1 Sometimes, the larger molars cause more discomfort due to their larger surface area that can't slice through the gum tissue as an erupting incisor is capable of doing.  Most children have a complete set of 20 deciduous teeth (known as baby teeth or milk teeth) by 30 months of age.
Nociceptive, or somatic, pain is the common discomfort we have all experienced as a result of injury -- a paper cut, a broken bone, or appendicitis, among other things. Somatic pain makes sense to us; we can understand the patient's pain.
Size constancy is an aspect of perceptual constancy in which an object will appear to be the same size to an observer despite of changes in light , rotation, distance, perspective etc. This skill is so important that is appears in an infant only a couple of weeks old. Ebbinghaus illusion.