Lower lip paresthesia as a sequel of mental nerve irritation secondary to periradicular periodontitis

The aim of this work was to present a case report describing lower lip paresthesia following failed endodontic treatment and development of periapical lesion. A 42-year-old female presented difficulty in swallowing with pain in right mandibular second premolar and numbness in the right side of her lower lip. Radiographic examination revealed inadequate root canal and a large periapical lesion in the mental nerve area. The lesion appeared extending into the inferior alveolar canal causing irritation of inferior alveolar nerve and its mental branch. Following root canal retreatment, there was improvement of the clinical symptoms and gradual reduction in size of the lesion. A full resolution of symptoms was demonstrated 4 months after successful endodontic therapy. It was concluded that careful clinical and radiographic diagnosis followed by proper endodontic treatment proved to be successful in treating lower lip paresthesia occurred following failed root canal therapy