Allogeneic tooth transplantation in the dog

Allogeneic tooth transplantation was evaluated as a functional and aesthetic treatment for dental fracture in the dog. Of 7 dogs that received tooth transplants, 5 were research animals and 2 were clinical patients. Canine teeth were transplanted immediately after extraction in the research dogs. Endodontic therapy had been performed on the affected canine tooth of one clinical patient. The other clinical patient had bilateral maxillary canine fractures 2 months earlier. One of the research dog transplants failed at 3 weeks as a result of improper surgical technique. Four of the research dogs had a solid implant for 18 months, after which time the dogs were euthanatized serially. All transplanted teeth were anchored firmly into the alveoli, but were nonviable. Root resorption, with bone replacement, was first noticed at 24 months. The transplanted tooth in the first clinical patient remained functional for 3 months, after which time the tooth was fractured. The right canine transplant in the second clinical patient failed by 3 months, probably because of preexisting periapical inflammation. The left transplanted tooth remains stable at 38 months. It was concluded that allogeneic tooth transplantation may have merit as a rapid and inexpensive method for replacement of fractured teeth in the dog. Function is compromised gradually as a result of root resorption and ankylosis, with tooth fracture likely to occur after 2 years.     

Regional anesthesia of the infraorbital and inferior alveolar nerves during noninvasive tooth pulp stimulation in halothane-anesthetized cats

OBJECTIVE: To determine whether anesthesia of the infraorbital and inferior alveolar nerves abolishes reflex-evoked muscle action potentials (REMP) during tooth-pulp stimulation in halothane-anesthetized cats. ANIMALS: 8 healthy adult cats. PROCEDURE: In halothane-anesthetized cats, an anodal electrode was attached to the tooth to be stimulated and a platinum needle cathodal electrode was inserted in adjacent gingival mucosa. Cathodal and anodal electrodes were moved to the upper and lower canine, upper fourth premolar, and lower first molar teeth for stimulation; baseline REMP was recorded. A 25-gauge 1-cm needle was inserted 0.5 cm into the infraorbital canal. A 25-gauge 1-cm needle was inserted 1 cm rostral to the angular process of the ramus, and advanced 0.5 cm along the medial aspect. Chloroprocaine was injected at each site. Each tooth was stimulated every 10 minutes for 90 minutes. RESULTS: REMP was abolished within 10 minutes for all upper teeth, except for the upper canine tooth in 1 cat, and abolished within 10 minutes for lower teeth in 4 cats. In 1 cat, REMP was not abolished in the lower first molar tooth. In 3 cats, REMP was not abolished in the lower canine and first molar teeth. At 90 minutes, REMP was restored for all teeth except the lower canine tooth in 1 cat, for which REMP was restored at 120 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Regional anesthesia of the infraorbital and inferior alveolar nerves may provide dental analgesia in cats.     

Influence of an interdental full pin on stability of an acrylic external fixator for rostral mandibular fractures in dogs

OBJECTIVE: To determine total stiffness and gap stiffness of an external fixation system in a canine mandibular fracture gap model incorporating a full interdental pin as the only point of rostral fixation in a bilateral type-I external fixator. SAMPLE POPULATION: 10 canine mandibles. PROCEDURE: Bilateral mandibular ostectomies were performed between premolars 3 and 4. A type-I external fixator incorporating a full interdental pin was placed to stabilize a 0.5-cm fracture gap. Four pin configurations (intact mandibular bodies with fixator; ostectomized mandibular bodies and complete fixator; ostectomized mandibular bodies with caudal pins of rostral fragment cut; ostectomized mandibular bodies with all pins of rostral fragment cut) were tested in dorsoventral bending 5 times on each mandible. The full interdental pin remained intact in all configurations. Total stiffness and gap stiffness were determined for each configuration on a materials testing machine. RESULTS: Total stiffness of intact mandibles was significantly greater than that of ostectomized mandibles, regardless of external fixator configuration. However, total stiffness and gap stiffness were not significantly different among different external fixator configurations applied to ostectomized mandibles. CONCLUSION AND CLINICAL RELEVANCE: External fixator configurations with only the full interdental pin engaging the rostral fragment were as stiff as configurations that had 2 or 4 additional pins in the rostral fragment for the applied loads. External fixators for rostral mandibular fractures may be rigidly secured with rostral fragment implants applied extracortically, avoiding iatrogenic trauma to teeth and tooth roots.     

Tooth resorption in the Swedish Eurasion lynx (Lynx lynx)

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 free-ranging 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.     

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.     

Lip avulsion and mandibular symphyseal separation repair in an immature cat

A 12-week-old kitten was presented for symphyseal separation, comminuted rostral fractures of the mandibles, avulsion of the mandibular lip, andfractured 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.     

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.     

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.     

Equine odontoclastic tooth resorption and hypercementosis

Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a progressive and painful disease syndrome that affects aged horses. It affects incisor, canine and infrequently cheek teeth, and is characterised by gingival inflammation, oedema and recession, calculus deposition, feed accumulation, subgingival swellings with or without associated draining tracts, bulbous enlargement of teeth, tooth mobility, associated periodontal disease, tooth fracture and/or tooth loss. The aetiology of EOTRH is likely to be multi‐factorial. However, histopathological findings consistently suggest an aetiological contribution of initial biomechanical stresses and strains, followed by secondary involvement of micro‐organisms. Diagnosis is based on clinical presentation, age and radiographic changes including lytic changes, widening or loss of the periodontal ligament, hypercementosis, tooth fracture and alveolar bone loss. Treatment of EOTRH is not currently possible, but the condition can be managed to some degree, quite successfully for many years in some cases. However, the disease is progressive and invariably results in extraction of the tooth or teeth involved. The prognosis is most probably guarded at best and poor in most cases; however, complete removal of affected teeth carries a good prognosis for an improved quality of life in the short to medium term.     

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.     

Extraction techniques for equine incisor and canine teeth

Extraction of equine incisor and canine teeth is a vital part of equine dentistry. Although dental pathology involving the incisor and canine teeth is less common, the practitioner should be prepared to diagnose conditions and develop a treatment plan. Depending on the pathology revealed via oral examination and intraoral radiographs, the treatment plan may include either simple (nonsurgical) or surgical extraction of an incisor or canine tooth. Technique and instrumentation refinement over the last 20 years has led to more precise extraction procedures with reduced secondary trauma to healthy tissues. As a result, incisor and canine extraction procedures are more predictable in execution and quality, with minimal complications.     

Complications of mandibular brachygnathism in a North African leopard

A 9-year-old, male North African leopard (Panhtera pardus) presented with mandibular brachygnathism and lingually displaced mandibular canine teeth causing a large left oronasal fistula, rhinitis and nasal discharge, and a right orocutaneous fistula. Surgical closure of the left oronasal defect, bilateral mandibular canine tooth crown reduction, and root canal therapy resulted in a positive clinical outcome. A small recurrent left oronasal fistula and the right orocutaneous fistula healed spontaneously after alleviating the occlusal contact with the mandibular canine teeth. At 12-months postoperatively, clinical signs of oral and dental disease had resolved.     

Extraction of 22 equine cheek teeth with displaced sagittal fractures using polymethylmethacrylate stabilisation (2011–2016)

Displaced sagittal cheek tooth fractures are a cause of oral pain, quidding and apical infection. Intraoral extraction is the preferred technique to remove affected teeth, but can be difficult due to displaced and friable fracture fragments. Stabilising fracture fragments via filling of the fracture space with polymethymethacrylate (PMMA) prior to removal may be a useful method to facilitate intraoral extraction. Case details were examined retrospectively. A total of 22 cheek teeth required extraction in 20 horses because of displaced sagittal fractures. Clinical diagnoses were made using oral examination, oral endoscopy, skull radiography and computed tomography. All procedures were performed in standing, sedated horses in stocks. Fracture spaces were cleaned and packed with PMMA and teeth removed using a routine intraoral extraction technique. Digital photographs of extracted teeth were taken and tooth measurements calibrated using digital image software. Intraoperative difficulties, as well as post-operative complications were recorded. A total of 21 maxillary and one mandibular cheek teeth were extracted. All maxillary teeth had advanced infundibular caries. Intraoral extraction was successful in 16 cases; six were unsuccessful and required repulsion due to tooth fragmentation or abnormal dental anatomy. In 11 cases, maxillary or conchofrontal sinus trephination was performed to either treat sinusitis, repulse the tooth, or both. Two horses developed short-term complications following local anaesthesia of the maxillary nerve. The mean ratio of fracture depth to tooth length was 0.59 and mean ratio of fracture width to tooth width 0.53. The limitations of the study are its small sample size, retrospective nature and lack of control group to compare extraction success in PMMA and non-PMMA groups. It was concluded that using PMMA to stabilise displaced sagittal fractures in equine cheek teeth is a simple, effective method of facilitating intraoral extraction and may reduce the need for more invasive procedures.     

Significant association between tooth extrusion and tooth resorption in domestic cats

Abnormal extrusion of canine teeth is often noted in middle-aged and geriatric domestic cats. The same age group of cats also is commonly affected by tooth resorption (TR). This study explored the relationship between these two phenomena of unknown etiology. Using digital radiography, the distance between the alveolar margin (AM) and cementoenamel junction (CEJ), referred to as the AM-CEJ distance, was measured in clinically and radiographically healthy maxillary canine teeth of 24 TR-affected and 29 TR-free cats. The mean AM-CEJ distance of maxillary canine teeth of cats with and cats without TR was 2.68-mm and 2.22-mm, respectively. An analysis of covariance adjusting for age revealed a significant correlation (p = 0.02) between tooth extrusion and TR. Extrusion of the maxillary canine teeth became clinically apparent when an AM-CEJ distance of 2.5-mm or greater was evident in the absence of horizontal or vertical alveolar bone loss. Based on this criterion, 15 of 24 cats with TR (63.0 %) exhibited extrusion of maxillary canine teeth, compared to 9 of 29 cats without TR (31.0 %). Four extruded and five non-extruded maxillary canine teeth were evaluated histologically. Cementum of extruded teeth was significantly thicker compared to that of non-extruded teeth. Four of 4 canine teeth with extrusion (100 %) showed histological evidence of resorption, compared to 1 of 5 canine teeth without extrusion (20.0 %). These results suggest that tooth extrusion is linked to or may be caused by similar factors responsible for the development of TR.     

A retrospective study of dental conditions of captive brown bears (Ursus arctos spp.) compared with free-ranging Alaskan grizzlies (Ursus arctos horribilis).

The teeth of 63 skulls of brown bears (Ursus arctos spp.) that had lived in the Bernese bear pit between 1850 and 1995 were examined and radiographed for occlusion, loss of teeth, calcified dental plaque and calculus, attrition, and caries. Dental pathology and periodontal status were evaluated with respect to age and location in the dentition. Further techniques such as computed tomography, microhardness testing, histologic sectioning, and scanning electron microscopy were used in selected cases to verify the macroscopic and radiographic diagnoses. Fourteen skulls originating from free-ranging wild Alaskan brown bears (Ursus arctos horribilis) were examined as a control group. For zoo bears over 10 yr old, severe enamel and dentinal attrition has been observed in canine teeth, with exposed pulp and proximal lesions in molar teeth. Deposits of calcified dental calculus were found in various locations and increased with age. A much lower degree of calculus deposition was found in the Alaskan grizzlies, whose average caries frequency was higher but with large individual variation and different locations in canine teeth and occlusal lesions in molar and premolar teeth. Radiographic evaluation of perialveolar osteolytic processes revealed a greater frequency of apical and combined apical-marginal lesions of the alveoli in zoo bears over 10 yr old. Stereotypical behavior like cage chewing is a suspected cause of canine tooth and secondary alveolar lesions, whereas a nutritionally inappropriate diet and inadequate opportunities for tooth-cleaning activities are responsible for the lack of natural cleaning and the extensive calculus formation that results. The methods used in this study are useful in assessing and comparing the dental health status of free-ranging bears, and those living in zoological gardens, by evaluating anesthetized bears or bear skull collections representing both groups.     

Equine odontoclastic tooth resorption and hypercementosis

A poorly described, painful disorder of incisor and canine teeth, variably causing periodontitis, with resorptive or proliferative changes of the calcified dental tissues, has recently been documented in aged horses. No plausible aetiopathogenesis for this syndrome has been recorded. Eighteen diseased teeth from eight horses were examined grossly and microscopically and showed the presence of odontoclastic cells by tartrate resistant acid phosphatase (TRAP) staining. A chronological sequence of odontoclastic resorption followed by hypercementosis was demonstrated and, consequently, the term equine odontoclastic tooth resorption and hypercementosis (EOTRH) is proposed for this disorder. EOTRH shares many features with similar dental syndromes described in humans and cats. An aetiological hypothesis proposes mechanical stress of the periodontal ligament as the initiating factor.     

Dental bulge restoration and gingival collar expansion after endodontic treatment of a complicated maxillary fourth premolar crown-root fracture in a dog

This case report describes endodontic, restorative, and periodontal treatment of a complicated crown-root fracture of the right maxillary fourth premolar tooth in a dog. A buccal portion ('slab') had separated from the tooth, which extended subgingivally into root structure. Following completion of standard root canal therapy, a periodontal flap was elevated. Alveolectomy and alveoloplasty were performed, and inflamed soft tissues were debrided. The fracture site was prepared, restored, and shaped to receive a dental bulge contour. A gingival collar expansion technique was utilized to allow for apical positioning of gingiva at the distobuccal crown-root segment. Clinical and radiographic examination 15-months following treatment showed no evidence of endodontic failure. The restorations were intact, and periodontal probing depths were slightly increased probably due to gingival enlargement from concurrent cyclosporine therapy. The importance of biologic width maintenance in periodontal surgery and need for owner compliance with home oral hygiene are discussed.     

Oral endoscopy as an aid to diagnosis of equine cheek tooth infections in the absence of gross oral pathological changes: 17 cases

Reasons for performing study: Removal of cheek teeth in all but the aged horse or pony is a serious undertaking with potentially deleterious sequellae. Rigid endoscopy permits detailed examination of the oral cavity and erupted dental tissues and has the potential to assist in the correct identification of the diseased tooth. Objectives: To document oral endoscopic findings associated with infected equine cheek teeth in cases without gross oral pathological changes and thereby determine the usefulness of rigid oral endoscopy as an aid to diagnosis of such infections. Methods: Records of all cases of equine cheek tooth removal attempted under standing sedation over a 38 month period were examined. Cases were excluded from the study if apical infection was associated with gross dental fracture, malalignment, diastema/periodontal pocketing or supernumerary teeth. Endoscopic and radiographic findings were analysed and correlated to diseased tooth location. Results: Seventeen cases of apical dental infection fitting the inclusion criteria (nonresponsive to antibiotics and with no gross oral abnormality of the affected arcade) were identified in which oral endoscopy was used as an aid to diagnosis. In 15 (88%) of the 17 cases, oral endoscopy revealed abnormalities specific to the infected tooth. Focal gingival recession (10/17 cases) was the most common visible abnormality associated with infected teeth. Conclusions: In the majority of cases of apical infection of equine cheek teeth there is visible intraoral evidence implicating the affected tooth. Potential relevance: Oral endoscopy facilitates detailed examination of the mouth and should be considered along with radiography as an important aid to diagnosis in cases of equine dental infection.     

Treatment of traumatic dental displacement in dogs: six cases of lateral luxation

In dogs and cats, the most common causes of dental injury are fights with other animals, car accidents, falls from a height, and chewing on hard materials such as bones or rocks. The trauma more often causes fracture of the teeth, but sometimes avulsion or luxation can occur. Avulsion is the complete displacement of the tooth out of the alveolar socket and luxation is the partial displacement of the tooth. Tooth luxation and avulsion represent dental emergencies. Time is an important factor for successful treatment; the prognosis becomes poorer the longer the tooth is out of the socket. This paper describes the guidelines for treatment of dental displacement in cats and dogs and presents six cases of dental lateral luxation in dogs seen at the Veterinary Hospital of the University of Pennsylvania (VHUP) in the period from May 1996 to September 1997.     

Determining the age of cats by pulp cavity/tooth width ratio using dental radiography

The purpose of this study was to evaluate the effect of age on the ratio of pulp cavity/tooth width (P/T ratio) in healthy cats. The dental radiographs of 32 cats (16 males and 16 females) were generated with a digital dental X-ray unit with the animals under general anesthesia. Standardized measurement of the canine teeth was performed by drawing a line on the radiograph perpendicular to the cementoenamel junction (CEJ) of the tooth. There was an inversely proportional correlation between chronological age and the P/T ratio. Moreover, a strong Pearson squared correlation (γ² = 0.92) was identified by the curved regression model. No significant differences in the P/T ratio based on gender or breed were found. These results suggest that determination of age by P/T ratio could be clinically useful for estimating the chronological age of cats.