Osteosclerotic lesions are a common finding on dental radiographs. They are considered developmental variants of a normal bone architecture and they usually do not need any treatment. The purpose of this article is to present a rare case of osteosclerotic lesion of the mandible causing trigeminal neuropathy by compression of the alveolar nerve. The pain started with dental hypersensitivity of the mandibular right first molar. Later on, signs of irreversible molar tooth pulpitis developed. Endodontic therapy and apicoectomy did not resolve the pain, which later intensified, and painful neuropathy localized to inferior alveolar nerve developed; therefore, surgical decompression was indicated. Treating a dental patient with neuralgic pain is always a challenge, especially if there is no obvious source or reason for this type of pain. A clear evaluation and treatment protocol are important to minimize the patient's morbidity and avoid unnecessary overtreatment. Keywords: alveolar nerve decompression, mandible, neuropathy, osteosclerosis, trigeminal nerve