Oral and Maxillofacial Surgery Clinics

Fronto-orbital advancement remains a powerful technique for the correction of anterior cranial vault differences related to metopic (trigonocephaly) or unilateral coronal (anterior plagiocephaly) craniosynostoses. Traditional fronto-orbital advancement requires access to the forehead and superior 2/3 of the orbit via a coronal incision. The frontal bone and orbital segment (bandeau) are then separated from the skull and reshaped. In patients with metopic craniosynostosis, the bandeau and frontal bone will need to be advanced and widened. In patients with unilateral coronal craniosynostosis, the bandeau will need to be “untwisted” to address the supraorbital retrusion on the affected side, the affected orbit will need to be shortened and widened, and the frontal bone flap will need to be proportionately advanced on the affected side. Overcorrection of the affected dimension should be undertaken to account for growth and relapse.

Patients with syndromic and nonsyndromic synostosis may have end-stage skeletal discrepancies involving the lower midface and mandible, with associated malocclusion. While orthognathic surgical procedures in this population can be reliably executed, the surgeon must be aware of the unique morphologic characteristics that accompany the primary diagnoses as well as the technical challenges associated with performing Le Fort I osteotomies in patients who have undergone prior subcranial midface distraction.

Patients with syndromic craniosynostosis can present with midface hypoplasia, abnormal facial ratios, and obstructive sleep apnea. These symptoms can all be improved with midface advancement, but it is essential to evaluate the specific morphologic characteristics of each patient’s bony deficiencies before offering subcranial advancement. Midface hypoplasia in Crouzon syndrome is evenly distributed between the central and lateral midface and reliably corrected with Le Fort III distraction. In contrast, the midface hypoplasia in Apert/Pfeiffer syndromes occurs in both an axial and a sagittal plane, with significantly more nasomaxillary hypoplasia compared with the orbitozygomatic deficiency.

The history of craniofacial surgery is one of many fundamental advances by monumental figures. Although craniosynostosis has been known to exist for multiple centuries, modern management has evolved over roughly the last century. An overview of early history, early scientific exploration, the advancement of surgical treatment of craniofacial deformities and the current state of craniosynostosis management is discussed. To fully appreciate the evolution of craniosynostosis surgery, one must understand the gradual advancements that have brought the specialty to this modern era.

Syndromic craniosynostosis (CS) represents a relatively uncommon disease process that poses significant reconstructive challenges for the craniofacial surgeon. Although there is considerable overlap in clinical features associated with various forms of syndromic CS, key extracranial features and close examination of the extremities help to distinguish the subtypes. While Virchow’s law can easily guide the diagnosis of single suture, nonsyndromic CS, syndromic CS traditionally results in atypical presentations inherent to multiple suture fusion. Coronal ring involvement in isolation or associated with additional suture fusion is the most common pattern in syndromic CS often resulting in turribrachycephaly.

Craniosynostosis, the premature fusion of the infant cranial skulls, can be recognized by characteristic head shape differences that worsen with head growth. Craniosynostosis can be syndromic or nonsyndromic and can involve one suture or multiple sutures. Timely cranial vault surgery is recommended to expand and reshape the skull, with a goal of preventing increased intracranial pressure and providing sufficient space for brain growth. Several gene variants and environmental exposures are known to increase the risk of single suture craniosynostosis (SSC), including in utero constraint, exposure to specific toxins and medications, and medical conditions such as thyroid dysregulation and metabolic bone disorders.

Early endoscopic-assisted correction of unicoronal and metopic synostosis is an excellent, safe, cost-effective, and highly effective option for affected patients. Although open calvarial remodeling has a place in the armamentarium of the craniofacial team, the skull base changes seen in endoscopic-assisted techniques are unparalleled. The procedures are associated with low morbidity and no mortality. There is minimal blood loss, decreased operating time, significantly reduced blood transfusion rates, decreased hospitalization length, decreased cost, and less pain and swelling. Early diagnosis and referral for surgical evaluation are critical to obtaining these results.

Infants and children with craniosynostosis require multidisciplinary care, and this is best accomplished when care is provided on a craniofacial team. Most patients with craniosynostosis will have non-syndromic presentations; however, longitudinal care remains critical to ensure appropriate growth and development throughout childhood. In patients with syndromic craniosynostoses, coordinated longitudinal care becomes even more paramount because of the high level of complexity across many different specialties or disciplines. Care delivery that includes perspective and expertise from multiple disciplines is important to help patients reach their full potential and optimal outcomes.

Although most reported cases of minor suture involvement include multiple sutures, isolated suture involvement has been reported. Morphologic differences such as scaphocephaly and anterior plagiocephaly have been reported. Management should involve proper identification and multidisciplinary treatment. Surgical treatment should involve the expansion of the cranial vault as well as the correction of the deformity.

Frontofacial surgery, encompassing the monobloc with or without facial bipartition and the box osteotomy, can treat the frontal bone and midface simultaneously, providing comprehensive improvement in facial balance. Complex pediatric patients with genetic syndromes and craniosynostosis are most optimized by an interdisciplinary team of surgeons, pediatricians, geneticists, speech pathologists, audiologists, dietitians, pediatric dentists, orthodontists, and psychosocial support staff to manage the myriad of challenges and complications throughout early childhood and beyond. Despite early treatment of the anterior and posterior cranial vault, these patients frequently have resultant frontal and/or midface hypoplasia and orbital abnormalities that are best managed with simultaneous surgical treatment.

The prevalence of sagittal and lambdoid suture craniosynostosis differs considerably, as they are notably the most and least prevalent sutures involved in isolated suture craniosynostosis, respectively. The goals of reconstructing the cranial vault in both entities is the same: to release the fused suture, expand cranial volume, restore normal head shape and morphology, and allow for normal growth of the cranial vault. With regards to sagittal suture synostosis, opinions vary on whether reconstruction should focus on either the anterior or poster cranial vault. In contrast, the poster cranial vault is always targeted in lambdoid suture craniosynostosis.

The head and neck region is unique from the other anatomic sites due to its rich blood supply and ability to heal well after surgery. Surgical extirpation of melanoma usually requires wide resection margins, and the defect from surgery can be devastating to the patient and impossible to conceal sometimes. Therefore, the goal of a reconstructive technique is to restore the uniformity of skin color, texture, and contour and preserve the function. In general, head and neck skin defects are reconstructed with local and regional flaps. In this paper, the authors review the most common flaps used in head and neck reconstruction.

Melanoma is a highly malignant tumor that is relatively common in the United States. Surgical extirpation is the mainstay in treatment, but a multimodal therapeutic approach is increasingly important in the era of highly effective immune and targeted therapies. Although resection of melanoma will continue to be the mainstay of management for the conceivable future, improvements in multimodality therapy have and will continue to rewrite the therapeutic playbook for this lethal and increasingly complex malignancy for head and neck surgeons treating patients with melanoma.

This issue of the Oral and Maxillofacial Surgery Clinics of North America is devoted to the important topic of head and neck melanoma. There are some important facts about melanoma that make it a dedicated issue. The incidence of melanoma is rising faster than any other cancer. Melanoma accounts for only about 1% of skin cancers but causes the vast majority of skin cancer deaths. It is one of the most common forms of cancer in young people, especially among young women. There have been significant advancements in the field of melanoma over the past decade.

Melanoma is often initially evaluated by the dermatologist. A methodical evaluation requires complete history and detailed clinical physical examination and appropriate decisions regarding biopsies. Accurate diagnosis and staging require clinicopathologic correlation and an excellent relationship with the dermatopathologist. Subsequent definitive treatment may be managed entirely by the dermatologist or might require a multidisciplinary team of specialists.

The rates of melanoma continue to rise, with recent estimates have shown that 18% to 22% of new melanoma cases occur within the head and neck in the United States each year. The mainstay of treatment of nonmetastatic primary melanomas of the head and neck includes the surgical resection and management of regional disease as indicated. Thorough knowledge of the classification and staging of melanoma is paramount to evaluate prognosis, determine the appropriate surgical intervention, and assess eligibility for adjuvant therapy and clinic trials. The traditional clinicopathologic classification of melanoma is based on morphologic aspects of the growth phase and distinguishes 4 of the most common subtypes as defined by the World Health Organization: superficial spreading, nodular, acral lentiginous, and lentigo maligna melanoma. The data used to derive the AJCC TNM Categories are based on superficial spreading melanoma and nodular subtypes. Melanoma is diagnosed histopathologically following initial biopsy that will assist with classifying the tumor to guide treatment. Classification is based on tumor thickness and ulceration (T stage, Breslow Staging), Regional Lymph Node Involvement (N Stage), and presence of metastasis (M Stage). Tumor thickness (Breslow thickness) and ulceration are 2 independent prognostic factors that have been shown to be the strongest predictors of survival and outcome. Clark level of invasion and mitotic rate are no longer incorporated into the current AJCC staging system, but still have shown to be important prognostic factors for cutaneous melanoma. For patients with metastatic (Stage IV) disease Lactate Dehydrogenase remains an independent predictor of survival. The Maxillofacial surgeon must remain up to date on the most current management strategies in this patient population. Classification systems and staging provide the foundation for clinical decision making and prognostication for the Maxillofacial surgeon when caring for these patients.

Melanoma is the most common cause of skin cancer-related death in the United States. Cutaneous melanoma is most prevalent in the head and neck. The long-term prognosis has been poor and chemotherapy is not curative. Complete surgical resection with locally advanced disease can be challenging and melanoma is resistant to radiation. Advances made in immunotherapy and genomically targeted therapy have transformed the treatment of metastatic melanoma; as of 2021, the 5-year survival for metastatic melanoma is greater than 50%. Ongoing clinical studies are underway to integrate these life-saving therapies into the presurgical or postsurgical settings. This article reviews that effort.

ELSEVIER

ORAL AND MAXILLOFACIAL SURGERY CLINICS OF NORTH AMERICA

Al Haitham Al Shetawi

RUI P. FERNANDES, MD, DMD, FACS, FRCS(Ed)

Management of Craniosynostosis

Accurate diagnosis and staging of malignant melanoma remain crucial components in the overall treatment and prognosis of the patient. Advanced imaging modalities as well as laboratory testing continue to constitute an important part of the workup in melanoma and have seen several developments in recent years. The authors discuss imaging techniques and serum biomarkers used in the assessment of the melanoma patient.

Surgical management of head and neck melanoma starts from the primary biopsy of the cutaneous site by a narrow excision with a 1 to 3 mm margins. The margin should include the whole breadth and sufficient depth of the lesion. The key is not to transect the lesion. With the advent of molecular testing, gene expression profiling, and immunotherapies, the surgical management of advanced melanoma has changed. Sentinel lymph node biopsy is an essential armamentarium for T2a and higher staging/greater than 1 mm thick and advance stage disease. Molecular pathogenesis and cancer immunology are recognized in the recent treatment protocols along with surgery in advanced stages of melanoma.

Surgical excision achieving clear histologic margins remains the mainstay treatment for primary cutaneous melanoma. Tumors of the head and neck, particularly those arising in chronically sun-damaged skin, often demonstrate extensive and asymmetric subclinical extension. Over the decades, this has proven to be a significant problem for tumors arising on the head and neck, as anatomic and functional complexities of these areas have led to suboptimal surgical treatment, yielding unacceptably high rates of local recurrence and persistently positive margins with traditional wide local excision. Patients who undergo Mohs micrographic surgery may have improved survival over those who undergo wide local excision.

The utilization of sentinel lymph node (SLN) biopsy has transformed the workup and staging of intermediate-thickness cutaneous melanomas. SLN biopsy, performed at the time of primary tumor excision, accurately maps lymph nodes at risk of harboring occult metastatic deposits from head and neck cutaneous melanomas and represents the current standard of care. Completion lymphadenectomy identifies additional tumor in 12% to 24% of SLN biopsy positive cases but does not affect melanoma-specific survival.

Head and neck mucosal melanomas are uncommon and aggressive malignancies that arise mainly in the nasal cavity and paranasal sinuses, with the next commonest site being the oral cavity. The mainstay of treatment is radical surgical resection. Adjuvant radiotherapy improves locoregional control but does not improve overall survival. Systemic treatment with immunotherapy or targeted therapies can offer scope for modifying the course of the disease in both the adjuvant and the recurrent and metastatic setting. Further understanding of the genomic landscape and factors regulating immunogenicity will lead to further therapeutic opportunities in this challenging disease.