Imaging Department, Langford Vets, Small Animal Referral Hospital, Bristol, UK.
Imaging Department, The University of Glasgow Small Animal Hospital, Glasgow, UK.
J Vet Dent. 2024 Mar;41(2):137-147. doi: 10.1177/08987564231171529. Epub 2023 Apr 27.
Temporomandibular joint (TMJ) incongruity and morphological variations can result in clinical signs but have also been reported in asymptomatic brachycephalic dogs. The purpose of this study was to assess TMJ morphology in a group of brachycephalic dogs using computed tomography (CT). French Bulldogs, English Bulldogs, Boxers, Cavalier King Charles Spaniels (CKCS), Chihuahuas, Lhasa Apsos, Pugs, Shih Tzus, and Staffordshire Bull Terriers were retrospectively enrolled. The severity of the TMJ morphological changes was determined using a modified 5-grade classification system. The intra- and inter-observer agreements were calculated. One hundred fifty-three dogs were included. When evaluating the medial aspect of the TMJ in the sagittal plane, there was a spectrum of variations in the shape of the head of the condylar process of the mandible, the mandibular fossa and the retroarticular process ranging from a rounded concave TMJ with a long retroarticular process to a flattened TMJ with an absent process. Variations in the articular surface of the head of the condyle in the transverse plane ranged from flat, through curved and trapezoid to sigmoid. The prevalence of severe TMJ dysplasia (grades B3 and C) in the CKCS and French Bulldog was high (69.2% and 53.8%, respectively). The intra- and inter-observer agreements were moderate. Variations in TMJ morphology exist in asymptomatic brachycephalic dogs. Marked changes seem to be highly prevalent in the French Bulldog and CKCS and should be considered a breed variation. The TMJ classification described in this study could be used to standardize assessment of canine TMJ morphology. However, further research is needed to determine its clinical application.
颞下颌关节（TMJ）不调和形态学变异可导致临床症状，但也有报道称在无症状短头犬中存在。本研究的目的是使用计算机断层扫描（CT）评估一组短头犬的 TMJ 形态。回顾性纳入法国斗牛犬、英国斗牛犬、拳击犬、骑士查理王小猎犬、吉娃娃犬、拉萨阿普索犬、哈巴狗犬、西施犬和斯塔福郡斗牛梗犬。使用改良的 5 级分类系统确定 TMJ 形态变化的严重程度。计算了观察者内和观察者间的一致性。共纳入 153 只犬。在评估矢状位 TMJ 的内侧时，下颌髁突的头部、下颌窝和关节后突的形状存在从圆形凹面 TMJ 伴长关节后突到扁平 TMJ 伴无关节后突的一系列变化。在横断面上，髁突头部的关节面变化范围从平坦、弯曲到梯形到 S 形。在骑士查理王小猎犬和法国斗牛犬中，严重 TMJ 发育不良（B3 和 C 级）的患病率很高（分别为 69.2%和 53.8%）。观察者内和观察者间的一致性为中度。无症状短头犬存在 TMJ 形态学变异。在法国斗牛犬和骑士查理王小猎犬中，明显的变化似乎非常普遍，应被视为一种品种变异。本研究中描述的 TMJ 分类可用于标准化犬 TMJ 形态的评估。然而，需要进一步的研究来确定其临床应用。
