Facial nerve paralisys (FNP) is the most commom cranial nerve disorders and it results in a characteristic facial distortion that is determined in part by the nerves branches involved. With multiples etiologies, these included trauma, tumor formation, idiopathic conditions, cerebral infarct, pseudobulbar palsy and viruses. FNP during dental treatment is very rare and can be associated with the injection of local anesthetic, prolonged attempt to remove a mandibular third molar and subsequent infection. We report a case of a 21 years-old black woman who developed a Bell?s palsy after an impacted third molar surgery under local anaesthesia, present a FNP classificated like a grade IV by the House-Brackmann?s grading system. The treatment was based of prescription of a citidine and uridine complex (NÚCLEO CMP tm) one tablet twice per day and a close follow up. Three months later that had begining the treatment, the patient recovery her normal facial muscle activity.