal abscess occurs alongside a tooth, and is different from the more common periapical abscess, which represents the spread of infection from a dead tooth (i.e. which has undergone pulpal necrosis). To reflect this, sometimes the term "lateral (periodontal) abscess" is used. In contrast to a periapical abscess, periodontal abscesses are usually associated with a vital (living) tooth. Abscesses of the periodontium are acute bacterial infections classified primarily by location.

Acute periapical periodontitis, also termed acute apical periodontitis, acute periradicular periodontitis, or symptomatic periapical periodontitis.

The radiographic features of periapical inflammatory lesions vary depending on the time course of the lesion. Because very early lesions

may not show any radiographic changes, diagnosis of these lesions relies solely on the clinical symptoms . More chronic lesions may show lytic (radiolucent) or sclerotic (radiopaque) changes, or both.

Acute pericoronitis (i.e. sudden onset and short lived, but significant, symptoms) is defined as "varying degrees of inflammatory involvement of the pericoronal flap and adjacent structures, as well as by systemic complications." Systemic complications refers to signs and symptoms occurring outside of the mouth, such as fever, malaise or swollen lymph nodes in the neck.

The signs and symptoms of pericoronitis depend upon the severity, and are variable:

- Pain, which gets worse as the condition develops and becomes severe. The pain may be throbbing and radiate to the ear, throat, temporomandibular joint, posterior submandibular region and floor of the mouth. There may also be pain when biting. Sometimes the pain disturbs sleep.

- Tenderness, erythema (redness) and Edema (swelling) of the tissues around the involved tooth, which is usually partially erupted into the mouth. The operculum is characteristically very painful when pressure is applied.

- Halitosis resulting from the bacteria putrefaction of proteins in this environment releasing malodorous volatile sulfur compounds.

- Bad taste in the mouth from exudation of pus.

- Intra-oral halitosis.

- Formation of pus, which can be seen exuding from beneath the operculum (i.e. a pericoronal abscess), especially when pressure is applied to the operculum.

- Signs of trauma on the operculum, such as indentations of the cusps of the upper teeth, or ulceration. Rarely, the soft tissue around the crown of the involved tooth may show a similar appearance to necrotizing ulcerative gingivitis.

- Trismus (difficulty opening the mouth). resulting from inflammation/infection of the muscles of mastication.

- Dysphagia (difficulty swallowing).

- Cervical lymphadenitis (inflammation and swelling of the lymph nodes in the neck), especially of the submandibular nodes.

- Facial swelling, and rubor, often of the cheek that overlies the angle of the jaw.

- Pyrexia (fever).

- Leukocytosis (increased white blood cell count).

- Malaise (general feeling of being unwell).

- Loss of appetite.

- The radiographic appearance of the local bone can become more radiopaque in chronic pericoronitis.

A phoenix abscess is a dental abscess that can occur immediately following root canal treatment. Another cause is due to untreated necrotic pulp (chronic apical periodontitis). It is also the result of inadequate debridement during the endodontic procedure. Risk of occurrence of a phoenix abscess is minimised by correct identification and instrumentation of the entire root canal, ensuring no missed anatomy.

Treatment involves repeating the endodontic treatment with improved debridement, or tooth extraction. Antibiotics might be indicated to control a spreading or systemic infection.

An odontogenic infection is an infection that originates within a tooth or in the closely surrounding tissues. The term is derived from "" (from ancient Greek "odous" - "tooth") and "" (from Greek "genos" - "birth"). Odontogenic infections may remain localized to the region where they started, or spread into adjacent or distant areas.

It is estimated that 90-95% of all orofacial infections originate from the teeth or their supporting structures. Furthermore, about 70% of odontogenic infections occur as periapical inflammation, i.e. acute periapical periodontitis or a periapical abscess. The next most common form of odontogenic infection is the periodontal abscess.

Sinusitis is inflammation of the paranasal air sinuses. Infections associated with teeth may be responsible for approximately 20% of cases of maxillary sinusitis. The cause of this situation is usually a periapical or periodontal infection of a maxillary posterior tooth, where the inflammatory exudate has eroded through the bone superiorly to drain into the maxillary sinus. Once an odontogenic infection involves the maxillary sinus, it is possible that it may then spread to the orbit or to the ethmoid sinus.

Gingival and periodontal pockets are dental terms indicating the presence of an abnormal depth of the gingival sulcus near the point at which the gingival tissue contacts the tooth.

Necrotic pulp is a finding in dentistry to describe dental pulp within a tooth which has become necrotic. Directly meaning, death of the pulp. It is a finding of interest to dentists as the process of pulp death may be painful causing a toothache.

Sequelae of a necrotic pulp include acute apical periodontitis, dental abscess or radicular cyst and discolouration of the tooth.

Tests for a necrotic pulp include: vitality testing using a thermal test or an electric pulp tester. Discolouration may be visually obvious, or more subtle.

Treatment usually involves endodontics or extraction.

Periapical cysts begin as asymptomatic and progress slowly. Subsequent infection of the cyst causes swelling and pain. Initially, the cyst swells to a round hard protrusion, but later on the body resorbs some of the cyst wall, leaving a softer accumulation of fluid underneath the mucous membrane.

Larger cysts may cause bone expansion or displace roots. Discoloration of the affected tooth may also occur. Patient will present negative results to electric and ice test of the affected tooth but will be sensitive to percussion. Surrounding gingival tissue may experience lymphadenopathy. The alveolar plate may exhibit crepitus when palpated.

Periapical cysts exist in two structurally distinct classes:

Periapical true cysts - cysts containing cavities entirely surrounded in epithelial lining. Resolution of this type of cyst requires surgical treatment such as a cystectomy.

Periapical pocket cysts - epithelium lined cavities that have an opening to the root canal of the affected tooth. Resolution may occur after traditional root canal therapy.

The periapical cyst (also termed radicular cyst or inflammatory cyst) is the most common odontogenic cyst. Periapical is defined as "the tissues surrounding the apex of the root of a tooth" and a cyst is "a pathological cavity lined by epithelium, having fluid or gaseous content that is not created by the accumulation of pus." Most frequently located in the maxillary anterior region, it is caused by pulpal necrosis secondary to dental caries or trauma. The cyst has lining that is derived from the epithelial cell rests of Malassez which proliferate to form the cyst. Highly common in the oral cavity, the periapical cyst is asymptomatic, but highly significant because a secondary infection can cause pain and damage. In radiographs, it appears a radiolucency (dark area) around the apex of a tooth's root.

As the original sulcular depth increases and the apical migration of the junctional epithelium has simultaneously occurred, the pocket is now lined by pocket epithelium (PE) instead of junctional epithelium (JE). To have a true periodontal pocket, a probing measurement of 4 mm or more must be clinically evidenced. In this state, much of the gingival fibers that initially attached the gingival tissue to the tooth have been irreversibly destroyed. The depth of the periodontal pockets must be recorded in the patient record for proper monitoring of periodontal disease. Unlike in clinically healthy situations, parts of the sulcular epithelium can sometimes be seen in periodontally involved gingival tissue if air is blown into the periodontal pocket, exposing the newly denuded roots of the tooth. A periodontal pocket can become an infected space and may result in an abscess formation with a papule on the gingival surface. Incision and drainage of the abscess may be necessary, as well as systemic antibiotics; placement of local antimicrobial delivery systems within the periodontal pocket to reduce localized infections may also be considered.

It is classified as supra bony and infra bony based on its depth in relation to alveolar bone.

1-increased localised pressure.

2- focal growth retardation and stimulation.

Invaginatus is an anomaly resulting from invagination forming within the enamel organ. Invagination ranges pitting occupying most of the crown and root. Although examination may reveal a fissure on the surface of anterior tooth, radiographic examination is the way.

Apical abscesses can spread to involve periodontal pockets around a tooth, and periodontal pockets cause eventual pulp necrosis via accessory canals or the apical foramen at the bottom of the tooth. Such lesions are termed periodontic-endodontic lesions, and they may be acutely painful, sharing similar signs and symptoms with a periodontal abscess, or they may cause mild pain or no pain at all if they are chronic and free-draining. Successful root canal therapy is required before periodonal treatment is attempted. Generally, the long-term prognosis of perio-endo lesions is poor.

Common marginal gingivitis in response to subgingival plaque is usually a painless condition. However, an acute form of gingivitis/periodontitis, termed acute necrotizing ulcerative gingivitis (ANUG), can develop, often suddenly. It is associated with severe periodontal pain, bleeding gums, "punched out" ulceration, loss of the interdental papillae, and possibly also halitosis (bad breath) and a bad taste. Predisposing factors include poor oral hygiene, smoking, malnutrition, psychological stress, and immunosuppression. This condition is not contagious, but multiple cases may simultaneously occur in populations who share the same risk factors (such as students in a dormitory during a period of examination). ANUG is treated over several visits, first with debridement of the necrotic gingiva, homecare with hydrogen peroxide mouthwash, analgesics and, when the pain has subsided sufficiently, cleaning below the gumline, both professionally and at home. Antibiotics are not indicated in ANUG management unless there is underlying systemic disease.

It is experienced as an uncomfortable sensation in the tooth, followed by an aching pain.

It may be noted on radiographs as a radiopaque (or lighter) mass at each root apex.

Type II would mostly cause discolouration to the primary teeth. Affected teeth usually appear as brownish-blue, brown or yellow. Translucent “opalescence” is often one of the characteristics to describe teeth with DD-2. In some cases teeth might show slightly amber coloured but in most of the cases permanent teeth are unaffected and appear normal regardless of colour, shape and size. Dental X-rays is the key to diagnose dentine dysplasia, especially on permanent teeth. Abnormalities of the pulp chamber is the main characteristic to make a definitive diagnosis.

In the primary teeth, coronal dentin dysplasia may appear similar to Dentinogenesis Imperfecta type II (DG-II) but if abnormalities features appear to be more pronounced in the permanent teeth, then consider changing the diagnosis to DGI-II instead of DD-2.

In other words, affect primary teeth usually have abnormal shaped or shorter than normal roots . “Crescent/ half-moon shaped” pulp chamber remnant in permanent teeth can be seen on x-rays. The roots may appear to be darker or radiolucent/ pointy and short with apical constriction. Dentine is laid down abnormally and causes excessive growth within the pulp chamber. This will reduce the pulp space and eventually cause incomplete and total pulp chamber obliteration in permanent teeth. Sometimes periapical pathology or cysts can be seen around the root apex. Most cases of DD associated with peri-apical radiolucency/ pathology have been diagnosed as radicular cysts, but some of them have been as diagnosed peri-apical grauloma instead.

Anterior space abscess can cause trismus (spasm of jaw muscle) and hard mass formation along the angle of the mandible, with medial bulging of the tonsil and lateral pharyngeal wall. Posterior space abscess causes swelling in posterior pharyngeal wall. Trismus (spasm of jaw muscle) is minimal. Posterior abscess may involve structures within the carotid sheath, causing rigors, high fever, bacteremia, neurologic deficit, massive haemorrhage caused by carotid artery rupture.

Fever, sore throat, odynophagia (painful swallowing), swelling in neck.