Related Experiment Video
Updated: Apr 22, 2026

The Slice Culture Method for Following Development of Tooth Germs In Explant Culture
Published on: November 13, 2013
Primary double teeth and their effect on permanent successors
A Z Zengin1, P Celenk1, K Gunduz1
1Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, University of Ondokuz Mayis, Turkey.
Aim:
Understanding the effects of primary double tooth (PDT) on permanent successors is important to ensure healthy permanent occlusion and aesthetics. The aim of this study is to determine the prevalence and type of PDT, their effect on permanent successors, and the accompanying dental anomalies/pathologies in a Turkish population.
Materials And Methods:
Study design: The records of 63 PDTs in 54 healthy Caucasian children among 10,000 patients were investigated. PDTs were classified according to Aguilo's classification.
Results:
The prevalence of PDT was 0.6%. Of the 63 PDTs, 14.3% were type I, 11.1% were type II, 31.7% were type III, and 41.3% were type IV; one (1.6%) was a triple tooth. Aplasia of the permanent lateral incisor was observed most frequently in association with type I (56%) PDT. All PDTs associated with a supernumerary permanent tooth were type IV. Dental anomalies/pathologies such as odontoma, talon cusp were observed. Caries involvement was observed most frequently in type IV (58.3%) PDT.
Statistics:
The chi-squared test was used to determine whether successor aplasia depended on PDT type, and contingency coefficients (%) were calculated to determine the degree of association between aplasia and PDT type.
Conclusion:
Clinicians should assess PDT clinically and radiographically to determine whether they are associated with aplasia of permanent lateral incisors (type I) or supernumerary permanent teeth (type IV). Type IV of PDT should be sealed with sealant or resin.
Related Concept Videos
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Development of the Oral Microbiota
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into ...
Sutures of the Skull
Sutures are immobile joints between adjacent bones of the skull. The narrow gap between the bones is filled with dense, fibrous connective tissue that unites the bones. The long sutures located between the skull bones are not straight but instead follow irregular, tightly twisting paths. These twisting lines tightly...
Probability Laws

