Osteonecrosis of the jaw is a condition in which bone cells die due to various causes. It is classified as drug-induced jaw osteonecrosis, osteoradionecrosis, traumatic, non-traumatic, and spontaneous osteonecrosis. Antiresorptive or antiangiogenic drugs cause drug-induced osteonecrosis. The combination of medications, microbial contamination, and local trauma induces this condition. Osteoradionecrosis is a severe radiation therapy side effect that can affect people with head and neck cancer. It is described as an exposed bone area that does not heal for longer than three months after the end of radiation treatment with the absence of any indications of an original tumor, recurrence, or metastasis. Trauma (tooth extraction), tumor site, radiation dose that the patient receives, the area of the bone which is irradiated, oral hygiene, and other factors are risk factors for the development of osteonecrosis. Less frequently, osteonecrosis can also be induced by non-traumatic and traumatic causes. Non-traumatic osteonecrosis is brought on by infections, acquired and congenital disorders, as well as the impact of chemicals. Traumatic osteonecrosis is brought on by thermal, mechanical, or chemical damage. The treatment of osteonecrosis can be conservative, which aims to be beneficial for the patient’s quality of life, and surgical, which involves debridement of the necrotic bone.

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology which affects the oral mucosa. OLP varies in its clinical features from a reticular form that is, in most cases, asymptomatic, to atrophic–erosive, and is accompanied by symptoms of burning sensation and pain followed by difficulty in eating. Given the fact that OLP is a disease of unknown etiology, the treatment is symptomatic and involves suppressing the signs and symptoms of the disease using various topical and systemic drugs. The first line of therapy for treating symptomatic OLP is topical corticosteroids, whereas systemic corticosteroids are used for treating persistent lesions that do not respond to local treatment. However, the lack of convincing evidence on the efficacy of previous therapies, including topical corticosteroids, and numerous side effects that have appeared over recent years has resulted in the emergence and development of new therapeutic options. Some of the therapies mentioned are tacrolimus, efalizumab, dapson, interferon, retinoic acid, photochemotherapy with psoralen and ultraviolet A rays (PUVA), aloe vera, antimalarials, antibiotics and others. These therapies only partially meet the properties of efficacy and safety of use, thus justifying the continuous search and testing of new treatment methods.

Oral squamous cell carcinoma (OSCC) constitutes 3 percent of all cancers with predominant occurrence in middle aged and elderly males. Tumour recurrence worsens disease prognosis and decreases quality of life in patients with OSCC. Proinflammatory cytokines such as interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α) have been suggested to play a certain role in variety of tumours. The aim of this study was to investigate the relationship of pretreatment serum IL-6 and TNF-α levels on tumour recurrence in patients with OSCC in order to identify potential biomarkers for the early detection of disease recurrence. The patients with newly diagnosed OSCC were treated and followed from the first visit from November 2006 until January 2008. Serum IL-6 and TNF-α concentrations were measured. The records of the patients were re-examined in July 2012 and data were recorded about cancer characteristics and tumour recurrence. Disease free survival was analyzed by Kaplan-Meier survival curves, log rank test and Cox proportional hazards regression. Serum IL-6 was shown as an independent risk factor for tumour recurrence. Pretreatment serum IL-6 concentration may be a useful biomarker for identification of OSCC patients with increased risk of the disease recurrence.