- Donate
- Understanding Rare Disease
- Living with a Rare Disease
- Community Support
- Advancing Research
- Driving Policy
- Get Involved
- Rare Disease News
- Resource Library
- About Us
- For Clinicians & Researchers
- For Patient Organizations
Last updated: March 31, 2008
Years published: 1988, 1989, 1998, 2005
Dentin dysplasia type I is an inherited disorder characterized by atypical development of the โdentinโ of a personโs teeth. Dentin makes up most of the tooth and is the bone-like material under the enamel. It serves to contain the pulp of the tooth. The pulp is a soft tissue that is well supplied with blood vessels and nerves. This disorder is also known as radicular dentin dysplasia because the underdeveloped, abnormal pulp tissue is predominately in the roots of the teeth. The teeth lack pulp chambers or have half-moon shaped pulp chambers in short or abnormally shaped roots. The condition may affect juvenile as well as adult teeth and, since the roots are abnormally short, usually leads to the premature loss of teeth. The color of the teeth is usually normal.
Some people with dentin dysplasia type I have teeth with a bluish-brown shine. In most instances, however, the teeth have normally colored enamel. It is clear from X-ray photos that the tooth pulp chambers in the roots are unusually small, half-moon shaped or lacking altogether. The roots are very short and may appear to be dark (radiolucent) on X-rays.
Both the baby teeth and the permanent teeth are affected. The teeth are often poorly aligned and can be chipped easily. Without treatment, persons with dentin dysplasia type I may lose their teeth by age 30-40.
Dentin dysplasia is inherited as an autosomal dominant trait. The defective gene has not been identified or traced to a particular site on a particular chromosome.
Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated โpโ and a long arm designated โqโ. Chromosomes are further sub-divided into many bands that are numbered. For example, โchromosome 11p13โ refers to band 13 on the short arm of chromosome 11. The numbered bands specify the location of the thousands of genes that are present on each chromosome.
Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.
Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.
Recessive genetic disorders occur when an individual inherits the same abnormal gene for the same trait from each parent. If an individual receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the defective gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier like the parents is 50% with each pregnancy. The chance for a child to receive normal genes from both parents and be genetically normal for that particular trait is 25%. The risk is the same for males and females.
All individuals carry 4-5 abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.
Dentin dysplasia type I appears to affect about 1 in 100,000 persons. Males and females are apparently equally at risk.
Diagnosis is usually based on x-rays taken when some abnormality is suspected.
Treatment
The affected teeth are usually treated by a dentist specializing in the care o. the roots and pulp of the teeth (endodontists). Filling the tips of the root canals may extend the period of time that the affected teeth remain fixed to the jaw. Sometimes, the affected teeth must be extracted and replaced with dentures.
Genetic counseling is recommended for families of children with dentin dysplasia type I.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government website.
For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
TEXTBOOK
Brenneise CV. Dentin Dysplasia. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:176-77.
JOURNAL ARTICLES
Hegde M, Hegde ND. Dentin dysplasia โ A case report. Endontol. 2004;16:16-18.
Seymen F, Akinci T. Dentinal Dysplasia Type I: Report of a case. Eur J Paediatr Dent. 2000;1:Abstract 71.
Leccisotti S, Eramo S, Palatella P, et al. Dentin dysplasia type I. Report of a case and ultrastructural study. Minerva Stomatol. 1998;47:545-51.
Brenneise CV, Dwornick RM, Benneise EE. Clinical radiographic and histological manifestations of dentin dysplasia, type I: report of a case. J Am Dent Assoc. 1989;119:721-23.
Witkop CJ Jr. Amelogenesis imperfecta, dentinogenesis imperfecta and dentition dysplasia revisited: problems in classification. J Oral Pathol. 1988;17:547-53.
Petrone JA, Noble ER. Dentin dysplasia type I: a clinical report. J Am Dent Assoc. 1981;103:891-93.
FROM THE INTERNET
McKusick VA, ed. Online Mendelian Inheritance In Man (OMIM). The Johns Hopkins University. Dentin Dysplasia, Type I. Entry Number; 125400: Last Edit Date; 3/18/2004.
McKusick VA, ed. Online Mendelian Inheritance In Man (OMIM). The Johns Hopkins University. Dentin Dysplasia, Type II. Entry Number; 125420: Last Edit Date; 2/3/2004.
McKusick VA, ed. Online Mendelian Inheritance In Man (OMIM). The Johns Hopkins University. Dentin Dysplasia with Sclerotic Bones. Entry Number; 125440: Last Edit Date; 3/18/2004.
Sedano HO. Abnormalities in Structure of Teeth. Oral Pathology I (DS482A). nd. 9pp.
www.dent.ucla.edu/2001/Lecture2.htm
Sedano HO. Premature Loss of Teeth. Periodontics Information Center. ยฉ1998. 4pp.
www.dent.ucla.edu/ftp/pic/visitors/Teethloss/page1.html
How exactly are various parts of the body affected by ED syndromes and what treatments are available? Teeth. National Foundation for Ectodermal Dysplasia. NFED. nd. 2pp.
www.nfed.org/FAQ.htm
NORD strives to open new assistance programs as funding allows. If we donโt have a program for you now, please continue to check back with us.
NORD and MedicAlert Foundation have teamed up on a new program to provide protection to rare disease patients in emergency situations.
Learn more https://rarediseases.org/patient-assistance-programs/medicalert-assistance-program/Ensuring that patients and caregivers are armed with the tools they need to live their best lives while managing their rare condition is a vital part of NORDโs mission.
Learn more https://rarediseases.org/patient-assistance-programs/rare-disease-educational-support/This first-of-its-kind assistance program is designed for caregivers of a child or adult diagnosed with a rare disorder.
Learn more https://rarediseases.org/patient-assistance-programs/caregiver-respite/The information provided on this page is for informational purposes only. The National Organization for Rare Disorders (NORD) does not endorse the information presented. The content has been gathered in partnership with the MONDO Disease Ontology. Please consult with a healthcare professional for medical advice and treatment.
The Genetic and Rare Diseases Information Center (GARD) has information and resources for patients, caregivers, and families that may be helpful before and after diagnosis of this condition. GARD is a program of the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health (NIH).
View reportOrphanet has a summary about this condition that may include information on the diagnosis, care, and treatment as well as other resources. Some of the information and resources are available in languages other than English. The summary may include medical terms, so we encourage you to share and discuss this information with your doctor. Orphanet is the French National Institute for Health and Medical Research and the Health Programme of the European Union.
View reportOnline Mendelian Inheritance In Man (OMIM) has a summary of published research about this condition and includes references from the medical literature. The summary contains medical and scientific terms, so we encourage you to share and discuss this information with your doctor. OMIM is authored and edited at the McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine.
View report
Your donation will help more than 30 million Americans with a rare disease navigate their diagnosis, receive financial assistance, and access the care and support they deserve. Make your tax-deductible gift today!