What Are the Craniofacial Disorders?
Craniofacial disorders compromise an individual's esthetics and functions like head size, jaw movements, jaw size, the number and size of teeth, gum disease, and orofacial complications that would be disfiguring. It is essential to know that many craniofacial disorders cannot be identified early in childhood, especially when known family history is absent. Also, the treatment of these patients may be complicated because of insufficient medical knowledge about craniofacial variations. Dental orthognathic surgery also remains a boon for esthetic and functional establishment without a proper diagnosis from the medical. For surgical teams, treatment for these individuals remains a challenge.
What Are the Common Craniofacial Syndromes of Genetic Origin?
The common craniofacial syndromes of genetic origin are listed below:
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Neurofibromatosis Type 1 (NF1): This craniofacial syndrome is a tumor or predisposing syndrome known to be caused by heterozygous mutations in the neurofibromin gene. Patients affected by NF1 commonly exhibit a short mandible, maxilla (short upper and low jaw), and a short cranial base with low face height. Regarding the oral manifestations, these patients of NF1 usually show a unilateral inflammation or swelling of the gums.The gum inflammation would be of a rather diffuse enlargement in the attached or interproximal gingiva region.
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Branchial Arch Syndromes: These are the group of syndromes affecting the first and second branchial arch derivatives. They are common causes of craniofacial deformities. Multiple syndromes in the category of branchial arch syndromes exist, for example, hemifacial microsomia (HFM), Treacher-Collins syndrome (TCS), and Möbius syndrome (MBS).
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Hemifacial Microsomia (HFM): This is the most frequent craniofacial condition out of the three syndromes. It nearly affects every one child in 4,000 to 5,600 births, according to medical literature.
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Dental Anomalies: These are most commonly reported in 60 percent of children suffering from Treacher Collins syndrome. Tooth agenesis (TA) is additionally the main anomaly common in all these syndromes. Most commonly, the mandibular second premolars are missing in these individuals, followed by maxillary second premolars or the lateral incisors.
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Syndromes Related to Cleft Lip and Palate: The 22q11.2 deletion syndrome (22q11.2DS) velocardiofacial (VCF) syndrome, and the Shprintzen or DiGeorge syndrome, are all related directly to the development of cleft lip or cleft palate. In these groups of craniofacial anomalies, it is also common to find clinical features or issues in the musculoskeletal system. There would be hypogonadism or undeveloped genital organs, mental retardation, or even hearing loss. In these groups of craniofacial conditions, one can expect to find individuals suffering from impacted upper (maxillary) supernumerary teeth that are hypoplastic and malpositioned. The maxillary central incisors are the commonly affected teeth.
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Kabuki Syndrome (KS): In this syndrome, the Individuals suffer from congenital mental retardation. This syndrome also has additional clinical features such as dwarfism and peculiar facies. The craniofacial characteristics of this condition are smaller head microcephaly, short columella, the flat and rather broad tip of the nose, high arched eyebrows, extra long eyelashes, etc. There would be long palpebral fissures and large protruded or cupped earlobes. The majority of the patients suffering from Kabuki syndrome show fewer teeth or hypodontia. This occurs in relation to missing (agenesis) incisors or premolars. Other oral and jaw manifestations are microdontia (smaller teeth) as well as screwdriver teeth (peg incisors).
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Congenital Hypogonadotropic Hypogonadism (CHH): This is a genetic syndrome that is caused due to deficiency in the gonadotropin-releasing hormone. Nearly half of CHH patients experience a reduced sense of smell (hyposmia or anosmia). Tooth agenesis (missing teeth) occurs in about 50 percent of cases. Also, these patients may have cleft lip or palate too. Dental agenesis would be highly variable, ranging from one or more multiple congenitally missing teeth. The most frequently missing teeth are the lateral lower(mandibular) incisors.
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Pierre Robin Syndrome: The primary cause of this syndrome is a growth defect that occurs in the embryonic stage during lower jaw or mandible development (due to mutation in the SOX9 gene). Nearly 75 to 100 percent of the affected individuals with PRS may have a cleft palate along with an abnormally dorsal position tongue (glossoptosis). These oral manifestations can result in patients suffering from respiratory obstruction commonly, vagal forms of systemic syncope, and even feeding problems faced by the mother.
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Van Der Woude Syndrome (VWS): This craniofacial syndrome is most commonly linked to cleft palate or cleft lip. It was first described in 1954 by Van Der Woude, and the condition is characterized by paramedian lip pits, sinuses apart from orofacial clefting in the child.
What Are the Medical and Cardiac Complications Associated?
All the enlisted craniofacial syndromes, that is, the NFS, branchial arch syndromes, VCS (Vascular closure system), KS (Kabuki Syndrome), VWS (Van Der Woude Syndrome), and PRS (Pierre Robin Syndrome), are directly associated with abnormalities developing in the cardiovascular system as well. Infants or children who suffer from these disorders may be prone to abnormalities of the cardiac septa and the aortic arch commonly.
What Is the Need for a Multidisciplinary Approach?
The need for a multidisciplinary approach is explained below:
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Care of these individuals as they grow older with the affecting craniofacial and dental or jaw structures should be encouraged. They are mostly treated by an interdisciplinary team very early in their childhood and onwards.
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In addition to the medical team and dental specialists or oral surgeons, for studying these genetic abnormalities, often molecular and developmental geneticists, computational biologists, or bioinformaticians are needed to initiate the correct treatment plan and to save their life in case of complications.
Conclusion:
Early diagnosis holds great importance and is crucial for the effective treatment of the affected individuals. Especially because the esthetic and functional aspects of their growth have commonly interfered with the clinical features, psychosocial support is much needed. Hence both dental and medical professionals should intervene as part of the multidisciplinary team to prevent craniofacial disorders from worsening in these individuals and stimulate the right functional development.
