title: Experimental surgical and orthodontic extrusion of teeth in dogs.
abstract: The purpose of this study was to evaluate histologically the root surfaces of teeth submitted to orthodontic and surgical extrusion procedures in a dog model. Eighteen adult male dogs, divided into six groups of three dogs each, were used in the study. Each animal underwent two procedures: rapid orthodontic extrusion and surgical extrusion of the maxillary lateral incisors. The animals were sacrificed to produce samples at 7, 14, 45, 90, 120, and 180 days after surgery for assessment of cross sections of the coronal, medial, and apical thirds of the treated teeth. At early time points, some active surface and inflammatory resorption was observed exclusively in the surgical extrusion group; however, samples collected at later times demonstrated functional repair of the resorption gaps in both groups. Ankylosis was observed as a minor event and was apparently of a transient nature in samples of the surgical extrusion group. The results demonstrate the importance of maintaining the periodontal ligament and cementum surface; both are vital for the prevention of root resorption. It may be postulated that orthodontic extrusion is more conservative and physiologic than surgical extrusion; however, the results showed that function was restored in both groups.
authors.affiliation: Department of Periodontology, Pontifical Catholic University of Parana, School of Dentistry, Curitiba, Brazil. sung.kim@pucpr.br
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Vinicius Augusto
authors.initials: VA
authors.lastname: Tramontina
authors.forename: Cassiana Maria
authors.initials: CM
authors.lastname: Ramos
authors.forename: Antonia Maria Binder do
authors.initials: AM
authors.lastname: Prado
authors.forename: Euloir
authors.initials: E
authors.lastname: Passanezi
authors.forename: Sebastiao Luiz Aguiar
authors.initials: SL
authors.lastname: Greghi
mesh_terms: D000818:Animals; D016556:Crown Lengthening / Q000009:adverse effects*; D003739:Dental Cementum / Q000502:physiology; D003799:Dental Stress Analysis; D004285:Dogs; D007180:Incisor / Q000601:surgery; D008297:Male; D050793:Orthodontic Extrusion; D010513:Periodontal Ligament / Q000502:physiology; D012391:Root Resorption / Q000209:etiology*; D014092:Tooth Root / Q000473:pathology; D019553:Tooth, Nonvital; D014945:Wound Healing / Q000502:physiology