What Is Juvenile Ossifying Fibroma?
Juvenile ossifying fibroma (JOF) is a benign tumor of the oral cavity and jaw bone and also a neoplastic lesion as well that is conventionally characterized by fibro-osseous lesions. This can be classified according to age, region of involvement, and clinical behavior. Because of its highly intense and aggressive nature (especially if it occurs in the facial bones), it has a very high tendency to recur as well.
In most cases, JOF is known to be more prevalent in the age group of 10 to 20 years, especially with more predilection in the male population. However, cases involving people aged more than 70 years of age are most commonly reported clinically in the surgical literature. Ninety percent of JOF lesions occur in the maxillary antrum region, facial bones, or paranasal sinus regions. JOF in the oral cavity affects both men and women equally, usually originating as a PDL infection (periodontal ligament infection). It accounts for 2 % of oral tumors in children.
What Is the Prevalence and Pathogenesis of Juvenile Ossifying Fibroma?
The prevalence of JOF in the oral cavity is low, which causes these lesions to be considered a rare benign neoplasm. It is most often seen in young patients (with 79 % of these cases less than 15 years of age). The affected age varies between the histopathologic forms that are mainly of two variants:
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Trabecular variant.
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Psammomatoid variant.
Patient presentation clinically and histopathologically is less observed for trabecular variants, while the more prevalent psammomatoid variant manifests in patients past 20 years of age. Mandibular JOF cases are characterized by not only expansion but aggressive destruction of the cortical bones. Hence, dental literature also terms this condition as an “active ossifying fibroma.”
Extension of JOF into the cranial bones can be life-threatening without timely surgical intervention. Because of the high rate of recurrence of these lesions and their histologic variants, identifying the tumor by timely diagnosis and post-surgical reconstruction modality will aid in faster healing in these cases.
What Are the Clinical Symptoms and Complications of Juvenile Ossifying Fibroma?
Clinically signs of JOF can be observed as:
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Asymptomatic painless expansion (the side of the upper or lower jaws).
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Discreet facial asymmetry.
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Nasal pain.
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Sudden tooth mobility or displacement.
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Ocular changes may also be observed. In rare cases, because of persistent and accelerated growth, the lesions may penetrate the orbital, nasal, and cranial cavities leading to possible blindness and intracranial involvement (thereby exhibiting neoplastic or spreading nature like aggressive cancers).
The aggressive forms or the rapidly growing lesions of JOF with cortical frailty, perforation, tooth displacement, and root resorption require a wide resection along with bone reconstruction that may prove mandatory.
An accurate diagnosis of JOF is usually made by the maxillofacial dental surgeon, the oncologist, or the general physician after correlating the clinical signs and symptoms of the patient with the CT (computed tomography) and MRI (magnetic resonance imaging) scans. The clinical behavior of JOF varies from gradual to aggressive with bone erosion and subsequent infiltration of surrounding structures. Lesions are well-circumscribed, lacking continuity of normal bone, and radiographically visualized as a radiolucent lesion with inner radiopacities.
What Are the Types of Juvenile Ossifying Fibroma?
According to the WHO (world health organization) in 2005, JOF can be divided into;
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Juvenile psammomatoid ossifying fibroma.
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Trabecular juvenile ossifying fibroma.
These lesions represent two distinct clinical and pathologic conditions. The most common is the psammomatoid pattern that appears in more than 70 % of cases and is located primarily around the paranasal sinuses and orbits, and trabecular juvenile ossifying fibroma is distinguished by fibrous trabeculae, usually affecting the jaw bone and the maxilla being the most commonly affected.
Histologically, these contain osteocytes that indicate an osteogenic origin. The 3-dimensional section of the CT scan demonstrates in the cases of JOF an expansive area involving multiple internal septa with areas of homogenous calcification.
How Can Juvenile Ossifying Fibroma Be Diagnosed Radiographically?
JOF is an expansive lesion with defined sclerotic borders and internal calcification. It is recognizable as isointense in T1-weighted images and hypointense or isointense in T2-weighted images with clear visualization of cystic areas. Following Gadolinium injections, an increase in contrast is observed to identify the tumor.
How Can Juvenile Ossifying Fibroma Be Treated?
The treatment for JOF varies according to clinical behavior.
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Minor or less aggressive lesions with clear demarcation between the affected tissue and healthy bone histopathologically seem to respond to complete resection and careful curettage.
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Hemimandibulectomy: This is a surgical procedure for eliminating (through the transmandibular approach) aggressive and expansive mandibular JOF tumors. The mandibular tissue that is unaffected by the tumor is spared along with the TMJ (temporomandibular joints) to allow bone grafts and osteogenic substances to reconstruct the part of the diseased mandible eliminated by the surgical resection.
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Bone reconstructions used for maxillary bone defects resulting from trauma and infections or after tumor resection have exhibited long-term stability. The choice of reconstruction technique depends primarily on the defect size.
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Microvascular grafts have been widely used as a significant recent advance in maxillofacial reconstruction procedures. It has favorable outcomes of both esthetic and functional prognosis in the cases suffering from aggressive JOF. The iliac crest and the fibula are the commonly used bone tissues for mandibular reconstruction (because the iliac crest exhibits structures and transmission of tension forces similar to the mandible).
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In addition to these cellular compounds, other growth factors such as platelet-rich plasma (PRP) and BMP (bone morphogenetic protein) are used to assist in reconstruction involving particulate bone grafts.
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Tibial Graft for Orofacial Reconstruction: The tibial graft is the particulate bone tissue used for orofacial procedures.
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CT scanning is done post-operatively after 24 months (a favorable bone volume with a good prognosis, that is, no tumor recurrence) depending on the extent of reconstruction to be done. Dental implantation post graft will greatly enhance the patient's prosthetic outcomes and masticatory functions.
Conclusion:
To conclude, even though JOF may be considered uncommon, it is an aggressive and recurrent tumor that needs immediate treatment and surgical resection by the maxillofacial surgeon. Facial reconstruction and dental implantation will favor the patient's normal recovery if timely surgical management is done.
