Gustavo Martins

Bone Healing After Bur and Er:YAG Laser Ostectomies

PURPOSE Ostectomies, performed by different methods, are often necessary in oral and maxillofacial surgery. Rotatory and reciprocating devices are most frequently used but have disadvantages, such as noise, vibration, and the potential for inducing thermal damage. Laser systems are interesting alternatives to these procedures. We analyzed bone healing in a rat model after mandibular ostectomy with a surgical bur or noncontact erbium:yttrium-aluminum-garnet laser using different energy levels. MATERIALS AND METHODS Four groups of 5 rats each underwent ostectomy of the bone cortical of the mandibular body, with irrigation, using a surgical bur or erbium:yttrium-aluminum-garnet laser with different energy parameters. A metal plate was used for morphologic standardization of the cavities. The samples collected after 7, 14, 45, 60, and 90 days were analyzed by optical microscopy. RESULTS The ostectomies performed with surgical burs resulted in bone healing from the cortical endosteum and remaining trabecular bone. The cortical endosteum was repaired after 45 days, followed by bone remodeling. After laser irradiation, healing involved bone neoformation from the external cortical surface and endosteum. Surface regions with thermal damage were observed after laser treatment in the 3 conditions used up to day 60, followed by bone remodeling. CONCLUSIONS Laser ostectomies resulted in a thin layer of thermal damage. Bone healing was faster when surgical burs were used, with similar results reached after 90 days.

Characterization of bone repair in rat femur after treatment with calcium phosphate cement and autogenous bone graft

BackgroundIn this study, the biocompatibility, stability and osteotransductivity of a new cement based on alpha-tricalcium phosphate (alpha-TCP) were investigated in a bone repair model using a rat model.MethodsThe potential of alpha-TCP on bone repair was compared to autogenous bone grafting, and unfilled cavities were used as negative control. Surgical cavities were prepared and designated as test (T), implanted with alpha-TCP blocks; negative control (C - ), unfilled; and positive control (C + ), implanted with autogenous bone graft. Results were analyzed on postoperative days three, seven, 14, 21 and 60.ResultsThe histological analyses showed the following results. Postoperative day three: presence of inflammatory infiltrate, erythrocytes and proliferating fibroblasts in T, C - and C + samples. Day seven: extensive bone neoformation in groups T and C + , and beginning of alpha-TCP resorption by phagocytic cells. Days 14 and 21: osteoblastic activity in the three types of cavities. Day 60: In all samples, neoformed bone similar to surrounding bone. Moderate interruption on the ostectomized cortical bone.ConclusionsBone neoformation is seen seven days after implantation of alpha-TCP and autogenous bone. Comparison of C - with T and C + samples showed that repair is faster in implanted cavities; on day 60, control groups presented almost complete bone repair. Alpha-TCP cement presents biocompatibility and osteotransductivity, besides stability, but 60 days after surgery the cavities were not closed.

Pseudoankylosis of the temporomandibular joint caused by zygomatic malformation

Temporomandibular joint (TMJ) pseudoankylosis is characterized by limited mouth opening and mandibular movements, resulting from factors outside the joint. The authors present a case of TMJ pseudoankylosis caused by congenital zygomatic malformation and hyperplasia of the coronoid process. Treatment with coronoidectomy and postoperative physiotherapy achieved favorable results.

Clinical management of angioneurotic oedema patient post-orthognathic surgery

Angioneurotic oedema is an acute swelling involving the submucosal or subcutaneous tissues; it is most often located in the oral and maxillofacial region, which can result in upper airway obstruction. Its aetiology is frequently associated with immunoglobulin-mediated hypersensitivity reactions that elicit a heightened inflammatory response. The objective of this study was to report the case of a patient who developed an episode of angioneurotic oedema following combined orthognathic surgery. Pharmacological and nonpharmacological interventions used in the treatment of this important clinical condition are described and discussed.