Related Experiment Video
Updated: Jun 7, 2026
10:23
Three-Dimensional Cephalometric Landmark Annotation Demonstration on Human Cone Beam Computed Tomography Scans
Published on: September 8, 2023
Correlation between genotype and supernumerary tooth formation in cleidocranial dysplasia
1Maxillofacial Orthognathics, Department of Maxillofacial Reconstruction and Function, Division of Maxillofacial/Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. n-suda.mort@tmd.ac.jp
Orthodontics & Craniofacial Research
|November 3, 2010
Summary
Cleidocranial dysplasia (CCD) is linked to RUNX2 gene mutations. However, supernumerary tooth formation in CCD patients shows wide variation, even among those with identical mutations, suggesting other factors are involved.
Area of Science:
- Genetics
- Developmental Biology
- Oral Health
Background:
- Cleidocranial dysplasia (CCD) is a genetic disorder affecting bone development, primarily characterized by clavicular hypoplasia, patent fontanelles, and short stature.
- Dental anomalies, including supernumerary teeth and delayed eruption, are common in CCD patients.
- Previous research indicated significant intrafamilial variability in supernumerary tooth formation associated with RUNX2 mutations.
Purpose of the Study:
- To investigate the correlation between RUNX2 gene mutations and the manifestation of supernumerary tooth formation in Japanese individuals with CCD.
- To further clarify the genetic and potentially non-genetic factors influencing dental anomalies in CCD.
Main Methods:
- Genetic mutational analysis of the RUNX2 gene was performed on nine Japanese CCD patients.
- Detailed dental and skeletal examinations, including radiographic analysis, were conducted for all participants.
Main Results:
- Four distinct RUNX2 mutations were identified, including one novel mutation. Four individuals carried the R225Q mutation, and three siblings had the P224S mutation.
- Significant variability in supernumerary tooth formation was observed among individuals with the same RUNX2 mutation.
- Discordance in supernumerary tooth formation was noted even in monozygotic twins, and asymmetry was observed in over half of the participants.
Conclusions:
- The genotype (RUNX2 mutations) alone does not fully explain the variation in supernumerary tooth formation in CCD.
- Environmental factors, epigenetic influences, and copy number variations likely play a significant role in regulating supernumerary tooth development in individuals with CCD.
Related Concept Videos
01:15Teeth
The formation of teeth, also known as odontogenesis, is a complex process that begins in utero, around the sixth week of embryonic development. There are three stages to this process: the bud stage, the cap stage, and the bell stage.
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 and...
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 and...
01:33Pleiotropy
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
01:21Tooth Anatomy
The human tooth enables us to eat a variety of foods, speak clearly, and even aid in shaping our faces. Teeth are composed of various elements that work together. Here's a detailed look at the anatomy of a human tooth.
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 grinding food.
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 grinding food.
01:51Determination
During embryogenesis, cells become progressively committed to different fates through a two-step process: specification followed by determination. Specification is demonstrated by removing a segment of an early embryo, “neutrally” culturing the tissue in vitro—for example, in a petri dish with simple medium—and then observing the derivatives. If the cultured region gives rise to cell types that it would normally generate in the embryo, this means that it is specified. In contrast, determination...
01:29Nondisjunction
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
01:43Incomplete Dominance
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.