Roentgen stereophotogrammetric analysis of growth at cranial value sutures in the rabbit

Biometric characterization of rabbit cranial vault bone separation was attempted to further elucidate sutural growth mechanisms. The internasal and frontonasal sutures, connected to the facial skeleton, were also investigated. 17 male New Zealand white rabbits were studied from age 4 to 21 weeks using roentgen stereophotogrammetry with tantalum implants. A uniform cranial growth pattern with successively decreasing rates was observed, as were different growth rates at the neurocranial bones relative to those of the facial skeleton. Anteroposterior length increase was due mainly to bone separation at the frontonasal suture. Growth at the sagittal suture was minimal. Minor rate fluctuations and compensatory rebounds after periods of reduced growth were continuously observable. Small left-right differences within each individual were registered. Oscillations in growth rate across adjacent sutural areas and occasional negative growth values imply that bone separation at sutures demonstrates an alternating pattern of translations and rotations. The experimental data demonstrated the plasticity and variability of normal cranial vault growth.