Hello, I can understand your concern. Unfortunately, you are suffering from oral submucous fibrosis due to gutkha chewing habit. As gutkha stays in contact with the cheek for long periods of time during day, the cheek skin and muscle has started to tighten and harden which is causing difficulty in opening mouth wider than three fingers. The skin has blackened inside cheek due to pigmentation of the gutkha as it it stays in constant contact with cheeks. Oral Submucous Fibrosis (OSMF) is a precancerous condition and if gukha is not left now, it might lead to development of cancer in future from the cheek area. Thus, the first thing you need to do is quit Gutkha. In addition, visit a dentist as soon as possible for examination of the oral cavity for development of any lesion in the cheek mucosa. Surgical treatment can be given by oral and maxillofacial surgeon to break the fibers in the cheek and rejoin them so that mouth can be opened wide. I hope this information helps you. Thank you for choosing HealthcareMagic. Take care. Best, Dr. Viraj Shah