Biomedical subjects

Franco Audia

Publications and source records attributed to Franco Audia.

3 recordsLinked to original sources

PubMed2006

Bone regeneration using rhBMP-2 induction in hemimandibulectomy type defects of elderly sub-human primates.

Our previous work has shown that total osseous reconstruction of large discontinuity hemimandibulectomy, critical-sized defects can be achieved easily in 8-year-old Macaca fascicularis monkeys (Boyne 1996). However the literature has indicated that animal aging decreases the BMP induction of stem cells in rats and in other rodent species. It was necessarily important that the rhBMP-2 be demonstrated in non-human primates to determine if this reduction in effectiveness also existed in the higher animals phylogenetically. The purpose of this study was to operate aged non-human primates duplicating the model used in middle-aged animals to demonstrate regeneration of hemimandibulectomy defects. This age group could be extrapolated to the 80-year-old clinic patient. Six non-human primates aged 20 years were rendered edentulous posteriorly and the mandibles allowed to heal. Three months postoperatively bilateral hemimandibulectomies were performed. The defects received BMP in a collagen sponge (Helistat) using a dose level of 0.75 mg of rhBMP-2. After the manner previously reported by Boyne (1996, 1999), at the end of four months the surgical sites were exposed by mucoperiosteal flap demonstrating complete regeneration of the critical-sized defects. The animals received two dental implants in restored areas. The implants were brought into function approximately four months later, and were allowed to function for eight months in all cases. The results indicate that the regeneration of mandibular critical-sized defects by the use of rhBMP-2 in aged animals is comparable to that of the middle-aged group. This study indicates that aged non-human primates, chronologically comparable to 80-year-old humans, respond as favorably to rhBMP-2 as do the middle-aged animals. Extrapolating the results to the clinical level, one would expect that rhBMP-2 would produce a comparable result in the regeneration of large hemimandibulectomy-type defects in clinical human patients.

Aging↗

PubMed2003

Medial approach for tibial bone graft: anatomic study and clinical technique.

PURPOSE: The purpose of this study is to quantify the amount of bone graft material present in the proximal tibia via a lateral versus a medial approach, as well as describe an alternative technique for obtaining this bone graft material. A quantitative anatomic and statistical analysis and comparison are presented. The goal of this study is to demonstrate the advantages and simplicity associated with utilizing the proximal tibia as a bone graft harvest site in oral and maxillofacial surgery via a medial approach. MATERIAL AND METHODS: Forty lower extremities from 20 cadavers were studied. All specimens were dissected, and anatomic landmarks were recorded. Anatomic structures, including vessels, nerves, muscle attachments, articular surfaces, and their relationships to various anatomic landmarks were identified, measured with a linear millimeter ruler, and recorded. Bone harvest was accomplished using either a medial (20 extremities) or lateral (20 extremities) approach. The amount of bone available for harvest using both techniques was compared. Variables evaluated included volume of graft, age, gender, and relationships among anatomic structures. RESULTS: The mean volume of bone harvested was 25.0 mL for the lateral approach and 24.9 mL for the medial approach (range, 14 to 34 mL). The Mann-Whitney U test revealed no significant difference in mean volume of graft obtained when comparing the medial and lateral approaches (P =.9250). Pearson's correlation test revealed no correlation between age (P =.089 medial and P =.174 lateral) or gender (P =.3120 medial and P =.4440 lateral). The lateral anatomic structures evaluated included the anterior tibial vessels that emerged from the interosseous hiatus 14.3 mm inferior to tibial perpendicular and 42.6 mm lateral to the tibial parallel line. The distance from the tibial perpendicular to the articular surface did not significantly differ when comparing the medial (33.65 mm) and lateral (33.25 mm) anterior tibial surfaces. The mean length of the oblique line was 17.9 mm, and the superior portion of this line was 14.65 mm above the tibial perpendicular line. CONCLUSIONS: Equal amounts of bone graft material are available for harvest from the medial and lateral aspects of the proximal tibia. Knowledge of important anatomic landmarks can be used preoperatively to allow for safe dissection and harvest of autogenous bone from the proximal tibia. The dissection of medial proximal tibia and harvest of bone graft material may be accomplished efficiently with minimal chances of damage or morbidity to vital adjacent structures.

Adult↗

PubMedDate not supplied

Maintaining vector control during alveolar distraction osteogenesis: a technical note.

Distraction osteogenesis is a predictable method for restoring missing tissue prior to implant placement. However, pull from the soft tissue can alter the desired direction of the distraction. This article describes and illustrates techniques that are useful for maintaining the desired vector during alveolar distraction osteogenesis. These methods can prevent the need for further intervention and allow for ideal placement of endosseous dental implants without compromising results.

Alveoloplasty↗