Facial development occurs between weeks 3 and 8. Key facial features such as the mouth, ears, eyes, and nose are clearly recognizable by week 8 (not 4). They become progressively defined from week 6 onwards (Fig. 27.1). Facial embryological structures originate from the frontonasal prominence of the forebrain, which forms the forehead, nasal dorsum, and medial and lateral nasal prominences. The lateral nasal prominences then form the nasal alae, but the premaxilla (along with the nasal tip, columella, philtrum) is formed from the medial nasal prominences. The first pharyngeal arch bifurcates to form the mandibular and maxillary processes, which then form the upper lateral and lower parts of the mouth. The external ear is formed from both the mandibular (first) and hyoid (second) pharyngeal arches.1–3 Fig. 27.1 Embryonic development of the human face. A, 4-week embryo. B, 5-week embryo. C, 6-week embryo. D, 6½-week embryo. E, 7-week embryo. F, 8-week embryo. (From Bentz ML, Bauer BS, Zuker RM. Principles & Practice of Pediatric Plastic Surgery. St Louis: Quality Medical Publishing, 2008.) A B C D E F Nasal placode Mandibular process Maxillary process Frontonasal prominence Stomodeum
2. Sadler TW, ed. Langman’s Medical Embryology. 13th ed. Philadelphia: Wolters Kluwer Health; 2014
3. Tepper OM, Warren SM. Craniofacial embryology. In: Weinzwig J, ed. Plastic Surgery Secrets Plus. 2nd ed. Philadelphia: Elsevier; 2010 TESSIER CLEFTS 2. Which one of the following statements is correct regarding Tessier clefts? Tessier described cleft numbers 0–14 relative to the midline and subgrouped them according to their location as oral- nasal, oral-ocular, lateral facial, and cranial. An additional cleft number 30 does not fit into this subcategorization. It passes inferiorly from the lower lip toward the neck and is not numbered according to the midline per se, although it is a midline cleft. Of this total 16 clefts the most common is a lateral cleft (number 7). The other lateral clefts (numbers 8 and 9), however, are rare. Oral-ocular clefts do not disrupt the integrity of the nose. They occur lateral to Cupid’s bow and extend through the cheek and maxillary process. This is called meloschisis (Fig. 27.2).1
Treacher Collins described this syndrome in 1900. It has an incidence of 1 in 10,000 to 1 in 50,000 live births. A genetic alteration occurs on chromosome 5, and the condition is inherited in an autosomal dominant pattern. Bilateral oral ocular and lateral facial clefts are typically seen, and the airway is a major priority in these patients, many of whom will require long-term tracheostomy placement. This is secondary to mandibular hypoplasia in combination with a narrow pharynx.1–3
The clinical findings in Treacher Collins syndrome include upper and lower eyelid deformity, absence of the zygomatic arch with a malar deficiency, and varying degrees of microtia. Patients do, however, generally have normal nasal development and would be least likely to require a rhinoplasty given the other options listed. The lower eyelid has coloboma and retraction, which may require reconstruction and the lateral canthi are displaced inferiorly and therefore may benefit from canthal elevation. The lack of cheek projection due to absence of the zygomatic arch and malar bone hypoplasia may require cheek reconstruction using composite flaps or lipofilling techniques. Formal ear reconstruction may be required using costal cartilage and local flaps. Upper eyelid surgery may be required as patients have an excess of upper eyelid skin laterally giving a false impression of ptosis.1–3
Goldenhar’s syndrome is a type of hemifacial microsomia with sporadic occurrence in which patients have a constellation of abnormalities including bilateral accessory auricular appendages, varying degrees of microtia, epibulbar dermoids, vertebral anomalies, a low anterior hairline, and mandibular hypoplasia. The description in this patient is most in keeping with auricular appendages and these may well comprise of skin and underlying cartilage. They can safely be excised under general anesthetic on an elective basis. Pedunculated papillomas and subcutaneous lipomas can have a similar appearance but are not typical of Goldenhar’s syndrome. Epibulbar dermoids and colobomas are characteristic of Goldenhar’s syndrome but affect the eye, not the cheek.1,2
Cleft number 7 is a lateral cleft that passes from the oral commissure toward the ear. It stops at the anterior border of the masseter. It is the most common overall cleft (1–6/8000 births) and may occur because of disruption of the stapedial artery. This cleft affects males more often than females and is bilateral in 10% of cases. It is associated with variable degrees of soft tissue and bony deformity including craniofacial microsomia, facial and trigeminal nerve paresis, microtia, and middle ear abnormalities. Cleft numbers 8 and 9 are also lateral clefts but are far less common than cleft 7. Cleft 8 is associated with Goldenhar’s syndrome and almost always exists in combination with another rare cleft. It is largely isolated to the orbital area with coloboma of the lateral commissure and absence of the lateral canthus. The zygoma is either hypoplastic or absent, and the lateral orbital wall is deficient. Cleft 9 is extremely rare and may be accompanied by encephaloceles. It is associated with soft tissue abnormalities of the lateral third of the upper eyelid and brow as well as hypoplasia of the greater wing of the sphenoid, which results in posterior displacement of lateral orbital rim. Cleft numbers 5 and 6 are both oral-ocular clefts which connect the oral and orbital cavities without disrupting the nose. They occur lateral to Cupid’s bow and extend through the soft tissue of the cheek and maxillary process. Cleft 5 is the rarest of the three oral-ocular clefts (Clefts 3, 4, and 5) and begins medial to the oral commissure and courses along the cheek lateral to the nasal ala to terminate in the lateral half of the lower eyelid. Cleft number 6 includes incomplete forms of Treacher Collins syndrome and represents a transition between oral-ocular and lateral facial clefts. The ear is normal but there is downslanting of the palpebral fissure as the lateral fissure and canthus are pulled inferiorly, creating an appearance of ectropion and colobomas of the lower eyelid. In addition, choanal atresia is common and the zygoma is hypoplastic.1,2
Cleft 14 is one of the cranial clefts and has a very poor prognosis. It is a midline cleft with associated central nervous system abnormalities including a midline encephalocele, holoprosencephaly, and microcephaly. It is often paired with a facial midline cleft 0 (not a cleft 3, which would pass through the alar rim). Hypertelorism is present because the cleft increases the distance between the bony orbits. A Harlequin deformity may be seen on radiographs due to upslanting of the anterior cranial fossa (Fig. 27.3).1–4 Fig. 27.3 Harlequin deformity.
Tessier described cleft 30 in his original 1976 publication.1 It is a very rare anomaly, with fewer than 70 cases described in the literature. In its milder form it may be limited to a defect of soft tissue in the lower lip. In more severe forms it may involve a cleft of the mandibular symphysis, absence of the hyoid, and hypoplasia of the thyroid cartilage, or strap muscles. The tongue abnormality ranges from total absence to a bifid anterior portion or complete duplication. A cleft of the mandibular symphysis usually passes between the central incisors, which are present. The thyroid gland itself is not involved, although the thyroid cartilage can be hypoplastic.1,2