Use of a novel three-dimensional anatomical plating system for treatment of caudal mandibular fractures in cats: 13 cases (2019-2023).

CASE SERIES SUMMARY: A total of 13 cases of cats with a caudal mandibular fracture treated with a novel surgical technique using the Ramus Anatomical Plate system were reviewed. Preoperative, immediate postoperative and a minimum of 8 weeks postoperative CT images were required as inclusion criteria. The outcome and complications were determined from clinical data and radiographic follow-up examinations. All cases achieved adequate anatomical reduction, resulting in a functional and atraumatic occlusion postoperatively. No intraoperative complications were reported. Time to voluntary food intake was in the range of 1-25 days. No evidence of disruptions to the implants or screw loosening was observed in the 8-week postoperative CT imaging, with radiographic evidence of complete osseous union in all fractures. The most common postoperative complication was swelling at the surgical site. Two cats had postoperative exophthalmos due to retrobulbar haemorrhage, and one cat exhibited partial wound dehiscence 5 days postoperatively, which resolved with medical management. Longer-term complications included intraoral plate exposure in one cat, which required plate removal 10 months postoperatively. RELEVANCE AND NOVEL INFORMATION: In this case series, rigid internal fixation of caudal mandibular fractures using the Ramus Anatomical Plate osteosynthesis system was associated with a minimal complication rate, and satisfactory radiographic and clinical outcomes. The reported outcomes of this novel technique are favourable when compared with previous techniques described for the management of these fracture types.

Mandibular fracture repair techniques in cats: a dentist's perspective.

PRACTICAL RELEVANCE: Feline head trauma injuries are common in general practice, often resulting in mandibular fracture. An understanding of the recent advances in the field of mandibular fracture repair will facilitate evidence-based decision-making in clinical practice. CLINICAL CHALLENGES: Feline maxillofacial and oral anatomy brings unique challenges in comparison with dogs. It has been commonplace to adapt techniques and equipment that are better suited to other body regions or are species-inappropriate for use in feline maxillofacial surgery, and this has traditionally resulted in high morbidity. AIMS: This review presents an overview of the diagnosis of, and decison-making for, maxillofacial trauma in cats, specifically with reference to the feline mandible. The challenges associated with the management of these injuries are presented. Techniques for repair that can be employed in general practice, as well as more advanced surgical options, are discussed, as well as the indications for invasive vs non-invasive management. Underutilised methods involving composite dental materials and their versatility for the repair of mandibular fractures in cats, and miniplates for caudal mandibular fractures in cats, are specifically covered, as well as other recent advances in the field, including three-dimensional printing and custom-printed implants. EVIDENCE BASE: Management of feline facial fractures is an often neglected topic, with very few published studies choosing to focus on head trauma outcomes in cats. Where available, however, this review draws on the published literature, as well as the authors' own clinical experience.

Treatment of a Mandibular Diastemal Fracture Using Locking Compression Plate and Cerclage Wire in a Mare.

This report describes the combination of two surgical fracture repair techniques and the postoperative management of a mandibular diastemal fracture in a two-year-old mare. The mare was referred to a veterinary hospital with a laceration over the body of the right mandible. Radiographic assessment revealed two mesial fracture lines involving the second premolar tooth and a ventrally displaced bone fragment. The mare was treated under general anesthesia and the fracture was corrected using open reduction and plate fixation. A 3.5 mm narrow 15-hole locking compression plate with seven locking screws were used in a bridge form. Cerclage wire was also used to anchor the incisor teeth to the second and third premolar teeth. The cerclage wire and incisor teeth were covered with polymethylmethacrylate to prevent implant failure and avoid injury to the oral mucosa. Implants were removed 55 days after surgery and the mare was discharged from hospital five days later. The mare returned for cerclage wire removal after 90 days and was allowed to resume exercise thereafter. The combination of two surgical techniques, proper implant choice and appropriate postoperative management, including use of pelleted feed, contributed to successful bone healing and return to function.

Approach and Interfragmentary Stabilization of Caudal Mandibular Fracture in the Cat.

An approach to caudal mandibular fracture stabilization is described along with three cases wherein the approach was applied in relatively young cats with traumatic mandibular fractures caudal to or involving the mandibular first molar. This approach was well-tolerated and facilitated a quick return to function as supported by minimal or no reliance on esophageal feeding tubes.

[Unilateral mandibular fracture in horse - Treatment with fixateur externe, a complication during implant removal and procedure for removal of implant fragments]. / Unilaterale Mandibulafraktur bei einem Pferd.

The first part of this case report describes the surgical treatment of a unilateral mandibular fracture in the standing horse by using a fixateur type I. By the time of implant removal, the fracture had completely healed. However, during implant removal, an implant failure of 2 of the 4 implants occurred with fragments remaining in the bone. The second part of the report focuses on the development of a special surgical instrument that was designed for removal of the implant fragments. Furthermore, the surgical method allowing the entire extirpation of the fragments within a second surgery is described.According to the authors' knowledge, this is the first case report showing the use of the presented surgical technique for the treatment of a mandibular fracture in the standing horse. Additionally, this report also provides an approach for removing implant fragments from the depth of the bone which may occur in case of implant breakage as a potential complication of the described surgery.

Application of locking compression plates as type 1 external fixators to treat unilateral mandibular fractures in four equids and one dromedary.

OBJECTIVES: To describe a novel fixation of open, unstable, unilateral mandibular fractures applying a locking compression plate as an external skeletal fixator (ESF-LCP). ANIMALS: Four horses and one dromedary. STUDY DESIGN: Short case series. METHODS: Animals presented with unstable, open, unilateral fractures of the mandible. Fracture fixation was performed under general anesthesia. A 4.5/5.5 narrow LCP was applied externally above the level of the skin and combined with intraoral tension band wiring. RESULTS: Fracture fixation was achieved successfully using an ESF-LCP. Minimal tissue manipulation was required during application and removal of the construct. The ESF-LCPs provided adequate access to the wounds at the fracture site, were well tolerated, and did not interfere with any objects in the animals' environment. Mild drainage at the screw-skin interface developed in all cases, requiring early implant removal due to surgical site infection in one case. The use of longer plates was associated with superficial pressure necrosis of the skin in the masseter area in two cases. Implants were removed after 3 to 12 weeks, and the long-term functional outcome after 11 to 41 (median 13) months was good in all cases. CONCLUSION: Stabilization of mandibular fractures with ESF-LCP led to good outcomes in this case series. The use of longer plates positioned more caudally and in a ventrolateral position seemed associated with surgical site infection and pressure necrosis of the skin. CLINICAL SIGNIFICANCE: Use of a locking compression plate as an external skeletal fixator seems to offer a viable alternative to treat unilateral mandibular fractures, especially when these are open and/or infected.

Polyaxial pedicle screw external fixation to stabilize oblique mandibular fractures in three standing, sedated horses.

OBJECTIVE: To report the radiographic, surgical and postoperative features in horses with unstable oblique mandibular fractures secured with polyaxial pedicle screws (PPS) external fixation construct and intraoral wiring. ANIMALS: Three client-owned horses. STUDY DESIGN: Short case series. METHODS: Two horses each had a unilateral fracture, which did not improve after conservative management, and one horse had bilateral fractures. Clinical and radiographic features were documented. Polyaxial pedicle screw external fixators and intraoral tension band wiring were applied in standing horses after combining sedation and regional nerve anesthesia. Intraoral wires were implanted through a lateral buccotomy between teeth (two horses) or burred through exposed crown (one horse) and then secured around the incisors. The PPS were inserted under radiographic guidance to avoid tooth roots. Healing was assessed with radiographic examination. The PPS external fixator rod and intraoral wires were removed first. The mandible was manipulated, and, if it was stable, the PPS were removed. RESULTS: Implants were removed at 6, 8, or 10 weeks after the mandibles were palpably stable. Complications included broken wires in one horse, bone sequestration in one horse, and infection in one horse. Follow-up communication with the owners 12 to 18 months later confirmed complete healing without further complications of the fractured mandibles or teeth. CONCLUSION: Polyaxial pedicle screw external fixation led to fracture healing and a return to function in all three horses. The complications encountered did not preclude a successful outcome. CLINICAL SIGNIFICANCE: Polyaxial pedicle screw external fixation coupled with intraoral wiring provides an alternative to treat unstable equine mandibular fractures without general anesthesia.

Can bone marrow aspirate improve mandibular fracture repair in camels (Camelus dromedarius)? A preliminary study.

BACKGROUND: Mandibular fractures are common in camels, leading to considerable economic losses. This study explored methods of improving mandibular fractures repair, adjuvant with interdental wire, or bone plate fixation. Autologous bone marrow (BM) injection enhances osteogenesis and rapid healing. OBJECTIVES: To investigate the effect of autologous BM aspirate as an adjuvant treatment for repairing mandibular fractures in camels with interdental wire, or bone plate fixation. METHODS: Thirty dromedary camels aged 5-8 years and of both sexes were randomly divided into 4 treatment groups: group 1 (n = 10) treated with stainless steel wire fixation and BM injection at the fracture line, group 2 (n = 10) treated with plate fixation and BM injection at the fracture line, group 3 (n = 5) treated with stainless steel bone wire fixation and placebo saline injection at the fracture line, and group 4 (n = 5) treated with plate fixation and placebo injection at the fracture line. The mandibular fractures were followed weekly for 12 weeks postoperatively to assess improvement and healing based on clinical evaluation, radiographic union scale, and bone turnover markers (i.e., bone alkaline phosphatase, osteocalcin, pyridinoline, and deoxypyridinoline). RESULTS: Compared to other groups, elevated bone turnover markers in group 1 were demonstrated (p < 0.05) on the seventh postoperative day. Likewise, compared to other groups, both clinical findings and radiographic union scale significantly improved (p < 0.05) in group 1 on the 56th postoperative day. CONCLUSIONS: BM aspirate has a promising beneficial osteogenic effect on mandibular fracture repair in camels, most notably when combined with interdental wire fixation.

Bilateral rostral mandibulectomy for treatment of necrotic mandibular open fractures in two Japanese Black cattle.

Two-month-old (Case 1) and one-year-old (Case 2) Japanese Black cattle presented with bilateral rostral mandibular open fractures. At presentation, the proximal edges of each fracture were discolored and had a severe stench, indicating necrosis caused by infection. In both cases, a bilateral rostral mandibulectomy over the symphysis was performed. Although the tongues of both animals prolapsed post-surgery, they had no significant problems with eating or drinking. Case 1 showed excellent growth during fattening, and Case 2 successfully became pregnant and gave birth. Rostral mandibulectomy can be an effective surgical option for the treatment of cattle with difficulty in internal or external fixation due to unfavorable necrotic cranial mandibular open fractures.

Influence of plate type and placement on the immobilization of bilateral equine mandibular osteotomies: Ex vivo study.

OBJECTIVE: To determine the influence of plate fixation (locking or dynamic compression) and the site of application (ventral [V] or ventrolateral [VL]) on the resistance to bending of transverse mandibular fractures. STUDY DESIGN: Ex vivo, simple randomized study. SAMPLE POPULATION: Mandibles harvested from adult equine cadavers (n = 18). METHODS: Bilateral osteotomies were created 1 cm caudal to the mental foramen and perpendicular to the long axis of each mandible. Mandibles were fixed with 1 of 3 methods: (1) VL dynamic compression plate (DCP), (2) V-DCP, or (3) VL locking compression plating (LCP). Constructs were mounted on a custom testing jig and tested for resistance in bending by applying force to the rostral aspect of the mandible. Stiffness and change of distance of the dorsal osteotomy at 200 N were compared among constructs. RESULTS: VL-LCP constructs were 5.25 and 2.42 times stiffer than V and VL constructs, respectively (P<.001). Change in the width of the osteotomy gap at 200 N of load was reduced 6.04 times when osteotomies were stabilized with VL compared to V (P<.001); no difference was detected between the VL and VL-LCP constructs (P=.836). CONCLUSION: Ventrolateral LCP fixation of equine transverse mandibular osteotomies provided greater resistance to bending compared with V and VL constructs. CLINICAL SIGNIFICANCE: These results provide evidence to recommend fixation of transverse interdental mandibular fractures with VL-LCP rather than with DCP in horses.

Printing 3D models of canine jaw fractures for teaching undergraduate veterinary medicine

Abstract Purpose To develop 3D anatomical models, and corresponding radiographs, of canine jaw fractures. Methods A base model was generated from a mandibular bone scan. With this model it was possible to perform fracture planning according to the anatomical location. Results The 3D base model of the canine mandible was similar in conformation to the natural bone, demonstrating structures such as canine tooth crowns, premolars and molars, mental foramina, body of the mandible, ramus of the mandible, masseteric fossa, the coronoid process, condylar process, and angular process. It was not possible to obtain detail of the crown of the incisor teeth, mandibular symphysis, and the medullary channel. Production of the 3D CJF model took 10.6 h, used 150.1 g of filament (ABS) and cost US$5.83. Conclusion The 3D canine jaw fractures models, which reproduced natural canine jaw fractures, and their respective radiographic images, are a possible source of educational material for the teaching of veterinary medicine.

Rostral mandibular fracture repair in a pet bearded dragon (Pogona vitticeps).

CASE DESCRIPTION A 2-year-old male bearded dragon (Pogona vitticeps) was evaluated because of a traumatic mandibular fracture. CLINICAL FINDINGS An open comminuted fracture of the rostral aspect of the right mandible was evident, with a fragment of bone exposed and dorsally displaced. Whole-body radiography revealed no evidence of additional injury. Other findings were unremarkable, except for moderate anemia (PCV, 19%). TREATMENT AND OUTCOME The fracture fragments were stabilized with 2 crossed 36-gauge interfragmentary wire loops. An external fixator device was fashioned from four 25-gauge needles inserted at alternating angles through the fracture fragments; plastic IV fluid line tubing filled with dental acrylic was used as a connecting bar. One day after surgery, the lizard had regained its typical activity level and appetite. Body weight was measured and the external fixator was inspected 1 week after surgery and monthly thereafter. Three months after initial injury, the fracture was stable, radiography revealed bony callus formation at the fracture site, and the external fixator was removed. Recheck radiography performed 5.5 months after initial injury revealed complete osseous union of the fracture fragments, and the interfragmentary wires were removed. CLINICAL RELEVANCE Surgical management of the traumatic comminuted mandibular fracture in this bearded dragon by means of a combination of internal and external fixation resulted in complete healing of the mandible and restoration of function. Management of this complicated fracture was achieved with the aid of readily available and inexpensive supplies in a clinical setting, which may be useful to other clinicians in the management of similar cases.

Mandibular body fracture repair with wire-reinforced interdental composite splint in small dogs.

OBJECTIVE: To report the outcome of mandibular body fractures treated with a wire-reinforced interdental composite splint (WRICS) in small breed dogs. STUDY DESIGN: Retrospective case series. ANIMALS: Client-owned small breed dogs (n = 24). METHODS: Medical records (1998-2012) of small breed dogs (<10 kg) with mandibular body fractures treated by WRICS were reviewed for signalment, history, type of fracture, treatment, and clinical and radiological follow-up. The angle of the fracture line (ANG) was measured on dental radiographs. A mandibular injury severity score (MISS) and a dental injury score (DIS) were evaluated as potential prognostic factors. RESULTS: Fractures most commonly involved P4-M1 (56%), and healed in a mean time of 2.37 ± 0.7 months. Healing was slower (P = .012) if teeth were present in the fracture line and required extraction, hemisection, or root canal therapy prior to WRICS placement (2.39 ± 0.7 months) than if no dental treatment was required (1.46 ± 0.8 months). Contrary to the MISS, the DIS was associated with longer time to bone healing (P = .001; r = .63) and risk of complications (P = .004). Bone healing time was decreased (P = .003; r = .61) with increasing fracture angles. CONCLUSION: WRICS can be considered to treat mandibular body fractures in small breed dogs if the fracture is not severely comminuted, and if at least the canine and first molar tooth can be used for anchorage. More severe lesions, such as those with teeth in the fracture line and a shorter fracture surface, are associated with prolonged bone healing.

Commissurorraphy in the Dog.

Commissurorraphy is a surgical procedure designed to move the lip commissure rostrally. This procedure may be helpful as a unilateral procedure in cases of unilateral mandibulectomy to support tongue function and improve esthetics. Bilateral commissurorraphy is utilized in cases of radical bilateral mandibulectomy and as a salvage procedure for support of bilateral mandibular fractures in cases where rigid surgical fixation is not feasible. Dehiscence is the most likely complication of commissurorraphy. Tension can be reduced at the rostral extent of the incision by utilizing mattress sutures, intravenous fluid tubing, and/or buttons to prevent tearing through sutures.

Conservative Management of Unilateral Fractures of the Mandibular Rami in Horses.

OBJECTIVE: To report the outcome of conservative management of unilateral fractures of the mandibular rami in horses. STUDY DESIGN: Retrospective case series. ANIMALS: 24 client-owned horses with unilateral mandibular fractures METHODS: Medical records (January 2000-January 2014) of horses with unilateral mandibular ramus fractures were retrieved. Only conservatively managed horses with follow-up information were included. Follow-up information on clinical outcome was retrieved from the medical records (n=11) or obtained by telephone interviews with the owners or trainers (n=13). RESULTS: Twenty-three horses (96%) returned to their previous or intended use and had no clinically evident masticatory or fracture healing-related problems at the time of follow-up. The owner of 1 horse (4%) reported it had tooth loosening, feed impaction, and masticatory problems. CONCLUSION: Conservative management of unilateral fractures of the mandibular rami is a treatment option in horses.

Distraction Osteogenesis Correction of Mandibular Ramis Fracture Malunion in a Juvenile Mute Swan ( Cygnus olor ).

A juvenile mute swan (Cygnus olor) was presented with right lateral deviation of the mandible. Radiographs demonstrated a healed fracture of the right mandibular ramis, which had compromised osteogenesis. A corrective osteotomy was performed and an osteogenic distractor was inserted over the lateral aspect of the right mandible. Dental acrylic implants were fixed to the rhinotheca to correct rotational alignment. A pharyngostomy tube was placed to facilitate administration of nutrition and medication. Postoperative images confirmed correct alignment of the mandible in relation to the maxilla. Implants were removed and postoperative complications were not reported. This is the first report of an osteogenic distractor used to correct mandibular deviation in an avian species. Distraction osteogenesis should be considered as a valid surgical option in juvenile or adult avian patients with pathologic bone shortening.

Successful Treatment of Mandibular Nonunion With Cortical Allograft, Cancellous Autograft, and Locking Titanium Miniplates in a Dog.

Discontinuities of the mandible can occur for a variety of reasons including primary pathology of bone, pathologic fracture secondary to periodontal disease, and segmental resection for the treatment of neoplasia. Surgical intervention is necessary in many cases to establish normal occlusion and normal mandibular function. Rigid stabilization and treatment of these defects can be challenging due to the limited availability of bone for fixation as well as limited soft tissue coverage. This case report describes successful treatment of a nonunion fracture using cortical allograft and locking titanium miniplates. Complete osseointegration and bone healing were achieved, allowing for complete return to normal occlusion and function.

Segmental Mandibulectomy in the Dog.

This step-by-step manuscript describes surgical technique of segmental mandibulectomy in the dog. This surgical procedure may be indicated for the excision of small- to mid-sized neoplasms or as a salvage procedure for mandibular fractures. Long-term postoperative complications are not common and cosmetic appearance following the procedure is generally acceptable to the pet owner.

False ankylosis of the temporomandibular joint in a cat. Correction by partial zygomatic arch resection.

OBJECTIVE: To describe the use of two-dimensional computer-assisted tomography (CT) with three-dimensional (3D) reconstruction in the diagnosis and planning of surgical treatment of a case of false ankylosis of the temporomandibular joint. CASE REPORT: A young European Shorthaired cat was presented with the complaint of inability to eat and open its jaws. A CT scan with 3D reconstruction allowed visualization of the lesion which was causing extra-articular ankylosis of the temporomandibular joint. Surgery was performed to resect an osseous lesion of the zygomatic arch, thus freeing the temporomandibular joint. Postoperative physical therapy was initiated immediately following surgery, and then carried out by the owner with a one year follow-up. Clinical examination of the cat was performed during regular office visits (at 1 month and 3 months following surgery), which allowed objective assessment of postoperative recuperation. At the end of a year, the owners reported that the cat had maintained sufficient jaw opening without any signs consistent with chronic pain. CONCLUSION: Computed tomography scan with 3D reconstruction allowed planning of the surgical correction of extra-articular ankylosis of the temporomandibular joint, and in this case condylectomy was avoided, since temporomandibular joint range-of-motion was maintained.

Initial Experience With rhBMP-2 Delivered in a Compressive Resistant Matrix for Mandibular Reconstruction in 5 Dogs.

OBJECTIVE: To document cumulative initial experience and long-term follow-up of the use of rhBMP-2/CRM for reconstruction of large mandibular defects (≥5 cm) in dogs. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 5). METHODS: Medical records (October 1999-April 2011) of dogs that had mandibular reconstruction for defects/resections of ≥5 cm using rhBMP-2/CRM were reviewed. Signalment, preoperative assessment/rationale for mandibular reconstruction, surgical methods, postoperative assessment of the reconstruction (evaluation of occlusion), and complications were recorded. A definitive histologic diagnosis was obtained in dogs that had mandibular resection for mass removal. Long-term complications were determined. A minimum time frame of 2-year in-hospital follow-up was required for case inclusion. RESULTS: Mandibular reconstruction was successfully performed in all dogs' defects where gaps of 5-9 cm were bridged. Surgical reconstruction rapidly restored cosmetic appearance and function. All dogs healed with new bone formation across the gap. New bone formation was present within the defects as early as 2 weeks after surgery based on palpation, and new bone formation bridging the gap was documented radiographically by 16 weeks. Minor complications occurred in all dogs in the early postoperative period, and included early firm swelling and gingival dehiscence in 1 dog; late plate exposure in 3 dogs; and exuberant/cystic bone formation in 2 dogs (related to concentration/formulation of rhBMP-2/CRM). Two dogs had minor long-term complications of late plate exposure and a non-vital canine tooth; the plates and the affected canine tooth were removed. Long-term in-hospital follow-up was 5.3 years (range, 2-12.5 years); further long-term telephone follow-up was 6.3 years (range, 2-12.5 years). All owners were pleased with the outcome and would repeat the surgery again under similar circumstances. CONCLUSION: The efficacy and success of this mandibular reconstruction technique, using rhBMP-2/CRM with plate fixation, was demonstrated with bridging of large mandibular defects regardless of the underlying cause, and with excellent cosmetic and functional results. Complications were common, but considered minor and easily treated. The complications encountered revealed the importance of tailoring the use of BMPs and fixation methods to this specific anatomic location and indication.