Oculo-Auriculo-Vertebral Spectrum (OAVS): An Overview

 

Mr. Rinu J George1, Mrs. Shiny. T. Sam2

1Department of Nursing and Midwifery, College of Public Health and Medical Science,  Jimma University, Jimma, Ethiopia

2Lecturer, MGM Muthoot College of Nursing, Pathanamthitta, Kerala, India

*Corresponding Author Email: rinugeorge57@yahoo.com

 

ABSTRACT:

Oculoauriculovertebral spectrum (OAVS) is a sporadic condition with an incidence of 3.8: 100000 newborns. The syndrome is characterized by a variable degree of underdevelopment of organs originating from the first and the second branchial arches: The major organs involved are eye, ear and spine. Associated abnormalities include vertebral, cardiac, urinary etc. even though no confirmed causes are been found yet, multifactorial reasons have been stated. Main observable signs include microtia, anotia, colomboma etc. Prenatal diagnosis with ultrasonography along with many tests after the birth like computer tomography, hearing tests, visions tests are now been used The coordinated efforts of a team of specialists who may need to work together to ensure a comprehensive, systematic approach to treatment.

 

KEYWORDS: (OAVS) Oculoauriculovertebral spectrum, (HFM) Hemifacial microsomia, TMJ (Temporomandibular joint).

 

 


INTRODUCTION:

Oculo-auriculo-vertebral spectrum (OAVS) which is a craniofacial developmental disorder affecting the development of the structures derived from the 1st and the 2nd branchial arches during embryogenesis. Its etiology is still poorly understood. Oculo-auriculo-vertebral spectrum (OAVS) encompasses of rare disorders that many clinicians believe to be intimately related to one another and which represent the range of severity of the same disorder. These disorders are apparent at birth (congenital).As the name suggests, they involve malformations of the eyes, ears and spine.

 

In most cases OAVS appears to occur randomly, with no apparent cause (sporadic). A multidisciplinary approach is adopted as to obtain comprehensive caring for the child.

 

DEFINITION:

Oculo-auriculo-vertebral spectrum:

Oculo auriculo vertebral spectrum, or OAVS (Oculo refers to the eye, auriculo to the ear, and vertebral to the spine.) As the name suggests, this spectrum involves the eye, ear, and spine. OAV spectrum encompasses both hemifacial microsomia and Goldenhar syndrome. It is thought that Goldenhar Syndrome may be a more complicated version of OAV while hemifacial microsomia may be a milder version. It is possible that someone with just a small ear, and no other problems, may be at the very mildest end of this spectrum [1]

 

Hemifacial microsomia (HFM):

Hemifacial means one side of the face. Microsomia means small. Hemifacial microsomia means that one side of the face is smaller than the other side, fig: [1]. Hemifacial microsomia tends to affect the right side of the face about 60% of the time. The reason why this side is more often affected than the left is not known. The jaw on the affected side may be smaller, as well as the eye. The cheekbones may not be as well developed, making the cheek on the affected side look a little flatter. The corner of the mouth on the affected side may be extended. The outer ear may be smaller (microtia), or in some cases absent (anotia). There may be extra bits of skin, called skin tags, or dimples called pits, in front of the ear. It is possible to have some hearing loss. A person with hemifacial microsomia may have all or just a few of these features. Most people with hemifacial microsomia have normal intelligence. Just having a small ear may be at the very mild end of this condition[1]

 

Classification:

Pruzanksky classified Hemifacial Microsomia patients into three different types:

·        Type I: Mild hypoplasia of the ramus, and the body of the mandible is slightly affected.

·        Type II: The condyle and ramus are small, the head of the condyle is flattened, the glenoid fossa is absent, the condyle is hinged on a flat, often convex, infratemporal surface, and the coronoid may be absent.

·             Type III: The ramus is reduced to a thin lamina of bone or is completely absent. There is no evidence of a TMJ(Temporomandibular joint).[2]

 

Goldenhar Syndrome:

People with this syndrome can have all the same features as those with hemifacial microsomia, but somewhere between 10 and 33% of people with Goldenhar syndrome have both sides of the face affected. One side is usually more affected than the other fig: [2]

·        In addition to the features of hemifacial microsomia, with Goldenhar syndrome the muscles in the mouth and tongue may be weaker and speech therapy is often advisable.

·        Teeth may erupt later than usual and some may be missing.

·        A cleft lip, a cleft palate, or a cleft lip and palate may be present. Cleft palate alone is more common than cleft lip or cleft lip and cleft palate together.

·        About 35% have a dermoid (cyst on the eye), which is usually not harmful and does not impair vision. If a dermoid is going to occur it will be present from birth.

·        There may also be a small notch in the upper eyelid called a coloboma.[1]

 

Fig. 1: Child with hemifacial microsomia[3]

 

Fig. 2: Child with goldenhar syndrome [4]

 

Prevalence:

On the basis of largest population-based epidemiological study to date, using data provided by the large network of congenital anomalies registries in Europe. The study population included infants diagnosed with oculo-auriculo-vertebral spectrum during the 1990–2009 period from 34 registries active in 16 European countries. Of the 355 infants diagnosed with oculo-auriculo-vertebral spectrum, there were 95.8% (340/355) live born, 0.8% (3/355) fetal deaths, 3.4% (12/355) terminations of pregnancy for fetal anomaly and 1.5% (5/340) neonatal deaths.

 

·        In 18.9%, there was prenatal detection of anomaly/anomalies associated with oculo-auriculo-vertebral spectrum, 69.7% were diagnosed at birth, 3.9% in the first week of life and 6.1% within 1 year of life. Microtia (88.8%), hemifacial microsomia (49.0%) and ear tags (44.4%) were the most frequent anomalies, followed by atresia/stenosis of external auditory canal (25.1%), diverse vertebral (24.3%) and eye (24.3%) anomalies.

·        There was a high rate (69.5%) of associated anomalies of other organs/systems.

·        The most common were congenital heart defects present in 27.8% of patients.

·        The prevalence of oculo-auriculo-vertebral spectrum, defined as microtia/ear anomalies and at least one major characteristic anomaly, was 3.8 per 100000 births. The high rate of different associated anomalies points to the need of performing an early ultrasound screening in all infants born with this disorder. [5].

 

Etiology of OAVS

·        Although knowledge of the genetic basis of human disease and its effect on embryonic development has greatly expanded in recent years, the causes of OAVS are still largely unknown, and the involvement of both genetic and environmental factors have been suggested.

·        OAVS involves primarily the derivatives of the first and second pharyngeal arches, so it has been proposed that the etiology and mechanisms of OAVS are related to the development of these structures. The pharyngeal arches, which start to develop in the 4th week of embryonic development, are composed of mesenchymal cells and give rise to various facial structures, including skeletal, muscular and neural elements, through a complex but poorly characterized signaling network. The morphogenesis of the pharyngeal arch derivatives depends on continuous and reciprocal tissue–tissue interactions.

·        One of the key features of craniofacial development is the formation of cranial neural crest cells, which migrate ventrolaterally as they populate the craniofacial regions. Disturbances in the specification, migration, proliferation, survival and ultimate fate determination of the cranial neural crest cells have been proposed as a possible mechanism for OAVS.

·        The phenotypic characteristics of OAVS and severity of the defects probably depend on how the expression and activation of certain developmental genes and proteins have been disrupted during facial development.

·        Microtia is a common phenotype in OAVS, which may arise as a consequence of neural crest cell defects and/or vascular disruption. This clinical feature can occur as an isolated defect or in association with other anomalies, although the role of these genes in external ear development is not clearly defined, it does show that single gene defects can cause this phenotype by interfering in the genetic pathways necessary for normal development of mesenchymal tissues during fetal development. Inheritance is more likely in familial cases of OAVS, sporadic cases may have polygenic or multifactorial causes.

·        Environmental factors, such as maternal diabetes during pregnancy, thalidomide, vasoactive drugs, smoking and multiple pregnancy may also play a part in causation of this condition.

·        One of the most favored hypotheses is that of vascular disruption of insufficiency in utero. In fact, disruption of embryonic blood flow during development, maternal vasoactive medication use, diabetes and twinning are predisposing factors to a number of structural congenital anomalies. Moreover, a great number of case reports on concordant and discordant twins with OAVS suggest that there might be an association between reproductive abnormalities, twinning and OAVS. [6]

 

Etiology of hemifacial microsomia (HFM)

·        Vascular problems that affect blood flow during pregnancy. Due to interrupted or faulty blood flow to the facial areas, the fetus begins to develop its face irregularly, with some areas growing at a slower pace. The specific cause of this vascular problem may be genetically informed, though research still has not determined any concrete links between genes and Hemifacial Microsomia.[7]

Etiology of goldenhar syndrome

·        Goldenhar syndrome its etiology is multifactorial, but familial cases have been described, with autosomal recessive, autosomal dominant, variable expressivity and incomplete penetrance. Several chromosomal abnormalities have also been described, associated with the syndrome, and the chromosomes most frequently involved are chromosome 22 (Deletion (Del) and duplication (dup) and trisomy of the long arm), chromosome 5 (Del short arm and translocation between chromosomes 5 and 8) and chromosome 18 (Del, and recombinant trisomy).

·        Goldenhar syndrome was associated with risk factors such as vasoactive drugs during pregnancy, bleeding in the second trimester, maternal diabetes, and multiple pregnancies.

·        Microtia, hemifacial microsomia and Goldenhar syndrome phenotypes characterizes oculoauriculo vertebral spectrum (OAV), within the group of syndromes developing first and second arches. For others, the OAV spectrum understand Goldenhar syndrome with changes in other organs or systems, the most common, cardiovascular (50%), central nervous system or mental impairment (5 to 10%) and renal / respiratory (5%). The risk of recurrence of the OAV spectrum, for first-degree relatives, is 6%. [6]

 

Signs & Symptoms:

There are many ways to describe and classify the appearance and function in HFM (hemifacial microsomia); one such system is the OMENS classification. The letters in OMENS stand for:

·        Orbit (or eye socket): the cavity in the skull that contains the eye

·        Mandible: the jawbones

·        Ear

·        Nerve

·        Soft tissues (in anatomy, this refers to skin, muscle, fat, tendons and ligaments – amongst other tissues that are not bone).

 

Common features of hemi facial microsomia include:

Orbit:

·        Normal

·        Small orbit and eye with normal vision

·        Small, underdeveloped eye (microphthalmos) with impaired vision

·        Absence of the eye (anophthalmic orbit)

·        Benign growths on the eye (epibulbar dermoids)

Mandible:

·        Underdevelopment of the upper and lower jaws on the affected side. They may be short and/or crooked.

·        Missing or overcrowding of teeth

·        Cleft lip and/or palate

·        Limited opening of the mouth (trismus

)

·        Non-opposing bite (malocclusion)

Ears:

·        Small tags of skin in front of the ear

·        External ear misshapen, very small, or even missing

·        Ear canal abnormally developed, or absent (aural atresia), resulting in partial or complete hearing loss

Nerve:

·        Partial or complete facial paralysis due to the facial nerve being affected

Soft tissues:

·        Flat cheekbone and unequal cheek fullness (underdeveloped bone, muscle and fat)

·        Flattened forehead

·        Asymmetric mouth with wide lateral cleft (macrostomia)

 

Other parts of the body:

Most babies with HFM have facial differences, but no other medical problems. In a minority of cases, babies with HFM may also have malformed vertebrae (bones of the spine), heart defects and abnormally shaped kidneys. [8]

 

Oculo-auriculo-vertebral spectrum represents three rare disorders that are apparent at birth (congenital), and are characterized by a wide spectrum of symptoms and physical features that may vary greatly in range and severity from case to case.

·        Such abnormalities tend to involve the cheekbones, jaws, mouth, ears, eyes, and/or bones of the spinal column (vertebrae).

·        In about 60 percent of the cases, such malformations involve one side of the body (unilateral). Yet, in approximately 10 to 33 percent of affected individuals, both sides of the body may be involved (bilateral), with one side usually more affected than the other (asymmetry). In many such cases, the right side is more severely affected than the left.

·        For unknown reasons, hemifacial microsomia (HFM) tends to affect only the right side of the face. IN HFM, both the jaw and the eye may be substantially smaller on the affected side.

·        The cheek on the affected side may appear to be flatter due to under development of the cheekbones on that side.

·        The external ear may be smaller (microtia) fig: [3] or even absent (anotia) fig: [4]. There may also be hearing loss. Intelligence is not affected.

People with the Goldenhar variant of OAVS present with most if not all of the signs of HFM, but in 10 to 33 percent of the cases, the symptoms affect both sides of the face (bilateral).

·        A cleft lip and/or cleft palate may be present but the presence of a cleft palate alone is more common.

·        The muscles of the tongue and cheeks may cause severe difficulties with speech.

·        Some tissue(s) of the eye may fail to close, presenting as a notch (coloboma) fig [5].of varying size.

·        In about one-third of cases, the patient presents with a cyst on the eye (dermoids cyst) fig [6]

·        Patients with Goldenhar syndrome can present pre-auricle tags: fig [3] with heart defects as well as kidney problems. People with Goldenhar syndrome may have underdeveloped kidneys on one side or even the lack of a kidney on the affected side. Two or more vertebrae may be fused or knitted together. Intelligence is not affected.[9]

 

             

Fig 3 Microtia[10]                                     Fig 4 Anotia[11]

 

Fig. 5 Coloboma [12]

 

Fig. 6 Dermoids Cyst [13]

 

·        Characterized by misshapen facial structures, disfigured ears and other symptoms include: disfigured ribs, fused vertebrae, misshapen cheek bones, large jaws, crossed eyes and underdeveloped heart and lungs. Those with Goldenhar often have poor facial muscles, benign growths of the eye, misshapen ears, and poor hearing and sight. [14]

Diagnosis:

·        Rarely, oculo-auriculo-vertebral spectrum may be detected before birth (prenatally) by specialized tests such as ultrasound imaging. In fetal ultrasonography, reflected sound waves may be used to create an image of the developing fetus, revealing characteristic findings. In the case of OAVS, such findings depend on the presence or absence of bone in the lower jaw (mandible), severe abnormalities of the outer ears, cleft palate, and/or cleft lip. OAVS may also be diagnosed and/or confirmed after birth (postnatally) by a thorough clinical evaluation, identification of characteristic physical findings, and advanced imaging techniques.

·        A variety of specialized tests may be conducted to confirm specific abnormalities potentially associated with oculo-auriculo-vertebral spectrum disorders.

·        Computer-assisted tomography (CT) scanning may be an essential aid in the detection of middle ear abnormalities that may contribute to hearing loss. Advanced imaging techniques may also be helpful in detecting and/or confirming other potential abnormalities of the skull, spinal column, lungs, and/or kidneys.

·        In some cases, additional specialized tests (e.g., echocardiograms, electro cardio-grams, cardiac catheterization, specialized x-ray studies, etc.) may be conducted to detect and/or confirm the presence of congenital heart defects that may be associated with the disorder.

·        Examination with an instrument (ophthalmoscope) that visualizes the interior of the eye may also be conducted to detect, confirm, and/or characterize certain eye (ocular) abnormalities, such as microphthalmia or anophthalmia, epibulbar dermoids and lipodermoids, strabismus, etc.

·        Swallowing and feeding difficulties in newborns with OAVS may suggest abnormalities such as esophageal atresia and tracheoesophageal fistula. These abnormalities may be detected by means of a flexible, hollow tube used to inject fluid into or drain fluid from the body (catheter). If it cannot pass from the mouth to the stomach, congenital malformations may be present.[9]

 

Treatment:

The treatment of OAVS is directed toward the specific symptoms that are apparent in each individual. Treatment may require the coordinated efforts of a team of specialists who may need to work together to ensure a comprehensive, systematic approach to treatment. Such specialists may include pediatricians; physicians who diagnose and treat disorders of the ears, nose, and throat (otolaryngologists); eye specialists (ophthalmologists); neurologists; heart (cardiologists) and/or lung (cardiothoracic) surgeons; physicians who specialize in the diagnosis and treatment of disorders of the kidneys (nephrologists), urinary tract (urologists), and digestive tract (gastroenterologists); plastic surgeons; specialists who assess and treat hearing problems (audiologists); speech pathologists; and/or other health care professionals.[14]

 

Hemifacial Microsomia Treatment:

v  Treatment for Hemifacial Microsomia may involve surgeries, grafting, orthodontics, and hearing aids. The precise scope and timing of the treatment may vary widely, depending on the individual patient’s condition. Because Hemifacial Microsomia affects the growth and development of the face from birth, it is vital to appropriately time any operations in concert with the individual’s growth. Changes to the facial structure send “messages” back to the body and can indirectly influence future growth. Therefore, in treating Hemifacial Microsomia, the medical team must carefully analyze the structures and growth patterns of each individual patient. [7]

v  If a cleft lip/palate or macrostomia is present, surgical repair begins at about 3 months of age. Skin tags may also be excised.

v  Reconstructive jaw surgery usually comes before ear reconstruction and involves a combination of orthodontic treatment and surgical correction. The mandible (jaw) may be lengthened through distraction osteogenesis or through a combination of surgical cuts in the bone with bone/cartilage grafts. This is usually done when the child is 4 to 5 years old or sooner if needed to facilitate removal of a tracheostomy. [15]

 

Below is a list of possible medical problems, and the treatment options:

·        Ears: skin tags can be easily removed. Surgery can improve the shape of the ear, after the child is at least six years old. Ear reconstruction using cartilage from the rib is a multiple-stage process, with several months in between procedures. In some cases an artificial (prosthetic) ear made of silicone can be fitted.

·        Mouth: a cleft lip can be surgically repaired when a baby is about four months old. A cleft palate is usually operated on when the child is one year old. Children with macrostomia (‘wide mouth’) will need surgery to make a complete ring of muscle around their mouth.

·        Eyes: epibulbar dermoids (growths on the eye) should be monitored by an ophthalmologist to make sure they do not interfere with the child's sight. A small eye socket may be enlarged while performing intracranial surgery. If there is no eye, it may be necessary to make an eye socket for an artificial eye.

·        Jaw and teeth: when the child is at least four years old a bone graft using a piece of bone taken from the ribs may be considered to lengthen the jaw. A less invasive procedure called ‘distraction osteogenesis’ is another option to increase the size of a child's lower jaw: it involves moving two segments of the jawbone slowly apart in such a way that new bone fills in the gap. General dental health and crowding of the teeth should be regularly monitored by a dentist and/or orthodontist. Some children may need a dental appliance or braces.

·        Facial palsy: when present, facial paralysis may improve during the first few years of life. Various medical treatments, therapies, and surgeries can help with facial palsy.

·        Facial contour: if the tissue of the face is underdeveloped, it can be replaced with skin, fat and sometimes muscle taken from another part of the body. Bone grafts taken from the skull or the hip may improve the facial shape.

·        Feeding and breathing problems: babies who have a small jaw and/or a cleft palate, or macrostomia (‘wide mouth’) may have difficulty feeding. It will be essential to check that they are gaining weight appropriately. If breathing is a problem, some options are available to manage and correct the cause, such as positioning devices, tubes and jaw advancement procedures.

·        Hearing impairment: after thorough hearing testing, an audiologist and an ENT doctor will determine the best ways of managing the child’s hearing, and whether hearing aids are needed. When the growth of the ear is nearly complete (at about four years old), a CT scan to examine the middle and inner ear may be helpful to find out whether surgery to restore hearing is likely to be successful.

·        Speech problems: some children with HFM have abnormalities in the muscles in the back of the mouth, which can lead to differences in the way they speak. In other cases, speech problems are caused by the loss of hearing. In these instances, speech therapy is indicated.[8]

 

Goldenhar Syndrome Treatment:

When Goldenhar syndrome is suspected, it is important for physicians to examine the body and ascertain whether normal biological functions are disrupted, such as breathing, swallowing, and eating. Since the problem seems to be caused by “bad programming” of the body, the improper growth patterns will continue and evolve as the patient grows. A treatment plan will, therefore, contain stages, with needed flexibility and steady attempts to repair or form tissues that the body is failing to form correctly. The primary goal of treatment is to ensure that the patient’s vital functions are not hindered in any way, with a secondary goal of giving the patient as “normal” an appearance as is practical and healthy.

 

Treatment for Goldenhar syndrome is regrettably limited to surgical intervention in an effort to help proper development of the various body parts that develop incorrectly. Stem cell therapy has had some success in dealing with eye dermoids, where the stem cells have been used to effectively “reprogram” cells. [16]

 

·        In uncomplicated cases, the treatment of the syndrome varies with age and systemic associations and it is mainly cosmetic.

·        Surgical management involves craniofacial reconstruction.

·        Reconstructive surgery of the external ear may be undertaken, usually around 6-8 years of age.

·        Jaw reconstructive surgery may be needed for some patients.

·        Supportive multidisciplinary management should be arranged, including departments such as pediatric cardiology, audiology, ophthalmology and plastic surgery. [17]

 

REFERENCE:

1.       Hospital, U. (2015). UC Davis Children's Hospital: Craniofacial Anomalies – Oculo-Auriculo-Vertebral Spectrum, Hemifacial. Ucdmc.ucdavis.edu. Retrieved 19 November 2015, from http://www.ucdmc.ucdavis.edu/children/clinical_services/cleft_craniofacial/anomalies/oculo.html

2.       Hemifacial microsomia Wikipedia, the free encyclopedia, [cited internet] available at https://en.wikipedia.org/wiki/ Hemifacial_ microsomia# Classification

3.       Wiki.ggc.edu, 'Hemifacial Microsomia - Ggcwiki'. N.p., 2015. Web. 19 Nov. 2015.

4.       Tumblr.com, 'Goldenhar Syndrome | Tumblr'. N.p., 2015. Web. 19 Nov. 2015.

5.       Prevalence, Prenatal Diagnosis and Clinical Features of Oculo-Auriculo-Vertebral Spectrum: A Registry-Based Study In Europe'. European Journal of Human Genetics (2015):

6.       Beleza-Meireles, A., Clayton-Smith, J., Saraiva, J., & Tassabehji, M. (2014). Oculo-auriculo-vertebral spectrum: a review of the literature and genetic update. Journal of Medical Genetics, 51(10), 635-645. http://dx.doi.org/10.1136/jmedgenet-2014-102476

7.       International Craniofacial Institute | Cleft Lip & Palate Treatment Center, Hemifacial Microsomia Syndrome Treatment in Dallas, TX, 2015, available at http://www.cranio facial.net/hemifacial-microsomia-syndrome-dallas/

8.       Facial Palsy UK, available at http://www.facialpalsy.org.uk/about-facial-palsy/causes-diagnoses/developmental/hemifacial-microsomia/277

9.       Goldenhar Syndrome and Oculo-Auriculo-Vertebral Spectrum (GS/OAVS): Clinical, Citogenomic and Molecular Study'. (2015): n. pag. Web.

10.     https://en.wikipedia.org/wiki/Anotia

11.     Design, Martin. 'Ear Prosthesis | Prosthetic Ear | Artificial Ear | Microtia | Medical Art Resources'. Medicalartresources.com. N.p., 2015. Web. 20 Nov. 2015.

12.     Health central, coloboma of the iris, 2015,availableat http://www.healthcentral.com/encyclopedia/adam/coloboma-of-the-iris-4018296/

13.     American Association for Pediatric Ophthalmology and Strabismus, Dermoid Cyst, http://www.aapos.org/terms/ conditions/41, Cited nov 2015

14.     NORD (National Organization for Rare Disorders),. (2015). Oculo-Auriculo-Vertebral Spectrum - NORD (National Organization for Rare Disorders). Retrieved 19 November 2015, from https://rarediseases.org/ rare-diseases/oculo-auriculo-vertebral-spectrum/

15.     Plastic and Craniofacial Surgery for Infants and Children, available at http://www.kidsplastsurg.com/hemifacial-microsomia.cfm

16.     International Craniofacial Institute | Cleft Lip & Palate Treatment Center, Goldenhar Syndrome Treatment in Dallas, TX, 2015, available at http://www.craniofacial.net/goldenhar-syndrome-dallas/

17.     Colin Tidy,  Louise Newson, Adrian Bonsall, Patient Trusted  Medical Information And Support, Goldenhar's Syndrome, 23 June 2015, available at http://patient.info/doctor/goldenhars-syndrome.

 

 

 

 

Received on 31.12.2015           Modified on 15.01.2016

Accepted on 21.02.2016           © A&V Publication all right reserved

Int. J. Nur. Edu. and Research. 2016; 4(2):217-222.

DOI: 10.5958/2454-2660.2016.00043.0