Introduction: Bisphosphonates have shown promise in reducing fractures in children with osteogenesis imperfecta (OI). To date, the effects of these drugs on the growing craniofacial skeleton have not been investigated.
Methods: To address this, alendronate (ALN) was evaluated in the growing oim/oim mouse, a model of moderate-to-severe OI. Wildtype (+/+) and oim/oim mice received saline solution or ALN at a dosage of 26 IJg ALN per kilogram per day from 6 to 12 weeks of age. Skulls (n = 49) were scanned at 12 weeks with microCT to create 3-dimensional reconstructions. Cranial and mandibular landmarks were digitized, and statistical shape analysis methods compared cranial and mandibular sizes and shapes between the groups. Back-scattered electron imaging of the spheno-occipital synchondrosis evaluated drug effects on bone quality.
Results and Conclusions: The oim/oim mice exhibited significant skull dysmorphology with parallels to human OI. The antiresorptive activity of ALN does not appear to compromise craniofacial growth. ALN treatment normalized FM morphology in oim/oim mice through improvements in skull bone quality.