Surgical management of ameloblastic fibroma in the cat

A 14-month-old spayed female domestic short-haired cat was presented for evaluation of a rostral mandibular mass diagnosed from biopsy as an ameloblastic fibroma. Radiographs of the mandible demonstrated marked osteolysis and cortical expansion. A rostral mandibulectomy was performed extending from the caudal edge of the second premolar on the right side to the caudal edge of the canine tooth on the left side. Histological evaluation of the excised mass confirmed the diagnosis of ameloblastic fibroma. Follow-up evaluation at eight months revealed normal oral function with the exception of occasional saliva soiling of the chin. The owner was satisfied with the cosmetic result.     

Mandibular Rim Excision in Seven Dogs

Objective— To describe a surgical technique for excision of minimally invasive mandibular tumors at the level of the premolar and molar teeth, and report outcome in 7 dogs that had mandibular rim excision. Study Design— Case series. Animals— Dogs (n=7) with a mandibular tumor at the level of the premolar and molar teeth. Methods— Using an intraoral approach to the mandible, buccal, and lingual mucosal incisions are made to obtain a 10 mm clean margin beyond neoplastic tissue. After subperiosteal soft tissue elevation, a curvilinear rim mandibulectomy is performed, leaving the mandibular canal and ventral cortex intact, followed by osteoplasty. The remaining attached gingiva and alveolar mucosa are sutured over the bony defect. Results— Seven dogs were treated (1997–2008) for odontogenic and early malignant neoplasms involving the mandible by mandibular rim excision. All dogs had healed, healthy gingival covering over the surgical defect, very good postoperative function, and good quality of life. Conclusion— Mandibular rim excision, with preservation of the ventral cortex and mandibular canal content, can be a good option for treatment of early odontogenic and malignant lesions of the mandible in medium to large breed dogs. Clinical Relevance— In medium to large dogs with minimally invasive mandibular neoplasia, mandibular rim excision should be considered as a viable surgical option.     

Area of desensitization following mental nerve block in dogs

Regional nerve blocks are commonly used to provide analgesia for dental and oral surgical procedures. The purpose of this study was to demarcate the areas of the mandible that would be desensitized by application of the mental nerve block. Seven healthy mixed-breed dogs were anesthetized for an annual dental examination and professional teeth cleaning procedure. Bupivacaine HCl (0.4 ml/ m2) was administered at one middle mental foramen based on previously described techniques for the mental nerve block. A noxious stimulus was applied at 23 predetermined ipsilateral mandibular locations using pressure from a mosquito hemostat on the mucocutaneous junction (MCJ) and a dental curette on the vestibular mucogingival line (MGL) at the incisor canine, and premolar teeth; and, the mesial and distal aspects of the first molar tooth. A thermal stimulus using a refrigerant spray on a cotton ball was applied to the ipsilateral canine, third premolar and fourth premolar teeth; and, the mesial and distal aspects of the first molar tooth. Demonstration of nociception or anesthesia was noted and the responses tabulated. The area of desensitized tissues was smaller than expected and highly variable within the study group. In conclusion, the unilateral mental nerve block does not reliably provide generalized desensitization to tissues of the incisive and rostral regions of the mandible. Although the mental nerve block is recommended, other modes of analgesia should be emphasized for surgical and dental procedures involving these areas.     

Mandible and mandibular first molar tooth measurements in dogs: relationship of radiographic height to body weight

Height measurements of the mandible and the mandibular first molar tooth were obtained from 234 dogs. Statistical analysis was performed to determine possible associations between these measurements and body weight, sex, age, and body condition. There was a statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and body weight (p < 0.0001) in all body weight groups. Small dogs had proportionally larger mandibular first molar teeth relative to mandibular height compared with larger dogs. This relationship may contribute to an increased susceptibility in small dogs for periodontitis and subsequent tooth loss. There was no statistically significant association between the mandible: mandibular first molar tooth height measurement ratio and other parameters evaluated in this study.     

Extensive bilateral odontogenic cysts in the mandible of a dog

A 5-year-old female neutered Boxer dog was diagnosed with extensive odontogenic cysts that affected the left and right mandibles. Rostral mandibular swelling was detectable clinically, and bilateral cystic mandibular lesions were identified radiographically. The dog's owners elected for euthanasia. A full postmortem was performed. Cystic cavities were confirmed in the body of each mandible, extending from the incisor teeth to the mid premolar region. Incisor, canine, and premolar tooth roots indented each cavity. Histologic examination of the cystic cavities reflected an inner lining of attenuated stratified squamous epithelium overlying a fibrous layer infiltrated by a mixed, predominantly mononuclear, inflammatory infiltrate.     

Rostral Mandibulectomy Three Case Reports in Dogs

A rostral mandibulectomy was performed on three dogs with mandibular neopiasia. The technique involves stabilization of the mandibular rami, excision of the mandible rostral to the frenulum of the tongue, and cosmetic closure of the wound. Two patients were living 11 months postoperatively. This technique is effective in treating some malignant neoplasms of the rostral mandible.     

Healing of Mandibular Body Osteotomies after Plate and Intramedullary Pin Fixation

Osteotomies were created in the left body of the mandible of nine dogs and immediately stabilized with either a six hole dynamic compression bone plate or an intramedullary pin. Cortical bone healing and vascular supply were evaluated at weeks 2, 5, and 10 by microradiography, microangiography, and correlated histology of selected mandibular slices. Perforating arterioles from the buccal mucosa maintained vascular supply to rostral mandibular segments. The mandibular body rostral to the osteotomy site and caudal to the canine tooth suffered an interruption of vascular supply that was replaced by a temporary extraosseous supply during healing of the osteotomy. Intramedullary pin placement resulted in destruction of rostral teeth. There was an inflammatory response around the rostral portion of all intramedullary pins. Osteotomy sites involving tooth roots resulted in no disruption of the normal vascular or neural structures of the tooth pulp.     

Orthodontic correction of a base narrow mandibular canine tooth in a cat

A 6-month-old cat was diagnosed with a lingually displaced mandibular canine tooth causing palatal trauma. This case report describes the correction and outcome for orthodontic movement of the left mandibular canine tooth.     

Mandibular canine tooth impaction in a young dog--treatment and subsequent eruption: a case report

Extraction of an embedded supranumerary incisor tooth and surgical exposure of the crown of an impacted left mandibular canine tooth were performed in a 5 month-old Doberman Pinscher dog. Six months following surgery, the canine tooth was fully erupted and in normal occlusion. A review of tooth eruption in the dog is provided.     

Ventral mandibulectomy for removal of oral tumours in the dog: Surgical technique and results in 19 cases

The purpose of this retrospective study is to describe in detail a novel ventral approach for mandibulectomy and the results in 19 dogs. The medical records of 19 dogs that received a partial or total unilateral mandibulectomy with the new ventral approach were reviewed. Information obtained included signalment, tumour type, extent of mandibulectomy, removal of regional lymph nodes, intrasurgical complications, immediate postoperative complications, histopathological diagnosis and study of margins. Intrasurgical complication occurred in one dog (haemorrhage) and required a blood transfusion. Postoperative morbidity was minor and included transient ventral cervical swelling and self‐limiting sublingual swelling (two dogs). All 19 animals were discharged between 24 and 48 hours of the procedure, and appetite was considered normal at discharge. Some perceived advantages of this procedure include easy identification of all the important anatomic structures in the area, including the inferior alveolar artery and temporo‐mandibular joint, and the fact that osteotomy of the zygomatic arch is not necessary (in case of caudal mandibulectomy). In addition, dissection of both mandibular and retropharyngeal lymph nodes is easily achieved by caudal extension of the same skin incision.     

Immediate mandibular reconstruction of a 5 cm defect using rhBMP-2 after partial mandibulectomy in a dog

Objective— To report treatment of a complex odontoma of the mandible by partial mandibulectomy and immediate surgical reconstruction using bridging plate fixation with a synthetic graft.
Study Design— Clinical case report.
Animals— A 4-year-old male castrated cocker spaniel.
Methods— Immediate reconstruction of the left mandible (5 cm gap) was performed after complete excision of a complex odontoma. Locking plate fixation was applied immediately before complete excision of the mass. Fixation was removed, then after partial mandibulectomy, including all abnormal tissue, restored to achieve occlusion. The resulting mandibular defect was filled with recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered in an absorbable collagen sponge containing hydroxyapatite/tricalcium phosphate granules (compression resistant matrix [CRM]).
Results— New bone growth was evident radiographically and on palpation at 3 months. Bony remodeling was evident during follow-up examinations up to 26 months. Bone collected by biopsy at the graft site at 7 months had robust new bone formation and evidence of continued remodeling. Only minor complications (repeated intraoral plate exposure) were encountered postoperatively and were easily resolved.
Conclusions— An osteoinductive factor (rhBMP-2/CRM) was successfully used as a graft substitute in immediate reconstruction of a large mandibular defect.
Clinical Relevance— Immediate reconstruction of large mandibular defects with osteoinductive materials as a graft substitute may be a viable alternative to partial mandibular resection or radiation therapy for benign odontogenic tumors in dogs.     

Mapping of the radiographic central point of feline dental resorptive lesions

Intraoral dental radiographs of 217 cats presented for dental treatment were examined. Radiographic signs of dental resorptive lesions were identified in 107 cats, and the apparent central point of each lesion was mapped on a diagram of the tooth. Mapping was only possible on maxillary and mandibular canine teeth and on mandibular third premolar, fourth premolar, and first molar teeth. Resorptive lesions were most common on the molar teeth (n = 103) and maxillary canine teeth (n = 96), and least common on fourth premolar teeth (n = 56). Resorptive lesions on premolar and molar teeth were widely scattered, noted more commonly in the coronal portions of the root. Resorptive lesions in canine teeth had a tendency to be located more apically on the roots.     

Diagnostic value of the use of lateral and occlusal radiographic views in comparison with periodontal probing for the assessment of periodontal attachment of the canine teeth in dogs

OBJECTIVE: To determine the diagnostic value of 2 intraoral bisecting angle radiographic views in comparison with periodontal probing for the assessment of periodontal attachment of the canine teeth in dogs. STUDY POPULATION: 466 canine teeth from 117 dogs. PROCEDURE: Periodontal probing measurements were recorded, and clinical attachment levels (CAL) were calculated at the mesial, buccal, distal, and lingual (or palatal) surfaces on each canine tooth. Occlusal and lateral radiographs of the canine teeth were obtained. Alveolar margin height (AMH) was measured at the same 4 surfaces. Values for AMH and CAL were compared on the basis of tooth surface, dental arch, and radiographic view. RESULTS: The AMH at the mesial and distal surfaces of the mandibular canine teeth was measurable on the lateral view and was significantly correlated with CAL. Similar results were found for the mesial and distal surfaces of the maxillary canine teeth. Buccal and lingual AMH were measured on the mandibular occlusal radiographic view, and values were significantly correlated with CAL, but only the buccal AMH could be assessed on the occlusal radiographic view of the maxilla with values that correlated significantly with CAL. CONCLUSIONS AND CLINICAL RELEVANCE: The lateral radiographic view is suitable for evaluating periodontal attachment at the mesial and distal surfaces of the canine teeth in dogs. The occlusal radiographic view is suitable for assessing buccal surfaces as well as the lingual surface of mandibular canine teeth but not the palatal surface of maxillary canine teeth in dogs.     

Interdental acrylic stabilisation of canine tooth root and mandibular fractures in a dog.

A two-year-old labrador had bilateral open fractures of the apical region of the mandibular canine tooth roots and the adjacent mandible. The fractures were reduced and held in place with an interdental acrylic splint, after which the tooth roots and mandible healed directly.     

Oral fractures in dogs of Brazil--a retrospective study

A retrospective study was performed in 100 dogs with 121 mandibular and 21 maxillary fractures. Dog fight (43.0%) and automobile (12.0%) trauma were the most common etiologies for fracture. The cause of fracture was unknown in 23.0% of the cases, while pathologic fractures occurred in 13.0% of cases. Young dogs (< 1-year-old) and dogs > 8-years of age were most affected. Mandibular fractures occurred in 90 dogs (90.0%), with two dogs (2.2%) having concurrent maxillary fractures. Maxillary fractures only were diagnosed in 10 dogs (10.0%). The molar region (47.1%) was the most commonly affected location for mandibular fracture, followed by fractures of the symphysis and parasymphysis (30.6%), premolar region (17.4%), angular process (4.1%) and vertical ramus (0.8%). In fractures of the mandibular region, the mandibular first molar tooth was often (85.9%) involved while the canine teeth were involved in 67.5% of symphyseal and parasymphyseal fractures. The most common fracture of the maxilla was the maxillary bone (52.4%), followed by the incisive (33.3%), palatine (9.5%), and nasal (4.8%) bones.     

Mandibular Fractures in the Dog A Retrospective Study of 157 Cases

One hundred fifty-seven mandibular fractures in 105 dogs occurred most frequently in male dogs less than 1 year of age. Automobile trauma was the most common cause. Fractures in the premolar region were significantly more frequent than fractures in other regions, and 113 fractures (72%) were open. One hundred forty-two fractures were stabilized, with tape muzzles being the most common method. Postoperative complications, the most common being dental malocclusion, occurred in 53 fractures (34%). Acceptable cosmetic and functional results were achieved in 89 dogs (85%). Fractures in the rostral portion of the mandible had shorter average time to clinical union than other mandibular fractures. Average time to clinical union for fractures in the caudal portions of the mandible was longer than that currently reported.     

Surgical treatment of a mandibular ameloblastic carcinoma with metastases to the mandibular lymph nodes in a pony

A 4-year-old Connemara filly was presented with a rapidly growing oral mass on the right rostrolateral mandible and a right mandibular lymphadenopathy. Radiographs of the rostral mandible revealed a lytic, infiltrative mass consistent with soft tissue and mineralised material, and displacement of tooth 403. A biopsy showed characteristic histopathological features of an ameloblastic carcinoma. Subsequent FNA of the right abnormally firm and enlarged mandibular lymph node confirmed the metastatic spread. Computed tomography of the head was performed for surgical planning, including sentinel lymph node mapping to rule out other lymph node involvement. An aggressive lesion, consistent with soft tissue of the rostral right mandible was identified with intralesional contrast injection showing drainage of contrast within the right mandibular lymph nodes (Sentinel node). Based on the infiltrative and destructive nature reported in ameloblastic carcinoma in humans, a rostral mandibulectomy was performed, along with complete mandibular lymphadenectomy. The horse recovered uneventfully from surgery. In the early post-operative period marked lymphoedema of the ventral mandibular region was observed, which resolved 4–5 days post-operatively. Optimal cosmesis was maintained post-operatively, and no recurrence has been observed to date – 12 months post-surgery.     

Mandibulectomy for treatment of fractures associated with severe periodontal disease

Six cases of mandibular fractures associated with severe periodontal disease that had been treated by mandibulectomy, due to intense bone loss, were evaluated retrospectively. The dogs were mainly older, small breed dogs that had suffered a traumatic event. Four dogs had a bilateral mandibulectomy and 2 a unilateral mandibulectomy.     

Dental Composite for the Fixation of Mandibular Fractures and Luxations in 11 Cats and 6 Dogs

Twenty-one mandibular fractures in 11 cats and 6 dogs were repaired during a 20-month period. A new technique using dental composite was used to stabilize the mandible. The canine teeth were pumiced, acid etched, and aligned with dental composite, leaving the mouth opened approximately 1 cm. Six weeks after surgery the composite was removed so that radiographs of the mandible could be made with the animal under general anesthesia. In 1 dog in which the fracture had not healed, the composite was replaced. The composite broke before 6 weeks in 8 animals; 2 required replacement of the dental composite. There were no other complications. The median time for fracture healing was 6 weeks. All fractures healed with anatomic dental occlusion. The advantages of this technique are that no further damage is caused to the teeth or to the blood supply of the bone, the occlusion is anatomic, dermatitis (which is seen with tape muzzles) is not a complication, and the technique is easy to use in brachycephalic breeds, cats, and animals with poor bone quality. The limiting factor of this technique is that it does require four salvageable canine teeth. This repair technique is still a viable option even if one or more of the canine teeth are fractured. Dental composite stabilization is fast, easy, inexpensive, and, in our series, it was 100% effective for the repair of mandibular fractures.     

Temporo-mandibular joint condylectomy and its effect over occlusion in cats: cadaveric study

Objective : To determine the effect of unilateral condylectomy on dental occlusion in cats. Methods : Twelve feline cadaver heads were randomly submitted to either a right or left unilateral condylectomy of the temporo‐mandibular joint. The distance between the mandibular and maxillary canine tooth was measured before (B0) and after the unilateral condylectomy (P0). A right or left latero‐‐lateral standardised force (4 N) was applied to the mandibular mentus area before and after the surgical procedure. These measurements were analysed with a linear model for repeated measures. Results : The comparative analysis between pre‐ and postsurgical values indicated no significant variation in teeth displacement following condylectomy between B0 and P0 measurements. Statistically significant differences were detected after either left or right condylectomy with respect to all measurements after application of the standardised forces. Occlusion changes are significant when comparing bites before and after surgery. Clinical Significance : Unilateral condylectomy causes a significant increase in latero‐lateral amplitude of jaw movement which might clinically affect feline dental occlusion. Clinical studies are required to determine the effect of unilateral condylectomies on mastication and dental occlusion in feline patients.