Abstract
BACKGROUND: Lemierre’s syndrome (LS) is a rare condition in the dental field but represents a potentially fatal complication of odontogenic infection. Although osteomyelitis has been reported in association with LS, delayed-onset chronic mandibular osteomyelitis occurring after completion of LS treatment is exceedingly rare. CASE PRESENTATION: A 16-year-old previously healthy male developed LS following odontogenic infection, complicated by septic thrombophlebitis of the external jugular and facial veins and septic pulmonary emboli. After surgical drainage and antibiotic therapy, clinical recovery was achieved. However, during post-treatment follow-up, radiographic evaluation revealed chronic osteomyelitis involving the entire mandible including both condyles. Extended antimicrobial therapy and close radiologic surveillance resulted in stabilization of the osteolytic changes and functional recovery. CONCLUSION: This case highlights a rare presentation of delayed-onset mandibular osteomyelitis as a sequela of Lemierre’s syndrome. Long-term follow-up after apparent resolution of LS is essential, particularly in odontogenic cases, and dental practitioners should be aware of this uncommon but clinically significant complication. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40902-026-00504-0.