The symptoms of gingivitis are somewhat non-specific and manifest in the gum tissue as the classic signs of inflammation:

- Swollen gums

- Bright red or purple gums

- Gums that are tender or painful to the touch

- Bleeding gums or bleeding after brushing and/or flossing

- Bad breath (halitosis)

Additionally, the stippling that normally exists in the gum tissue of some individuals will often disappear and the gums may appear shiny when the gum tissue becomes swollen and stretched over the inflamed underlying connective tissue. The accumulation may also emit an unpleasant odor. When the gingiva are swollen, the epithelial lining of the gingival crevice becomes ulcerated and the gums will bleed more easily with even gentle brushing, and especially when flossing.

Gingivitis is a non-destructive disease that occurs around the teeth. The most common form of gingivitis, and the most common form of periodontal disease overall, is in response to bacterial biofilms (also called plaque) that is attached to tooth surfaces, termed "plaque-induced gingivitis".

While some cases of gingivitis never progress to periodontitis, data indicates that periodontitis is always preceded by gingivitis.

Gingivitis is reversible with good oral hygiene; however, without treatment, gingivitis can progress to periodontitis, in which the inflammation of the gums results in tissue destruction and bone resorption around the teeth. Periodontitis can ultimately lead to tooth loss. The term means "inflammation of the gum tissue".

In the early stages, periodontitis has very few symptoms, and in many individuals the disease has progressed significantly before they seek treatment.

Symptoms may include:

- Redness or bleeding of gums while brushing teeth, using dental floss or biting into hard food (e.g., apples) (though this may occur even in gingivitis, where there is no attachment loss)

- Gum swelling that recurs

- Spitting out blood after brushing teeth

- Halitosis, or bad breath, and a persistent metallic taste in the mouth

- Gingival recession, resulting in apparent lengthening of teeth. (This may also be caused by heavy-handed brushing or with a stiff toothbrush.)

- Deep pockets between the teeth and the gums (pockets are sites where the attachment has been gradually destroyed by collagen-destroying enzymes, known as collagenases)

- Loose teeth, in the later stages (though this may occur for other reasons, as well)

Patients should realize gingival inflammation and bone destruction are largely painless. Hence, people may wrongly assume painless bleeding after teeth cleaning is insignificant, although this may be a symptom of progressing periodontitis in that patient.

The "severity" of disease refers to the amount of periodontal ligament fibers that have been lost, termed "clinical attachment loss". According to the American Academy of Periodontology, the classification of severity is as follows:

- Mild: of attachment loss

- Moderate: of attachment loss

- Severe: ≥ of attachment loss

In the early stages some patients may complain of a feeling of tightness around the teeth. Three signs/symptoms must be present to diagnose this condition:

- Severe gingival pain.

- Profuse gingival bleeding that requires little or no provocation.

- Interdental papillae are ulcerated with necrotic slough. The papillary necrosis of NUG has been described as "punched out".

Other signs and symptoms may be present, but not always.

- Oral malodor (intraoral halitosis).

- Bad taste (metallic taste).

Malaise, fever and/or cervical lymph node enlargement are rare (unlike the typical features of herpetic stomatitis). Pain is fairly well localized to the affected areas. Systemic reactions may be more pronounced in children. Cancrum oris (noma) is a very rare complication, usually in debilitated children. Similar features but with more intense pain may be seen in necrotizing periodontitis in HIV/AIDS.

Necrotizing gingivitis is part of a spectrum of disease termed necrotizing periodontal diseases. It is the most minor form of this spectrum, with more advanced stages being termed necrotizing periodontitis, necrotizing stomatitis and the most extreme, cancrum oris.

Acute necrotizing ulcerative gingivitis (ANUG) refers to the clinical onset of NUG. The word acute is used because usually the onset is sudden. Other forms of NUG may be chronic or recurrent.

Necrotizing ulcerative periodontitis (NUP) is where the infection leads to attachment loss, and involves only the gingiva, periodontal ligament and alveolar ligament. Progression of the disease into tissue beyond the mucogingival junction characterizises necrotizing stomatitis.

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.

Pericoronitis may also be chronic or recurrent, with repeated episodes of acute pericoronitis occurring periodically. Chronic pericoronitis may cause few if any symptoms, but some signs are usually visible when the mouth is examined.

In the early stages, chronic periodontitis has few symptoms and in many individuals the disease has progressed significantly before they seek treatment.

Symptoms may include the following:

- Redness or bleeding of gums while brushing teeth, using dental floss or biting into hard food (e.g. apples) (though this may occur even in gingivitis, where there is no attachment loss)

- Gum swelling that recurs

- Halitosis, or bad breath, and a persistent metallic taste in the mouth

- Gingival recession, resulting in apparent lengthening of teeth. (This may also be caused by heavy-handed brushing or with a stiff tooth brush.)

- Deep pockets between the teeth and the gums (pockets are sites where the attachment has been gradually destroyed by collagen-destroying enzymes, known as "collagenases")

- Loose teeth, in the later stages (though this may occur for other reasons as well)

Gingival inflammation and bone destruction are often painless. Patients sometimes assume that painless bleeding after teeth cleaning is insignificant, although this may be a symptom of progressing chronic periodontitis in that patient.

Subgingival calculus is a frequent finding.

There is a slow to moderate rate of disease progression but the patient may have periods of rapid progression ("bursts of destruction"). Chronic periodontitis can be associated with local predisposing factors(e.g. tooth-related or iatrogenic factors). The disease may be modified by and be associated with systemic diseases (e.g. diabetes mellitus, HIV infection) It can also be modified by factors other than systemic disease such as smoking and emotional stress.

Major risk factors: Smoking, lack of oral hygiene with inadequate plaque biofilm control.

Measuring disease progression is carried out by measuring probing pocket depth (PPD) and bleeding indices using a periodontal probe. Pockets greater than 3mm in depth are considered to be unhealthy. Bleeding on probing is considered to be a sign of active disease. Discharge of pus, involvement of the root furcation area and deeper pocketing may all indicate reduced prognosis for an individual tooth.

Age is related to the incidence of periodontal destruction: "...in a well-maintained population who practises oral home care and has regular check-ups, the incidence of incipient periodontal destruction increases with age, the highest rate occurs between 50 and 60 years, and gingival recession is the predominant lesion before 40 years, while periodontal pocketing is the principal mode of destruction between 50 and 60 years of age."

It is one of the seven destructive periodontal diseases as listed in the 1999 classification.

Gum recession is generally not an acute condition. In most cases, receding of gums is a progressive condition that occurs gradually over the years. This is one reason that it is common over the age of 40. Because the changes in the condition of the gums from one day to another are minimal, patients get used to the gums' appearance and tend not to notice the recession visually. Receding gums may remain unnoticed until the condition starts to cause symptoms.

The following signs and symptoms may indicate gum recession:

- Tooth mobility

- Dentin hypersensitivity (over-sensitive teeth) - short, sharp pain is triggered by hot, cold, sweet, sour, or spicy food and drink. If the cementum covering the root is not protected anymore by the gums, it is easily abraded exposing the dentin tubules to external stimuli.

- Teeth may also appear longer than normal (a larger part of the crown is visible if gums are receding)

- The roots of the tooth are exposed and visible

- The tooth feels notched at the gum line

- Change in the tooth’s color (due to the color difference between enamel and cementum)

- Spaces between teeth seem to grow (the space is the same, but it seems larger because the gums do not fill it any more)

- Cavities below the gum line

If the gum recession is caused by gingivitis, the following symptoms may also be present:

- Puffy, red, or swollen (inflamed) gums

- Gum bleeding while brushing or flossing

- Bad breath (halitosis)

In some cases, it is the treatment of gingivitis that reveals a gum recession problem, that was previously masked by the gums swelling.

There are many possible causes for gingival recession:

- By far the most common cause is gum disease (periodontal disease).

- Overaggressive brushing is often assumed to cause gum recession, however a systematic review of the literature concludes that "The data to support or refute the association between tooth brushing and gingival recession are inconclusive." A subsequent study found horizontal tooth brushing technique (versus Bass technique or circular methods), medium-hardness toothbrush use and brushing only once daily were associated with gingival recession.

- Hereditary thin, fragile or insufficient gingival tissue predisposes to gingival recession.

- Dipping tobacco, which affects the mucous membrane lining in the mouth and will cause receding gums over time

- Self-inflicted trauma, such as habits like digging a fingernail or pencil into the gum. This type of recession more commonly associated with children and persons with psychiatric disorders.

- Scurvy (lack of dietary vitamin C)

- Acute necrotizing ulcerative gingivitis

- Abnormal tooth position, such as tooth crowding, giving inadequate cover of one or more teeth by the jaw bone.

- Piercings in the lip or tongue that wear away the gum by rubbing against it.

- Intentional gingival retraction. For example, the adult tooth may not grow out of the gum, and to remedy this, a procedure called an exposure is done. It involves the gum tissue being cut open to allow the adult tooth to grow out. This is a less common cause of gum recession.

Dental plaque is a biofilm or mass of bacteria that grows on surfaces within the mouth. It is a sticky colorless deposit at first, but when it forms tartar, it is often brown or pale yellow. It is commonly found between the teeth, on the front of teeth, behind teeth, on chewing surfaces, along the gumline, or below the gumline cervical margins. Dental plaque is also known as microbial plaque, oral biofilm, dental biofilm, dental plaque biofilm or bacterial plaque biofilm.

Progression and build-up of dental plaque can give rise to tooth decay – the localised destruction of the tissues of the tooth by acid produced from the bacterial degradation of fermentable sugar – and periodontal problems such as gingivitis and periodontitis; hence it is important to disrupt the mass of bacteria and remove it. Plaque control and removal can be achieved with correct daily or twice-daily tooth brushing and use of interdental aids such as dental floss and interdental brushes.

Oral hygiene is important as dental biofilms may become acidic causing demineralization of the teeth (also known as dental caries) or harden into dental calculus (also known as tartar). Calculus cannot be removed through tooth brushing or with interdental aids, but only through professional cleaning.

Dental plaque accumulates at the surfaces when proper cleaning and maintaining is not done. There is inflammation due to the bacteria released from the toxins. calculus forms and if not removed, causes this disease.

Since alveolar osteitis is not primarily an infection, there is not usually any pyrexia (fever) and cervical lymphadenitis (swollen glands in the neck), and only minimal edema (swelling) and erythema (redness) is present in the soft tissues surrounding the socket.

Signs may include:

- An empty socket, which is partially or totally devoid of blood clot. Exposed bone may be visible or the socket may be filled with food debris which reveals the exposed bone once it is removed. The exposed bone is extremely painful and sensitive to touch. Surrounding inflamed soft tissues may overlie the socket and hide the dry socket from casual examination.

- Denuded (bare) bone walls.

Symptoms may include:

- Dull, aching, throbbing pain in the area of the socket, which is moderate to severe and may radiate to other parts of the head such as the ear, eye, temple and neck. The pain normally starts on the second to fourth day after the extraction, and may last 10–40 days. The pain may be so strong that even strong analgesics do not relieve it.

- Intraoral halitosis (oral malodor).

- Bad taste in the mouth.

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.

Pericoronitis is inflammation of the soft tissues surrounding the crown of a partially erupted tooth. The lower wisdom tooth is the last tooth to erupt into the mouth, and is, therefore, more frequently impacted, or stuck, against the other teeth. This leaves the tooth partially erupted into the mouth, and there frequently is a flap of gum (an operculum), overlying the tooth. Bacteria and food debris accumulate beneath the operculum, which is an area that is difficult to keep clean because it is hidden and far back in the mouth. The opposing upper wisdom tooth also tends to have sharp cusps and over-erupt because it has no opposing tooth to bite into, and instead traumatizes the operculum further. Periodontitis and dental caries may develop on either the third or second molars, and chronic inflammation develops in the soft tissues. Chronic pericoronitis may not cause any pain, but an acute pericoronitis episode is often associated with pericoronal abscess formation. Typical signs and symptoms of a pericoronal abscess include severe, throbbing pain, which may radiate to adjacent areas in the head and neck, redness, swelling and tenderness of the gum over the tooth. There may be trismus (difficulty opening the mouth), facial swelling, and rubor (flushing) of the cheek that overlies the angle of the jaw. Persons typically develop pericoronitis in their late teens and early 20s, as this is the age that the wisdom teeth are erupting. Treatment for acute conditions includes cleaning the area under the operculum with an antiseptic solution, painkillers, and antibiotics if indicated. After the acute episode has been controlled, the definitive treatment is usually by tooth extraction or, less commonly, the soft tissue is removed (operculectomy). If the tooth is kept, good oral hygiene is required to keep the area free of debris to prevent recurrence of the infection.

Angular cheilitis is a fairly non specific term which describes the presence of an inflammatory lesion in a particular anatomic site (i.e. the corner of the mouth). As there are different possible causes and contributing factors from one person to the next, the appearance of the lesion is somewhat variable. The lesions are more commonly symmetrically present on both sides of the mouth, but sometimes only one side may be affected. In some cases, the lesion may be confined to the mucosa of the lips, and in other cases the lesion may extend past the vermilion border (the edge where the lining on the lips becomes the skin on the face) onto the facial skin. Initially, the corners of the mouth develop a gray-white thickening and adjacent erythema (redness). Later, the usual appearance is a roughly triangular area of erythema, edema (swelling) and breakdown of skin at either corner of the mouth. The mucosa of the lip may become fissured (cracked), crusted, ulcerated or atrophied. There is not usually any bleeding. Where the skin is involved, there may be radiating rhagades (linear fissures) from the corner of the mouth. Infrequently, the dermatitis (which may resemble eczema) can extend from the corner of the mouth to the skin of the cheek or chin. If "Staphylococcus aureus" is involved, the lesion may show golden yellow crusts. In chronic angular cheilitis, there may be suppuration (pus formation), exfoliation (scaling) and formation of granulation tissue.

Sometimes contributing factors can be readily seen, such as loss of lower face height from poorly made or worn dentures, which results in mandibular overclosure ("collapse of jaws"). If there is a nutritional deficiency underlying the condition, various other signs and symptoms such as glossitis (swollen tongue) may be present. In people with angular cheilitis who wear dentures, often there may be erythematous mucosa underneath the denture (normally the upper denture), an appearance consistent with denture-related stomatitis. Typically the lesions give symptoms of soreness, pain, pruritus (itching) or burning or a raw feeling.

A great many diseases involve the mouth, jaws and orofacial skin. Some example pathologies which can involve the oral and maxillofacial region are listed. Some are more common than others, and this list is by no means complete. The examples are considered according to a surgical sieve.

Bleeding on probing which is also known as bleeding gums or gingival bleeding is a term used by dentists and dental hygienists when referring to bleeding that is induced by gentle manipulation of the tissue at the depth of the gingival sulcus, or interface between the gingiva and a tooth. Bleeding on probing, often abbreviated BOP, is a sign of inflammation and indicates some sort of destruction and erosion to the lining of the sulcus or the ulceration of sulcular epithelium. The blood comes from lamina propria after the ulceration of the lining.

A gingival disease is the term given to any disorder primarily affecting the gingiva.

An example is gingivitis.

Oral and maxillofacial pathology (also termed oral pathology, stomatognathic disease, dental disease, or mouth disease) refers to the diseases of the mouth ("oral cavity" or "stoma"), jaws ("maxillae" or "gnath") 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 and maxillofacial 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.

Since dry socket occurs exclusively following a dental extraction, it could be considered both a complication and an iatrogenic condition, but this does not take into account both the reason why the tooth required extraction (i.e., extraction may have been unavoidable due to significant pain and infection) and also the fact that many dry sockets are the result of poor compliance with postoperative instructions, notably refraining from smoking in the days immediately after the procedure.

An examination by the dentist or dental hygienist should be sufficient to rule out the issues such as malnutrition and puberty. Additional corresponding diagnosis tests to certain potential disease may be required. This includes oral glucose tolerance test for diabetes mellitus, blood studies, human gonadotrophin levels for pregnancy, and X-rays for teeth and jaw bones.

In order to determine the periodontal health of a patient, the dentist or dental hygienist records the sulcular depths of the gingiva and observes any bleeding on probing. This is often accomplished with the use of a periodontal probe. Alternatively, dental floss may also be used to assess the Gingival bleeding index. It is used as an initial evaluation on patient's periodontal health especially to measure gingivitis. The number of bleeding sites is used to calculate the gingival bleeding score.

Peer-reviewed dental literature thoroughly establishes that bleeding on probing is a poor positive predictor of periodontal disease, but conversely lack of bleeding is a very strong negative predictor. The clinical interpretation of this research is that while BOP presence may not indicate periodontal disease, continued absence of BOP is a strong predictor (approximately 98%) of continued periodontal health.

Desquamative gingivitis involves lesions of the free and attached gingiva. Unlike plaque-induced inflammation of the gums (normal marginal gingivitis), desquamative gingivitis extends beyond the marginal gingiva, involving the full width of the gingiva and sometimes the alveolar mucosa. The term "full width gingivitis" usually refers to the oral lesions of orofacial granulomatosis however. The color is another dissimilarity between typical marginal gingivitis and desquamative gingivitis, in the latter it is dusky red. Plasma cell gingivitis is another form of gingivitis which affects both the attached and free gingiva.