The actual incidence of this disease is not known, but only 243 cases have been reported in the scientific literature, suggesting an incidence of on the order of one affected person in ten million people.

The cause of Goldenhar syndrome is largely unknown. However, it is thought to be multifactorial, although there may be a genetic component, which would account for certain familial patterns. It has been suggested that there is a branchial arch development issue late in the first trimester.

An increase in Goldenhar syndrome in the children of Gulf War veterans has been suggested, but the difference was shown to be statistically insignificant.

There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery

Genetic counseling and screening of the mother's relatives is recommended.

Prevalence ranges from 1 in 3500 to 5600 live births. Male-female ratio is found to be 3:2.

This syndrome is due to mutations in the Nance Horan gene (NHS) which is located on the short arm of the X chromosome (Xp22.13).

Currently there are no open research studies for otodental syndrome. Due to the rarity of this disease, current research is very limited.

The most recent research has involved case studies of the affected individuals and/or families, all of which show the specific phenotypic symptoms of otodental syndrome. Investigations on the effects of FGF3 and FADD have also been performed. These studies have shown successes in supporting previous studies that mutations to FGF3 and neighboring genes may cause the associated phenotypic abnormalities. According to recent studies involving zebrafish embryos, there is also support in that the FADD gene contributed to ocular coloboma symptoms as well.

Future research studies are required in order to better grasp the specific relationship between the gene involved and its effect on various tissues and organs such as teeth, eyes, and ear. Little is known and there is still much to be determined.

Children with Pfeiffer syndrome types 2 and 3 "have a higher risk for neurodevelopmental disorders and a reduced life expectancy" than children with Pfeiffer syndrome type 1, but if treated, favorable outcomes are possible. In severe cases, respiratory and neurological complications often lead to early death.

Otodental syndrome is a rare condition that is genetically inherited in an autosomal dominant manner. Although there is no specific biological mechanism for otodental syndrome, what is recognized is that there is a genetic mutation, known as haploinsufficiency, that occurs in the fibroblast growth factor 3 (FGF3) gene (11q13). This is the alleged cause of the physical abnormalities and symptoms associated with otodental syndrome. Although in individuals with signs of ocular coloboma, a microdeletion in the Fas-associated death domain (FADD) gene (11q13.3) was also found to be responsible. There is variable penetrance and variable gene expression within these genetic mutations. Individuals with sensorineural hearing loss are believed to have a local lesion in the auditory segment of the inner ear, known as the cochlea. The biological mechanism for this is currently unknown as well.

ODD is typically an autosomal dominant condition, but can be inherited as a recessive trait. It is generally believed to be caused by a mutation in the gene GJA1, which codes for the gap junction protein connexin 43. Slightly different mutations in this gene may explain the different way the condition manifests in different families. Most people inherit this condition from one of their parents, but new cases do arise through novel mutations. The mutation has high penetrance and variable expression, which means that nearly all people with the gene show signs of the condition, but these signs can range from very mild to very obvious.

There are approximately three hundred known cases of Carpenter Syndrome in the United States. Only 1 in 1 million live births will result in an infant affected by Carpenter Syndrome (RN, 2007).

Carpenter Syndrome is an autosomal recessive disease which means both parents must have the faulty genes in order to pass the disease onto their children. Even if both parents possess the faulty gene there is still only a twenty five percent chance that they will produce a child affected by the syndrome. Their children who do not have the disease will still be carriers and possess the ability to pass the disease onto their offspring if their spouse is also a carrier of the particular gene.

TCS occurs in about one in 50,000 births in Europe. Worldwide, it is estimated to occur in one in 10,000 to one in 50,000 births.

Branchio-oculo-facial syndrome is difficult to diagnose because it has incomplete penetrance. It is often misdiagnosed as branchio-oto-renal syndrome because of their similarities in symptoms.

The disorder can be associated with a number of psychological symptoms, anxiety, depression, social phobia, body image disorders, and patients may be subjected to discrimination, bullying and name calling especially when young. A multi-disciplinary team and parental support should include these issues.

Individuals affected by certain ED syndromes cannot perspire. Their sweat glands may function abnormally or may not have developed at all because of inactive proteins in the sweat glands. Without normal sweat production, the body cannot regulate temperature properly. Therefore, overheating is a common problem, especially during hot weather. Access to cool environments is important.

One dental textbook defines it as: “Dollicofacial, there is excess of lower facial height usually associated with lower occlusal and mandibular plane angles.” This is often associated “with vertical maxillary excess and mandibular hypoplasia.” Luc P. M. Tourne, a Fellow in the Department of TMJ and Craniofacial Pain at the University of Minnesota School of Dentistry, noted: "There is a clinically recognizable facial morphology, the long face syndrome, which has been incompletely described in the literature," However, her study of 31 adults with this syndrome, which included "analysis of esthetics, skeletal morphology, and occlusion" confirmed "this basic dentofacial deformity" has associations " with excessive vertical growth of the maxilla." She reported that closed bite and dental open are two pf the syndrome's variants.

The treatment for young patients troubled by long face syndrome is to halt and control descent of the lower jaw and to prevent the eruption of posterior teeth. In severe cases of deformity, a mixture of orthodontics and orthognathic surgery may be the only effective solution. The long term (more than 6 years) effectiveness of surgical treatments for long face syndrome has been subject to study.

"In the American literature, the terms long-face syndrome and short-face syndrome are often used." To be sure, there are reported "long and the short face anomalies" and open bite cases. However, in the opinion of Hugo Obwegeser, there is no medical justification for naming theme as a "syndrome" the signs and symptoms do not meet the definitional threshold.

There is controversy concerning the use of the descriptor "long-face syndrome." While increased anterior "total and lower face height" in many ages, combined with vertical maxillary excess in adults has been observed, the causes are controversial. Specifically, there is disagreement about possible potential environmental influences on genetic components.

Anecdotally, it was said to be a genetic condition, which could only be corrected with “massive amounts” of debilitating, frequent and long dental and facial reconstructive surgery.

For children, there is a concern that mouth breathing can contribute to the development of long face syndrome. A recent study finds that it is a growing problem which should be treated as "It won't just go away." In addition to mouth breathing, it may be associated with sleep apnea.

Because of Long face syndrome's sometime association with pediatric obstructive sleep apnea (OSA) and allergic reactions, it is essential that treating physicians differentiate the conditions and the treatments; treating one may not cure the other. Multilevel coblation surgery is sometimes used to correct moderate to severe OSA, and Long Face Syndrome can be a rare factor in considering surgery.

These lesions usually present in neonates, although they may not come to clinical attention until adulthood (for cosmetic reasons). There is no gender predilection. They are present in approximately 3-6 per 1000 live births.

The key problem is the early fusion of the skull, which can be corrected by a series of surgical procedures, often within the first three months after birth. Later surgeries are necessary to correct respiratory and facial deformities.

Recent research has been focused on studying large series of cases of 3-M syndrome to allow scientists to obtain more information behind the genes involved in the development of this disorder. Knowing more about the underlying mechanism can reveal new possibilities for treatment and prevention of genetic disorders like 3-M syndrome.

- One study looks at 33 cases of 3M syndrome, 23 of these cases were identified as CUL7 mutations: 12 being homozygotes and 11 being heterozygotes. This new research shows genetic heterogeneity in 3M syndrome, in contrast to the clinical homogeneity. Additional studies are still ongoing and will lead to the understanding of this new information.

- This study provides more insight on the three genes involved in 3M syndrome and how they interact with each other in normal development. It lead to the discovery that the CUL7, OBS1, and CCDC8 form a complex that functions to maintain microtubule and genomic integrity.

Several studies have examined salivary flow rate in individuals and found parotid and submandibular salivary flow ranging from 5 to 15 times lower than average. This is consistent with the salivary glands being of ectodermal origin, although some findings have suggested that there is also mesodermal input.

Long face syndrome, also referred to as skeletal open bite, is a relatively common condition experienced by orthodontic patients which caused excessive vertical facial development. Its causes may be either genetic or environmental. Long face syndrome is “a common dentofacial abnormality.” Its diagnosis, symptomology and treatments are complex and controversial. Indeed, even its existence as a "syndrome" is disputed.

3-M syndrome is most often caused by a mutation in the gene CUL7, but can also be seen with mutations in the genes OBS1 and CCDC8 at lower frequencies. This is an inheritable disorder and can be passed down from parent to offspring in an autosomal recessive pattern. An individual must receive two copies of the mutated gene, one from each parent, in order to be have 3-M syndrome. An individual can be a carrier for the disorder if they inherit only one mutant copy of the gene, but will not present any of the symptoms associated with the disorder.

Since 3-M syndrome is a genetic condition there are no known methods to preventing this disorder. However, genetic testing on expecting parents and prenatal testing, which is a molecular test that screens for any problems in the heath of a fetus during pregnancy, may be available for families with a history of this disorder to determine the fetus' risk in inheriting this genetic disorder.

The cause of talon cusp is unknown. The anomaly can occur due to genetic and environmental factors but the onset can be spontaneous. Prevention is difficult because the occurrence happens during the development of teeth.

Talon cusp affects men and women equally, however the majority of reported cases are of the male gender. Individuals of Asian, Arabic, Native American and Inuit descent are affected more commonly. Talon cusp is also highly observed in patients with orofacial digital II syndrome and Rubinstein Taybi syndrome. Other anomalies that occur with talon cusp can include peg laterals, supernumerary teeth, dens envaginatus, agenesis and impaction. A person belonging to one of these particular demographics or one who has any of these deformities or syndromes may have a higher risk of having a talon cusp.

OAFNS is a combination of FND and oculo-auriculo-vertebral spectrum (OAVS).

The diagnosis of OAVS is based on the following facial characteristics: microtia (underdeveloped external ear), preauricular tags, facial asymmetry, mandibular hypoplasia and epibulbar lipodermoids (benign tumor of the eye which consists of adipose and fibrous tissue).

There still remains discussion about the classification and the minimal amount of characteristics. When someone presents with FND and the characteristics of OAVS, the diagnosis OAFNS may be made.

As the incidence of OAFNS is unknown, there are probably a lot of children with mild phenotypes that aren’t being diagnosed as being OAFNS.

The cause of OAFNS is unknown, but there are some theories about the genesis. Autosomal recessive inheritance is suggested because of a case with two affected siblings and a case with consanguineous parents. However, another study shows that it is more plausible that OAFNS is sporadic.

It is known that maternal diabetes plays a role in developing malformations of craniofacial structures and in OAVS. Therefore, it is suggested as a cause of OAFNS. Folate deficiency is also suggested as possible mechanism.

Low-dose CT protocols should be considered in diagnosing children with OAFNS.

There is still some discussion on whether FND is sporadic or genetic. The majority of FND cases are sporadic. Yet, some studies describe families with multiple members with FND. Gene mutations are likely to play an important role in the cause. Unfortunately, the genetic cause for most types of FND remains undetermined.

Future studies will look further into the relationship of talon cusp and Rubinstein-Taybi syndrome and other oral-facial-digital syndromes. A former study showed a direct correlation in which 45 affected patients with Rubinstein-Taybi syndrome, 92% of these patients had talon cusp. Other researchers are attempting to trace talon cusp to ancestors and comparing dentition to modern humans. Another study done in 2007 examined the dentition of 301 Native American Indian skeletons for the presence or absence of talon cusp. The results showed five skeletons (2 percent) in the population had the trait.

In 2011, only 21 cases of talon cusp have been reported and are in literature. It appears that as of 2014 and 2015, additional research continues in hopes of finding the cause and mechanism of talon cusp. With the majority of cases of talon cusp being unreported, it remains difficult to conduct tests, come up with conclusions, conduct surgery and perform research with small numbers.