Dentinogenesis imperfecta is a hereditary defect in the development of dentin. With type 1 of the disease, the teeth acquire a gray color, the shape of the crowns is more often within the normal range, pathological erasability is observed. Children complain of increased bleeding of the gums, the appearance of tooth mobility. In type 2, amber-colored teeth are detected with progressive enamel erasure, resulting in dentin hyperesthesia. Diagnostics includes anamnesis collection, clinical examination, radiography, EDI. If there are indications, endodontic treatment is carried out with subsequent coating of teeth with crowns. With the loss of several teeth, the integrity of the dentition is restored with the help of removable dentures.
Dentinogenesis imperfecta (hereditary opalescence of dentin) is a genetically determined disease that occurs due to a violation of the laying of mesodermal germ tissue (or mesodermal and ectodermal in Stanton-Capdepon syndrome). In 50% of cases, type 1 dentinogenesis imperfecta is combined with osteogenesis imperfecta. The main type of inheritance is autosomal dominant. The frequency of diagnosis of type 1 dentinogenesis imperfecta is 1:50,000. The disease is more often detected in males. Both temporary and permanent teeth can be affected, but in a temporary bite, dentinogenesis imperfecta is detected more often.
Type 2 dentinogenesis imperfecta is transmitted by an autosomal dominant pathway with complete penetrance. It is the most common form of the disease, the frequency of occurrence in the population is 1:8000. Temporary and permanent teeth are affected equally. The disease was described in 1892 by Stanton, 13 years later in 1905 by Capdepon. Disease of type 3 is very rarely detected in isolated populations of the USA and among Ashkenazi Jews.
Dentinogenesis imperfecta develops as a result of impaired dentin formation at the stage of tissue differentiation. As a result, amorphous, unorganized, atubular dentin with a high content of organic substances is formed. Dentinogenesis imperfecta type 1 is manifested by a deficiency of collagen formation. Type 2 of the disease is associated with a mutation of the dentin-sialo-phosphoprotein gene (DSPP), which encodes the formation of a specific matrix protein (located on the fourth chromosome). The cause of type 3 of dentinogenesis imperfecta is violations of the dentine matrix of phosphoprotein 1 (DMPI).
Histological changes in three forms of dentinogenesis imperfecta are as follows: in the surface layer, the normal structure of dentin is preserved. In the periculpular dentin, along with areas containing abnormal dentine tubules, there are also zones of their complete absence.
The classification of dentinogenesis imperfecta according to Shields is most often used in dentistry:
- 1 type. The structure of the enamel is within normal limits. The structure of the periculpar dentin is disturbed. The dentine tubules are narrowed, obliterated. Dentin hypomineralization is observed. Precollagen fibers do not turn into collagen fibers.
- Stanton-Capdepon syndrome (type 2). It is characterized by a violation of the structure of the enamel, a decrease in its thickness, an inhomogeneous structure of dentin, progressive calcification of the pulp chamber, degenerative changes in cement. The number of tubes in the dentin is reduced, there is a low content of mineral substances.
- 3 type. The dentine matrix is atypical, with characteristic manifestations of fibrosis. There is an increased amount of interglobular dentin, an inhomogeneous structure of the pulpar dentin, and an expansion of the pulp chamber.
With dentinogenesis imperfecta of type 1, the size and dimensions of the teeth, the timing of eruption are within the norm. The main complaints are reduced to the appearance of bleeding gums, tooth mobility of 1-2 degrees can be observed. Sometimes there is a bulbous shape of crowns. Teeth acquire a more intense watery-gray color. Root fractures, signs of pathological erasability are often diagnosed. If type 1 dentinogenesis imperfecta is associated with imperfect osteogenesis, then the severity of tooth damage does not correlate with the severity of the underlying disease.
Stanton-Capdepon syndrome is usually an isolated pathology. The teeth are amber, watery gray, opalescent. Rare cases of purple coloration have been recorded. Sometimes there are shortened clinical crowns in the form of an onion. With dentinogenesis imperfecta of type 2, progressive obliteration of the pulp chambers is observed, which begins even before the eruption. The enamel quickly chips off, which leads to the exposure of dentin, a decrease in the height of the bite, a displacement of the head of the temporomandibular joint.
Due to the staining of dentin, the teeth acquire a brown hue. The roots are twisted and thinned. Retention of permanent teeth or, conversely, their early change is possible. With dentinogenesis imperfecta, 3 types of permanent teeth crowns have the shape of a bell. The color can vary from yellow-brown to gray-blue. Multiple autopsies of the pulp chamber of temporary teeth are observed.
An important stage of diagnosis is the collection of anamnesis in order to identify hereditary factors of the disease. Clinical signs vary depending on the form of dentinogenesis imperfecta. During the physical examination, the dentist determines the discoloration of the teeth. Crowns acquire an atypical spherical shape due to a significant narrowing in the neck area. They also reveal pathological erasability, a decrease in the lower third of the face.
Radiological signs of dentinogenesis imperfecta type 1 are thinning of the cortical layer of the jaw, large-cell structure of the spongy substance, slowly progressive calcification of the roots after eruption. With Stanton-Capdepon syndrome, reduced pulp chambers and obliterated channels are detected using radiography. Periapical foci of bone tissue rarefaction are often diagnosed. During electro-dental diagnostics, a decrease in the excitability of the pulp is determined.
It is necessary to differentiate dentinogenesis imperfecta not only with amelogenesis imperfecta, dentin dysplasia, acid necrosis, anomalies of dental development, but also with other dentin changes associated with common diseases. We are talking about brachioskeletogenital syndrome, marble disease, hypophosphatasia, Ehlers-Danlos syndrome. In order to identify genetically determined factors of the disease, a medical and genetic consultation is indicated.
Treatment of dentinogenesis imperfecta requires a comprehensive approach. The main task is to preserve teeth in the most gentle way. For this purpose, remineralizing therapy is indicated. Calcium- and fluorine-containing agents are used as preparations for the restoration of the mineral composition. In the presence of apical foci of rarefaction of bone tissue, endodontic treatment is carried out with subsequent coating of teeth with crowns. In case of loss of teeth, orthopedic treatment is indicated. Removable dentures are used to replace defects in the dentition, as well as to prevent the development of dental deformities. Fixed bridge-like structures with dentinogenesis imperfecta are rarely used. The increase in the height of the bite is carried out with the help of removable mouthguards.
If disease is an isolated pathology, the prognosis is more favorable. With early treatment of patients, effective endodontic treatment, timely covering of affected teeth with crowns, the functional integrity of the dental system can be preserved.