Cysts rarely cause any symptoms, unless they become secondarily infected. The signs depend mostly upon the size and location of the cyst. If the cyst has not expanded beyond the normal anatomical boundaries of the bone, then there will be no palpable lump outside or inside the mouth. The vast majority of cysts expand slowly, and the surrounding bone has time to increase its density around the lesion, which is the body's attempt to isolate the lesion. Cysts that have expanded beyond the normal anatomic boundaries of a bone are still often covered with a thin layer of new bone. At this stage, there may be a sign termed "eggshell cracking", where the thinned cortical plate cracks when pressure is applied. A lump may be felt, which may feel hard if there is still bone covering the cyst, or fluctuant if the cyst has eroded through the bone surrounding it. A cyst may become acutely infected, and discharge into the oral cavity via a sinus. Adjacent teeth may be loosened, tilted or even moved bodily. Rarely, roots of teeth are resorbed, depending upon the type of cyst. The inferior alveolar nerve runs through the mandible and supplies sensation to the lower lip and chin. As most cysts expand slowly, there will be no altered sensation (anesthesia or paraesthesia), since the inferior alveolar canal is harmlessly enveloped or displaced over time. More aggressive cysts, or acute infection of any cyst may cause altered sensation.

Odontogenic cysts have histologic origins in the cells of the dental structures. Some are inflammatory while others are developmental.

- Radicular cyst is the most common (up to two thirds of all cysts of the jaws). This inflammatory cyst originated from a reaction to dental pulp necrosis.

- Dentigerous cyst, the second most prevalent cyst, is associated with the crown of non-erupted tooth.

- Odontogenic keratocyst, which now is considered as tumor, and therefore called "Keratocystic odontogenic tumor". This lesion may be associated with the Nevoid basal cell carcinoma syndrome.

- Buccal bifurcation cyst which appears in the buccal bifurcation region of the mandibular first molars in the second half of the first decade of life.

- Eruption cyst; a small cyst in the gingiva as a tooth erupts, forming from the degenerating dental follicle

- Primordial cyst; previous thought to be a unique entity. Most primordial cysts have proven to be Keratocystic odontogenic tumors

- Orthokeratinized odontogenic cyst; a variant of the Keratocystic odontogenic tumor

- Gingival cyst of the newborn; an inclusion cyst from remanents of the dental lamina on a newborn gingiva

- Gingival cyst of the adult; a soft tissue variant of the lateral periodontal cyst

- Lateral periodontal cyst; a non-inflammatory cyst (vs a radicular cyst) on the side of a tooth derived from remanents of the dental lamina

- Calcifying odontogenic cyst; a rare lesion with cystic and neoplastic features and significant diversity in presentation, histology and prognosis

- Glandular odontogenic cyst; cyst with respiratory like epithelial lining and the potential for recurrence with characteristics similar to a central variant of low-grade mucoepidermoid carcinoma

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.

Periapical cysts comprise approximately 75% of the types of cysts found in the oral region. The ratio of individuals diagnosed with periapical cysts is 3:2 male to female, as well as individuals between 20 and 60 years old. Periapical cysts occur worldwide.

Types of Periapical cysts:

Apical: 70%

Lateral: 20%

Residual: 10%

Odontogenic cyst are a group of jaw cysts that are formed from tissues involved in odontogenesis (tooth development). Odontogenic cysts are closed sacs, and have a distinct membrane derived from rests of odontogenic epithelium. It may contain air, fluids, or semi-solid material. Intra-bony cysts are most common in the jaws, because the mandible and maxilla are the only bones with epithelial components. That odontogenic epithelium is critical in normal tooth development. However, epithelial rests may be the origin for the cyst lining later.

Not all oral cysts are odontogenic cyst. For example, mucous cyst of the oral mucosa and nasolabial duct cyst are not of odontogenic origin.

In addition, there are several conditions with so-called (radiographic) 'pseudocystic appearance' in jaws; ranging from anatomic variants such as Stafne static bone cyst, to the aggressive aneurysmal bone cyst.

Most cysts in the body are benign (dysfunctional) tumors, the result of plugged ducts or other natural body outlets for secretions. However, sometimes these masses are considered neoplasm:

- Keratocyst

- Calcifying odotogenic cyst

- According to the current (2005) classification of the World Health Organization, both (parakeratizied) odontogenic keratocyst and calcifying odotogenic cyst have neoplastic characteristics, thus renamed as Keratocystic odontogenic tumor and Calcifying odotogenic tumor, respectively.

- Cystic ameloblastoma

- Long standing dentigerous cyst, odontogenic keratocyst, and residual cyst may have neoplastic potential converting into the locally aggressive ameloblastoma, or the malignant squamous cell carcinoma and mucoepidermoid carcinoma.

The globulomaxillary cyst is a cyst that appears between a maxillary lateral incisor and the adjacent canine. It exhibits as an "inverted pear-shaped radiolucency" on radiographs, or X-ray films.

The globulomaxillary cyst often causes the roots of adjacent teeth to diverge.

This cyst should not be confused with a nasopalatine cyst.

The developmental origin has been disputed. Today, most literature agree based on overwhelming evidence that the cyst is predominantly of tooth origin (odontogenic), demonstrating findings consistent with periapical cysts, odontogenic keratocysts or lateral periodontal cysts.

Gingival cyst of adult is a rare condition. The incidence is less than 0.5%. It is formed from the rests of dental lamina. It is found in the soft tissues on the buccal and labial portions of the jaw. It usually occurs on the facial gingiva as a single small flesh colored swelling, sometimes with a bluish hue due to the cystic fluid. Sometimes, it may occur in cluster, either unilaterally or bilaterally or on the lingual surface of the alveolar process. It is most commonly seen in the canine and premolar regions of the mandible, and are sometimes confused with lateral periodontal cysts. It is not normally problematic, but when it grows larger, it can cause some discomfort. It can be removed by simple surgical excision. They are developed late in life, generally up to the sixth decade of age.

The botryoid odontogenic cyst is a multi-compartmentalized variant of the lateral periodontal cyst. It is similar to the lateral periodontal cyst in all its features except that its polycystic nature is often evident through its multilocular pattern on radiographs.

There are no symptoms, and no signs can be elicited on examination. Medical imaging such as traditional radiography or computed tomography is required to demonstrate the defect. Usually the defect is unilateral, but occasionally can be bilateral.

The median alveolar cyst is a rare cyst, occurring in the bony alveolus between the maxillary central incisors. It is distinguished from a periapical cyst by the fact that adjacent teeth are vital.

A dentigerous cyst or follicular cyst is an odontogenic cyst - thought to be of developmental origin - associated with the crown of an unerupted (or partially erupted) tooth. The cyst cavity is lined by epithelial cells derived from the reduced enamel epithelium of the tooth forming organ. Regarding its pathogenesis, it has been suggested that the pressure exerted by an erupting tooth on the follicle may obstruct venous flow inducing accumulation of exudate between the reduced enamel epithelium and the tooth crown.

In addition to the developmental origin, some authors have suggested that periapical inflammation of non-vital deciduous teeth in proximity to the follicles of unerupted permanent successors may be a factor for triggering this type of cyst formation.

Histologically a normal dental follicle is lined by enamel epithelium, whereas a dentigerous cyst is lined by non-keratinized stratified squamous epithelium. Since the dentigerous cyst develops from follicular epithelium it has more potential for growth, differentiation and degeneration than a radicular cyst. Occasionally the wall of a dentigerous cyst may give rise to a more ominous mucoepidermoid carcinoma. Due to the tendency for dentigerous cysts to expand rapidly, they may cause pathological fractures of jaw bones.

On Fine needle aspiration, thin straw colored fluid is seen.

The usual radiographic appearance is that of a well-demarcated radiolucent lesion attached at an acute angle to the cervical area of an unerupted tooth. The border of the lesion may be radiopaque. The radiographic differentiation between a dentigerous cyst and a normal dental follicle is based merely on size. Radiographically, a dentigerous cyst should always be differentiated from a normal dental follicle. Dentigerous cysts are the most common cysts with this radiographic appearance. Radiographically the cyst appears unilocular with well defined margins and often sclerotic borders but sometimes it may be multilocular in appearance and may also have a continuous cystic membrane. Infected cysts show ill-defined margins. Follicular space more than 3mm is to be considered a dentigerous cyst.

Radiographically there are three types of dentigerous cyst, namely the Central type, Lateral type and the Circumferential type.

The most common location of dentigerous cysts are the Mandibular 3rd Molars and the Maxillary Canines, and they rarely involve deciduous teeth and are occasionally associated with odontomas.

A dentigerous cyst is often treated by excision of the cyst along with the extraction of the associated tooth.

In case of a large cyst marsupialization is done.

Cementoblastoma usually occurs in people under the age of 25, particularly males. It usually involves the permanent mandibular molars or premolars. The involved tooth usually has a vital pulp. It is attached to the tooth root and may cause its resorption, may involve the pulp canal, grows slowly, tends to expand the overlying cortical plates, and, except for the enlargement produced, is usually asymptomatic. This involves the buccal and lingual aspects of the alveolar ridges. But may be associated with diffuse pain and tooth mobility, but the tooth is still vital.

Since a cementoblastoma is a benign neoplasm, it grossly forms a mass of cementum-like tissue as an irregular or round mass attached to the roots of a tooth, usually the permanent mandibular first molar.

Botryoid odontogenic cyst is a variant of the lateral periodontal cyst. It is more often found in middle-aged and older adults, and the teeth more likely affected are mandibular (lower) canines and premolars. On radiographs, the cyst appears "grape-like". Often patients with this condition are symptomatic.

The nasopalatine cyst is the most common non-odontogenic cyst of the oral cavity, at an estimated occurrence rate of 73%.

The lateral periodontal cyst is a non-inflammatory developmental cyst that arises from the epithelial post-functional dental lamina, which is a remnant from odontogenesis. It is more common in middle-aged males. Usually asymptomatic, it presents as a regular well-corticated radiolucency on the side of a mandibular canine or premolar root. Histologically, the cyst appears similar to the gingival cyst of the adult, having a non-keratinized squamous epithelial lining. The involved tooth is usually vital and has no indication for root canal treatment unless the signs of non-vital or necrotic pulpal tissue were confirmed. The cysts arise from epithelial rest cells in the periodontal ligament, although it is unknown whether from the cell rests of Malassez, reduced enamel epithelium or dental lamina remnants, and are generally treated by surgical enucleation.

Gingival cyst (or dental lamina cyst) is a type of cysts of the jaws that originates from the dental lamina and is found in the mouth parts. It is a superficial cyst in the alveolar mucosa. It can be seen inside the mouth as small and whistish bulge. Depending on the ages in which they develop, the cysts are classsfied into gingival cyst of newborn (or infant) and gingival cyst of adult. Structurally, the cyst is lined by thin epithelium and shows a lumen usually filled with desquamated keratin, occasionally containing inflammatory cells. The nodes are formes as a result of cystic degeneration of epithelial rests of the dental lamina (called the rests of Serres).

Gingival cyst was first described by a Czech physician Alois Epstein in 1880. In 1886, a German physician Heinrich Bohn described another type of cyst. Alfred Fromm introduced the classification of gingival cysts in 1967. According to him, gingival cysts of newborns can be further classsified based on their specific origin of the tissues as Epstein’s pearls, Bohn’s nodules and dental lamina cysts.

It is a classed as a pseudocyst, since there is no epithelial lining or fluid content. This defect is usually considered with other cysts of the jaws, since it can be mistaken for such on a radiograph.

The epidermoid cyst may have no symptoms, or it may hurt when touched. It can release pus. It is very common for women on the major or minor labia. In contrast to pilar cysts, epidermoid cysts are usually present on parts of the body with relatively little hair.

Occasionally, an epidermoid cyst will present with Trigeminal neuralgia.

Although they are not malignant, there are rare cases of malignant tumors arising from an epidermoid cyst.

Nasopalatine duct cysts usually present as asymptomatic palatal swellings, but they may rarely be accompanied by pain and/or purulent discharge. The cysts are generally treated by .

The scalp, ears, back, face, and upper arm, are common sites of sebaceous cysts, though they may occur anywhere on the body except the palms of the hands and soles of the feet. In males a common place for them to develop is the scrotum and chest. They are more common in hairier areas, where in cases of long duration they could result in hair loss on the skin surface immediately above the cyst. They are smooth to the touch, vary in size, and are generally round in shape.

They are generally mobile masses that can consist of:

- Fibrous tissues and fluids,

- A fatty (keratinous) substance that resembles cottage cheese, in which case the cyst may be called "keratin cyst". This material has a characteristic "cheesy" or foot odor smell,

- A somewhat viscous, serosanguineous fluid (containing purulent and bloody material).

The nature of the contents of a sebaceous cyst, and of its surrounding capsule, differs depending on whether the cyst has ever been infected.

With surgery, a cyst can usually be excised in its entirety. Poor surgical technique, or previous infection leading to scarring and tethering of the cyst to the surrounding tissue, may lead to rupture during excision and removal. A completely removed cyst will not recur, though if the patient has a predisposition to cyst formation, further cysts may develop in the same general area.

A cementoblastoma in a radiograph appears as a well-defined, markedly radiopaque mass, with a radiolucent peripheral line, which overlies and obliterates the tooth root. it is described as having a rounded or sunburst appearance. There is usually apparent external resorption of the root where the tumor and the root join. Severe hypercementosis and chronic focal sclerosing osteomyelitis are lesions to consider in the differential diagnosis of this lesion.

A primordial cyst is a developmental odontogenic cyst. It is found in an area where a tooth should have formed but is missing. Primordial cysts most commonly arise in the area of mandibular third molars. Under microscopes, the cyst looks like an odontogenic keratocyst (also called a Keratocyst odontogenic tumor) whereby the lesions displays a parakeratinized epithelium with palisading basal epithelial cells.

The term "Primordial cyst" is considered an outdated term and should be avoided. Most "primordial cysts" are actually Keratocyst odontogenic tumors (KOT's).

Thyroglossal duct cysts most often present with a palpable asymptomatic midline neck mass above the level of the hyoid bone. The mass on the neck moves during swallowing or on protrusion of the tongue because of its attachment to the tongue via the tract of thyroid descent. Some patients will have neck or throat pain, or dysphagia.

The persistent duct or sinus can promote oral secretions, which may cause cysts to become infected. Up to half of thyroglossal cysts are not diagnosed until adult life. The tract can lie dormant for years or even decades, until some kind of stimulus leads to cystic dilation. Infection can sometimes cause the transient appearance of a mass or enlargement of the cyst, at times with periodic recurrences. Spontaneous drainage may also occur. Differential diagnosis are ectopic thyroid, enlarged lymph nodes, dermoid cysts and goiter.

Thyroglossal cyst usually presents as a midline neck lump (in the region of the hyoid bone) that is usually painless, smooth and cystic, though if infected, pain can occur. There may be difficulty breathing, dysphagia (difficulty swallowing), or dyspepsia (discomfort in the upper abdomen), especially if the cyst becomes large.

The most common location for a thyroglossal cyst is midline or slightly off midline, between the isthmus of the thyroid and the hyoid bone or just above the hyoid bone. A thyroglossal cyst can develop anywhere along a thyroglossal duct, though cysts within the tongue or in the floor of the mouth are rare.A thyroglossal cyst will move upwards with protrusion of the tongue.Thyroglossal cysts are associated with an increased incidence of ectopic thyroid tissue. Occasionally, a lingual thyroid can be seen as a flattened strawberry-like lump at the base of the tongue.

A median mandibular cyst is a type of cyst that occurs in the midline of the mandible, thought to be created by proliferation and cystic degeneration of resting epithelial tissue that is left trapped within the substance of the bone during embryologic fusion of the two halves of the mandible, along the plane of fusion later termed the symphysis menti. A ture median mandibular cyst would therefore be classified as a non-odontogenic, fissural cyst. The existence of this lesion as a unique clinical entity is controversial, and some reported cases may have represented misdiagnosed odontogenic cysts, which are by far the most common type of intrabony cyst occurring in the jaws. It has also been suggested that the mandible develops as a bilobed proliferation of mesenchyme connected with a central isthmus. Therefore, it is unlikely that epithelial tissue would become trapped as there is no ectoderm separating the lobes in the first instance.