Syndromes of the Head and Neck, An Issue of Atlas of the Oral & Maxillofacial Surgery Clinics (eBook)

Dean M. DeLuke (Autor)

eBook Download: PDF | EPUB

2014 | 1. Auflage
100 Seiten
Elsevier Health Sciences (Verlag)
978-0-323-32314-7 (ISBN)

Infos

This issue of the Atlas of the Oral and Maxillofacial Surgery Clinics of North America serves as an aid to identification of 70 of the more important head and neck syndromes, and organized using the same nosology as in the landmark text of Robert Gorlin. As such, it should be useful to a varied audience, including not only the oral and maxillofacial surgeon but also the oral pathologist, the practitioner of oral medicine, and members of the craniofacial team--the orthodontist, pediatric dentist, speech and language specialist, geneticist, plastic surgeon, ENT specialist, pediatrician, nurse coordinator, and others. Areas covered include: Craniosynostosis Syndromes; Syndromes Affecting Bone; Metabolic and Autoimmune Syndromes; Syndromes Affecting Skin and Mucosa; Hamartoneoplastic Syndromes; Branchial Arch Syndromes; Clefting Syndromes; Syndromes Affecting the Central Nervous System; Chromosomal Syndromes; Syndromes with Unusual Facies; and Syndromes with Unusual Dental Findings or Gingival Components.

Textauszug

Craniosynostosis Syndromes

Carolyn Dicus Brookes, DMD, MD, Brent A. Golden, DDS, MD and Timothy A. Turvey, DDS∗[e-mail],     Department of Oral & Maxillofacial Surgery, University of North Carolina-Chapel Hill, 149 Brauer Hall, CB #7450, Chapel Hill, NC 27599-7450, USA

∗Corresponding author.

Keywords

Craniofacial dysostosis

Craniosynostosis syndromes

Crouzon

Apert

Pfeiffer

Muenke

Key points

• Craniosynostosis syndromes have wide phenotypic variability. Understanding of the underlying genetic causes continues to develop.

• Children with these syndromes are best managed at a multidisciplinary craniofacial center.

• Early management focuses on airway protection, preservation of vision and hearing, and feeding.

• Timing of craniofacial reconstruction is driven by growth and development of the area of interest.

• In the past, intellectual disability was assumed. However, many patients with craniofacial dysostosis syndromes live rich lives and have normal or even exceptional intellect provided they are raised in a nurturing, stimulating environment.

Craniosynostosis is premature fusion of cranial sutures, and it occurs in 1:2000 to 1:2500 live births.1,2 Most cases are nonsyndromic. Craniosynostosis syndromes, more than 150 of which have been identified, affect 1:25,000 to 1:100,000 infants.2,3 The most common are reviewed in this article.

Craniosynostosis syndromes are diagnosed based on clinical features. Abnormal head shape and midface deficiency with exorbitism are typical craniofacial expressions,1,2,4–6 and syndromes with these traits may be called craniofacial dysostosis syndromes. Limb and visceral manifestations further delineate each syndrome.

Fibroblast growth factor receptor (FGFR) and TWIST mutations are the most commonly associated with craniosynostosis syndromes. Although genotype-phenotype correlations have been characterized, phenotypically similar patients may have genetically distinct syndromes and identical mutations have been found in patients with different clinical diagnoses.2,7,8 Fibroblast growth factors participate in myriad processes including skeletogenesis and limb development. Gain-of-function mutations in FGFR1, FGFR2, and FGFR3 cause the FGFR-related craniosynostosis syndromes, which include Crouzon, Apert, Pfeiffer, Beare-Stevenson, Jackson-Weiss, and Muenke syndromes as well as Crouzon syndrome with acanthosis nigricans and FGFR2-related isolated coronal synostosis. These syndromes account for approximately 17% of craniosynostosis cases.9

Crouzon syndrome

Genetics

• FGFR2 mutations

• Autosomal dominant; complete penetrance, variable expressivity

 Occasionally de novo

• 1.6:100,000; 4.5% of craniosynostosis cases2,10

Clinical features

Cardinal features:

• Craniosynostosis

• Midface/orbital hypoplasia

• Clinically normal hands/feet

Crouzon syndrome, like all craniofacial dysostosis syndromes, is classically characterized by premature fusion of the coronal and frontosphenoidal sutures and the sphenoethmoidal synchondrosis.11 Fusion results in brachycephaly; midface deficiency; and a short, wide anterior cranial base. The forehead is prominent because of compensatory growth at unaffected sutures. Additional sutures may be involved and rarely there is no sutural involvement (Fig. 1).6,12,13

Fig. 1 Crouzon syndrome. Frontal views of a child with Crouzon syndrome. The only prior procedures performed were placement of PET and VP shunt. PET, pressure equalization tubes; VP, ventriculoperitoneal.

Exophthalmos is always present, largely because of orbital hypoplasia with retruded supraorbital, infraorbital, and lateral orbital rims. The widened cranial base can result in hypertelorism. Most patients have exotropia;14 orbital dystopia and strabismus can be observed.15 Approximately 20% of patients develop optic atrophy.14

Anteroposterior and vertical midface hypoplasia are consistent features. Dental crowding, crossbite, and apertognathia are typical. Cleft lip and palate are rare.15

Other features

• Typically normal intellect

• Hydrocephalus (up to 30%); occasional nonprogressive ventriculomegaly16,17

• Hearing loss common18

• Classically normal limbs/axial skeleton (occasional mild anomalies)19–23

• Cardiovascular anomalies rare

Differential diagnosis

If choanal atresia is present, consider Crouzon syndrome with acanthosis nigricans. Apert, Pfeiffer, Jackson-Weiss, and Saethre-Chotzen syndromes are diagnostic considerations.6

Apert syndrome

Genetics

• FGFR2 mutations

 Specific mutations linked to clinical features (ie, severe craniofacial involvement)24

• Most are de novo

 Sometimes autosomal dominant; complete penetrance.2

• 1:100,000; 4% to 5% of craniosynostosis cases2,25,26

Clinical features

Cardinal features:

• Craniosynostosis

• Midface/orbital hypoplasia

• Bilateral syndactyly of hands/feet (minimally second to fourth digits)

Craniofacial anomalies are generally more severe in Apert than in Crouzon syndrome.13 Asymmetry frequently affects the cranial base, orbits, and midface.15 Megalencephaly is common.27

Infants with Apert syndrome have bicoronal synostosis with a midline calvarial defect from glabella to the posterior fontanelle that predictably obliterates over time.12,13 The anterior cranial base is short. Patients often have a flattened occiput and a wide, steep forehead. The skull is wide with temporal bulging; temporal fat pads are prominent (Fig. 2).15,28

Fig. 2 Apert syndrome. (A–C) Frontal, lateral and superior views of a 3-D CT reconstruction of an infant with Apert syndrome. Note the wide midline calavarial defect and turribrachycephaly.

The orbits are hypoplastic; exophthalmos and hypertelorism are always observed.14 Supraorbital and infraorbital rims are retruded. The lateral orbital wall is ballooned; lateral orbital rim projection is near normal. Palpebral fissures are often downslanting.15 Exotropia, refractive errors, and strabismus are common;14 optic atrophy is seen more in Crouzon syndrome.29,30 Eyebrows may be interrupted over a bony defect at the lateral supraorbital rim.15

The midface is retrusive. The nose is short with a depressed bridge and rounded tip.15 Ears tend to be large and may be low set.15,31

Lips are hypotonic.15 Lateral palatal swellings contain mucopolysaccharides and grow with age; the palate is highly arched.32,33 The soft palate is often long and thick.33 Cleft palate is seen more than in Crouzon syndrome or the general population. Delayed and ectopic dental eruption are common. Most patients have dental crowding, crossbite, and apertognathia (Fig. 3).15,34,35

Fig. 3 Apert syndrome. (A) Frontal and profile views of another infant with Apert syndrome. (B) Hands and feet of the same child demonstrating polysyndactyly. (C) Palatal view of the same patient as a teenager. Note the significant crowding, lateral palatal swellings, and highly arched palate.

Other manifestations

• Ventriculomegaly common; progressive hydrocephalus rare16,36

• Mental retardation more common than in Crouzon...

Produkt-Details

• Erscheint lt. Verlag: 28.9.2014
• Sprache: englisch
• Themenwelt: Medizinische Fachgebiete ► Chirurgie ► Ästhetische und Plastische Chirurgie
• Themenwelt: Medizin / Pharmazie ► Zahnmedizin ► Chirurgie
• ISBN-10: 0-323-32314-6 / 0323323146
• ISBN-13: 978-0-323-32314-7 / 9780323323147