If an individual has an obvious deformity, improvement of the area can be performed before 4 years of age when long-term memory and self-esteem begin to form. Early skeletal intervention, however, may be associated with a higher rate of recurrent deformity compared with delayed treatment. Another period to consider intervention for psychosocial morbidity is when the patient is older and requests surgery. Correction of a malocclusion or an occlusal cant is typically not initiated until completion of facial growth (16 years old in females and 18 years old in males). If a vascular anomaly of the face or cranium is causing significant symptoms (for example, bleeding, infection, pain, and threatening vital structures), intervention is necessary independent of the age of the patient (see Video 12-1, Craniofacial Bones).

SURGICAL MANAGEMENT

CAPILLARY MALFORMATION

A capillary malformation is the most common type of vascular malformation and frequently affects the head and neck. Soft tissue and bone underneath the cutaneous stain can hypertrophy over time; the mechanism is unclear. Facial lesions can cause overgrowth of the maxilla and/or mandible that may result in asymmetry, occlusal cant, or malocclusion. A LeFort I osteotomy can improve vertical maxillary overgrowth; other orthognathic procedures may be necessary to correct occlusion or mandibular enlargement. In some cases orthodontic intervention can improve the occlusion to maximize masticatory function until children have completed facial growth and are candidates for orthognathic procedures. Overgrowth of the facial bones causing a deformity can be corrected by burring the cortex to reduce the projection of the area at any age. Although capillary malformation of the scalp may cause hypertrophy of the underlying cranium, treatment is rarely necessary, because the area is camouflaged by hair.

VENOUS MALFORMATION

A venous malformation causes bone destruction and ultimately hypoplasia. The most common location of an intraosseous venous malformation is the craniofacial region. Bony involvement can occur in combination with adjacent soft tissue disease, or the bone can be affected primarily. In the literature intraosseous venous malformations have been erroneously called hemangiomas. (infantile hemangiomas do not involve bone). Venous malformations of the craniofacial region typically cause osteolysis, with a spongy, sunburst-like expansion of the bone.

LYMPHATIC MALFORMATION

A lymphatic malformation can cause either bone overgrowth or loss. The most common osseous site of a lymphatic malformation is the craniofacial region. Isolated macrocystic or microcystic lymphatic malformations involving soft tissues and bone can cause hypertrophy. Osteolysis and marginal sclerosis are illustrated on radiographic examination; solitary spaces less than 2 cm may be present. Lesions of the scalp may result in a prominence of the cranium that may not be camouflaged by hair. The area can be flattened by burring the ectocortical surface. A lymphatic malformation of the maxilla or mandible can lead to facial asymmetry, occlusal cant, and/or malocclusion. Ostectomy or orthognathic procedures may be necessary.

Gorham-Stout disease and generalized lymphatic anomaly are anomalies that primarily affect bone. Gorham-Stout (“disappearing bone disease”) causes osteolysis of contiguous sites. The bone resorbs, resulting in pain, fractures, and significant morbidity. Imaging shows progressive osteolysis and cortical loss. The ribs are most commonly involved, followed by the cranium, clavicle, and cervical spine. Almost all lesions have an adjacent soft tissue lymphatic malformation. Patients are treated with weekly subcutaneous interferon and monthly intravenous bisphosphonates. Recently oral sirolimus has shown efficacy. These drugs may prevent continued bone loss but rarely cause remineralization. Severe morbidity can require surgical intervention with bone grafts that have a high resorption rate, because they are placed into a diseased recipient site.

Generalized lymphatic anomaly (“lymphangiomatosis”) is a multisystem disorder affecting noncontiguous sites. Osseous lesions have discrete lytic areas and radiolucencies confined to the medullary cavity. The number and size may increase, but progressive osteolysis and cortical loss do not occur. Approximately one half of individuals have a soft tissue lymphatic anomaly at the site of bone involvement. Patients can also have lesions of the spleen or liver and pleural effusions. Symptomatic individuals are treated similarly to patients with Gorham-Stout disease.

An arteriovenous malformation can cause bone overgrowth and destruction. Imaging typically illustrates osteolysis, thinning of the cortex, expansion, and trabeculation. An osseous AVM is almost always associated with adjacent soft tissue disease. Lesions are seldom localized and thus are rarely amenable to complete excision. An osseous AVM is associated with significant bleeding, unlike other vascular anomalies that affect bone. The most common site of hemorrhage is the tooth-bearing alveolar area. Embolization can ameliorate bleeding and may require serial treatments. Recalcitrant hemorrhage requires resection and reconstruction with bone grafts or alloplastic materials. Because the reconstructed area is typically surrounded by a soft tissue AVM, recurrence and complications are common. If the lesion involves the oral cavity, periodontal ligament space, and erupted teeth, infections and gingival hypertrophy can occur. Removal of teeth in the affected areas may be necessary to reduce the risk of infection and bleeding.

If the AVM is causing bone hypertrophy that is contributing to overgrowth of the face, patients may request intervention to improve their appearance. The frontal bone, zygoma, maxilla, or mandible can be reduced with contour burring. Involved portions of the mandible can be resected and reconstructed with bone grafts that have a more favorable contour. If an occlusal cant or malocclusion is present, orthognathic procedures can be considered in late adolescence. An AVM of the jaws frequently results in destruction of teeth that require removal. Extractions may be associated with significant bleeding and should be performed under general anesthesia. Replacement of missing teeth is challenging, because dentures can cause recurrent gingival bleeding, and diseased bone often cannot accept implants. Restorative plans with dental implants usually require extensive bony resection and grafting.

VASCULAR TUMOR

The most common vascular tumors that affect the craniofacial skeleton are hemangioendotheliomas (epithelioid or kaposiform). An epithelioid hemangioendothelioma has an unpredictable clinical course and a chromosomal translocation, resulting in WWTR1-CAMTA1 fusion. Lesions may remain stable, slowly grow, or metastasize (30%). Seven percent affect the pediatric population and can involve skin, bone, liver, lung, or other sites. When bone is involved, the cranium is the most common site (about 50%). On radiographic examination lesions appear as areas of osteolysis with cortical erosion and expansion. Treatment is based on the clinical course of the disease. If serial imaging shows minimal progression, patients can be observed. Severe symptoms, progression, or metastasis requires systemic chemotherapy, radiation, and/or resection. An epithelioid hemangioma is a benign lesion on the spectrum of epithelioid hemangioendotheliomas that can affect the mandible or cranial base; problematic osseous lesions are treated with curettage.

An osseous kaposiform hemangioendothelioma usually affects the extremity but can involve the craniofacial skeleton. Lesions are rarely isolated to bone but also involve the skin and soft tissue. Imaging shows irregular osteolysis with soft tissue disease. Treatment is either intravenous vincristine or oral sirolimus. Resection of the involved bone and reconstruction are rarely indicated.

VENOUS MALFORMATION

Patient A