J Vet Dent 27(4) - Winter 2010

Finite Element Modeling for Development and Optimization of a Bone Plate for Mandibular Fracture in Dogs

Elisângela P. Freitas, DVM, MS; Sheila C. Rahal, DVM, PhD; Marco Antonio Gioso, DVM, PhD; Luiz Carlos Vulcano, DVM, PhD; Antonio Carlos Shimano, PhD; Jorge Vicente Lopes da Silva,PhD; Pedro Y. Noritomi, PhD; Alexander O. El Warrak, DVM, MSc, PhD

Summary: This study aimed to develop a plate to treat fractures of the mandibular body in dogs and to validate the project using finite elements and biomechanical essays. Mandible prototypes were produced with 10 oblique ventrorostral fractures (favorable) and 10 oblique ventrocaudal fractures (unfavorable). Three groups were established for each fracture type. Osteosynthesis with a pure titanium plate of double-arch geometry and blocked monocortical screws of free angulation were used. The mechanical resistance of the prototype with unfavorable fracture was lower than that of the favorable fracture. In both fractures, the deflection increased and the relative stiffness decreased proportionally to the diminishing screw number. The finite element analysis validated this plate study, since the maximum tension concentration observed on the plate was lower than the resistance limit tension admitted by the titanium. In conclusion, the double-arch geometry plate fixed with blocked monocortical screws has sufficient resistance to stabilize oblique fractures, without compromising mandibular dental or neurovascular structures. J Vet Dent 24(4); 212-221, 2010

Tooth Resorption in the Swedish Eurasion Lynx (Lynx lynx)

Ann Pettersson, VMD, PhD

Summary: The etiology of tooth resorption in the domestic cat remains unknown. The high prevalence and progressive nature of the disease complicates defining healthy control
groups. In order to evaluate the possible influence of various life style changes on the prevalence of tooth resorption, healthy control groups are a prerequisite. This paper presents a prevalence study for tooth resorption in a free-ranging wild felidae population. Skulls from 46 freeranging Eurasian lynx (Lynx lynx) were examined. The age of the animals had previously been estimated based on cementum annuli in the maxillary right canine tooth. The dental examination included both dental probing and radiographic imaging. Complicated fractures of the canine teeth were found in 9/46 (19.5 %) skulls. In one fractured canine, apical root resorption and periapical lucency was detected. The root resorption was attributed to inflammatory resorption as a consequence of the initial dental trauma and necrotic pulp. No signs of tooth resorption were found in the remaining teeth. Supernumerary roots were detected in 18/46 skulls (39.1 %). Supernumerary “peg” teeth caudal to the mandibular first molar tooth were detected in 6/46 (13.0 %) skulls. Although further studies on dental ultra-structure are needed, the Swedish Eurasian lynx may, in the future, be useful as a healthy comparative model for studies on the etiopathogenesis of tooth resorption in the domestic cat. J Vet Dent 27(4), 222 - 226, 2010

Lip Avulsion and Mandibular Symphyseal Separation Repair in an Immature Cat

Tammy L. White, DVM

Summary: A 12-week-old kitten was presented for symphyseal separation, comminuted rostral fractures of the mandibles, avulsion of the mandibular lip, and fractured teeth. Oral examination and intraoral dental radiographs demonstrated a mandibular symphyseal separation and the presence of developing tooth buds. Cerclage wire was placed circumferentially around the mandibles for 2-weeks to provide stabilization of the mandibular symphyseal separation. Clinical examination 9.5-months following surgery demonstrated normal occlusion with enamel hypoplasia affecting the mandibular canine teeth. Intraoral dental radiographs showed a partial bony union of the mandibular symphysis and vital, developing mandibular canine teeth. J Vet Dent 27 (4); 228 - 233, 2010

Intraosseous Maxillary Hemangioma in an Immature Bassett Hound

Donnell Hansen, DVM; Gary Goldstein, DVM; Laura Crews, DVM, MS; Laura Snyder, DVM; Molly C. Speltz, DVM

Summary: A 6-month-old Bassett Hound dog presented for evaluation of recurrent oral bleeding and a right maxillary swelling. Oral examination revealed right maxillary enlargement extending from the level of the right maxillary canine tooth to the area of the second and third premolar teeth. A discolored persistent right maxillary deciduous canine tooth and gingival inflammation was noted. Biopsies taken at the time of extraction of the persistent deciduous canine tooth resulted in significant hemorrhage and a biopsy report of reactive bone. The right maxillary enlargement did not resolve following the extraction procedure and empirical antimicrobial therapy. The owner elected euthanasia and post-mortem evaluation. Histopathologic assessment provided a diagnosis of maxillary hemangioma. J Vet Dent 27(4); 234 - 241, 2010

Multifocal Odontoblastic Dysplasia in a Dog

Christopher W. Smithson, DVM; Mark M. Smith, VMD; David A. Gamble, DVM, PhD

Summary: A two-year-old Boerboel dog presented for a discolored left maxillary canine tooth. Dental radiographs revealed abnormally mineralized pulp within the discolored tooth. Similar radiographic findings were also seen in both maxillary third incisor teeth and in the remaining canine teeth to varying degrees. The discolored tooth was treated by surgical extraction and histopathology revealed abnormal dentin deposition within the canal indicative of dentin dysplasia. Although not previously documented in the dog, the pulpal changes in multiple teeth of the dog reported here were similar to those described for odontoblastic dysplasia in humans. This case report includes a review of developmental abnormalities of dentin in humans and pulpal response to inflammation and injury. J Vet Dent 27(4); 242 - 247, 2010

FOUNDATIONS - The Basics of Saliva

Diana L. Eubanks, DVM, MS; Kimberly A. Woodruff, DVM

STEP-BY-STEP - Surgery for Cervical, Sublingual, and Pharyngeal Mucocele

Mark M. Smith, VMD