Craniofacial Growth Of Streptozotocin-induced Diabetes mellitus In Rat

Objectives:  The understanding of craniofacial growth is important in the practice of clinical orthodontics. This may have a considerable impact on diagnosis, treatment goals, treatment planning and the eventual outcome of orthodontic treatment. The goal of this study was to assess the effect of Type 1 diabetes mellitus (T1DM) on the craniofacial growth and skeletal maturation using the Streptozotocin diabetic rat model (STZ-DM rat model).  Methods: Experimental T1DM was induced in 3-week old male Wistar rats by a single dose of 60mg/Kg body weight of streptozotocin (STZ). Body weights, the presence of glucose in urine and blood glucose levels were recorded on day 0,2,7,14,21 and 28 after STZ injection. Lateral and dorsoventral X-rays of the head were taken at the age of 7-weeks. Prior to each radiographic session, each animal was anesthetized and then placed in a specially-designed apparatus to maintain standardized head posture and contact with the film. The X-rays were scanned, digitized and selected angles and linear distances of neurocranium, viscerocranium and mandible were measured and analyzed statistically.  Results: DM group showed a significant decrease in weight. After STZ injection by 48 hours the urine test showed that the entire DM group had a high glucose level and this was confirmed by the high blood glucose measurements. In STZ-DM statistical cephalometric analysis revealed a reduction in neurocranium, viscerocranium and mandibular growth manifested by significant changes in the angular and linear measurements (P‹0.05).  Conclusion: T1DM reduces craniofacial growth, resulting in retardation of all skeletal development. These findings should be considered when orthodontic problems are diagnosed and treated in T1DM. A better understanding of how diabetes affects bone will improve our ability to protect bone health during orthodontic treatment in diabetic patients.