Dental features:

- small teeth in males

- pointed (screwdriver shaped or conical) incisors (sometimes called Hutchinson teeth)

- incisors with an irregulal incisal edge

- canines: enlarged and globular; may be dome or bud shaped with trilobed edge

- premolars and molars: small, round and globular; may have supernumary lobes (mulberry or lotus flower shape)

- widely separated teeth (diastemma)

- hypoplastic enamel

- dental agenesis

- presence of mesiodents (median incisor behind normal upper incisors)

- pulp chamber anomalies

Facial features:

- anteverted pinnae

- long face

- prominent nasal bridge and nose

- prognathism occasionally

Ophthalmic features:

- bilateral congenital nuclear opacities (100%)

- severe amblyopia

- nystagmus (93%)

- strabismus (43%)

- microcornea (96%)

- congenital glaucoma

- scleral staphylomas

- retinal cystoid degeneration

- microphthalmia

These lead to severe visual impairment in affected males.

Other:

- The fourth metacarpal may be shortened

30% of patients also have some degree of intellectual impairment: of these 80% are mildly to moderately affected: the other 20% may have developmental delays and behavior problems.

Carrier females display milder variable symptoms of disease. Ocular signs are present in 90% of heterozygous females. These are typically lens opacities often involving the posterior Y sutures. More rarely dental anomalies and the characteristic facial features may also occur.

The following are symptoms characteristic with individuals having the disorder. Individuals may display some, most, or all of these symptoms throughout the course of their life, though symptoms may vary with each patient.

- Abnormal hair (coarse, thick, brittle)

- Calvarial hypomineralization (soft skull)

- Y-shaped cataracts by 1–2 years of age

- Skeletal defects

- Hypertelorism (wide-set eyes)

- Facial dysmorphisms

- Late-closing fontanels

- Abnormal accumulation of proteins in the endoplasmic reticulum

- Scoliosis

- Broad forehead, nose

- Missing, small teeth or abnormal teeth positioning

- Poor skull calcification

- Flat foot

- Motor delay

- Abnormal vertebrae

- Prominent forehead and brow

- High nose bridge

- Capillary hemangioma

- Delayed tooth eruption

- Long upper lip groove

- Large mouth

- High arched palate

- Narrow hips and rib cage

- Thin lips

- Narrow and sloping shoulders

- Hyperpigmentation

- Hyperextensible joints

Onset of the disease is in neonatal development and infancy, and symptoms tend to become evident soon after birth.

Talon Cusp will show physical signs of the irregular dental formation of the teeth and cause other symptoms of the disease that could possibly lead to dental problems in the future depending on severity of the deformity. Most commonly, the extra cusp is located on the lingual surface, giving a three-pronged appearance which has been described as an eagle talon. Rarely however the extra cusp may be situated on the facial surface, or there may be extra cusps on both lingual and facial surfaces. There may be a deep groove between the talon cusp and the rest of the tooth. The extra cusp typically contains pulp tissue. When viewing talon cusp from the occlusal, the projection will appear "x-shaped" as well as appears conical and mimicking the shape of an "eagle's talon".

Symptoms of talon cusp include:

- Interference with occlusion or bite

- Irritation of soft tissues and tongue

- Accidental cusp fracture

- Susceptible to dental caries

Symptoms of otodental syndrome can and usually appear in early development and progress with age. Although the specific frequency of the symptoms is not known, the duration is recognized to be for life; assuming no treatment has been undergone. The symptoms are variable to each individual, can range greatly in severity and are dependent on gene expression.

More severe symptoms include:

- Globodontia – an abnormal condition that can occur in both primary and secondary tooth development, in which the molars and canines are greatly enlarged. It refers to the enlarged bulbous fused malformed posterior teeth with almost no discernible cusps or grooves. The molars are known to have a rounded globe-like shape. Can attribute to pain.

- Sensorineural hearing loss (SNHL) – also known as nerve related hearing loss, is a form of hearing loss associated with complications within the inner ear.

- Taurodontism – known as a condition in which the body of a tooth is enlarged at the expense of the roots. This results in an enlarged pulp chamber, lack of proper bonding at the cementoenamel junction, and can cause the pulpal floor to be displaced towards the root. Discomfort and pain are usually associated with these characteristics.

- Endodontic-Periodontic lesions – oral lesions that can potentially form into abscesses. May cause further soreness and pain.

Other possible, less severe, symptoms involve:

- Absent premolars – individuals suffering from otodental syndrome will typically lack the ability to develop premolars due to its genetic related affects.

- Ocular coloboma – an existent hole within the eye of the individual. The hole can be present in either the iris, choroid, optic disc, or retina and is acquired during early/prenatal development. Individuals with these symptoms may exhibit sensitivity to light, blurred vision, and/or blind spots; depending on the size of the missing tissue and its location in the eye.

Maxillary lateral incisor agenesis (MLIA) is lack of development (agenesis) of one or both of the maxillary lateral incisor teeth. In normal human dentition, this would be the second tooth on either side from the center of the top row of teeth. The condition is bilateral if the incisor is absent on both sides or unilateral if only one is smissing. It appears to have a genetic component.

Children with the Sanjad Sakati syndrome have a triad of:

a) hypoparathyroidism (with episodes of hypocalcemia, hypocalcemic tetany and hypocalcemic seizures.

b) severe mental retardation and

c) dysmorphism.

Typically, children with this syndrome are born low-birth-weight due to intrauterine growth retardation. At birth, there is dysmorphism, which is later typified into the features described below. The child is stunted, often with demonstrable growth hormone deficiency and has moderate to severe mental retardation, mainly as a consequence of repeated seizures brought on by the low blood ionic calcium levels. The immuno-reactive parathormone levels are low to undetectable, with low calcium and high phosphate levels in the blood.

"Dysmorphism" is most evident on the face, with the following features:

- Long narrow face

- Deep-set, small eyes

- Beaked nose

- Large, floppy ears

- Small head (microcephaly) and

- Thin lips with a long philtrum.

All teeth, although the same size, grow in larger than normal. This is seen in cases of growth hormone excess called pituitary gigantism. It is the rarest of the types.

This anomaly is large enough to be seen with the naked eye. One can see the projection on the incisal edge of a tooth looking into the mouth of the affected person. The structure is described to be "T'shaped" or "X-shaped" however will differ depending on its shape, size, structure, location and site of origin. X-rays and radiographs can also show evidence of the abnormality. The digital images would show a tooth with talon cusp as if it were "double teeth".

When looking at a radiograph some features to look for would be location, edge, shape and number. The location would be on an anterior tooth, the edge would be clear and well defined and can be seen even by the naked eye, and the shape would appear "talon-like" over the top portion or crown of the affected tooth. There could potentially be one, two or multiple protrusions depending on the type of cusp.

Talon cusp can fall under three categories: Type I, Type II and Type III. They are created based on the cusp formation shape and length of extension.

- Type I - Talon: The additional cusp or talon projects from the palatal surface of a primary or permanent anterior (front) tooth that extends at least half of the distance from the cemento enamel junction to the incisal edge.

- Type II - Semi Talon: The semi talon cusp measures about 1mm or more in length but extends less than half of the distance seen in Type I Talon.

- Type III - Trace Talon: The projection originates from the cingulum (also known as the "cervical third") of the root and is enlarged or prominent in any form (conical, or tubercle-like)

Since many cases of Talon cusp go unreported, it is hard to draw linkage maps but it is safe to assume that dental formation is influenced by genetic factors. Talon cusp is also seen in association with conditions such as Rubinstein-Taybi syndrome, Mohr syndrome, Ellis–van Creveld syndrome, Incontinentia pigmenti achromians, Berardinelli-Seip syndrome, and Sturge–Weber syndrome.

Neu-Laxova syndrome presents with severe malformations leading to prenatal or neonatal death. Typically, NLS involves characteristic facial features, decreased fetal movements and skin abnormalities.

Fetuses or newborns with Neu–Laxova syndrome have typical facial characteristics which include proptosis (bulging eyes) with eyelid malformations, nose malformations, round and gaping mouth, micrognathia (small jaw) and low set or malformed ears. Additional facial malformations may be present, such as cleft lip or cleft palate. Limb malformations are common and involve the fingers (syndactyly), hands or feet. Additionally, edema and flexion deformities are often present. Other features of NLS are severe intrauterine growth restriction, skin abnormalities (ichthyosis and hyperkeratosis) and decreased movement.

Malformations in the central nervous system are frequent and may include microcephaly, lissencephaly or microgyria, hypoplasia of the cerebellum and agenesis of the corpus callosum. Other malformations may also be present, such as neural tube defects.

Macrodontia of a single tooth is attributed to a disturbance of morphodifferentiation. Generalized macrodontia is usually attributed to some hormonal imbalance (e.g., pituirary gigantism). It can also be associated with facial hemihyperplasia. Macrodontia stems from systematic disturbances. These include KBG syndrome, otodental syndrome, and insulin-resistant diabetes. Ethnicity and gender also factors that influence macrodontia. Asians and males are more likely to be effected.

Other features include:

- Stunting

- Small hands and feet with long, tapering fingers and clinodactyly

- Dental anomalies in the form of malalignment and malocclusion

In another study of six patients, the patients were investigated further. They were found to have low levels of IGF-1 and markedly retarded bone age.

Because MLIA can be detected from partial skeletal remains, it is useful in the field of anthropology. Anthropologically-interesting human remains often have relatively well preserved skeletons, but no soft tissues or intact DNA. This makes it hard to determine relationships between the deceased individuals. MLIA is sometimes related to inbreeding, so the presence of MLIA in many members of a large collection of remains can indicate that the population that lived there was relatively inbred. This technique has been used to study a group of Neolithic farmers.

frequency:- rare type of cyst

It can occur at any age, mostly between 2nd and 3rd decade of life.

Diameter is 2 to 4 cm

swelling pain maybe present.

intra bony expansions may produce hard bony expansion.

may perforate cortical bones

also it extends to soft tissue

maybe asymptomatic

Eye agenesis is a medical condition in which people are born with no eyes.

Oculocerebrocutaneous syndrome (also known as Delleman–Oorthuys syndrome) is a condition characterized by orbital cysts, microphthalmia, porencephaly, agenesis of the corpus callosum, and facial skin tags.

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.

Otodental syndrome, also known as otodental dysplasia, is an exceptionally rare disease that is distinguished by a specific phenotype known as globodontia, that in rare cases can be associated with eye coloboma and high frequency hearing loss. Globodontia is an abnormal condition that can occur in both the primary and secondary dentition, except for the incisors which are normal in shape and size. This is demonstrated by significant enlargement of the canine and molar teeth. The premolars are either reduced in size or are absent. In some cases, the defects affecting the teeth, eye and ear can be either individual or combined. When these conditions are combined with eye coloboma, the condition is also known as oculo-otodental syndrome. The first known case of otodental syndrome was found in Hungary in a mother and her son by Denes and Csiba in 1969. Prevalence is less than 1 out of every 1 million individuals.

The cause of otodental syndrome is considered to be genetic. It is an autosomal dominant inheritance and is variable in its expressivity. Haploinsufficiency in the fibroblast growth factor 3 (FGF3) gene (11q13) has been reported in patients with otodental syndrome and is thought to cause the phenotype. Both males and females are equally affected. Individuals diagnosed with otodental syndrome can be of any age; age is not a relevant factor.

Currently there are no specific genetic treatments for otodental syndrome. Dental and orthodontic management are the recommended course of action.

The calcifying odotogenic cyst or the Gorlin cyst, now known in the WHO Classification of Tumours as the calcifying cystic odontogenic tumor, is a benign odontogenic tumor of cystic type most likely to affect the anterior areas of the jaws. It is most common in people in their second to third decades but can be seen at almost any age. On radiographs, the calcifying odontogenic cyst appears as a unilocular radiolucency (dark area). In one-third of cases, an impacted tooth is involved. Microscopically, there are many cells that are described as "ghost cells", enlarged eosinophilic epithelial cells without nuclei.

Diagnosis is often confirmed by several abnormalities of skeletal origin. There is a sequential order of findings, according to Cormode et al., which initiate in abnormal cartilage calcification and later brachytelephalangism. The uniqueness of brachytelephalangy in KS results in distinctively broadened and shortened first through fourth distal phalanges, while the fifth distal phalanx bone remains unaffected. Radiography also reveals several skeletal anomalies including facial hypoplasia resulting in underdevelopment of the nasal bridge with noticeably diminished alae nasi. In addition to distinguishable facial features, patients generally demonstrate shorter than average stature and general mild developmental delay.

If Turner's hypoplasia is found on a canine or a premolar, the most likely cause is an infection that was present when the primary (baby) tooth was still in the mouth. Most likely, the primary tooth was heavily decayed and an area of inflamed tissues around the root of the tooth (called a periapical inflammation), affecting the development of the permanent tooth. The tooth most likely affected by this cause is the canine tooth. The appearance of the abnormality will depend on the severity and longevity of the infection.

If Turner's hypoplasia is found in the front (anterior) area of the mouth, the most likely cause is a traumatic injury to a primary tooth. The traumatized tooth, which is usually a maxillary central incisor, is pushed into the developing tooth underneath it and consequently affects the formation of enamel. Because of the location of the permanent tooth's developing tooth bud in relation to the primary tooth, the most likely affected area on the permanent tooth is the facial surface (the side closer to the lips or cheek). White or yellow discoloration may accompany Turner's hypoplasia. Enamel hypoplasia may also be present.

Turner's hypoplasia usually affects the tooth enamel if the trauma occurs prior to the third year of life. Injuries occurring after this time are less likely to cause enamel defects since the enamel is already calcified.

The same type of injury is also associated with the dilaceration of a tooth.

In medicine, agenesis () refers to the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue. Many forms of agenesis are referred to by individual names, depending on the organ affected:

- Agenesis of the corpus callosum - failure of the Corpus callosum to develop

- Renal agenesis - failure of one or both of the kidneys to develop

- Phocomelia - failure of the arms or legs to develop

- Penile agenesis - failure of penis to develop

- Müllerian agenesis - failure of the uterus and part of the vagina to develop

- Agenesis of the gallbladder - failure of the Gallbladder to develop. A person may not realize they have this condition unless they undergo surgery or medical imaging, since the gallbladder is neither externally visible nor essential.

Nance–Horan syndrome is a rare X linked syndrome characterized by congenital cataract leading to profound vision loss, characteristic dysmorphic features and dental anomalies. Microcornea, microphthalmia and mild or moderate mental retardation may accompany these features. Heterozygous females often manifest similarly but with less severe features than affected males.

This syndrome consists a number of typical features. These include

- Agenesis of the corpus callosum (80-99% patients)

- Hypopigmentation of the eyes and hair (80-99% patients)

- Cardiomyopathy (80-99% patients)

- Combined immunodeficiency (80-99% patients)

- Muscular hypotonia (80-99% patients)

- Abnormality of retinal pigmentation (80-99% patients)

- Recurrent chest infections (80-99% patients)

- Abnormal EEG (80-99% patients)

- Intellectual disability (80-99% patients)

- Cataracts (75%)

- Seizures (65%)

- Renal abnormalities (15%)

Infections of the gastrointestinal and urinary tracts are common. Swallowing and feeding difficulties early on may result in a failure to thrive. Optic nerve hypoplasia, nystagmus and photophobia may occur. Facial dysmorphism (cleft lip/palate and micrognathia) and syndactyly may be present. Sensorineural hearing loss may also be present.

Death in infancy is not uncommon and is usually due to cardiac complications or severe infections.

In dentistry, hypodontia is the condition at which the patient has missing teeth as a result of the failure of those teeth to develop (also called tooth agenesis). Hypodontia describes a situation where the patient is missing up to five permanent teeth, excluding the 3rd molars. Missing third molars occur in 9–30% of studied populations. In primary dentition the maxilla is more affected, with the condition usually involving the maxillary lateral incisor.

The condition of missing over five (six or more) permanent teeth, excluding 3rd molars or wisdom teeth, has been called oligodontia. The condition for missing all teeth, either primary and/or permanent), is called anodontia. A similar condition is hyperdontia, in which there are more than the usual number of teeth, more commonly called supernumerary teeth.

Many other terms to describe a reduction in number of teeth appear in the literature: aplasia of teeth, congenitally missing teeth, absence of teeth, agenesis of teeth and lack of teeth.

Genitopatellar syndrome is a rare condition characterized by genital abnormalities, missing or underdeveloped kneecaps (patellae), intellectual disability, and abnormalities affecting other parts of the body.

Genitopatellar syndrome is also associated with delayed development and intellectual disability, which are often severe. Affected individuals may have an unusually small head (microcephaly) and structural brain abnormalities, including underdeveloped or absent tissue connecting the left and right halves of the brain (agenesis of the corpus callosum).