Types of Dentitions


Monophyodont Presence of only one set of dentition for entire life. 
• Presence of two sets of dentition 
• Human beings are diphyodonts 
Polyphyodont Presence of more than two sets of dentition. 
All the teeth have same shape without distinction such as incisors, canines, premolars and molars. 
Heterodont Presence of different groups of teeth. 
• Primitive type of teeth seen in primates like cats, dogs, etc. 
• Contains simple conical cusps. 
• Seen in reptiles like crocodiles. 
• Simplest cone form of teeth with single root.
• Only simple hinge movements of jaws are seen. 
• Seen in early mammals. 
• Three cusps are arranged in line with the largest cusp in the center.
Tritubercular stage
• Three cusps are arranged in triangle form.  
Quadritubercular stage
• 4th cusp is formed and an occlusal contact relationship between the upper and lower 
jaws is established. 

Except molars, all the permanent teeth (incisors, canines and premolars) are known as succedaneous teeth because they take the place of their primary predecessors.

Permanent molars are not succedaneous teeth, as they develop from the distal extension of the dental
lamina. Successional lamina, which is present on the  lingual side of primary dental lamina, is absent for permanent molars.

Tooth attachment can be of two types :
a) Ankylosis or direct attachment of tooth to bone.
Pleurodont: Tooth attached to inner margins of  bone.
Acrodont: Tooth is attached to crest of bone.

b) Attachment of tooth to bone socket.
Gomphosis: The tooth is attached to bony socket through periodontal membrane, which allows only limited movement.

• Thecodont: The tooth is attached by periodontal membrane and it does not undergone significant

The first primary tooth to erupt into oral cavity is  mandibular central incisors. The first permanent tooth  to erupt into oral cavity is mandibular 1st molar.