Osteoradionecrosis (ORN) is a nonhealing wound of the bone that is difficult to manage. Combined treatment with pentoxifylline and vitamin E reduces radiation-induced fibrosis and ORN with a good prognosis. We previously showed that the combination of pentoxifylline and vitamin E with clodronate (PENTOCLO) is useful in healing sternocostal and some mandibular ORN. Is PENTOCLO effective in ORN of poor prognosis? 54 eligible patients previously irradiated for head and neck cancer (among 72 treated) a mean 5 years previously received exteriorized refractory mandibular ORN for 1.4 ± 1.8 years, mainly after local surgery and hyperbaric oxygen had been ineffective. The mean length of exposed bone (D) was 17 ± 8 mm as primary endpoint, and the mean Subjective, Objective, Management, and Analytic evaluation of injury (SOMA) score was 16 ± 4. Between August 2000 and August 2008, all patients were given daily oral PENTOCLO: 800 mg pentoxifylline, 1,000 IU vitamin E, and 1,600 mg clodronate 5 days per week alternating with 20 mg prednisone and 1,000 mg ciprofloxacin 2 days per week. The duration of treatment was related to consolidated healing. Prolonged treatment (16 ± 9 months) was safe and well tolerated. All patients improved, with an exponential progressive–(f[t] = a.exp(-b.t)–and significant (p < 0.0001) reduction of exposed bone (D), respectively (months): D(2) -42%, D(4) -62%, D(6) -77%, D(12) -92%, and D(18) -96%, combined with iterative spontaneous sequestrectomies in 36 patients. All patients experienced complete recovery in a median of 9 months. Clinical improvement was measured in terms of discontinuation of analgesics, new fracture, closed skin fistulae, and delayed radiologic improvement: SOMA(6) -64%, SOMA(12) -89%, and SOMA(30) -96%. Long-term PENTOCLO treatment is effective, safe, and curative for refractory ORN and induces mucosal and bone healing with significant symptom improvement. These findings will need to be confirmed in a randomized trial. Delanian, Chatel, Porcher, Depondt, Lefaix, , , , (2011). Complete restoration of refractory mandibular osteoradionecrosis by prolonged treatment with a pentoxifylline-tocopherol-clodronate combination (PENTOCLO): a phase II trial. International journal of radiation oncology, biology, physics, 2011 Jul;80(3):832-9. https://www.ncbi.nlm.nih.gov/pubmed/20638190