This clinical case describes mandibular osteomyelitis in a healthy 31-year-old man as a severe complication following third molar removal. Recurrent abscess formations were treated with intensive therapy involving antibiotics, surgical debridement of the affected region, and hyperbaric oxygen. In the follow-up, despite microbiologic study to determine the indicated treatment approach, a severe osteomyelitis was present, clinically and radiographically. Finally, a partial resection of the mandible, including exarticulation, was indicated to manage this severe complication. Keywords: facial swelling, healthy man, hyperbaric oxygen, mandible, osteomyelitis, paramandibular abscess, third molar