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.

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".

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.

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.

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.

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.

The term "necrotizing ulcerative gingivostomatitis" is sometimes used as a synonym of the necrotizing periodontal disease more commonly termed necrotizing ulcerative gingivitis, or a more severe form (also termed necrotizing stomatitis). The term "necrotizing gingivostomatitis" is also sometimes used.

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

An example is gingivitis.

Also called smoker's palatal keratosis, this condition may occur in smokers, especially pipe smokers. The palate appears dry and cracked, and white from keratosis. The minor salivary glands appear as small, red and swollen bumps. It is not a premalignant condition, and the appearance reverses if the smoking is stopped.

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

Caused by various autoimmune diseases as well as allergies. Erosive lichen planus, mucous membrane pemphigoid, pemphigus vulgaris, and lupus erythematosus.

Plasma cell gingivitis appears as mild gingival enlargement and may extend from the free marginal gingiva on to the attached gingiva. Sometimes it is blended with a marginal, plaque induced gingivitis, or it does not involve the free marginal gingiva. It may also be found as a solitude red area within the attached gingiva (pictures). In some cases the healing of a plaque-induced gingivitis or a periodontitis resolves a plasma cell gingivitis situated a few mm from the earlier plack-infected marginal gingiva. In case of one or few solitary areas of plasma cell gingivitis, no symptoms are reported from the patient. Most often solitary entities are therefore found by the dentist.

The gums are red, friable, or sometimes granular, and sometimes bleed easily if traumaticed. The normal stippling is lost. There is not usually any loss of periodontal attachment. In a few cases a sore mouth can develop, and if so pain is sometimes made worse by toothpastes, or hot or spicy food. The lesions can extend to involve the palate.

Plasma cell cheilitis appears as well defined, infiltrated, dark red plaque with a superficial lacquer-like glazing. Plasma cell cheilitis usually involves the lower lip. The lips appear dry, atrophic and fissured. Angular cheilitis is sometimes present.

Where the condition involves the tongue, there is an erythematous enlargement with furrows, crenation and loss of the normal dorsal tongue coating.

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.

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.

Signs and symptoms may include:

- Persistent or recurrent enlargement of the lips, causing them to protrude. If recurrent, the interval during which the lips are enlarged may be weeks or months. The enlargement can cause midline fissuring of the lip ("median cheilitis") or angular cheilitis (sores at the corner of the mouth). The swelling is non-pitting (c.f. pitting edema) and feels soft or rubbery on palpation. The mucous membrane of the lip may be erythemaous (red) and granular. One or both lips may be affected.

- Oral ulceration (mouth ulcers) which may be aphthous like, or be more chronic and deep with raised margins. Alternatively, lesions similar to pyostomatitis vegetans may occur in OFG, but this is uncommon.

- "Full width" gingivitis (compare with marginal gingivitis).

- Gingival enlargement (swelling of the gums).

- Fissured tongue (grooves in the tongue).

- Enlargement of the mucous membrane of the mouth, which may be associated with cobblestoning and mucosal tags (similar lesions often occur on the intestinal mucosa in Crohn's disease).

- Enlargement of the perioral and periorbital soft tissues (the tissues of the face around the mouth and the eyes). The facial skin may be dry, exfoliative (flaking) or erythematous.

- Cervical lymphadenopathy (enlarged lymph nodes in the neck).

- Facial palsy (weakness and altered sensation of the face).

The enlargement of the tissues of the mouth, lips and face seen in OFG is painless. Melkersson-Rosenthal syndrome is where OFG occurs with fissured tongue and paralysis of the facial nerve. The cause of the facial paralysis is thought to be caused by the formation of granulomas in the facial nerve, which supplies the muscles of facial expression.

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.

Erythematous (atrophic) candidiasis is when the condition appears as a red, raw-looking lesion. Some sources consider denture-related stomatitis, angular stomatitis, median rhombiod glossitis, and antiobiotic-induced stomatitis as subtypes of erythematous candidiasis, since these lesions are commonly erythematous/atrophic. It may precede the formation of a pseudomembrane, be left when the membrane is removed, or arise without prior pseudomembranes. Some sources state that erythematous candidiasis accounts for 60% of oral candidiasis cases. Where it is associated with inhalation steroids (often used for treatment of asthma), erythematous candidiasis commonly appears on the palate or the dorsum of the tongue. On the tongue, there is loss of the lingual papillae (depapillation), leaving a smooth area.

Acute erythematous candidiasis usually occurs on the dorsum of the tongue in persons taking long term corticosteroids or antibiotics, but occasionally it can occur after only a few days of using a topical antibiotic. This is usually termed "antibiotic sore mouth", "antibiotic sore tongue", or "antibiotic-induced stomatitis" because it is commonly painful as well as red.

Chronic erythematous candidiasis is more usually associated with denture wearing (see denture-related stomatitis).

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.

Signs and symptoms are dependent upon the type of oral candidiasis. Often, apart from the appearance of the lesions, there are usually no other signs or symptoms. Most types of oral candidiasis are painless, but a burning sensation may occur in some cases. Candidiasis can therefore sometimes be misdiagnosed as burning mouth syndrome. A burning sensation is more likely with erythematous (atrophic) candidiasis, whilst hyperplastic candidiasis is normally entirely asymptomatic. Acute atrophic candidiasis may feel like the mouth has been scalded with a hot liquid. Another potential symptom is a metallic, acidic, salty or bitter taste in the mouth. The pseudomembranous type rarely causes any symptoms apart from possibly some discomfort or bad taste due to the presence of the membranes. Sometimes the patient describes the raised pseudomembranes as "blisters." Occasionally there can be dysphagia (difficulty swallowing), which indicates that the candidiasis involves the oropharynx or the esophagus, as well as the mouth. The trachea and the larynx may also be involved where there is oral candidiasis, and this may cause hoarseness of the voice.

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.

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.

The signs and symptoms depend upon the type of OM, and may include:

- Pain, which is severe, throbbing and deep seated.

- Initially fistula are not present.

- No dental pain, but headache or other facial pain, as in the descriptive former term "neuralgia-inducing" (cavitational osteonecrosis).

- Fibromyalgia.

- Chronic fatigue syndrome.

- Swelling. External swelling is initially due to inflammatory edema with accompanying erythema (redness), heat and tenderness, and then later may be due to sub-periosteal pus accumulation. Eventually, subperiosteal bone formation may give a firm swelling.

- Trismus (difficulty opening the mouth), which may be present in some cases and is caused by edema in the muscles.

- Dysphagia (difficulty swallowing), which may be present in some cases and is caused by edema in the muscles.

- Cervical lymphadenitis (swelling of the lymph nodes in the neck).

- Aesthesia or paresthesia (altered sensation such as numbness or pins and needles) in the distribution of the mental nerve.

- Fever which may be present in the acute phase and is high and intermittent

- Malaise (general feeling of being unwell) which may be present in the acute phase

- Anorexia (loss of appetite).

- Leukocytosis (elevated numbers of white blood cells) which may be present in the acute phase

- Elevated erythrocyte sedimentation rate and C reactive protein are sometimes present.

- An obvious cause in the mouth (usually) such as a decayed tooth.

- Teeth that are tender to percussion, which may develop as the condition progresses

- Loosening of teeth, which may develop as the condition progresses.

- Pus may later be visible, which exudes from around the necks of teeth, from an open socket, or from other sites within the mouth or on the skin over the involved bone.

- Fetid odor.

Unlike acute OM in the long bones, acute OM in the jaws gives only a moderate systemic reaction and the person remains surprisingly well. Acute OM of the jaws may give a similar appearance to a typical odontogenic infection, but cellulitis does not tend to spread from the periosteal envelope of the involved bone. If the infection is not controlled, the process becomes chronic and systemic symptoms are usually present, including draining fistulas, loosening of teeth and sequestra formation. Untreated chronic osteomyelitis tends to feature occasional acute exacerbations.

Depending upon the site of involvement, this condition could be considered a type of gingivitis (or gingival enlargement); a type of cheilitis; glossitis; or stomatitis. Sometimes the lips, the gums and the tongue can simultaneously be involved, and some authors have described this triad as a syndrome ("plasma-cell gingivostomatitis"). The mucous membranes of the genitals can also be involved by a similar condition, termed "plasma cell balanitis" or "plasma cell vulvitis".

Other synonyms for this condition not previously mentioned include atypical gingivitis, allergic gingivitis, plasmacytosis of the gingiva, idiopathic gingivostomatitis, and atypical gingivostomatitis. Some of these terms are largely historical.

Plasma cell gingivits has been subclassified into 3 types based upon the cause; namely, allergic, neoplastic and of unknown cause.