Interview: Molar Incisor Hypomineralization – a silent epidemic in children
Molar Incisor Hypomineralization (MIH) is a condition that is considered to have grown to epidemic proportions in children. Crumbling deciduous teeth – commonly known as “chalky teeth” – appear to be an increasing problem. We talked to an MIH expert and this is what she had to say.
Professor Bekes, what is Molar Incisor Hypomineralization?
The term Molar Incisor Hypomineralization (MIH) is more commonly known as “chalky teeth”. It refers to a special type of enamel defect which is caused by systemic hypomineralization. Originally, the disease pattern was defined as primarily affecting the permanent first or six-year molars – that is tooth 16, 26, 36 and 46 – and in some cases the permanent incisor teeth. In the meantime, however, clinical evidence of this type of damage has also been seen in deciduous and other permanent teeth in individual cases.
How does the disease manifest itself and what are the degrees of MIH?
The severitye of enamel softening and discolouration varies. The teeth may show opaque yellowish-white or yellowish-brown areas or even severe enamel and dentin decay. The tooth enamel of affected patients is highly porous and prone to fracture. Hypomineralized teeth are often very sensitive to cold in particular. The condition often causes considerable emotional distress in patients.
How widespread is MIH and who does it affect?
Studies from different parts of the world* show a wide regional variation of 0.5 to 40.2 per cent in the prevalence of the disease. One example: The 5th German oral health study revealed a prevalence of 28.7 per cent in twelve-year-old children.
What causes MIH?
Unfortunately, the cause of MIH is still unknown. Prenatal, perinatal and postnatal influences are being evaluated. Furthermore, environmental conditions and a variety of diseases occurring in the first few years of a child’s life may have an influence.
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What are the signs and symptoms of MIH?
The main symptoms of MIH include
- enamel fractures;
- hypersensitivity to hot and cold foods and
- esthetic problems in the anterior region.
What kind of challenges are dentists faced with in the treatment of MIH?
Various problems dominate in the treatment of MIH. First, it is difficult to assess the extent of the destruction of the tooth structure in hypomineralized enamel. Second, it is difficult to establish how likely it is for discoloured, but not yet damaged enamel to fracture in the near future.
Furthermore, it is important to note that many of the teeth affected by MIH show a certain degree of hypersensitivity, which could lead to serious complaints in intact or already fractured teeth and represent a considerable risk for these teeth. This must be taken into consideration in the daily oral hygiene regime and the treatment of MIH teeth.
In short, MIH molars have two main problems:
- reduced fracture resistance;
- in some cases, considerable hypersensitivity.
In 2016, an international working group, of which you were a part, developed a new index for screening and treating patients with MIH.
That’s correct. An international working group developed the MIH-Treatment Need Index (MIH-TNI) on the basis of the most significant clinical problems related to MIH. This index allows dental practitioners to conduct not only epidemiological studies on large cohorts, but also to individually diagnose patients and set up treatment plans for them.
This index was created with two goals in mind. The second goal was to develop a treatment plan for practitioners on the basis of the MIH-TNI.
Could you explain this in more detail?
The MIH-TNI takes into consideration the extent of the destruction of the tooth structure, including any of the hypersensitivity associated with MIH. Within the context of individual examinations, this scoring system is intended to provide a basis for a standardized treatment approach, which takes into account all the problems typical of MIH. In addition, it establishes a reference against which decisions can be made in the different MIH treatment studies that are being planned. The index is made up of four severity levels and can be used to score permanent as well as deciduous teeth.
The treatment approach addresses prevention, regeneration, immediate treatment and long-term planning. The caries risk of the patient also represents an important aspect. In the course of our discussions, we soon realized that the specific caries risk of the patient would determine whether certain treatment modalities could be used or not. As a result, two structurally identical schemes were developed: one for low caries risk patients and one for high caries risk patients.
How is MIH treated?
First, it is important to diagnose the MIH patient as early as possible and to provide them with comprehensive care and to set up a very strict recall schedule. These steps help to increase the chance of satisfactorily restoring the function and esthetics of the teeth.
Various treatment options are available. The most suitable one will depend on the caries risk of the patient and the MIH-TNI. Ideally, the treatment should involve preventive, regenerative and immediate measures and long-term planning. A prophylactic program could offer a sound treatment possibility. It should include
- regular oral hygiene appointments and professional tooth cleaning;
- the use of fluoride-containing preparations (topical fluoride application);
- the use of CPP-ACP-containing products and sealants.
If restorations are needed to repair extensive tooth damage, several treatments are available, for example:
- composite resin restorations for small to medium lesions (bonding to healthy enamel);
- steel crowns as long-term temporaries for repairing severe defects (subsequent placement of lab-fabricated restorations) and
- indirect restorations (lab or CAD/CAM-fabricated) made of composite resin or ceramic.
The damaged teeth are permanently repaired with dental crowns once the patient reaches early adulthood. In cases where fracturing of the tooth structure progresses very rapidly, the teeth may have to be extracted. However, this is the last resort.
Professor Bekes, thank you very much for this interesting interview.
Prof. Dr Katrin Bekes is the director of the pediatric dentistry department at the Medical University of Vienna, Austria.