Doi:10.1016/j.joms.2005.05.227

trauma. Roughly half of the laryngeal fractures in our and then stapled closed. Third, spectral imaging was used to series were managed non-operatively although approxi- determine the distances from the distal end of the flap to the mately three-quarters required airway intervention rang- zones of stasis and zones of normal flow. Finally, animals were ing from intubation to emergent cricothyroidotomy. Cli- sacrificed and the flaps removed and photographed. Digital nicians treating maxillofacial trauma need to be familiar images of the flaps were used to determine the percent of with the signs and symptoms of this injury. A timely black, discolored (gray/red), and normal tissue.
evaluation of the larynx and rapid airway intervention are essential for a successful outcome. The Schaefer classification of injury severity and corresponding treat- ment guidelines were consistent with our study.
c. Statistical methods: One-way analysis of variance Leopold DA: Laryngeal trauma. A historical comparison of treatment Results: The orthogonal polarization spectral imaging results showed a significant decrease in the zone of Schaefer SD, Stringer SP: Laryngeal trauma, in Bailey BJ, Pillsbury necrosis (no vessels present) in rats treated with silden- HC, Driscoll BP (eds): Head and Neck Surgery: Otolaryngology. Phila- afil one and three days after surgery. We also found a delphia, PA, Lippincott-Raven, 1998, pp 947-956 significant decrease in the total affected area, whichconsists of the zones of necrosis and stasis, in treated rats Short and Long Term Effects of Sildenafil
three days after surgery. Digital photography analysis on Skin Flap Survival in Rats
also showed a significant decrease in the area of necrosis(black tissue) at three days. These findings support the Kristopher L. Hart, DDS, 705 Aumond Rd, Augusta, GA results obtained using spectral imaging. No significant 30909 (Baur D; Hodam J; Wood LL; Parham M; Keith differences were found between sildenafil treated and control animals five and seven days after surgery.
Conclusion: These results demonstrated that 45 mg/ Statement of the Problem: Annually in the United States, kg/d IP of sildenafil may have a beneficial effect on skin approximately 175,000 people sustain severe facial trauma survivability at the early stages of wound healing. Or- requiring major surgical repair. These injuries often cause thogonal polarization spectral imaging has been proven significant loss of facial skin, leading to severe aesthetic and to predict areas of necrosis more accurately than photo- functional deficits. Skin flaps are the foundation for recon- graphic analysis. This method allowed us to observe structing such defects. The most important factor deter- differences between sildenafil treated and control rats as mining the survival of these flaps is the delivery of oxygen early as 24 hours and as late as three days after surgery.
via the circulation. A number of therapeutic modalities Although we did not see any benefit when animals were have been explored to improve blood flow and oxygen- treated with 45 mg/kg/d IP five and seven days after ation of flap tissue. One principal approach has been to surgery, we believe that changes in the treatment regi- increase blood flow by vasodilation. However, due to their men may enhance long-term flap survivability.
hypotensive effects, the vasodilators tested thus far havenot been utilized in surgical repair of facial skin. Phospho- diesterase (PDE)-inhibitors, which includes the drug silden-afil, are a relatively new class of FDA approved drugs whose Olivier WA, Hazen A, Levine JP, et al: Reliable assessment of skin flap viability using orthogonal polarization imaging. Plast Reconst Surg effect on tissue viability has not been widely explored. The vasodilatory effects of these drugs have the potential to Sarifakioglu N, Gokrem S, Ates L, et al: The influence of sildenafil on enhance blood flow to wound sites, improve oxygen sup- random skin flap survival in rats: An experimental study. Br J Plast Surg ply, and promote wound repair. In this study, we examined whether administering sildenafil intraperitoneally at a dose of 45 mg/kg/d has a beneficial effect on the survival ofsurgical skin flaps in rats.
Materials and Methods: Surgical skin flaps were evaluated 2005 Straumann Resident Scientific
using orthogonal polarization spectral imaging, flap image Award Winner
analysis, and histology at 1, 3, 5, and 7 days. Orthogonalpolarization spectral imaging provides high quality, high con- Histomorphometric Assessment of Bony
trast images of the microcirculation of skin flaps. Areas of Healing of Rabbit Critical-Sized
normal capillary flow are easily differentiated from areas of Calvarial Defects With Hyperbaric
stasis and areas completely devoid of vessels. First, rats wereassigned to either sildenafil treated (45 mg/kg/day IP), vehicle Oxygen Therapy
control, or sham (no injection) groups. Second, caudally based Ahmed M. Jan, DDS, The Hospital for Sick Children, dorsal rectangular (3 x 10 cm) flaps were completely raised S-525, 555 University Ave, Toronto, Ontario M5G 1X8, AAOMS • 2005
Muhonen A, Haaparanta M, Gronroos T, et al: Osteoblastic activity and neoangiogenesis in distracted bone of irradiated rabbit mandiblewith or without hyperbaric oxygen treatment. Int J Oral MaxillofacSurg 33:173, 2004 Statement of the Problem: A critical-sized defect is the smallest osseous wound that will not heal spontaneouslywith bony union over the lifetime of an animal. Practi- Craniofacial Growth Following Cytokine
cally, the defect should not heal spontaneously during Therapy in Craniosynostotic Rabbits
the experimental period. Hyperbaric oxygen therapy Harry Papodopoulus, DDS, MD, University of Pittsburgh (HBO) is used to improve the healing of a variety of School of Dental Medicine, 3501 Terrace Street, problem wounds. This study evaluated the effect of HBO Pittsburgh, PA 15261 (Ho L; Shand J; Moursi AM; on the healing of critical-sized defects in the rabbit cal- Burrows AM; Caccamese J; Costello BJ; Morrison M; varial model and whether HBO administration can result Cooper GM; Barbano T; Losken HW; Opperman LM; in the healing of a larger “supracritical-sized” defect.
Materials and Methods: Twenty New Zealand rabbits were divided into 2 groups of 10 animals. Full thickness Statement of the Problem: Craniosynostosis affects 300- calvarial defects were created in their parietal bones bilat- 500/1,000,000 births. It has been suggested that an over- erally. Defects were critical-sized (15 mm) on one side and expression of Tgf-beta 2 leads to calvarial hyperostosis and supracritical (18 mm) on the contralateral side. Group 1 suture fusion in craniosynostotic individuals. This study received a 90 minute HBO therapy session at 2.4 ATA daily was to test the hypothesis that neutralizing antibodies to for 20 consecutive days. Group 2 served as a control group Tgf-beta 2 may block its activity in craniosynostotic rabbits, receiving only room air. Five animals in each group were preventing coronal suture fusion in affected individuals, sacrificed at 6 and 12 weeks postoperatively.
and allowing unrestricted craniofacial growth.
Method of Data Analysis: Data analysis included qual- Materials and Methods: Twenty-eight New Zealand itative assessment of the calvarial specimens as well as White rabbits with bilateral delayed-onset coronal suture quantitative histomorphometric analysis to compute the synostosis had radiopaque dental amalgam markers placed amount of regenerated bone within the defects. Hema- on either side of coronal sutures at 10 days of age (synos- toxylin and eosin stained sections were sliced and cap- tosis occurs at approximately 42 days of age). At 25 days, tured by a digital camera (RT Color; Diagnostic Instru- the rabbits were randomly assigned to three groups: 1) ments Inc, Sterling Heights, MI). A blinded investigator Sham control rabbits (n ϭ 10); 2) Rabbits with non-spe- examined merged images and analyzed them for quantity cific, control IgG antibody (100ug/suture) delivered in a of new bone regeneration. Statistical significance was slow release collagen vehicle (n ϭ 9); and 3) Rabbits with Tgf-beta 2 neutralizing antibody (100ug/suture) delivered Results: The HBO group showed bony union and demon- in slow release collagen (n ϭ 9). The collagen vehicle in strated more bone formation than the control group at 6 groups Two and Three was injected subperiosteally above weeks (p Ͻ .001). The control group did not show bony the coronal suture. Longitudinal lateral and dorsoventral union in either defect by 12 weeks. There was no significant head radiographs and somatic growth data were collected difference in the amount of new bone formed in the HBO from each animal at 10, 25, 42, and 84 days of age.
group at 6 weeks compared with 12 weeks (p ϭ .309).
Method of Data Analysis: Significant mean differences However, the bone at 6 weeks was more of a woven charac- were assessed using a one-way analysis of variance.
ter, while at 12 weeks it was more lamellated and more Results: Radiographic analysis showed significantly mature. Again, in the HBO group both the critical-sized and greater (p Ͻ 0.05) coronal suture marker separation, the supracritical-sized defects healed equally (p ϭ .520).
overall craniofacial length, cranial vault length and Conclusion: HBO therapy has facilitated the bony heal- height, cranial base length, and more lordotic cranial ing of both critical-sized and supracritical-sized rabbit base angles in rabbits treated with anti-Tgf-beta-2 anti- calvarial defects. Since bony healing was achieved early, body than groups at 42 and 84 days of age.
it is reasonable to assume that an even larger than 18 mm Conclusion: These data support our initial hypothesis defect (if it were technically feasible) might have healed that interference with Tgf-beta-2 production and/or within the 12 week period of study aided by HBO.
function may rescue prematurely fusing coronal sutures Adjunctive HBO, based on histomorphometrics, doubles and facilitate craniofacial growth in this rabbit model.
the amount of new bone formed within both the critical These findings also suggest that this cytokine therapy sized and the supracritical-sized defects. It allowed an may be clinically significant in infants with insidious or increase in the critical size by more than 20%.
progressive postgestational craniosynostosis.
`ndor GK, Holmes HI, et al: Histomorphometric Poisson E, Sciote JJ, Koepsel R, et al: Transforming growth factor- evaluation of bone regeneration using allogeneic and alloplastic bone beta isoform expression in the perisutural tissue of craniosynostotic substitutes. J Oral Maxillofac Surg 62:202, 2004 rabbits. Cleft Palate Craniofac J 41:392, 2004 AAOMS • 2005

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