The most constant and valuable trait to differentiate among maxillary first second and third molars is the depth of central fossae

During eruption of permanent teeth, alveolar bone is resorbed and deposited intermittently

The primary teeth begin to form in utero at about six weeks. Hard tissue formation occurs in all primary teeth by the 18th week in utero. 3. The permanent teeth begin to develop at approximately four months of age in utero. Maxillary and mandibular first molars begin to calcify at birth.

The smallest and most inaccessible root canal-in the maxillary second molar is the distobuccal

madibular first molar normally have 3 root canals