**3. Etiology**

The exact cause of OFG is yet to be elucidated, although various etiological agents have been proposed such as genetic predisposition, contact allergies, various microbiological agents, and immunologic causes [9]. The role of genetic predisposition has been evaluated in different studies, but there is a lack of conclusive evidence between HLA and pathogenesis of orofacial granulomatosis [14–16]; there is no evidence to support genetics causes for OFG [16]. Because of involvement of OFG in CD and sarcoidosis, the possible role of infections in the pathogenesis of OFG has been suggested [17]. Several studies have suggested that there is no conclusive evidence to support the role for allergy in OFG [18]. Recently, a monoclonal lymphocytic expansion in OFG lesion has been identified that may be responsible for the granuloma formation through cytokine production in lesions [19, 20].

## **4. Presentation**

The diagnosis of OFG is based on clinical presentation, but it can be highly variable. The clinical features of OFG are mainly similar to orofacial manifestations of CD without apparent lesions in the bowels and may also mimic orofacial manifestations of sarcoidosis [21] labial enlargement, and sometimes oral ulcers are the main clinical features of OFG [22].

#### **4.1 Lips**

The lips are the most common sites of involvement in OFG. Labial swelling can involve the lower or upper lip or both. This feature of OFG is persistent but may eventually become recurrent. Each episode in this inflammatory process usually lasts several weeks to months [23]. The swelling varies in consistency from soft to rubbery [24].

**3**

*Introductory Chapter: Orofacial Sarcoidosis and Noncaseating Granulomatosis*

• Chronic and deep ulcers in the buccal or labial vestibules with surrounding

• Superficial aphthous-like ulcers on any oral mucosal surface (less common).

• Pustules on the anterior gingivae and/or labial vestibules or soft palate (the

In asymptomatic patients, enlargement of the salivary glands is the first identifiable sign of the disease [8]. Involvement of salivary glands has been reported in the maxillofacial region that xerostomia or bilateral parotid swelling is the result of this involvement [26, 27]. Inflammation of salivary glands differentiates OFG from other granulomatous diseases such as cheilitis glandularis, Wegener's granulomato-

Since sarcoidosis is a multi-organ disorder, it can be difficult to diagnose with a single specific diagnostic test; and also, the presence of noncaseating granulomas alone does not confirm the presence of the disease because many other diseases can cause granulomas. On the other hand, these structures can be formed in various disorders [29]. In as much as in most cases of sarcoidosis, oral involvement often appears as the first manifestation of the disease; in diagnosis, the following criteria

• Clinical and radiological findings compatible with a diagnosis of systemic

• Pathologic evidence of noncaseating granulomas in the soft tissues of the oral

• Exclusion of other causes of oral granulomatosis by histology of oral tissue

As mentioned above, because of the same clinical features of orofacial lesions in granulomatous diseases, differential diagnoses must be considered for such diseases

• **Infections**, including tuberculosis, syphilis, leprosy, cat-scratch disease, and

• **Crohn's disease** with the development of ulcers in the GI tract as the main

• No clinical evidence of other granulomatous diseases.

*DOI: http://dx.doi.org/10.5772/intechopen.83364*

raised borders (most common).

sis, sarcoidosis, and deep fungal infections [28].

• Symptomatic oral manifestations

biopsy negative for fungus

and other conditions including [31]:

**5.1 Differential diagnosis**

mycosis.

manifestation.

least common).

**4.3 Salivary gland**

**5. Diagnosis**

are considered [30]:

sarcoidosis

cavity

#### **4.2 Oral lesions**

Three types of oral ulcers may occur in OFG as follows [25]:

*Introductory Chapter: Orofacial Sarcoidosis and Noncaseating Granulomatosis DOI: http://dx.doi.org/10.5772/intechopen.83364*

