Effects of the condylar process fracture on facial symmetry in rats submitted to protein undernutrition

Abstract

PURPOSE: To investigate the facial symmetry of rats submitted to experimental mandibular condyle fracture and with protein undernutrition (8% of protein) by means of cephalometric measurements. METHODS: Forty-five adult Wistar rats were distributed in three groups: fracture group, submitted to condylar fracture with no changes in diet; undernourished fracture group, submitted to hypoproteic diet and condylar fracture; undernourished group, kept until the end of experiment, without condylar fracture. Displaced fractures of the right condyle were induced under general anesthesia. The specimens were submitted to axial radiographic incidence, and cephalometric mensurations were made using a computer system. The values obtained were subjected to statistical analyses among the groups and between the sides in each group. RESULTS: There was significative decrease of the values of serum proteins and albumin in the undernourished fracture group. There was deviation of the median line of the mandible relative to the median line of the maxilla, significative to undernutrition fracture group, as well as asymmetry of the maxilla and mandible, in special in the final period of experiment. CONCLUSION: The mandibular condyle fracture in rats with proteic undernutrition induced an asymmetry of the mandible, also leading to consequences in the maxilla.

Effects of temporal muscle detachment and coronoidotomy on facial growth in young rats

“…The possibility of maxillary growth influencing mandibular growth and vice versa by occlusal intercuspation has been described. 1,16 Occlusal disturbances have been described as the main cause of asymmetry of the maxilla after experimental fractures 17 and as a complication of condylar fractures. 18 Cephalometric evaluations based on radiographs of the skulls and hemimandibles of dissected specimens using a computerized system lead to reliable measurements.…”

Facial symmetry evaluation after experimentally displaced condylar process fracture in methotrexate treated rats

“…Distances found were similar to those noted in other experiments 5,28,29 . In the cephalometric evaluation it was possible to measure linear distances, and also the mandibular deviation, by measuring the angles α and  3,5,9,30,31 . From an experimental model, only cautious conclusions can be drawn concerning human subjects.…”

“…There was a tendency towards deviation of the mandible to the fracture side 9 . However, there was significance only in MTX high dose group, indicating negative effects on the fracture repair.…”

“…However, there is some concern regarding skeletal changes, represented by mandibular asymmetry [7][8][9] .…”

“…The experimental model of condylar fracture, unilateral and medially displaced, allows the histological study of healing of fracture and articular sites 3,6 , as well as allows cephalometric analyses of their effects on facial structures 5,9 . This model follows the most frequent form of mandibular condyle fracture 1,2,10 .…”