POSTER 42Zygomatic Complex and Arch Fractures:A 5-Year Study in BrazilLuis Augusto Passeri, DDS, MS, PhD, Av. Limeira, 901,Piracicaba, Sao Paulo 13414-903, Brazil (Gomes PP;Barbosa JRA)

Statement of the Problem: The purpose of this studywas review, during a five-year period, the zygomatic-orbital complex and zygomatic arch fractures treated bythe Division of Oral and Maxillofacial Surgery of Piraci-caba Dental School, Unicamp, Brazil.

Materials and Methods: The age and sex distribution,anatomical types of fractures, associated maxillofacialand nonmaxillofacial trauma, and causes of injuries weredescribed. One thousand eight hundred and fifty sevenpatients with oral and maxillofacial trauma were evalu-ated from April 1999 to March 2004.

Method of Data Analysis: A description of retrospec-tive chart records analysis.

Results: A total of 371 zygomatic-orbital complex andzygomatic arch fractures cases were found in the popula-tion. The majority of fractures were sustained by males(82.75%) and whites (56.84%). The age group ranging from21 to 40 years was most afflicted by zygomatic-orbitalcomplex and zygomatic arch fractures (59.84%). Most pa-tients presented tobacco and alcohol addiction (45.55%)and regular oral hygiene (54.45%). The etiology includedfalls (21.83%), altercations (19.41%), cyclic accidents(15.63%), car accidents (12.67%), motorcycle accidents(13.48%), sport related accidents (7.82%), and work acci-dents (3.77%). Isolated zygomatic-orbital complex fracturescomprised 266 cases (38.27%) and zygomatic arch frac-tures 39 cases (10.51%). Additional facial trauma ofteninvolved mandible (7.55%), maxilla (5.39%), and nasal(5.12%) fractures. Associated nonmaxillofacial trauma waspresent in 45.55% of cases, involving upper extremities(61.54%), lower extremities (36.09%), skull (24.85%), tho-racic (17.75%), abdominal (5.33%), and neck (4.73%). Thetreatment of zygomatic-orbital complex and zygomaticarch fractures depended on the type of fracture and thegiven circumstance. In this study, 56.60% of the patientshad no surgical intervention. The complication incidencewas 6.20% related mainly with infection (17.39%), hyper-trophic scars (8.70%), ectropion (8.70%), and scleral show(8.70%). One patient developed visual deficiency (4.35%).It was noticed most injuries were low-energy trauma,caused by falls and cyclic accidents, involving mainly youngadult males.

Conclusion: Based on the results, this study gives im-portant epidemiologic data to plan prevention and treat-ment of maxillofacial trauma of this population at SaoPaulo State, Brazil.

References

Ellis E III, El-Attar A, Moos KF: An analysis of 2,067 cases of zygo-matico-orbital fractures. J Oral Maxillofac Surg 43:417, 1985

Souyris F, et al: Malar bone fractures and their sequelae. A statisticalstudy of 1,393 cases covering a period of 20 years. J CraniomaxillofacSurg 17:64, 1989

Zingg M, et al: Classification and treatment of zygomatic fractures: Areview of 1,025 cases. J Oral Maxillofac Surg 50:778, 1992

POSTER 43The Effects of Dioxin on Osseous WoundHealing in a Rat Extraction ModelChris Fenton, BSc, DDS, 503-77 Gerrard St. W,Toronto, Ontario M5G 2A1, Canada (Tenenbaum H;Casper R; Sandor G; Heersche J)

Statement of the Problem: Introduction: It has beensuggested that aryl hydrocarbons (Ah), found in indus-trial pollutants and cigarette smoke might be a linked toperiodontal disease and poor wound healing in bone.The mechanism by which these compounds exert theireffects is uncertain, but recent research has shown thataryl hydrocarbon receptor may play a role. Purpose: Todetermine if dioxin, a prototypical Ah receptor ligandaffects osseous wound healing.

Materials and Methods: A rat incisor tooth extractionmodel was used. Female Sprague-Dawley rats were as-signed randomly into three treatment groups, with 20animals per group (control:olive oil carrier vehicle,0.25ug/kg dioxin, 1.0 ug/kg dioxin). They were given atotal of 8 intraperitoneal injections of the assignedagents biweekly starting the day before incisor extrac-tion. The animals were sacrificed at 28 days, and lungtissue was harvested to assay for CYP1A1 upregulation, apositive control indicator of drug activity. The mandibleswere demineralized, sectioned, and stained.

Method of Data Analysis: Analysis of wound closurewas determined in a blinded fashion using a bone histo-morphometry program. All data were analyzed usingone-way analysis of variance to evaluate the differencesbetween the three treatment groups.

Results: Western blotting results clearly demonstratedinduction of CYP 1A1 product in the dioxin-treatedgroups indicating that the dioxin was pharmacologicallyactive. Wound closure was unaffected by treatment withdioxin, all extraction site wounds healing at the samerate.

Conclusion: Dioxin did not alter bone wound healingin this model. This may be related to the fact that dioxindoes not seem to interfere with function of fully differ-entiated osteoblasts. Given dioxin’s clear inhibitory ef-fects on bone cell differentiation, this could mean thathealing in this model is mediated by more differentiatedcells lining the socket but further study is required toeither confirm or rule out this possibility.

Scientific Poster Session

102 AAOMS • 2005

References

Lee LL, Lee JSC, Waldman SD, et al: Polycyclic aromatic hydrocar-bons present in cigarette smoke cause bone loss in an ovariectomizedrat model. Bone 30:917, 2002

Singh S, Casper R, Fritz P, et al: Inhibition of dioxin effects on boneformation in vitro by newly described aryl hydrocarbon receptor an-tagonist, reseveratrol. J Endocrinol 176:183, 2000

Funding Source: CIHR and Innovalife Technologies

POSTER 44Repair of Traumatic Facial DefectsUtilizing Local and Regional FlapsRick Rawson, DDS, 11092 Anderson St., Rm. 3306,Loma Linda, CA 92350 (Herford A)

Statement of the Problem: Trauma can lead to com-plex facial injuries with missing tissue. Early manage-ment leads to better restoration of form and functionwith early rehabilitation. Local and regional flaps oftenproduce superior results. Advantages include the prox-

imity of the tissue to the defect and also the color matchof the recruited tissue.

Materials and Methods: Seventeen flaps were used torestore missing tissue in fifteen consecutive patients.The types of injuries included eyelid (3), nasal injuries(4), lip (4), and cheek (4). Flaps were either local (13) orregional (4).

Method of Data Analysis: Analysis was performed byclinical evaluation and photographs of the reconstructedpatient.

Results: All patients had restoration of their missingtissue. Ten flaps were performed as a single stagewhereas seven flaps were staged. Postoperative healingwas judged to be good or excellent in sixteen patients.

Conclusion: Local and regional flaps provide optimalrestoration of missing tissue for patients suffering trau-matic tissue loss.

References

Herford AS: Early Repair of avulsive facial wounds secondary totrauma using interpolation flaps. J Oral Maxillofac Surg 62:959, 2004

Blackwell KE, Buchbinder D, Biller HF, et al: Reconstruction ofmassive defects in the head and neck: The role of simultaneous distantand regional flaps. Head Neck 19:620, 1997

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