|Classification and external resources|
Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. This condition is a type of dentin dysplasia that causes teeth to be discolored (most often a blue-gray or yellow-brown color) and translucent giving teeth an opalescent sheen. Teeth are also weaker than normal, making them prone to rapid wear, breakage, and loss. These problems can affect both primary (deciduous) teeth and permanent teeth. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Dentinogenesis imperfecta affects an estimated 1 in 6,000 to 8,000 people.
Type I: Type of dentinogenesis imperfecta with similar dental abnormalities usually an autosomal dominant trait with variable expressivity but can be recessive if the associated osteogenesis imperfecta is of recessive type.
Type II : Occurs in people without other inherited disorders (i.e. Osteogenesis imperfecta). It is an autosomal dominant trait. A few families with type II have progressive hearing loss in addition to dental abnormalities. Also called hereditary opalescent dentin.
Type III: Type is rare; its predominant characteristic is bell-shaped crowns, especially in the permanent dentition. Unlike Types I and II, it involves teeth with shell-like appearance and multiple pulp exposures.
Mutations in the DSPP gene have been identified in people with type II and type III dentinogenesis imperfecta. Type I occurs as part of osteogenesis imperfecta.
Clinical appearance is variable. However, the teeth usually involved and more severely affected are primary teeth in type I; whereas in type II both the dentitions are equally affected.
The teeth may be gray to yellowish brown. They exhibit translucent or opalescent hue. Enamel is usually lost early due to loss of scalloping at the dentoenamel junction (DEJ). However, the teeth are not more susceptible to dental caries than normal ones.
However, certain patients with dentinogenesis imperfecta will suffer from multiple periapical abscesses apparently resulting from pulpal strangulation secondary to pulpal obliteration or from pulp exposure due to extensive coronal wear. They may need apical surgery to save the involved teeth.
Type I and II show total obliteration of the pulp chamber.
Type III shows thin dentin and extremely enormous pulp chamber.These teeth are usually known as "shell teeth".
Dentinal tubules are irregular and are bigger in diameter. Areas of uncalcified matrix are seen. Sometimes odontoblasts are seen in dentin.
Preventive and restorative care are important as well as esthetics as a consideration. In most cases, full-coverage crowns are needed for esthetic appearance, as well as to prevent further attrition. Another treatment option is bonding, putting lighter enamel on the weakened enamel of the teeth and with lots of treatments of this bonding, the teeth appear whiter to the eye, but the teeth on the inside and under that cover are still the same. Due to the weakened condition of the teeth, many common cosmetic procedures such as braces and bridges are inappropriate for patients with Dentinogenesis imperfecta and are likely to cause even more damage than the situation they were intended to correct.
Dental whitening (bleaching) is contraindicated although it has been reported to lighten the color of DI teeth with some success; however, because the discoloration is caused primarily by the underlying yellow-brown dentin, this alone is unlikely to produce normal appearance in cases of significant discoloration.
- Illustrated Dental Embryology, Histology, and Anatomy, Bath-Balogh and Fehrenbach, Elsevier, 2011, page 64
- Ten Cate's Oral Histology, Nanci, Elsevier, 2013, page 15
- American Academy of Pediatric Dentistry, Guideline on Dental Management of Heritable Dental Developmental Anomalies, 2013, http://www.aapd.org/media/Policies_Guidelines/G_OHCHeritable.pdf
This article incorporates public domain text from The U.S. National Library of Medicine