<prompt> Coronal suture completely fuses by the age of:20yrs.30 yrs.40 yrs.45 yrs.  <response>: Actually Coronal suture completely fuses by 50-60 years, but the maximum age given in this question is 45 years and hence the answer. Age from Skull Sutures- Two halves of mandible unite at- 2 years. Metopic suture 2 halves of frontal bone closes at: 3 years. Coronal, Sagittal, Lambdoid sutures sta to close on inner side at- 25 years. On outer side, fusion occurs in the following order- 1 Posterior 13rd sagittal suture- 30-40 yrs. 2 Anterior 13rd sagittal suture lower 12 of coronal suture- 40-50 yrs. 3 Middle 13rd sagittal suture upper 12 coronal suture- 50-60 yrs. Sutures on inner side close- 5-10 years earlier than outer side. For viewing X-rays, lateral view is preferable and the most successful estimation is done from sagittal suture, next lambdoid and then coronal. Lapsed union occurs commonly in sagittal suture failure of ectrocranial suture closure. 