May 24, 2021
The human teeth is made up of two layers of hard tissues that protect an underlying soft tissue that houses the blood vessels and nerves of the teeth. The two hard tissues are the enamel and dentin whereas the soft tissue is the pulp. The enamel is the outermost and a highly mineralized covering of the teeth. The dentin is sandwiched between the enamel and pulp. Apart from being a hard tissue that gives strength to the teeth, the dentin also is a centre that contains nerve endings. If a tooth is subject to decay, then it progresses faster in the dentin since it is less mineralized compared to enamel and has a porous structure.
The dentin consists of dentinal tubules arranged in fixed directions. These tubules contain nerve endings that cause sensitivity if contacted with a noxious stimuli. The dentin is also responsible for the color of the teeth. A defect in dentin changes the translucency of the teeth and thus the shade changes. Thus, the dentin plays a key role in pain sensation, teeth strength and esthetics of the teeth.
During the development of teeth, due to genetic reasons, the formation of dentin is improper or may not take place at all. This condition is called dentinogenesis imperfecta (DI). Although most of its cases are of genetic origin, DI can happen in patients with metabolic disorders that hinders calcification or mineralization of the tissues. The repercussions of not having dentin can cause severe oral health problems.
Firstly, the color of the teeth can be anywhere between brownish to greyish. This can directly affect the appearance of the patient. Social development and quality of life thus becomes compromised.
Secondly, since the dentinal layer is obliterated multiple teeth are decayed. The decayed quickly reaches the pulp and is capable of producing multiple infectious lesions under the affected teeth. These infections are diagnosed on a radiograph. Teeth appear in the shape of a shell and the roots are deficient in structure. The pulp appears larger than normal with the affected teeth abruptly constricting towards rhe underlying bone.
Sensitivity issues are common in patients with DI. The internal strength of the teeth is compromised. This leads to the teeth getting weared off and its layers getting chipped off at regular intervals. These issues are commonly seen in both deciduous and permanent teeth. The most commonly affected region in the oral cavity is the lower front teeth area. Hearing loss and blue sclera are often associated with DI. The condition often presents in patients with a short height.
DI is also seen with other disorders called osteogenesis imperfecta (OI) where the growth of the bone is compromised. The condition of teeth is further deteriorated in this condition. The teeth are mobile in most cases and need to be extracted. Any treatment procedure needs to be carried out with extreme caution in such patients.
The treatment of DI involves restoring the teeth with biocompatible dental materials. The restoration can be done with cements or crowns can be placed on the affected teeth. The cements can give internal strength whereas the crowns help teeth in regaining their functional efficacy. The restorations also help in increasing the height of the face vertically as the bite increases too. In cases where pulp is infected, root canal treatment is often indicated in order to cease and remove the infection from the teeth. Areas with loss of multiple teeth may require a bridge. In later stages of life, if the bone condition is good, DI patients can be given dental implants. In terms of aesthetics, bleaching of teeth with DI should not be done as the main cause of discoloration is due to the absence of dentinal layer. Restoration with tooth-colored materials is preferred instead.
Dentinogenesis Imperfecta is a serious condition that needs to be addressed to retain the esthetics and function of the oral cavity. The treatments can also help in establishing proper speech of the patient. Ever since its discovery in 1882, DI poses a challenge for both the patient and the dentist. In kids, it needs to be treated at the earliest. This is because untreated milk teeth can affect the development of the future permanent teeth. DI is thus a serious disorder that needs to be intervened into the moment it is recognized.