Resolution of pain and complete healing of mandibular osteoradionecrosis using pentoxifylline and tocopherol: a case report

Is the use of Pentoxifylline and Tocopherol effective in the treatment of Osteoradionecrosis of the jaws or for the treatment of medicationosteonecrosis of the jaw? An overview

PURPOSE

The aim of the present study was to determine the methodological quality of systematic reviews that evaluated the effectiveness of pentoxifylline and tocopherol (PENTO) in the treatment of osteoradionecrosis of the jaw (ORNJ) and medication-related osteonecrosis of the jaw (MRONJ).

METHODS

Searches were performed in Databases including PubMed, Scopus, LILACS, DARE, Cochrane Library, and SIGLE through OpenGrey until March 2024, were evaluated by two independent reviewers to answer the following question: Is the use of PENTO protocol effective in the treatment of ORNJ or for the treatment of MRONJ?

RESULTS

A total of 256 articles were initially identified; however, following the use of appropriate inclusion and exclusion criteria, five systematic reviews were identified for detailed analysis. The final study sample comprised 588 patients: 397 patients with ORN and 197 patients with MRONJ who were treated with PENTO. The total recovery of individuals who used the PENTO protocol was 62,2 % for ORN and 100 % for MRONJ, with a follow-up period of 1 month to 10 years. The methodological quality of the studies was assessed using the AMSTAR 2 tool, in which four were of low quality and 1 moderate quality.

CONCLUSION

The treatment of ORN and MRONJ with pentoxifylline and tocopherol has shown good results in the studies presented, with a partial or total reduction in bone exposure. However, the low quality of the relevant reports highlights the need for primary and secondary studies with better methodological rigor to reduce bias and provide reassurance for this treatment option.

Pentoxifylline and tocopherol (vitamin E) with/without clodronate for the management of osteoradionecrosis: A scoping review

BACKGROUND

Treatment of osteoradionecrosis (ORN) is not a straightforward task, and it is unpredictable. However, a combination of pentoxifylline; an antioxidant drug, and tocopherol (vitamin E) works as a potent antifibrotic agent and have shown recently both significant and impressive results.

AIMS

This scoping review aims to investigate the most prescribed regimen of pentoxifylline and tocopherol with/without clodronate for the management of ORN.

METHODS

Ovid MEDLINE and EMBASE databases were used to retrieve eligible studies using planned search keywords. PROSPERO and Cohcarne library were also searched for ongoing or published systematic reviews, respectively. Included articles were grouped thematically according to the type of studies and accordingly they were summarized.

RESULTS

A total of 27 articles met the inclusion criteria and included in the data analyses. All the included articles were published between 1997 and 2020. Of these 27 included studies, two were randomized control trials, two were systematic reviews, six were retrospective studies, five were observational studies, seven were narrative reviews, four were case reports, and lastly one was an in-vitro study.

CONCLUSIONS

Treatment by PENTO (800 mg of pentoxifylline + 1000 IU of tocopherol) once daily for an early established ORN or PENTOCLO (PENTO regimen + 1600 mg of clodronate) once daily for the refractory/severe cases of ORN appears to be the most prescribed regimen used for the treatment of ORN using these drugs. These drugs appear safe, effective and inexpensive for the treatment of ORN.

Therapeutic effects of hyperbaric oxygen: integrated review

Hyperbaric oxygen therapy refers to inhalation of pure oxygen in a closed chamber. Hyperbaric oxygen has a therapeutic effect in numerous pathological conditions, such as decompression sickness, arterial gas embolism, carbon monoxide poisoning and smoke inhalation, osteomylitis, osteoradionecrosis and wound healing. Hyperbaric oxygen therapy is used for treating underlying hypoxia. This review indicates the action of hyperbaric oxygen on biochemical and various physiological changes in cellular level. Narrative review covers the current indications and contraindications of hyperbaric oxygen therapy. The review also focuses on the therapeutic effects of hyperbaric oxygen pretreatment and precondition in different pathological conditions. The complications and side effects of hyperbaric oxygen therapy are discussed.

The use of pentoxifylline, tocopherol and clodronate in the management of osteoradionecrosis of the jaws

AIMS

Medical management of osteoradionecrosis (ORN) via pentoxifylline, tocopherol (PENTO) and clodronate (PENTOCLO) has shown both promise and early positive outcomes. We aimed to determine clinical outcomes for patients with established ORN managed solely via PENTO or PENTOCLO.

METHODS

The study retrospectively reviewed and collected data from the medical records of 169 patients diagnosed with ORN and treated via medical management. Patients that received any additional interventions such as surgery or hyperbaric oxygen were not included.

RESULTS

Medical management led to healed ORN in 54.4% (n = 92/169) of patients after an average of 12.9 months. Outcome comparison between PENTO and PENTOCLO identified the former regime to be significantly superior (p = 0.0001). There is an inverse relationship with increasing ORN severity and healing with medical management (p < 0.0001) with oropharyngeal cancer (p = 0.0347) patients responding favourably via this approach. Infection had a critical role in the final outcome with those healing requiring 1.3 antibiotic prescriptions, while those that had disease progression requiring 4.3 prescriptions.

CONCLUSION

Medical management is a viable treatment option for ORN. It appears to be most effective in Notani I and non-infected ORN. When healing was not achieved the regime was able to stabilise the condition.

The effect of two phosphodiesterase inhibitors on bone healing in mandibular fractures (animal study in rats)

OBJECTIVES

Despite advances in maxillofacial surgery, impaired bone healing remains a concern for surgical teams. Many studies have evaluated the effects of sildenafil and pentoxifylline on bone healing. However, their effects on healing of bone fractures have not been well investigated. This study aimed to assess the effects of the phosphodiesterase inhibitors sildenafil and pentoxifylline on healing of mandibular fractures in rats.

MATERIALS AND METHODS

A total of 60 rats were randomly divided into six groups of 10. Mandibular fracture was induced in all rats. After the surgical procedure, group C1 received saline, group S1 received 10 mg/kg sildenafil and group P1 received 50 mg/kg pentoxifylline. The rats were sacrificed after 1 week. Groups C4, S4, and P4 received pharmaceutical therapy as in groups C1, S1, and P1 but were sacrificed after 4 weeks. The samples then underwent histological analysis.

RESULTS

The mean rate of bone healing of mandibular fractures in groups S1 and P1 was significantly higher than in group C1 at 1 week (P<0.001). The mean rate of bone healing of mandibular fractures in group P1 was higher than in group S1 at 1 week (P=0.04). The mean rate of bone healing of mandibular fractures in groups S4 (P=0.001) and P4 (P=0.004) was significantly higher than in group C4 at 4 weeks, but no significant difference was noted in the rate of healing between groups P4 and S4 (P=0.53).

CONCLUSION

Sildenafil and pentoxifylline can be used as adjuncts to enhance bone healing in rats.

A study on the protective effect of molecular hydrogen on osteoradionecrosis of the jaw in rats

The aim of this study was to investigate the protective effect of hydrogen in a rat model of osteoradionecrosis of the jaw (ORNJ). The rats and bone marrow-derived mesenchymal stem cells (BMSCs) were pre-treated with hydrogen before receiving irradiation (7Gy per fraction, five fractions in total once a day for rats, 4Gy for BMSCs). Reactive oxygen species (ROS) and cell differentiation were measured in the BMSCs. Also, the radioprotective effect of hydrogen for ORNJ in Sprague-Dawley rats was examined by gross clinical manifestations, micro-computed tomography, and histology. Hydrogen significantly reduced the production of ROS in BMSCs after irradiation. The cell viability was significantly decreased after irradiation (P= 0.001), but pre-treatment with hydrogen before irradiation increased the cell viability (P= 0.025). Hydrogen considerably increased the cellular differentiation potential of the irradiated cells. Comparing with the rats underwent irradiaton only, those rats treated by hydrogen-rich saline significantly appeared improved occlusion, salivation, alopecia, oral ulcer, and less bone necrosis. Myofibroblasts accumulated overwhelmingly in the fibrosis medulla and around the sequestrum after irradiation, and this was decreased in the group pre-treated with hydrogen. Hydrogen may represent a strategy for the prevention and treatment of ORNJ. Its high efficacy and low toxicity suggest possible therapeutic application.

Biomechanical, histological, and radiological effects of different phosphodiesterase inhibitors on femoral fracture healing in rats

PURPOSE

To investigate the biomechanical, histological, and radiological effects of sildenafil and pentoxifylline on femoral fracture healing in rats.

METHODS

Forty-eight Sprague-Dawley rats were divided into three groups equally according to the pharmacological agents to be investigated. Femoral shaft fractures were formed in the left side. Group 1 (control group), group 2, and group 3 were administered with saline, sildenafil, and pentoxifylline during the fracture healing process, respectively. Eight rats from each group were euthanized on days 15 and 30. X-ray images of the rats were taken after euthanasia for radiographical examination. Femur samples were subjected to histopathological and biomechanical (three-point bending) examinations.

RESULTS

Radiologically, no difference between the Goldberg scores of the groups was found for day 15 ( p > 0.05), while higher Goldberg scores were obtained from group 2 than that of group 1 ( p > 0.05) and group 3 ( p < 0.05) for day 30. In the biomechanical analysis, higher mean breaking forces were found both for day 15 and day 30 from group 2 than those obtained from group 1 (for day 15 p > 0.05 and day 30 p > 0.05) and group 3 (for day 15 p < 0.05 and day 30 p < 0.01). Higher mean absorbed energy values were obtained from group 2 than those obtained from group 1 (for day 15 p > 0.05 and day 30 p < 0.05) and group 3 (for day 15 p < 0.01 and day 30 p < 0.01). A significant difference was not found between the histological scores of all groups ( p > 0.05) for day 15, while the histological score of group 1 on day 30 was found to be significantly lower than that of sildenafil and pentoxifylline groups ( p < 0.05).

CONCLUSION

Sildenafil had a positive effect on fracture healing, while pentoxifylline did not provide consistent positive effect.

Styloid Process Osteoradionecrosis: Report of 3 Cases

We report the imaging and clinical findings in 3 patients with osteoradionecrosis of the styloid process, an uncommon consequence of radiation therapy for head and neck malignancy.

Protective role of α2-macroglobulin against jaw osteoradionecrosis in a preclinical rat model

OBJECTIVE

We have previously demonstrated the effect of alpha-2-macroglobulin (α2M) in the remediation of radiation-induced cellular damage. Here, we investigated the protective effects of α2M in a preclinical rat model of jaw osteoradionecrosis (ORN).

METHODS

Eighteen rats were divided randomly into three groups: the control group, the radiation therapy (RT) alone group, and the radiated mandibles pretreated with α2M (α2M + RT) group. One month after radiation, all left molar teeth were extracted. After another 3 months, the animals were sacrificed and body weight, histopathology, microcomputed tomography and immunofluorescence were evaluated in all groups.

RESULTS

The RT group showed serious alopecia, bone exposure, inflammation, necrosis, fibrosis, and the absence of new bone formation within the socket. The α2M + RT group exhibited less alopecia than the RT group and slight inflammation and fibrosis in the bone marrow cavity. The cortical bone was similar to normal bone tissue. Interestingly, compared with RT group, serum superoxide dismutase levels in the α2M + RT group increased at the 1th day (P = 0.037), 14th day (P = 0.012), while reactive oxygen species levels clearly decreased at the 1th day (P< 0.001), 14th day (P = 0.007), and 28th day (P = 0.013).

CONCLUSIONS

A clinically translational model of jaw ORN was successfully established and the application of α2M prior to radiation protected the bone from being injured by the radiation, possibly related to oxidative stress.

Pentoxifylline - a review of its use in osteoradionecrosis

Pentoxifylline has been used to treat complications related to fibrosis for over 20 years. Formerly used to treat those after radiotherapy such as osteoradionecrosis (ORN), it is now being tried for medication-related osteonecrosis of the jaw (MRONJ), which can occur after prolonged use of bisphosphonates. We review theories on the formation of fibrosis in patients with ORN, discuss the pharmacology of pentoxifylline and vitamin E, and report published outcomes. To our knowledge no prospective randomised controlled trial has investigated the benefits of these agents in cases of ORN, but reported outcomes in many published case series are encouraging.

The role of myofibroblasts in the development of osteoradionecrosis in a newly established rabbit model

This study aimed to establish a proper animal model of osteoradionecrosis of jaws (ORNJ) and to observe preliminarily the characteristics of myofibroblasts, the key effector cell of fibrosis, in ORNJ. Rabbit mandibles were irradiated at three different doses based on a human equivalent radiation schedule, and examined by gross manifestation, single-photon emission computed tomography (SPECT), micro-computed tomography, sequential fluorochrome labeling, and histology. Immunohistochemistry staining of α-SMA was applied to detect the existence of myofibroblasts. The exposed necrotic bone, which is the main indication of ORNJ, started to be observed at all rabbits at 9 Gy. With the radiation dose increasing, the microarchitecture of the irradiated mandibles was more destroyed, the metabolism and mineralization of the irradiated mandibles diminished, the osteocytes number decreased, and more mature bones were substituted by fibrosis in the irradiated mandibles. In addition, as the radiation dose increased, the myofibroblast number increased and collected around the separated sequestrum, which indicated that myofibroblasts might relate to the pathogenesis of ORNJ. In summary, a clinically translational ORNJ model was successfully established in our study, and the role of myofibroblasts in the pathogenesis of ORNJ is described for the first time.

Effect of Pentoxifylline Administration on an Experimental Rat Model of Femur Fracture Healing With Intramedullary Fixation

Background:

Globally, musculoskeletal injuries comprise a major public health problem that contributes to a large burden of disability and suffering. Pentoxifylline (PTX) has been originally used as a hemorheologic drug to treat intermittent claudication. Previous test tube and in vivo studies reported the beneficial effects of PTX on bony tissue.

Objectives:

This study aims to evaluate the effects of different dosages of PTX on biomechanical properties that occur during the late phase of the fracture healing process following a complete femoral osteotomy in a rat model. We applied intramedullary pin fixation as the treatment of choice.

Materials and Methods:

This experimental study was conducted at the Shahid Beheshti University of Medical Sciences, Tehran, Iran. We used the simple random technique to divide 35 female rats into five groups. Group 1 received intraperitoneal (i.p.) PTX (50 mg/kg, once daily) injections, starting 15 days before surgery, and group 2, group 3, and group 4 received 50 mg/kg, 100 mg/kg, and 200 mg/kg i.p. PTX injections, respectively, once daily after surgery. All animals across groups received treatment for six weeks (until sacrificed). Complete surgical transverse osteotomy was performed in the right femur of all rats. At six weeks after surgery, the femurs were subjected to a three-point bending test.

Results:

Daily administration of 50 mg/kg PTX (groups 1 and 2) decreased the high stress load in repairing osteotomized femurs when compared with the control group. The highest dose of PTX (200 mg/kg) significantly increased the high stress load when compared with the control group (P = 0.030), group 1 (P = 0.023), group 2 (P = 0.008), and group 3 (P = 0.010), per the LSD findings.

Conclusions:

Treatment with 200 mg/kg PTX accelerated fracture healing when compared with the control group.

Pentoxifylline and electromagnetic field improved bone fracture healing in rats

Background

The aim of this study was to evaluate the effects of a phosphodiesterase inhibitor pentoxifylline (PTX), electromagnetic fields (EMFs), and a mixture of both materials on bone fracture healing in a rat model.

Materials and methods

Eighty male Wistar rats were randomly divided into four groups: Group A, femur fracture model with no treatment; Group B, femur fracture model treated with PTX 50 mg/kg/day intraperitoneal injection; Group C, femur fracture model treated with EMF 1.5±0.2 Mt/50 Hz/6 hours/day; and Group D, femur fracture model treated with PTX 50 mg/kg/day intraperitoneal injection and EMF 1.5±0.2 Mt/50 Hz/6 hours/day.

Results

Bone fracture healing was significantly better in Group B and Group C compared to Group A (P<0.05), but Group D did not show better bone fracture healing than Group A (P>0.05).

Conclusion

It can be concluded that both a specific EMF and PTX had a positive effect on bone fracture healing but when used in combination, may not be beneficial.

Dental management of patients irradiated for head and neck cancer

Patients undergoing radiation therapy as either primary, adjuvant, combination therapy or palliative management of head and neck malignancies are prone to a range of dental complications. Strategies for prevention and management of such complications may be controversial. This article aims to highlight the current understanding and management of the dental needs for patients before, during and after radiation therapy.

Osteoradionecrosis of mandible: Case report with review of literature

Osteoradionecrosis (ORN) of the jaws, particularly of the mandible, is a long-term and serious complication of therapeutic radiotherapy for head and neck cancer. The mandible is affected more commonly than any other bones of the head and neck region. The incidence of ORN of mandible is reported to be between 2% and 22%. With the older radiation techniques, the rate of ORN was reported to be between 5% and 15%, whereas with newer techniques such as 3D conformal therapy and intensity modulated radiotherapy the rate of ORN has decreased to 6% or less. We here report a case of mandibular ORN and the literature review discusses the clinical features, pathogenesis, preventive measures, and management of ORN.