Effect of bisphosphonate on temporomandibular joint in osteopenia-induced rats by botulinum toxin A injection on masticatory muscle: a preliminary study / 대한악안면성형재건외과학회지

BACKGROUND: Botulinum toxin injection on the masticatory muscle induces the osteopenic condition on the ipsilateral condyle. Bisphosphonate suppresses bone resorption and is used to treat osteopenic or osteoporotic condition. This study aimed to evaluate the effect of bisphosphonate administration on prevention of condylar resorption and botulinum toxin A-induced disuse osteopenia in rats. RESULTS: The volume of the condyle and bone volume/tissue volume (BV/TV, %) showed a strong tendency towards statistical significance (p = 0.052 and 0.058). Trabecular thickness (Tb.Th, mm) and trabecular number (Tb.N, 1/mm) were significantly smaller in the Botox group than in the other groups (p < 0.05). The volume of the condyle and BV/TV in the bisphosphonate 100 and bisphosphonate 200 groups showed similar values when compared with the control group. CONCLUSION: Bisphosphonate administration after botulinum toxin A injection in the masticatory muscles appears to prevent condyle resorption and botulinum toxin-induced disuse osteopenia in rats.

Development of animal model for Bisphosphonates-related osteonecrosis of the jaw (BRONJ) / 대한악안면성형재건외과학회지

BACKGROUND: The aim of this study is to develop a rat model of bisphosphonates-related osteonecrosis of the jaw (BRONJ) that would be verified with clinical, radiological and histological examination, and to confirm the influence of concurrent bisphosphonates and steroids use upon the occurrence and aggravation of BRONJ. METHODS: Twenty seven rats were divided into 3 groups; Saline group (I), Zoledronate group (II), Zoledronate and Dexamethasone group (III). Rats got weekly intraperitoneal injection for 4 times and extraction of left maxillary and mandibular 1st, 2nd molars were followed. Consecutive injections were performed, and blood sampling for measurements of C-terminal crosslinked telopeptide of type I collagen and tartrate-resistant acid phosphate 5b rats were performed at the time of 2, 4 and 8 weeks. And then, rats were sacrificed and evaluated clinically, radiologically and histologically. RESULTS: 12/18 (66.6 %) of experimental group were diagnosed as BRONJ. There was no significant difference in incidence between zoledronate alone group (ll) and concurrent use of zoledronate and dexamethasone group (lll). CONCLUSIONS: Concurrent use of bisphosphonates and steroids increase incidence of BRONJ compared to saline group (l). Zoledronate alone group (ll) and concurrent use of zoledronate and dexamethasone group (lll) shows same incidence of BRONJ. Based on this study, the rat treated with bisphosphonates and steroids can be considered a novel, reliable and reproducible model to understand pathology of BRONJ.

Mandibular condyle and infratemporal fossa reconstruction using vascularized costochondral and calvarial bone grafts

There are some difficulties in approaching and removing the lesion in infratemporal fossa because of its anatomical location. After wide excision of tumor lesion, it is also difficult for reconstruction of mandibular condyle and cranium base on infratemporal fossa. Besides, there are some possibilities of cerebrospinal fluid leakage, intracranial infection and bone resorption. It is also challenging for functional reconstruction that allows normal mandibular movement, preventing mandibular condyle from invaginating into the skull. In this report, we present 14-month follow-up results of a patient who had undergone posterior segmental mandibulectomy including condyle and infratemporal calvarial bone and mandible reconstruction with free vascularized costochondral rib and calvarial bone graft to restoration of the temporomandibular joint area.

Tunnelized-facial Artery Myomucosal Island Flap (t-FAMMIF) for Palatomaxillary Reconstruction: A Report of Two Cases

Myofibroblastic sarcoma of the mandible: a case report

Myofibroblastic sarcoma is a rare tumor that mostly develops in the soft tissues of the head and neck. Within the oral cavity, a tongue lesion is the most common. A myofibroblastic sarcoma tends to recur locally instead of metastasizing. We encountered a myofibroblastic sarcoma of the mandible of a 9-year-old male and performed mass excision and additional marginal alveolectomy. So far, there is neither recurrence nor metastasis. We report this case because of the uncommon location of this tumor type and its surgical approach compared to other forms of sarcomas.