CC
A 14-year-old male previously diagnosed with Apert syndrome presents to the multidisciplinary cleft and craniofacial team for evaluation of his anterior open bite (apertognathia) with a chief complaint of “difficulty chewing.”
HPI
The patient was diagnosed with Apert syndrome shortly after birth. Craniosynostosis is one of the many clinical characteristics of Apert syndrome, and the patient underwent a fronto-orbital advancement at 9 months of age. At age 2 years, he underwent craniofacial advancement to address the midface hypoplasia in the form of a monobloc frontofacial advancement. The parents report moving frequently and have had difficulty establishing long-term follow-up at times. Currently, the parents are unhappy with the child’s appearance because children at his school continually mock him about his appearance, particularly his open bite. The parents believe that this has affected their son’s self-confidence and performance. The patient’s mother indicates that the child has difficulty biting hard foods, such as steak and pizza, and must use only his posterior teeth for chewing. He is currently undergoing presurgical orthodontic treatment in preparation for combined surgical–orthodontic correction of the skeletal malocclusion. The parents are also concerned about their son’s continued “sunken” face appearance (midface hypoplasia), which has persisted despite his corrective surgery at age 2 years. The parents and patient deny any changes in vision, headaches, seizures, or loss of consciousness but do note that he wakes frequently at night and is often tired throughout the day.
PMHX/PDHX/medications/allergies/SH/FH
The patient was diagnosed with a heart murmur at birth and subsequently had corrective surgery without complications. (Cardiovascular and valvular abnormalities, such as patent ductus arteriosus, are seen in 10% of patients with Apert syndrome.) He is physically active without significant restrictions. In addition, the patient had a history of hydronephrosis at birth, which resolved without surgery. (Genitourinary abnormalities are seen in about 10% of patients.) At age 4 weeks of age, he was diagnosed with pyloric stenosis, thickening of the pyloric valve that results in gastric obstruction (gastrointestinal abnormalities are seen in 1.5% of patients) and successfully underwent a laparoscopic pyloroplasty. The family history reveals that his two brothers and one sister are healthy. (Most cases of Apert syndrome are sporadic in nature, although autosomal dominance inheritance has been reported.) Cognitive assessments at school have revealed that the patient is slightly developmentally delayed for his age. (About 65% of patients have an intelligence quotient of less than 70, and attention-deficit hyperactivity disorder is also common.)
Examination
General. The patient is moderately cooperative. He has a poor attention span (secondary to developmental delay) but is able to follow simple commands. He has a short stature for his age and compared with his parents. (Megalocephaly [large head] results in the weight and height being above the 50th percentile early, but this decreases with age.)
Maxillofacial. Examination of the skull reveals a steep frontal bone ( Fig. 94.1 A), flat occipital region, and bulging temporal region. (Bitemporal enlargement is characteristic of Apert syndrome and has surgical implications when considering osteotomies such as a fronto-orbital advancement.) He exhibits mild ocular esotropia (cross-eyed) and hypertelorism (diverging and widely spaced pupils, respectively). There is underdevelopment of the maxilla and zygomas bilaterally (midface hypoplasia; Fig. 94.1 B).
Intraoral. The patient has an anterior open bite (apertognathia) with a narrow, high (V-shaped) maxillary arch ( Fig. 94.1 C) and a class III molar relationship. (Class III malocclusion with an anterior open bite is almost universal for Apert syndrome.) Only two posterior molars are in contact on either side. There is no apparent hard or soft tissue clefting of the palate (this is seen in 30% of patients with Apert syndrome).
Extremities. The index, middle, and ring fingers are fused, and there is a common nail in both hands (symmetrical syndactyly) ( Fig. 94.1 D). The thumb and small fingers are not affected in either hand and show normal strength and mobility. The feet are normal and are not affected. (The lower extremities may be involved.)
Skin. The child has yellow, raised papules on the dorsum of the hands. (Acne vulgaris involving the hands is seen in 70% of patients with Apert syndrome.)
Imaging
A panoramic radiograph and periapical radiographs are required to evaluate for supernumerary teeth, root crowding, and morphology and to detect caries. When impacted teeth are present (excluding third molars), periapical films from various angles can be obtained to evaluate the buccolingual position of the tooth (Clark’s rule). A cone-beam computed tomography (CBCT) scan is often beneficial for determining the spatial relationship of the maxillomandibular complex. It is also an efficient initial screening tool to evaluate the orbits and cranium, and residual full- or partial-thickness defects of the skull should be appreciated preoperatively. A lateral cephalometric radiograph, along with cephalometric analysis, is used for evaluation and treatment of the skeletal facial deformity. A conventional helical CT scan is not required but can be used for evaluation of opacified sinuses (which are common in maxillary hypoplasia) and for visualization of the three-dimensional anatomy as an aid in treatment planning. This is important for appreciation of vascular and foramina proximity to potential osteotomies and for evaluation of additional bone formation in the midface or orbital region resulting from prior surgeries. For more complex cases requiring orthognathic surgery, CT-guided treatment planning is generally used. Magnetic resonance imaging is not required but can be useful in select cases for evaluation of soft tissue anatomy, such as brain parenchyma, orbital tissue, or pharyngeal structures. Obstructive sleep apnea is commonly seen in patients with Apert syndrome, and the mentioned imaging modalities may be used to assess the posterior airway anatomy.
In the current patient, a panoramic radiograph, lateral cephalometric radiograph, initial CBCT scan, and subsequent medical-grade CT scan were obtained and used in treatment planning. No teeth crowding, impactions, or supernumerary teeth were found; therefore, no periapical radiographs were obtained.
Labs
Preoperative laboratory testing includes a complete blood count and a basic metabolic panel. For the current patient, neither of these demonstrated any abnormalities.
Assessment
Apert syndrome with maxillary hypoplasia and apertognathia requiring combined surgical orthognathic and orthodontic treatment.
Treatment
It is important to understand, to the best of one’s ability, what procedures exactly a patient with syndromic dysostosis has previously undergone. This is true for all patients, but particularly for these patients, there is significant variability of surgical treatments and more importantly variability of the timing during development that such craniofacial surgical treatments may be rendered. The initial evaluation of patients with Apert syndrome at birth focuses on the airway, central nervous system (CNS) malformations, and feeding assessment. A retruded maxilla and limited nasopharyngeal airway increases the work of breathing and may require advanced airway interventions. This may include tracheostomy. An inability to pass a nasogastric tube may indicate nasopharyngeal obstruction. Most often these infants compensate with obligate mouth breathing and hence have an “open mouth” appearance, but the effort expended by an infant to breathe in this manner as well as feed may ultimately outweigh the energy and nutrition obtained by feeding. The CNS symptoms may manifest as seizures, hypotonia or hypertonia, and apnea. The high-arched palate and possible clefting may also add to difficulties with feeding and obtaining appropriate nutrition. These patients may need a nasogastric or orogastric feeding tube or placement of a percutaneous gastrostomy tube.
The primary craniofacial surgical management of patients with Apert syndrome early in life centers on treatment of craniosynostosis. Cranial dysmorphology varies greatly between the multiple craniosynostosis syndromes, and treatment is based on the presenting craniofacial anomaly. Patients with Apert syndrome present with severe turribrachycephaly. Both coronal sutures are typically fused early, but the anterior fontanelle is usually quite large. As noted previously, enlargement of the temporal lobes of the brain is common. Sleep apnea is also common along with posterior cranial vault constriction, and hydrocephalus is a less frequent finding than in patients with Crouzon syndrome, for example. Surgical management of the craniosynostosis involves a staged reconstructive approach. There is no clear consensus on the most appropriate timing and technique for each reconstructive stage.
It is important to evaluate syndromic craniofacial patients in a team setting for these reasons. For Apert syndrome, a potential surgical approach frequently advocated is an initial decompressive craniectomy of the fused coronal sutures bilaterally. This allows continued growth of the anterior cranial vault in particular when performed around 2 to 3 months of life but may have variable results. This approach also relies on the growth potential of the underlying brain and presumes that there is no significantly contributing abnormality of the skull base that could contribute to craniocerebral disproportion in syndromic patients, which may not be the case. However, assuming such initial interventions were reasonably successful, consideration could be given to the neurologic and cranial dysmorphology of the posterior cranial vault.
Surgical interventions involving the posterior cranial vault between 6 and 10 months of age may help significantly with sleep apnea if it is present and should be tailored to the patient’s respiratory status. This type of surgical sequencing allows for potentially a more definitive correction of the orbits and anterior cranial vault with a fronto-orbital advancement that could be completed at a later age, such as 12 to 18 months. Although this group of surgical treatments (three) early in life is a notable number, when fronto-orbital advancement and anterior cranial vault reconstruction is performed early, patients with syndromic craniosynostosis frequently require a second fronto-orbital advancement and anterior cranial vault expansion procedure for protection of the globes several years later by around the age of 3 or 4 years. Repeating this surgery can be quite difficult, and if a posterior cranial vault reconstructive procedure is undertaken before this age of repeating the anterior cranial surgery, then the total number of surgeries would be the same. Surgical outcomes vary significantly from surgeon to surgeon and team to team.
When a more definitive initial fronto-orbital advancement and anterior cranial vault reconstruction is performed later than earlier, the potential secondary correction may be incorporated within a monobloc or facial bipartition procedure. This treatment sequence cannot be assumed and must incorporate frequent reevaluation with neuro-ophthalmology, neurosurgery, and craniofacial surgery specialists. Cranial growth is mostly complete around 6 years of age, and orbital growth mostly complete around 8 or 9 years of age. When performed at earlier ages, some of the significant complications such as infection or bony or soft tissue wound problems are often lessened for significant procedures such as a monobloc frontofacial advancement and facial bipartition. Earlier performance of these procedures often does not require managing the frontal sinus as well. These may be followed by definitive Le Fort I level surgery and potential mandibular surgery in coordination with orthodontics later in life.
A patient with craniofacial dysostosis despite all of these earlier interventions should still be expected to require definitive orthognathic and orthodontic treatment of their skeletal facial discrepancy later in life in the majority of cases. For this reason, a patient may opt for a Le Fort III level advancement slightly later as an alternative, assuming sufficient fronto-orbital advancement for protection of the globes followed by Le Fort I advancement and potential mandibular surgery. Overall, the goals are to minimize the number of surgical interventions, protect the eyes and brain growth, and minimize the effect of surgery on growing structures such as the midface as much as possible.
The current patient’s initial treatments in infancy and childhood deviated significantly from these suggested treatment sequences. When a craniofacial procedure such as a monobloc advancement is performed at 2 or 3 years of age, significant midface and orbital growth restriction and abnormalities should be expected. Before considering any surgical treatment in this patient, an evaluation with neuro-ophthalmology is indicated for fundoscopic evaluation of any signs of papilledema or optic nerve atrophy that could be the result of a craniocerebral disproportion, increased intracranial pressure being present in up to 43% of young patients with syndromic craniosynostosis. A preoperative sleep study should be considered to evaluate the extent of sleep apnea. The current patient was treated with a Le Fort III level advancement. Mounted models with lateral cephalometric analysis as well as virtual surgical planning were used to evaluate the extent of surgical movement. A custom-made, prefabricated occlusal splint was used to guide the position of the maxilla intraoperatively. Using a bicoronal incision, it is possible to complete the desired osteotomies without requiring transconjunctival (or subtarsal) or circumvestibular maxillary incisions. Osteotomies were made along the roof on the orbit and lateral orbital wall, extending laterally and inferiorly to the pterygomaxillary fissure. The medial orbital wall osteotomy was connected to the inferior orbital fissure. This can be done by lifting the lacrimal sac without interruption of the medial canthal ligament or by placing osteotomies more posterior in the orbit. The nasofrontal osteotomy was extended laterally and inferiorly (behind the lacrimal groove) to meet the inferior cut. Then Rowe disimpaction forceps were used to mobilize and advance the midface. The position of the maxillary unit is dictated by the prefabricated splint. Bone grafts, or distraction osteogenesis, or both may be used in select patients. The decision for which advancement method may largely depend on the extent and type of prior surgeries performed and subsequent scar tissue formation. In patients with a normal occlusion, a Le Fort III with concurrent Le Fort I can be used. If the bizygomatic prominence is appropriate, Le Fort II osteotomy may be sufficient, though this is not common for patients with Apert syndrome specifically. Malar deficiencies may be addressed with augmentation bone grafts at the same time if indicated.
Complications
There are few reports in the literature on complications of Le Fort II and III orthognathic procedures. Complications of Le Fort I osteotomy have been extensively studied in the orthognathic surgery population and reported at a rate of about 6% to 9%. Most severe complications of Le Fort osteotomy (I, II, or III) result from an unwanted pterygomaxillary separation, with fractures extending to the skull base, orbital wall, and pterygoid plates. This is seen with a higher frequency in patients with craniosynostosis. Skull base fractures can result in a subarachnoid hemorrhage; there have been seven reported cases of skull base fracture in patients with craniosynostosis ( Box 94.1 ). It is prudent to discuss this complication before surgery. Other complications include increased frequency of intracranial aneurysms, seen in patients with Crouzon syndrome. Sporadic cases of blindness have also been reported after Le Fort I osteotomies. The proximity of the pterygomaxillary fissure and pterygoid plates in patients with severe or total midface hypoplasia and conditions affecting the orbit can be extremely close and are more easily appreciated on three-dimensional reconstructions preoperatively.
