There may or may not be any evidence of history of HGF in the family nor any usage of taking long-term medicines for any particular disease when it comes to diagnosing HGF. There also may or may not be any signs of medical and/or family history of mental retardation, hypertrichosis, nor clinical symptoms that can be associated with gingival enlargement. Although, enlargement of gingiva, interdental papilla, hindered speech, and secondary inflammatory changes taking place in the mouth commonly at the marginal gingiva are all very indicative of this condition. Commonly the patient will have mandiblular and maxilliary inflammation and overgrowth as opposed to the traditional pink, firm, and fleshy consistency of healthy gingiva. The patient's jaw may also appear distorted because of the gingiva englargements. Overgrowth of the gingiva can range from slightly covering the surface of teeth or it can even completely cover the surrounding teeth. The patient can also experience damage or loss of teeth.

Hereditary gingival fibromatosis (HGF), also known as idiopathic gingival hyperplasia, is a rare condition of gingival overgrowth. HGF is characterized as a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of keratinized gingiva. It can cover teeth in various degrees, and can lead to aesthetic disfigurement. Fibrous enlargement is most common in areas of maxillary and mandibular tissues of both arches in the mouth. Phenotype and genotype frequency of HGF is 1:175,000 where males and females are equally affected but the cause is not entirely known. It mainly exists as an isolated abnormality but can also be associated with a multi-system syndrome.

Robinow noted the resemblance of affected patients' faces to that of a fetus, using the term "fetal facies" to describe the appearance of a small face and widely spaced eyes. Clinical features also may include a short, upturned nose, a prominent forehead, and a flat nasal bridge. The upper lip may be "tented", exposing dental crowding, "tongue tie", or gum hypertrophy.

Though the eyes do not protrude, abnormalities in the lower eyelid may give that impression. Surgery may be necessary if the eyes cannot close fully. In addition, the ears may be set low on the head or have a deformed pinna.

Patients suffer from dwarfism, short lower arms, small feet, and small hands. Fingers and toes may also be abnormally short and laterally or medially bent. The thumb may be displaced and some patients, notably in Turkey, experience ectrodactyly. All patients often suffer from vertebral segmentation abnormalities. Those with the dominant variant have, at most, a single butterfly vertebra. Those with the recessive form, however, may suffer from hemivertebrae, vertebral fusion, and rib anomalies. Some cases resemble Jarcho-Levin syndrome or spondylocostal dysostosis.

Genital defects characteristically seen in males include a micropenis with a normally developed scrotum and testes. Sometimes, testicles may be undescended, or the patient may suffer from hypospadias. Female genital defects may include a reduced size clitoris and underdeveloped labia minora. Infrequently, the labia majora may also be underdeveloped. Some research has shown that females may experience vaginal atresia or haematocolpos.

The autosomal recessive form of the disorder tends to be much more severe. Examples of differences are summarized in the following table:

Focal palmoplantar and gingival keratosis is a rare autosomal dominant disease whose clinical features, and in particular, pathologic alterations and molecular mechanisms remains to be well defined.

The RASopathies are developmental syndromes caused by germline mutations (or in rare cases by somatic mosaicism) in genes that alter the Ras subfamily and mitogen-activated protein kinases that control signal transduction, including:

- Capillary malformation-AV malformation syndrome

- Autoimmune lymphoproliferative syndrome

- Cardiofaciocutaneous syndrome

- Hereditary gingival fibromatosis type 1

- Neurofibromatosis type 1

- Noonan syndrome

- Costello syndrome, Noonan-like

- Legius syndrome, Noonan-like

- Noonan syndrome with multiple lentigines, formerly called LEOPARD syndrome, Noonan-like

Juvenile hyaline fibromatosis (also known as "Fibromatosis hyalinica multiplex juvenilis," "Murray–Puretic–Drescher syndrome") is a very rare, autosomal recessive disease due to mutations in capillary morphogenesis protein-2 (CMG-2 gene). It occurs from early childhood to adulthood, and presents as slow-growing, pearly white or skin-colored dermal or subcutaneous papules or nodules on the face, scalp, and back, which may be confused clinically with neurofibromatosis.

HIES often appears early in life with recurrent staphylococcal and candidal infections, pneumonias, and eczematoid skin.

- Autosomal dominant Hyper-IgE Syndrome caused by STAT3 defects, called Job Syndrome, have characteristic facial, dental, and skeletal abnormalities. Patients with STAT3 HIES may have either delay of or failure in shedding of primary teeth. The characteristic facial features are usually set by age 16. These include facial asymmetry, a prominent forehead, deep-set eyes, a broad nasal bridge, a wide, fleshy nasal tip, and mild prognathism. Additionally, facial skin is rough with prominent pores. Finally, some patients with STAT3 HIES have scoliosis, as well as bones that fracture easily.

- Autosomal recessive

Signs and symptoms include:

- syndromic facies

- hearing loss

- facial paralysis

Gingival fibroma is a cutaneous condition that may be observed with another condition, tuberous sclerosis.

The peripheral odontogenic fibroma is an uncommon gingival mass. It affects people across a large age range. It can be confused with the peripheral ossifying fibroma. In contrast to the peripheral ossifying fibroma, the peripheral odontogenic fibroma is a rare lesion.

No specific gender predilection while the ages of the patients ranged from 5 to 65 years.commonly seen in mandible than maxilla.

slow growing, solid, firmly attached gingival mass sometimes arising between teeth and sometimes displacing teeth.

consists of cellular fibrous connective tissue parenchyma with non neoplastic islands, strands of clouman or cuboidal odontogenic epithelium.

Medical conditions include frequent ear infection, hearing loss, hypotonia, developmental problems, respiratory problems, eating difficulties, light sensitivity, and esophageal reflux.

Data on fertility and the development of secondary sex characteristics is relatively sparse. It has been reported that both male and female patients have had children. Males who have reproduced have all had the autosomal dominant form of the disorder; the fertility of those with the recessive variant is unknown.

Researchers have also reported abnormalities in the renal tract of affected patients. Hydronephrosis is a relatively common condition, and researchers have theorized that this may lead to urinary tract infections. In addition, a number of patients have suffered from cystic dysplasia of the kidney.

A number of other conditions are often associated with Robinow syndrome. About 15% of reported patients suffer from congenital heart defects. Though there is no clear pattern, the most common conditions include pulmonary stenosis and atresia. In addition, though intelligence is generally normal, around 15% of patients show developmental delays.

The presentation of this condition includes a characteristic facies. The cardiac manifestations include patent ductus arteriosus, congenital hypertrophy of the left ventricle, and pericardial effusions.

Neurodevelopmental outcome appears normal, but obsessive traits and anxiety have been reported. It may also be associated with recurrent infections with low immunoglobulin levels and gastric bleeding, and additional possible associations include lymphoedema and heterochromia iridis.

It is characterized by recurrent "cold" staphylococcal infections, unusual eczema-like skin rashes, severe lung infections that result in pneumatoceles (balloon-like lesions that may be filled with air or pus or scar tissue) and very high concentrations of the serum antibody IgE. Inheritance can be autosomal dominant or autosomal recessive. Many patients with autosomal dominant STAT3 hyper-IgE syndrome have characteristic facial and dental abnormalities, fail to lose their primary teeth, and have two sets of teeth simultaneously.

Symptoms include gingival fibromatosis, associated with hypoplasia of the distal phalanges, nail dysplasia, joint hypermobility, and sometimes hepatosplenomegaly. The nose and pinnae are usually large and poorly developed, which gives the individuals with the syndrome abnormal facial characteristics. Mental retardation may also occur. Both males and females are equally affected. Gingival fibromatosis is usually present at birth or appears short after. The term Zimmermann–Laband was coined by Carl Jacob Witkop in 1971.

This type of epulis is neither pyogenic ("pus producing") nor a true granuloma, but it is a vascular lesion. About 75% of all pyogenic granulomas occur on the gingiva, although they may also occur elsewhere in the mouth or other parts of the body (where the term epulis is inappropriate). This common oral lesion is thought to be a reaction to irritation of the tissues and poor oral hygiene. It is more common in younger people and in females, and appears as a red-purple swelling and bleeds easily.

Associated symptoms range from things such as colobomas of the eyes, heart defects, ichthyosiform dermatosis, intellectual disability, and ear abnormalities. Further symptoms that may be suggested include characteristic facies, hearing loss, and cleft palate.

Epulis (; plural "epulides") is any tumor like enlargement (i.e. lump) situated on the gingival or alveolar mucosa. The word literally means "(growth) on the gingiva", and describes only the location of the mass and has no further implications on the nature of the lesion. There are three types: fibromatous, ossifying and acanthomatous. The related term parulis (commonly called a gumboil) refers to a mass of inflamed granulation tissue at the opening of a draining sinus on the alveolus over (or near to) the root of an infected tooth. Another closely related term is gingival enlargement, which tends to be used where the enlargement is more generalized over the whole gingiva rather than a localized mass.

Being an extremely rare autosomal genetic disorder, differential diagnosis has only led to several cases since 1972. Initial diagnosis lends itself to facial abnormalities including sloping forehead, maxillary hypoplasia, nasal bridge depression, wide mouth, dental maloclusion, and receding chin. Electroencephalography (EEG), computed tomography (CT) scanning, and skeletal survey are further required for confident diagnosis. Commonly, diffuse cartilage calcification and brachytelephalangism are identified by X-radiation (X-ray), while peripheral pulmonary arterial stenosis, hearing loss, dysmorphic facies, and mental retardation are confirmed with confidence by the aforementioned diagnostic techniques.

Infantile systemic hyalinosis or juvenile systemic hyalinosis is an allelic autosomal-recessive condition characterized by multiple skin nodules, hyaline deposition, gingival hypertrophy, osteolytic bone lesions, and joint contractures.

Zori–Stalker–Williams syndrome, also known as pectus excavatum, macrocephaly, short stature and dysplastic nails, is a rare autosomal dominant congenital disorder associated with a range of features such as pectus excavatum, macrocephaly and dysplastic nails, familial short stature, developmental delay and distinctive facies. Further signs are known to be associated with this syndrome.

The name originates from the researchers who first defined and noticed the syndrome and its clinical signs.

It is believed that the syndrome is inherited in an autosomal dominant pattern, though there has been no new research undertaken for this rare disease.

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.

Zimmermann–Laband syndrome (ZLS), also known as Laband–Zimmermann syndrome, and Laband's syndrome, is an extremely rare autosomal dominant congenital disorder.

Infantile digital fibromatosis (also known as an "Inclusion body fibromatosis," "Infantile digital myofibroblastoma," and "Reye tumor") usually occurs as a small, asymptomatic, nodular, dermal fibrous proliferation at the extensor or lateral surface of a finger or toe.

Restrictive dermopathy is a rare, lethal autosomal recessive skin condition characterized by syndromic facies, tight skin, sparse or absent eyelashes, and secondary joint changes.

RL syndrome is characterized by renal dysplasia, growth retardation, phocomelia or mesomelia, radiohumeral fusion (joining of radius and humerus), rib abnormalities, anomalies of the external genitalia and potter-like facies among many others.