title: Choosing sheep (Ovis aries) as animal model for temporomandibular joint research: Morphological, histological and biomechanical characterization of the joint disc.
abstract: Preclinical trials are essential to the development of scientific technologies. Remarkable molecular and cellular research has been done using small animal models. However, significant differences exist regarding the articular behavior between these models and humans. Thus, large animal models may be more appropriate to perform trials involving the temporomandibular joint (TMJ). The aim of this work was to make a morphological (anatomic dissection and white light 3D scanning system), histological (TMJ in bloc was removed for histologic analysis) and biomechanical characterization (tension and compression tests) of sheep TMJ comparing the obtained results with human data. Results showed that sheep processus condylaris and fossa mandibularis are anatomically similar to the same human structures. TMJ disc has an elliptical perimeter, thinner in the center than in periphery. Peripheral area acts as a ring structure supporting the central zone. The disc cells display both fibroblast and chondrocyte-like morphology. Marginal area is formed by loose connective tissue, with some chondrocyte-like cells and collagen fibers in diverse orientations. Discs obtained a tensile modulus of 3.97±0.73MPa and 9.39±1.67MPa, for anteroposterior and mediolateral assessment. The TMJ discs presented a compressive modulus (E) of 446.41±5.16MPa and their maximum stress value (σmax) was 18.87±1.33MPa. Obtained results suggest that these animals should be considered as a prime model for TMJ research and procedural training. Further investigations in the field of oromaxillofacial surgery involving TMJ should consider sheep as a good animal model due to its resemblance of the same joint in humans.
authors.affiliation: Hospital de Santa Maria, Faculty of Medicine, Lisbon, Portugal. Electronic address: david.serrano.angelo@gmail.com.
authors.forename: D F
authors.initials: DF
authors.lastname: Angelo
authors.affiliation: Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, Leiria, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Morouço
authors.affiliation: Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, Leiria, Portugal.
authors.forename: N
authors.initials: N
authors.lastname: Alves
authors.affiliation: Centre for Rapid and Sustainable Product Development, Polytechnic Institute of Leiria, Leiria, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Viana
authors.affiliation: CIISA, Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Lisbon, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Santos
authors.affiliation: Infanta Cristina Hospital, Faculty of Medicina, University of Extremadura, Badajoz, Spain.
authors.forename: R
authors.initials: R
authors.lastname: González
authors.affiliation: Infanta Cristina Hospital, Faculty of Medicina, University of Extremadura, Badajoz, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Monje
authors.affiliation: Department of Anatomy, Faculty of Medicina, University of Extremadura, Badajoz, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Macias
authors.affiliation: CIISA, Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Lisbon, Portugal.
authors.forename: B
authors.initials: B
authors.lastname: Carrapiço
authors.affiliation: Hospital de Santa Maria, Faculty of Medicina, Lisbon, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Sousa
authors.affiliation: National Institute of Agrarian and Veterinary Research, Santarém, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Cavaco-Gonçalves
authors.affiliation: Hospital de Santa Maria, Faculty of Medicina, Lisbon, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Salvado
authors.affiliation: CIISA, Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Lisbon, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Peleteiro
authors.affiliation: Interdisciplinary Centre of Research in Animal Health, Faculty of Veterinary Medicine, Lisbon, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Pinho
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D019245:Compressive Strength; D004210:Dissection; D005260:Female; D021621:Imaging, Three-Dimensional; D008335:Mandibular Condyle / Q000033:anatomy & histology*; D023421:Models, Animal; D034561:Sheep, Domestic / Q000033:anatomy & histology*; D019224:Temporomandibular Joint Disc / Q000033:anatomy & histology* / Q000166:cytology / Q000000981:diagnostic imaging; D013718:Tensile Strength
keywords: Anatomie; Anatomy; Articulation temporomandibulaire; Biomechanical characterization; Biomécanique; Histologie; Histology; Mouton; Sheep; Temporomandibular joint