Enamel hypoplasia is an insufficient development of the surface layer (enamel) of milk or permanent teeth. An extremely pronounced form of enamel hypoplasia is aplasia – its complete absence. It is manifested by a change in the shape and appearance of teeth, the presence of whitish or depigmented areas, grooves, depressions, with aplasia – pain on various stimuli. Most often, enamel hypoplasia leads to the development of deep caries, pulpitis, and the formation of malocclusion.
Meaning
Enamel hypoplasia is a congenital malformation of the tooth or its tissues associated with metabolic disorders in the fetus. Enamel aplasia is an extreme expression of hypoplasia and is manifested by the complete absence of enamel coating or the absence of a tooth.
Causes
Enamel hypoplasia occurs due to serious metabolic disorders in the fetus. And the main reason is either the pathology of the bookmarks of the embryo cells, or unfavorable factors that negatively affect the fetus.
It is not entirely correct to say that enamel hypoplasia occurs only due to a violation of mineral metabolism and areas of hypoplasia are nothing more than a demineralization zone. If this was the main cause of enamel hypoplasia, then the pathology would not be so widespread. To date, the incidence is constantly increasing, as harmful factors begin to act on the rudiments of teeth long before the formation and birth of the fetus. Conclusions that toxicosis and infectious diseases in a pregnant woman lead to fetal abnormalities are quite reasonable. Studies confirm that enamel aplasia and other dental anomalies are more common in children whose mothers suffered from acute respiratory infections, rubella, and toxoplasmosis during pregnancy. Or if part of the pregnancy proceeded with serious toxicosis. The underdevelopment of enamel is observed in premature babies and in children who were injured during childbirth. Predisposing factors are encephalopathy, atopic dermatitis, rickets and other disorders of calcium metabolism.
Enamel hypoplasia to one degree or another is found in almost half of preschool and primary school age children. At the same time, it is systemic in nature and more often there are lesions of several teeth. Enamel hypoplasia with profound changes is diagnosed in 40% of clinically healthy children.
Enamel hypoplasia is diagnosed on milk and permanent teeth, while it is more common on permanent teeth, which leads to an increased risk of dental diseases in older age. Violations of the enamel coating of milk teeth are associated with pathologies occurring in a woman’s body during pregnancy. Whereas hypoplasia of the enamel of permanent teeth is caused by metabolic disorders in the child’s body, which develop starting from 5-6 months of life. And since diseases during the first year of life are much more common than serious pathologies during pregnancy, respectively, hypoplasia of the enamel of permanent teeth prevails, which is a serious problem.
Localization and group affiliation of teeth with enamel hypoplasia depends on the age at which the child suffered the disease, which became the main pathogenetic link. Thus, diseases suffered in the first months of life lead to hypoplasia of the enamel of the cutting edge of the central incisors and the tubercles of the sixth teeth. This is due to the formation of these teeth at 5-6 months of a child’s life.
At 8-9 months, the formation of the second incisors and canines occurs, and diseases at this age lead to hypoplasia of the enamel of the lateral incisors and the cutting edge of the canines. That is, metabolic disorders affect all teeth that have formed by this period. But after complete teething, the areas of hypoplasia are at different levels, since the timing of tooth formation is not the same.
If the diseases cause profound changes in the child’s metabolism or continue for a long time, then areas of enamel hypoplasia are observed along the entire length of the crown and on the surface of the tooth. The uneven structure of the enamel indicates the duration and waviness of diseases suffered during the formation of teeth. The severity of the transferred diseases also affects the depth of changes in the enamel. So, minor pathologies can manifest only as chalky spots, and severe diseases can cause underdevelopment of the enamel up to its aplasia.
With local enamel hypoplasia, only part of the teeth are affected. Usually its occurrence is associated with localized metabolic disorders near the rudiments of permanent teeth. Inflammatory processes in the area of the apex of the roots of milk teeth contribute to the occurrence of local enamel hypoplasia. This type of hypoplasia is more common on small molars, because their rudiments are located between the roots of the milk molars.
Symptoms
Systemic hypoplasia
Depending on the severity, systemic enamel hypoplasia may be manifested by a change in the color of the enamel, its underdevelopment or complete absence.
The change in the color of the enamel is manifested in the form of symmetrical white spots of various shapes, which are located on the teeth of the same name. Chalk spots are found on the vestibular surface and are not accompanied by unpleasant or painful sensations. A diagnostic sign is that the outer layer of enamel on the affected area is smooth, shiny and does not change color when interacting with dyes. Over the course of a lifetime, the stain will not change either color or shape.
More severe manifestations of hypoplasia are often not noticeable during a routine examination. Wavy, dotted and furrowed enamel appears after drying the surface. Upon careful examination, the dentist becomes aware of the alternation of small rollers and recesses with unchanged enamel. More often, this form of hypoplasia manifests itself in the form of point depressions in the enamel, which are located at different levels. At first, these areas have a normal color, but as the tooth grows further, these areas gradually become pigmented. In some cases, enamel hypoplasia manifests itself as a single hyperpigmented strip on the crown of the tooth. Sometimes this groove is quite deep and there is a noticeable decrease in the size of the tooth crown in the form of interception, this form of hypoplasia is called furrowed. Stair hypoplasia is very rarely observed when several grooves form on the crown of the teeth. But it is characteristic that even with severe forms of such hypoplasia of the enamel, its integrity is not violated.
Less often than other changes, enamel aplasia occurs in a certain area. In this case, the pain syndrome is formed upon contact with the stimulus and passes after its elimination. Clinically, this pathology is manifested by the absence of enamel on part of the crown of the tooth, but more often at the bottom of the cup-shaped recess, or in the groove covering the crown of the tooth. Often, with enamel aplasia, there is also an underdevelopment of dentin. This is manifested by changes in the shape of the teeth characteristic of this group.
Changes in the shape of teeth
- Getchinson’s teeth. In this pathology, the upper central incisors have a screwdriver-shaped or barrel-shaped shape. Their size at the neck is slightly larger than that of the cutting surface and there is a semilunar notch at the cutting edge. Previously, it was believed that this symptom is observed only in congenital syphilis, but later it was found that the anomaly occurs for other reasons.
- Pfluger teeth. With this symptom, the first molars are affected, the size of the crown in the cheek is larger than that of the chewing surface. The bumps are underdeveloped, which gives the teeth a resemblance to a cone.
- Fournier’s teeth. Clinically, they look the same as with Getchison’s symptom, but without a semilunar notch.
Local enamel hypoplasia
Such hypoplasias occur on permanent teeth due to the involvement of the rudiments of the teeth in the inflammatory process or due to mechanical trauma of the developing rudiment. Clinically, this type of hypoplasia manifests itself in the form of white or yellowish-brown spots, and more often in the form of dotted depressions over the entire surface. In some cases, the enamel of the tooth crown is completely or partially absent.
Hypoplasia of the enamel of teeth leads to the fact that microbes more aggressively affect the dentin, freely penetrating into it and causing deep caries. The second serious complication is the lesion of other tooth tissues – cement, dentin and pulp, since enamel hypoplasia rarely occurs in isolation. Many children subsequently develop malocclusion.
Treatment
Treatment tactics depend on the severity of hypoplasia, so with single spots and shallow enamel lesions, etiotropic treatment is not carried out. Caries prevention is carried out and more attention is paid to oral care. Sometimes, if the spots are located on the vestibular surface of the teeth, they become a cosmetic defect, since they are clearly visible during a conversation. To eliminate them, sealing with composite materials is carried out. If there are changes in the enamel in the form of point depressions and interceptions, then they are also eliminated with the help of sealing.
Pronounced defects of enamel and dentin are an indication for orthopedic treatment with the installation of metal-ceramic crowns. Prevention of enamel hypoplasia is the harmonious development of the child in order to prevent serious diseases during the formation of immunity.
Literature
- Jacobsen P. E., Haubek D., Henriksen T. B., Østergaard J. R., Poulsen S. Developmental enamel defects in children born preterm: a systematic review // Eur J Oral Sci. — 2014; 122 (1): 7-14.link
- Lygidakis N. A., Dimou G., Briseniou E. Molar-incisor-hypomineralisation (MIH). Retrospective clinical study in Greek children. I. Prevalence and defect characteristics // Eur Arch Paediatr Dent. — 2008; 9 (4): 200-206 link
- Almuallem Z., Busuttil-Naudi A. Molar incisor hypomineralisation (MIH) – an overview // British Dental Journal. — 2018; 225: 601-609.link