Development of tooth is a very complex tangled process and here we will try to untangle it for better understanding. In the chronology of deciduous teeth, we have read that their development begins in utero, that is, in the embryo stage. Now in the embryo at about 6 weeks of age, the stomodeum or the primitive oral cavity, which will form the oral cavity in future, is lined by oral ectoderm. This oral ectoderm is a stratified squamous epithelium of 3-4 cell layer thickness with connective tissue beneath. The connective tissue is many times referred as 'ectomesenchyme' just to emphasize its origin from the Neural Crest Cells, which are ectodermal initially and later become mesodermal. At about 6 weeks of embryonic life, the basal cells of the oral ectoderm in some areas start proliferating into the underlying connective tissue. They form a continuous band of thickened epithelium called the Primary Epithelial Band. This band is formed in between the developing tongue on one side and developing cheek and lip on the other side of the stomodeum. This band is horse-shoe shaped and determines the position of the future dental arch in maxilla and mandible, which is similar in shape. At about 7th week this Primary Epithelial Band gives two sub-divisions called the Dental Lamina which helps in the initiation of tooth development and Vestibular Lamina which forms vestibule. The one on inner side or towards the tongue is the Dental Lamina. The one on the outer side is the Vestibular Lamina. The word lamina means layer or a plate. Just like the Primary Epithelial Band, both these lamina are horse-shoe shaped. The Vestibular Lamina continues to grow deep into the connective tissue. The Vestibular Lamina is also called the Lip Furrow Band, as it delineates tooth bearing areas from the lips and cheek. As the lamina continues to grow deep into the connective tissue the cells in the center continuously undergo degeneration. This helps in forming the horse shoe shaped sulcus called vestibule. Coming to our lamina of concern, the Dental Lamina. Like Vestibular Lamina, it is also a horse shoe shaped plate. The Dental Lamina shows increased cell multiplication in some areas and forms a localized thickening, or placodes, called the Enamel Organ. Dental lamina is the structure which gives rise to all the deciduous teeth. During the later part of development, as the jaw grows posteriorly the Dental Lamina gives a 'distal extension' from which the 3 permanent molars develop gradually. The development of 1st molar is initiated at 4th month of fetal age, 2nd molar at 1st year after birth and 3rd molar at 5 years of age. From the Dental Lamina, in areas of deciduous teeth development, a lingual extension develops which is called as the Successional Lamina. This Successional Lamina gives rise to the development of the 'succedaneous teeth'. That is, permanent incisors, permanent canines and permanent premolars. The development of succedaneous teeth begins between 5th month of fetal age to 10th month of age after birth. So we see, that the function of Dental Lamina can be seen till the age of 5 years as the last tooth to start its development is the 3rd molar. Once the function of Dental Lamina is over, which is the initiation of tooth development, it starts undergoing degeneration. The epithelial cells of Dental Lamina are replaced by connective tissue, so that the connection of the developing tooth and oral ectoderm breaks. But this degeneration is not complete in all areas and may leave some remnants known as Cell rests of Serres. These remnants of the Dental Lamina may be present in alveolar bone or gingiva. These rests are dormant and have no function, though they may lead to pathologies like tumors or cysts later in life. The placodes on the dental lamina called the Enamel Organ are so named as it gives rise to the enamel of the tooth. The ectomesenchyme just beneath the Enamel Organ is called Dental Papilla, it gives rise to dentin and pulp. The ectomesenchyme around the Enamel Organ and Dental Papilla is called Dental Sac or Dental Follicle which gives rise to cementum, periodontal ligament alveolar bone. All these structures together, the Enamel Organ, Dental Papilla and Dental Sac form the tooth germ. A tooth germ passes through similar stages of tooth development be it any tooth in the jaw. For better understanding, The tooth development has been divided into stages depending on the morphology of the Enamel Organ as it undergoes changes during the development. Hence, these are called as the Morphological Stages of Tooth Development. These stages are Bud stage, Cap stage, Bell stage. Bell stage is further divided into Early bell stage and Advanced bell stage.