Use of a synthetic bone substitute to retard molariform tooth drift after maxillary tooth loss in ponies

OBJECTIVE: To evaluate the effect of alveolar bone substitute on post-extraction drift of maxillary cheek teeth in ponies. STUDY DESIGN: In vivo longitudinal experimental study. ANIMALS: Five ponies (5-7 years) with a healthy dentition. METHODS: Both maxillary 4th premolar teeth (Triadan 08) were surgically removed. One alveolus was filled with a biocompatible non-resorbable bone substitute (Bioplant 24), whereas the other healed by second intention. A polyvinylsiloxane plug and spring wire isolated the bone substitute from the oral environment. Pathologic changes to dentition and adjacent soft tissue were recorded. Tooth drift was calculated after 1 and 2 years. RESULTS: At 1 month, bone substitute material was incorporated into healthy tissue. Tooth drift was observed but differed significantly between control and treated sides at 2 years (P<.01). For both techniques, tooth drift differed significantly between years 1 and 2 (P<.001). Total drift in control arcades for year 1 was 10.69+/-2.12 mm and for year 2 was 9.08+/-0.87 mm, whereas for bone substitute arcades it was 9.90+/-1.60 mm for year 1 and 5.60+/-1.78 mm for year 2. CONCLUSIONS: Partial tooth replacement therapy after maxillary P4 extraction provided good healing in the immediate post-surgical phase. Alveolar filling with bone substitute material significantly slowed post-extraction tooth drift but did not stop it completely. Clinical Relevance- Important changes occur in equine dentition after maxillary cheek teeth removal. Further longer term observations are needed to fully validate study findings.     

Radiographic evaluation of tooth drift after cheek tooth extraction and insertion of an intra-alveolar prosthesis in ponies

The aim of the study was to investigate post-extraction tooth drift in ponies and the influence of an intra-alveolar prosthesis. The maxillary 08 was bilaterally repulsed in five ponies under general anaesthesia. On one side the alveolus was left to granulate, and on the other a synthetic bone substitute prosthesis was fitted. Standard radiographic projections of the head were taken monthly during the first year and at 24 months post-operatively. Different cephalometric parameters were measured and statistically analyzed. Rostral and caudal drift were recognized in molar and premolar teeth, respectively. The prosthesis significantly slowed down tooth drift (P<0.001). Although differences in the degree of secondary mandibular overgrowths (on 06s, 11s and 08s) were found between treatments, this had no important clinical consequences. Premolars showed significantly more tooth wear in comparison with molars (P<0.001). Tooth attrition was higher in the prosthesis treated sides (P<0.001).     

Histologic and micro-computed tomographic evaluation of the osseointegration of a nonresorbable bone substitute in alveoli of ponies after tooth extraction

OBJECTIVE: To evaluate the biological behavior of a nonresorbable bone substitute (NRBS) in the alveoli of ponies, compared with tissue quality in naturally healing alveoli, after cheek tooth extraction. ANIMALS: 5 clinically normal ponies. PROCEDURES: In each pony, both maxillary fourth premolars (Triadan 108/208) were repulsed bilaterally during anesthesia. One randomly chosen alveolus was filled with NRBS and isolated from the oral cavity by use of dental impression material and a spring-wire retention device. The other alveolus was occluded in its occlusal third portion with dental impression material. One year after surgery, cylindrical lateromedial biopsy specimens were collected from the apical, middle, and occlusal level of each alveolus. Biopsy samples were evaluated for bone mineral density and bone volume via micro-computed tomography; qualitative histologic characteristics were evaluated via light microscopy. RESULTS: Bone mineral density and bone volume were greater in control alveoli, compared with NRBS-treated alveoli. Control alveoli were characterized by the presence of few mature bone trabeculae and wide spaces containing fat tissue and mesenchymal stroma. In treated alveoli, biocompatibility and osteoconductive properties of the NRBS were excellent; continuous bone formation and bone remodeling were also evident. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the NRBS was integrated well in calcified alveolar tissues in ponies 1 year after maxillary cheek tooth extraction. Further research is necessary to establish the benefits of this NRBS in the development of a dental implant surgical technique in equids.     

Structure of peripheral cementum of normal equine cheek teeth

The structure of peripheral cementum of mandibular and maxillary cheek teeth was studied by gross observation, light microscopy, and scanning and transmission electron microscopy. Teeth from four horses aged 4, 8, 17, and 30-years-old were examined. The cementum of the occlusal surface was thicker on the buccal aspect when compared with the lingual aspect of mandibular teeth. The cementum of the occlusal surface was thicker on the palatal aspect when compared with the buccal aspect of maxillary teeth. There was no peripheral cementum on the interdental aspects of either mandibular or maxillary cheek teeth. In the adult tooth, cementum covered the crown and root surfaces. The peripheral cementum of the gingival region showed a dramatic increase in thickness compared with cementum covering the alveolar portion of the embedded tooth. At a microscopic level, three layers (primary, secondary, and tertiary) were identified within cementum. The increase in cementum in the gingival region was of tertiary cementum. All three layers contained vital cementocytes. There was a well-developed vascular system within the cementum. Nerve bundles were also present. Three cementoblast profiles were identified at the junction of the cementum with the periodontal ligament. The results reported in this paper show that cementum is a dynamic vital tissue. These findings should contribute to a greater understanding of the etiology and pathogenesis of cemental caries and periodontal disease in the horse.     

Bilateral maxillary periodontal ligament hamartoma in a dog

A 12.5-year-old dog was presented for severe periodontal disease and bilateral maxillary enlargement. Radiographs of the maxilla showedgeneralized root resorption, ankylosis, and rarefaction of bone with focal radiodense areas. Surgical tooth extraction of multiple maxillary teeth and bilateral incisional biopsies of the periodontal tissue and maxilla in the region of the maxillary fourth premolars were performed. Histopathologic examination showed features typical of fully differentiated periodontal ligament with abundant cementum/alveolar lining bone and sparce odontogenic epithelial cell rests. Histopathology in conjunction with radiographic and clinical signs suggested a diagnosis of bilateral periodontal ligament hamartoma. Examination 3-months postoperatively indicated uncomplicated healing of the extraction and biopsy sites with no resolution of the maxillary enlargement.     

Equine dental disease part 2: a long-term study of 400 cases: disorders of development and eruption and variations in position of the cheek teeth

Of 400 referred horses with dental disorders, 349 cases suffered from primary disorders of their cheek teeth, ninety of these from disorders of development or eruption, or displacements. These included 20 cases with rostral maxillary and caudal mandibular cheek teeth overgrowths, 16 with diastemata, 15 with grossly enlarged mandibular 'eruption cysts', 4 with grossly enlarged maxillary cheek teeth 'eruption cysts', 10 cases with supernumerary cheek teeth and 23 cases with displaced cheek teeth. These displacements were believed to be developmental in 16 cases and acquired in the remaining 7 cases. Long-term response to treatments, that included removal of overgrowths and extraction of teeth with deep secondary periodontal disease was excellent for most disorders except diastemata.     

Repair of experimental plaque-induced periodontal disease in dogs

Forty mongrel dogs were used in this study for induction of periodontal disease by placing subgingival silk ligatures affecting maxillary and mandibular premolar teeth during a 12-month period. Experimental premolar teeth received monthly clinical, radiographic, and histometric/pathologic assessments. The results demonstrated significant increases in scores and values of periodontal disease parameters associated with variable degrees of alveolar bone loss. The experimental maxillary premolar teeth exhibited more severe and rapid rates of periodontal disease compared with mandibular premolar teeth. Histometric analysis showed significant reduction in free and attached gingiva of the experimental teeth. Histopathological examination of buccolingual sections from experimental premolar teeth showed the presence of rete pegs within the sulcular epithelium with acanthosis and erosive changes, widening of the periodontal ligament, and alveolar bone resorption. Various methods for periodontal repair were studied in 194 experimental premolar teeth exhibiting different degrees of periodontal disease. The treatment plan comprised non-surgical (teeth scaling, root planing, and oral hygiene) and surgical methods (closed gingival curettage, modified Widman flap, and reconstructive surgery using autogenous bone marrow graft and canine amniotic membrane). The initial non-surgical treatment resulted in a periodontal recovery rate of 37.6% and was found effective for treatment of early periodontal disease based on resolution of gingivitis and reduction of periodontal probing depths. Surgical treatment by closed gingival curettage to eliminate the diseased pocket lining resulted in a recovery rate of 48.8% and proved effective in substantially reducing deep periodontal pockets. Open root planing following flap elevation resulted in a recovery rate of 85.4% and was effective for deep and refractory periodontal pockets. Autogenous bone graft implantation combined with canine amniotic membrane as a biodegradable membrane was used in 18 premolar teeth and failed to improve advanced furcation defects in most teeth.     

Measurement of clinical crown length of incisor and premolar teeth in clinically healthy rabbits

The clinical crown length of rabbit teeth has not been well documented. The aim of this study was to determine the clinical crown length of incisor and cheek teeth, and the periodontal probing depth in young healthy rabbits without clinical signs of dental disease. Two groups of 20 male rabbits were measured, the first in 2007 and the second in 2008/2009. The measurements were taken with rabbits under general anesthesia using a periodontal probe. The average crown length (mm) of the mandibular third and fourth premolar, and maxillary second premolar teeth was 3.1 +/- 0.4, 2.6 +/- 0.4, and 1.5 +/- 0.4, respectively. The periodontal probing depth for the cheek teeth in the maxilla and the mandible was very similar (0.5 - 1.0-mm). There was a minor difference in the average crown length (mm) of the mandibular (6.4 +/- 0.6) and maxillary (6.1 +/- 0.9) incisor teeth. The periodontal probing depth (mm) was different when comparing maxillary (2.2 +/- 0.4) and mandibular (5.1 +/- 0.8) incisor teeth. The divergence in tooth length in individual rabbits and between the two groups was minimal. Measuring the crown length of the rostral cheek and incisor teeth with a periodontalprobe is easy to do in the rabbit and should be integrated into the clinical examination. The measurement results of this study can be used as a reference when trimming teeth.     

Immunohistochemical identification of lymphatic vessels in the periodontium of equine cheek teeth

Immunohistochemical detection of lymphatic capillaries was performed in the periodontium of maxillary and mandibular cheek teeth from 6 horses (aged 3-23 years). Tissue sections of the periodontium were taken at 4 different horizontal levels along the long axis of the tooth. The specimens were processed for immunoreaction with anti-Prox1, in order to distinguish lymphatic endothelium from blood vascular endothelium. Lymphatic vessels were detected in all periodontal tissues except for the dental cementum. Lymphatic capillaries were most densely distributed in the gingiva compared to other tissues of the periodontium. Lymphatic capillaries were found most consistently in samples taken from the gingival and subgingival regions in all horses examined. Within these levels, the gingiva as well as the spongiosa of the maxillary and mandibular bone had the greatest incidence of lymphatic vessels. Considering the distinct distribution of the lymphatic capillaries in the periodontium of the maxillary and mandibular cheek teeth, two complementary lymphatic drainage pathways are proposed: (1) superficial lymph drainage via the gingiva, emptying into the mandibular lymph nodes; (2) deep lymph drainage via the mandibular and maxillary spongiosa, emptying into the mandibular and retropharyngeal lymph nodes, respectively.     

Relationship between diet, dental calculus and periodontal disease in domestic and feral cats in Australia

Objective To compare the dental calculus scores and prevalence of periodontal disease in domestic cats eating commercially available canned and dry foods with those in feral cats consuming a diet consisting of small mammals, birds, reptiles and insects.
Animals Twenty-nine feral cats and 20 domestic cats were included in the study.
Procedure A dental chart and dental calculus scores were recorded using the maxillary canine, maxillary third and fourth premolar, mandibular canine, mandibular fourth premolar and first molar teeth on both sides. Periodontal disease was recorded using gingival recession, increased periodontal pocket formation, radiographic alveolar bone loss, osteomyelitis, furcation and root exposure, and the presence of calculus as indicators.
Results Dental calculus scores were significantly higher in domestic cats than in feral cats. There was no statistical difference in the prevalence of periodontal disease between the two groups.
Conclusion It can be inferred that diet may play a role in the accumulation of calculus, but a diet based on live prey does not protect cats against periodontal disease.     

Repair of a gingival cleft associated with a maxillary canine tooth in a dog

This case report describes repair of a gingival cleft located on the labial aspect of the maxillary left canine tooth in a client-owned dog. Multiple procedures were performed including elevation of a pedicle flap, granulation tissue removal, alveoloplasty and root planing, and placement of an osteoconductive bone graft material. The surgical site was closed with a laterally repositioned flap. Postoperative examinations were performed at 2 and 3-weeks without chemical restraint and at 3 and 10-months postoperatively under general anesthesia. At the 10-month postoperative examination, a broad band of gingiva surrounded the maxillary left canine tooth, and probing revealed absence of periodontal pockets. Intraoral dental radiographs indicated maintenance of alveolar bone height and incorporation of the bone graft material into alveolar bone.     

Quantitative and qualitative assessments of intraoral lesions in 180 small herbivorous mammals

Between 2002 and 2005 210 rabbits, 257 guinea pigs and 123 chinchillas were examined; oral disease was diagnosed in 38.1 per cent of the rabbits, 23.4 per cent of the guinea pigs and 32.5 per cent of the chinchillas. In the rabbits, the maxillary right P3, mandibular right P3, P4 and M1 and mandibular left P3, P4, and M1 were the teeth most frequently affected; in the guinea pigs, the mandibular right P4 and both the mandibular left incisor and P4 were most often affected; and in the chinchillas the maxillary right P4 and M1 and maxillary left P4 were most often affected. The incisors and first mandibular cheek teeth of the guinea pigs were significantly more often affected than those in the chinchillas or rabbits. Bilateral lesions of the maxillary cheek teeth were significantly more common in the chinchillas. The highest incidence of gingival hyperplasia was recorded in the rabbits. The incidence of gingival erosions and gingivitis were significantly higher in the chinchillas.     

Polyodontia in donkeys

Polyodontia is defined as the presence of teeth in excess of the normal dental formula. In equids, supernumerary teeth are uncommon but, when present, are usually located mainly in the caudal aspects of the cheek teeth rows (distomolars), also being found adjacent to normal cheek teeth or even in an ectopic location. It is believed that this disorder is a result of an inappropriate differentiation of dental germinal tissue during gestational development, with external trauma also acting as an initiating factor, when teeth germs are affected. The presence of these abnormal teeth can lead to axial displacement, dental overgrowths, dental‐related soft tissue damage, diastemata formation, periodontal disease and development of secondary sinusitis. A large prospective, cross‐sectional study was performed in 800 donkeys, with the aim to investigate the prevalence and aetiopathogenesis of clinically diagnosed oral and dental disorders. Polyodontia was recorded in 2.25% of the donkeys, presenting 36 supernumerary teeth, with 2.80% being incisors and 97.20% cheek teeth, with prevalence increasing with age. The caudal aspects of the maxillary cheek teeth rows were the most common locations for supernumerary teeth development (distomolars). The mandible was far less commonly affected than the maxilla. Although polyodontia is uncommon in donkeys, it should be considered in the differential diagnosis of dental disease. A methodical oral examination and a complete radiographic survey of the entire dental arcades are crucial for a correct early diagnosis and treatment plan implementation. The increasing prevalence of fully erupted supernumerary teeth recorded in older groups suggested a late onset eruption process, and therefore, in donkeys undergoing regular dental prophylaxis, the presence of previously unnoticed supernumerary teeth should always be sought.     

Transmaxillary anchored silicon embedded gauze plug in the post-operative treatment of a large oromaxillary fistula caused by a supernumerary cheek tooth

A 9-year-old Hungarian sport horse gelding was presented to the clinic in poor condition displaying malodorous bilateral purulent nasal discharge. Oral examination revealed the presence of supernumerary 111 and 211. Bilateral diastema formation between the third maxillary molars and the supernumerary teeth with deep periodontal pockets and massive food impactions were diagnosed endoscopically. Radiography revealed inhomogenous sinus opacities in the left and right paranasal sinuses. Following bilateral oral extractions of the supernumerary cheek teeth and third maxillary molars, bilateral oromaxillary fistula formations were diagnosed (about 17 mm diameter on the right side). Bilateral frontal and right-sided maxillary trephinations and resection of the right bulla of the maxillary septum were performed. Massive food impactions of the left and right paranasal sinuses were removed under endoscopic control. Repeated trans-endoscopic sinus lavage was performed post-operatively. After 2.5 months, the large right-sided oromaxillary communication was temporarily closed with a transmaxillary anchored, gauze-cored silicon plug on an outpatient basis. Follow-up examination after 187 days revealed complete closure of the oromaxillary fistula and absence of sinusitis. In a 1.5-year follow-up control, no pathological conditions were found.     

The relationship of maxillary cheek tooth development to age in young Friesian cattle.

Radiographs were taken of both the right and left sets of maxillary teeth in 23 Friesian cattle of known age. The stage of development of each permanent tooth was ascertained and the degree of root resorption in the deciduous premolars was noted. All stages in individuals were later than for those of the mandibular cheek teeth except in the case of the first permanent premolar. As with mandibular cheek tooth development stages of formation occurred within certain age limits.     

Finite element analysis in 3-D models of equine cheek teeth

Periodontal diseases occur frequently in equine dentistry and excessive strain in biological tissues is assumed to be a predisposing factor in their development. Finite element (FE) analysis enables strains and stresses occurring in the periodontium to be calculated and is a useful tool for testing this hypothesis. The current study aimed to establish reliable 3-D models from equine maxillary and mandibular cheek teeth for use in FE simulations, with particular attention to the detailed construction of the periodontal ligament (PDL). Age-related morphological aspects of the teeth and the periodontium were also considered by constructing different models for three defined age groups. Finally, the biomechanical behaviour of the equine PDL was examined during experimental tooth intrusion (i.e. axial displacement of the tooth into its alveolar socket). The results showed an increase in intrusion with increasing age due to age-related changes in the periodontal elastic properties. The general stress level in PDL and surrounding bone also increased with age. Reliable FE models were established to calculate aetiologically relevant biomechanical effects occurring in the equine periodontium.     

Maxillary dentigerous cyst in a cat

A dentigerous cyst was diagnosed in the right rostral maxilla of a 6-month-old Siamese cat affecting the maxillary right canine tooth. The deciduous maxillary right canine tooth was extracted and the dentigerous cyst wall was curetted. The permanent tooth was not removed, however it was mobile following the surgical procedure. Examination 6-months following surgery indicated appropriate development of the tooth with no mobility or periodontal pocket formation. The maxillary right canine tooth had an abnormal shape but was functional with an acceptable appearance.     

Occlusal angles of cheek teeth in normal horses and horses with dental disease

The angle between the occlusal surface of the tooth and the horizontal plane of 687 cheek teeth from the skulls of 22 horses without gross dental disorders and 11 horses with dental disorders were measured by using stiff malleable wire as an imprint. Each measurement was repeated five times and the mean angle was recorded. In the normal skulls, the mean occlusal angles of the mandibular cheek teeth ranged from 19.2 degrees at the Triadan 06 position to 30 degrees at the 11 position, and these angles were significantly greater than the occlusal angles of the opposing maxillary cheek teeth (range 12.5 degrees to 18 degrees) at all the positions except the 06. The rostral mandibular cheek teeth had significantly lower occlusal angles than the caudal mandibular cheek teeth, but the converse was true for the maxillary teeth. In the skulls with dental disorders the occlusal angles of the mandibular cheek teeth ranged from 15.6 degrees to 28.5 degrees , and of the maxillary cheek teeth from 9.2 degrees to 16.4 degrees. They were not significantly different from the angles of the teeth from the normal skulls, except at the 06 position, where they were smaller.     

Dental diastemata and periodontal disease secondary to axially rotated maxillary cheek teeth in three horses

Malerupted axially rotated maxillary cheek teeth (CT) were identified as the primary cause of diastemata and severe periodontitis in 3 horses. Diastema widening and periodontal debridement was performed initially in one case but did not resolve clinical signs. Subsequently, all 3 cases underwent extraction of the axially rotated teeth per os without complication. Follow‐up indicated remission of periodontitis and signs of oral pain. In these cases, maxillary CT had erupted in a manner that resulted in axial rotation of CT with undulating buccal and palatal surfaces aligned with the interproximal surfaces of adjacent normally orientated teeth. This resulted in poor interproximal compression and diastemata causing severe periodontitis. Axially rotated maxillary CT and the severe periodontitis that they precipitate, have not been previously described as a discrete dental disease entity.     

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.