Oral and maxillofacial osteosarcoma in dogs: a review

Osteosarcoma in dogs is a heterogeneous disease entity with regard to its histologic, clinical and biologic behaviour. Differences in behaviour are associated with tumour location. Oral and maxillofacial osteosarcomas are typically reported as a component of the broader classifications of axial osteosarcoma or osteosarcoma of flat bones to differentiate them from appendicular osteosarcoma. Similar to human oral and maxillofacial osteosarcoma, in dogs, these also appear to have less aggressive behaviour than appendicular osteosarcoma. Ideally, local control is achieved with wide surgical resection that results in tumour‐free margins. Failure of local control is the most common contributor to poor prognosis. Chemotherapy and radiation treatment are reported to have variable outcomes. The aim of this article is to review the literature on oral and maxillofacial osteosarcoma in dogs in comparison to appendicular and axial osteosarcoma. Similarities and differences between oral and maxillofacial osteosarcoma in humans are addressed.     

Use of an external fixator to correct a wry nose in a yearling

Wry nose is a rare condition. The resultant deviation of the nasal septum and maxilla/premaxilla often complicates deglutition and respiration. Traditional treatment consists of internal fixation with pins after an osteotomy and a rib graft. A 17‐month‐old Arab yearling was presented for evaluation of deviation of the maxilla and nasal septum. This deviation was managed using an external fixation device after bilateral osteotomy of the maxilla/premaxilla and reduction of the deviation. Partial resection of the nasal septum by a dorsal approach was also performed. The dental malocclusion and respiratory noise were corrected.     

一例哈利犬牙结石的诊治分析

牙结石是成年犬门诊较为常见的一种口腔疾病,它是由牙菌斑和牙垢钙化后沉积在牙齿表面引起。牙结石是龋齿、牙周炎、溃疡性口炎、牙龈炎和齿髓炎等多种口腔疾病的主要诱因。本文通过对一例哈利犬的牙结石病例的诊治分析及经验总结,以期为宠物门诊常见疾病之牙结石的临床诊断、治疗和预防提供参考。     

Donkey dental anatomy. Part 2: Histological and scanning electron microscopic examinations

Ten normal cheek teeth (CT) were extracted at post mortem from donkeys that died or were euthanased for humane reasons. Decalcified histology was performed on three sections (sub-occlusal, mid-tooth and pre-apical) of each tooth, and undecalcified histology undertaken on sub-occlusal sections of the same teeth. The normal histological anatomy of primary, regular and irregular secondary dentine was found to be similar to that of the horse, with no tertiary dentine present. Undecalcified histology demonstrated the normal enamel histology, including the presence of enamel spindles. Scanning electron microscopy was performed on mid-tooth sections of five maxillary CT, five mandibular CT and two incisors. The ultrastructural anatomy of primary and secondary dentine, and equine enamel types-1, -2 and -3 (as described in horses) were identified in donkey teeth. Histological and ultrastructural donkey dental anatomy was found to be very similar to equine dental anatomy with only a few quantitative differences observed.     

Pathological studies of cheek teeth apical infections in the horse. 1: Normal endodontic anatomy and dentinal structure of equine cheek teeth

Morphological examinations were performed on 100 normal equine cheek teeth (CT) of 1–12 years dental age (i.e. time since eruption), using gross examination, dissection microscopy, computerised axial tomography, and decalcified and undecalcified histology. The CT in Triadan 07–10 positions consistently had five pulp horns, but the 06 CT had an additional pulp horn more rostrally. Mandibular and maxillary Triadan 11s had six and seven pulp horns, respectively. Sections of CT taken 2–6 mm below the occlusal surface (variation due to normal undulating occlusal surface) showed the presence of pulp in up to 50% of individual maxillary CT pulp horns, and in up to 25% of individual mandibular CT pulp horns. The histological appearances of primary and secondary dentine were described and it is proposed that the type of dentine present most centrally in every pulp chamber examined, currently termed tertiary dentine, should be re-classified as irregular secondary dentine, and that the term tertiary dentine be reserved for the focal areas of dentine laid down following insult to dentine or pulp.     

细胞凋亡在牙齿发育中的研究进展

细胞凋亡是多细胞生物调节机体发育,维护内环境稳态,由基因控制的细胞主动死亡的一种生理性过程。细胞凋亡在牙齿发育中有重要的调控作用,参与了牙上皮与间充质的相互作用。牙齿发育中的细胞凋亡是在特定时空发生的由一系列基因严格调控的程序化过程。本文主要介绍牙齿发育中的细胞凋亡及其相关凋亡因子的研究进展。     

Clinical dental findings in 203 working donkeys in Mexico

Clinical dental examinations of 203 unsedated working donkeys in tropical and temperate climatic areas in Mexico revealed a high prevalence (62%) of dental disease with sharp enamel points present in 98% of the animals. More significant dental disorders (diastemata, 4%; overgrown teeth, 18%; worn teeth, 16%; missing teeth, 0.5%; displaced teeth, 1.5%; fractured teeth, 2%) with welfare implications that required immediate treatment were also present in 18% of donkeys.The high prevalence of buccal ulcers (14.3%) and calluses (13.3%) present in this population was believed to be due to the high prevalence of sharp enamel points in conjunction with the use of tight nose bands and head collars. Dental disease was significantly associated with age groups, but not with body condition score or to the climatic area where the donkeys lived. As part of more general examinations, 81% of donkeys that had faecal egg counts performed, had parasite burdens which mainly showed a moderate level of infection. This study concluded that dental disease is a welfare concern in working donkeys in Mexico.