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.
Noxious stimulus. It is a prerequisite for nociception, which itself is a prerequisite for nociceptive pain. Noxious stimuli can either be mechanical (e.g. pinching or other tissue deformation), chemical (e.g. exposure to acid or irritant), or thermal (e.g. high or low temperatures).