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.

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.

The clinical presentation of HFM is quite variable. The severity may depend on the extent of the area with an insufficient blood supply "in utero", and the gestational age of the fetus at which this occurs. In some people, the only physical manifestation may be a small and underdeveloped external ear. In more severe cases, multiple parts of the face may be affected. Some people with HFM may have sensorineural hearing loss and decreased visual acuity or even blindness.

Goldenhar syndrome can be thought of as a particularly severe form of HFM, in which extracranial anomalies are present to some extent. Some of the internal organs (especially the heart, kidneys, and lungs) may be underdeveloped, or in some cases even absent altogether. The affected organs are typically on the same side as the affected facial features, but bilateral involvement occurs in approximately 10% of cases. Deformities of the vertebral column such as scoliosis may also be observed in Goldenhar syndrome.

While there is no universally accepted grading scale, the OMENS scale (standing for Orbital, Mandible, Ear, Nerves and Soft tissue) was developed to help describe the heterogeneous phenotype that makes up this sequence or syndrome.

Intellectual disability is not typically seen in people with HFM.

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 condition is also known by various other names:

- Lateral facial dysplasia

- First and second branchial arch syndrome

- Oral-mandibular-auricular syndrome

- Otomandibular dysostosis

- Craniofacial microsomia

The symptoms of Freeman–Sheldon syndrome include drooping of the upper eyelids, strabismus, low-set ears, a long philtrum, gradual hearing loss, scoliosis, and walking difficulties. Gastroesophageal reflux has been noted during infancy, but usually improves with age. The tongue may be small, and the limited movement of the soft palate may cause nasal speech. Often there is an H- or Y-shaped dimpling of the skin over the chin.

Children with Weaver syndrome tend to look similar and have distinctive physical and craniofacial characteristics, which may include several, but not all of the following features:

- Macrocephaly

- Large bifrontal diameter

- Flattened occiput

- Long philtrum

- Retrognathia

- Round face in infancy

- Prominent chin crease

- Large ears

- Strabismus

- Hypertelorism

- Epicanthal folds

- Downslanting palpebral fissures

Other features may include loose skin, thin deep-set nails, thin hair, short ribs, limited elbow and knee extension, camptodactyly, and a coarse, low-pitched voice. Delayed development of motor skills such as sitting, standing, and walking are commonly exhibited in early childhood. Patients with Weaver syndrome typically have mild intellectual disability with poor coordination and balance. They also have some neurological abnormalities such as speech delay, epilepsy, intellectual disability, hypotonia or hypertonia, and behavioral problems.

As a result of the changes to the developing embryo, the symptoms are very pronounced features, especially in the face. Low-set ears are a typical characteristic, as in all of the disorders which are called branchial arch syndromes. The reason for this abnormality is that ears on a foetus are much lower than those on an adult. During normal development, the ears "travel" upward on the head; however, in Crouzon patients, this pattern of development is disrupted. Ear canal malformations are extremely common, generally resulting in some hearing loss. In particularly severe cases, Ménière's disease may occur.

The most notable characteristic of Crouzon syndrome is craniosynostosis, as described above; however it usually presents as brachycephaly resulting in the appearance of a short and broad head. Exophthalmos (bulging eyes due to shallow eye sockets after early fusion of surrounding bones), hypertelorism (greater than normal distance between the eyes), and psittichorhina (beak-like nose) are also symptoms. Additionally, external strabismus is a common occurrence, which can be thought of as opposite from the eye position found in Down syndrome. Lastly, hypoplastic maxilla (insufficient growth of the midface) results in relative mandibular prognathism (chin appears to protrude despite normal growth of mandible) and gives the effect of the patient having a concave face. Crouzon syndrome is also associated with patent ductus arteriosus (PDA) and aortic coarctation.

For reasons that are not entirely clear, most Crouzon patients also have noticeably shorter humerus and femur bones relative to the rest of their bodies than members of the general population. A small percentage of Crouzon patients also have what is called "Type II" Crouzon syndrome, distinguished by partial syndactyly.

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.

The most severe problem associated with Stickler syndrome is Pierre Robin syndrome. This refers to a cleft palate resulting from a very small lower jaw. During early fetal life, the roof of the mouth is normally open and the sides of the palate have to come together to close. If the jaw is too small, there is not enough room for the tongue which is then pushed up and gets in the way of the closing palate. Sometimes the chin is so small the baby has problems with eating and breathing if the tongue blocks the back of the throat. Cleft palate is found less frequently in Marshall Syndrome than in Stickler syndrome but still more frequently than in the general population.

The facial features of Marshall Syndrome include a flat midface, the appearance of large eyes, short upturned nose, and a round face. The facial features of Stickler syndrome are less prominent but include a rather long flat face, and depressed nasal bridge.

Hemangiomas associated with PHACE Syndrome are usually small or not visible at birth, but are easier to see during the first days to weeks of life. They can grow rapidly. Hemangiomas linked with PHACE Syndrome tend to cover a large area of the face, head or neck, either as one lesion or as many single lesions.

The joint changes include hyperextensibility (double-jointedness) and arthritis. Babies and young children with Stickler syndrome usually have very hyperextensible joints. As an affected child gets older, they may experience pain and stiffness from overuse of a joint. Osteoarthritis of the large joints often develops during the third or fourth decade. The joint changes in Marshall syndrome are of the same type but to a lesser degree. There also may be changes in the bones that show up on X-ray but generally are not a problem.

Many of the physical features associated with the disorder are congenital. Characteristic craniofacial abnormalities typically include a long, narrow head that is disproportionate to the body size, a broad and prominent forehead, and a triangular-shaped face with a hypoplastic midface, pointed chin, prominent mouth, fleshy tipped upturned nose, large ears, and full lips. The teeth may be abnormally crowded together in some affected individuals.

Posterior fossa malformations–hemangiomas–arterial anomalies–cardiac defects–eye abnormalities–sternal cleft and supraumbilical raphe syndrome (also known as "PHACES Syndrome") is a cutaneous condition characterized by multiple congenital abnormalities.

PHACE syndrome should be considered in infants with large plaque-type facial hemangiomas. Children presenting with this dermatologic manifestation should receive careful ophthalmologic, cardiac, and neurologic assessment.

According to one study in infants with large hemangiomas, one-third have extracutaneous manifestations consistent with the diagnosis of PHACE syndrome. The most common are cerebrovascular and cardiovascular anomalies.

The Pai Syndrome is a rare subtype of frontonasal dysplasia. It is a triad of developmental defects of the face, comprising midline cleft of the upper lip, nasal and facial skin polyps and central nervous system lipomas. When all the cases are compared, a difference in severity of the midline cleft of the upper lip can be seen. The mild form presents with just a gap between the upper teeth. The severe group presents with a complete cleft of the upper lip and alveolar ridge.

Nervous system lipomas are rare congenital benign tumors of the central nervous system, mostly located in the medial line and especially in the corpus callosum. Generally, patients with these lipomas present with strokes. However, patients with the Pai syndrome don’t. That is why it is suggested that isolated nervous system lipomas have a different embryological origin than the lipomas present in the Pai syndrome. The treatment of CNS lipomas mainly consists of observation and follow up.

Skin lipomas occur relatively often in the normal population. However, facial and nasal lipomas are rare, especially in childhood. However, the Pai syndrome often present with facial and nasal polyps. These skin lipomas are benign, and are therefore more a cosmetic problem than a functional problem.

The skin lipomas can develop on different parts of the face. The most common place is the nose. Other common places are the forehead, the conjunctivae and the frenulum linguae. The amount of skin lipomas is not related to the severity of the midline clefting.

Patients with the Pai syndrome have a normal neuropsychological development.

Until today there is no known cause for the Pai syndrome.

The large variety in phenotypes make the Pai syndrome difficult to diagnose. Thus the incidence of Pai syndrome seems to be underestimated.

Skeletal anomalies aren't present at birth but develop in the individual and include delayed bone maturation, slender long tubular bones, and tall vertebral bodies. Joint hyper-mobility and increased risk of hip dislocation has been presented in individuals. Abnormal spinal curvature, either kyhoscholiosis or hyperlordosis, causing back pain can also be experienced from this disorder.

Common relevant features of acrocephalosyndactyly are a high-arched palate, pseudomandibular prognathism (appearing as mandibular prognathism), a narrow palate, and crowding of the teeth.

Enophthalmos (recession of the eyeball within the orbit) is the most common eye abnormality observed in Parry–Romberg syndrome. It is caused by a loss of subcutaneous tissue around the orbit. Other common findings include drooping of the eyelid (ptosis), constriction of the pupil (miosis), redness of the conjunctiva, and decreased sweating (anhidrosis) of the affected side of the face. Collectively, these signs are referred to as Horner's syndrome. Other ocular abnormalities include ophthalmoplegia (paralysis of one or more of the extraocular muscles) and other types of strabismus, uveitis, and heterochromia of the iris.

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:

The features of this syndrome affect the face, skin, brain and the body.

Face:

- downslanting palpebral fissures

- pointed chin

- prominent forehead

- proptosis

- thin upper lip

- wide nasal bridge

Skin:

- fragile

- hyperelastic

Brain:

- Low IQ

- Periventricular white matter lesions

Body:

The height, lower-segment, hand, and foot length are all greater than usual.

This classification is based on the morphologic characteristics of FND, that describes a variety of phenotypes

Both of these classifications are further described in table 1. This table originates from the article ‘Acromelic frontonasal dysplasia: further delineation of a subtype with brain malformations and polydactyly (Toriello syndrome)', Verloes et al.

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.

The cranium consists of three main sections including the base of the cranium (occipital bone), the face (frontal bone), and the top (parietal bones) and sides (temporal bone) of the head. Most of the bones of the cranium are permanently set into place prior to birth. However, the temporal and parietal bones are separated by sutures, which remain open, allowing the head to slightly change in shape during childbirth. The cranial sutures eventually close within the first couple of years following birth, after the brain has finished growing.

In individuals with SCS, the coronal suture separating the frontal bones from the parietal bones, closes prematurely (craniosynostosis), occasionally even before birth. If the coronal suture closes asymmetrically or unilaterally, then the face and forehead will form unevenly, from side-to-side. People with SCS have pointy, tower-like heads because their brain is growing faster than their skull, resulting in increased intracranial pressure (ICP) and causing the top of the head and/or forehead to bulge out to allow for brain growth. The face appears uneven, particularly in the areas of the eyes and cheeks, and the forehead appears wide and tall.

Because of the abnormal forehead, there is less space for the normal facial features to develop. This results in shallow eye sockets and flat cheekbones. The shallow eye sockets make the eyes more prominent or bulging and cause the eyes to be more separated than normal (hypertelorism). The underdeveloped eye sockets, cheekbones, and lower jaw cause the face to appear flat. Furthermore, the minor downward slant of the eyes along with the drooping eyelids (ptosis) adds to the overall unevenness of the face.

Neurological abnormalities are common. Roughly 45% of people with Parry–Romberg syndrome are also afflicted with trigeminal neuralgia (severe pain in the tissues supplied by the ipsilateral trigeminal nerve, including the forehead, eye, cheek, nose, mouth and jaw) and/or migraine (severe headaches that may be accompanied by visual abnormalities, nausea and vomiting).

10% of affected individuals develop a seizure disorder as part of the disease. The seizures are typically Jacksonian in nature (characterized by rapid spasms of a muscle group that subsequently spread to adjacent muscles) and occur on the side contralateral to the affected side of the face. Half of these cases are associated with abnormalities in both the gray and white matter of the brain—usually ipsilateral but sometimes contralateral—that are detectable on magnetic resonance imaging (MRI) scan.

Pilotto syndrome is a rare syndrome which affects the face, heart, and back. The syndrome can cause a cleft lip and palate, scoliosis, and mental retardation. The Office of Rare Diseases and National Institutes of Health have classified this syndrome as affecting less than 200,000 people in the United States.