**5. Diagnosis**

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 are considered [30]:

