1. MIH Molar Incisor Hypomineralization
Dr S E Jabbarifar 2010
Lecturer in Paediatric Dentistry (Paediatric Dentistry)

2. MIH
Introduction
Clinical Presentation
Prevalence
Aetiology
Treatment

3. MIH
Molar-Incisor hypomineralization is defined as a hypomineralization of systemic origin that affects one to all of the first permanent molars and is often associated with affected permanent incisors (Weerheijm et al., 2001)

4. MIH
MIH molars can create serious problems for the dentist as well as for the child affected

5. MIH Dentists Child rapid caries development
inability to anaesthetize the MIH molar
unpredictable behaviour of apparently intact opacities
restoration difficulties
Child
experience pain and sensitivity (even when the enamel is intact)
Pain during brushing
appearance of their incisor teeth

6. Clinical Features Primary teeth are not affected
one, two, three or four permanent first molars affected
white/yellow/brown opacities
well demarcated compared to normal enamel

7. Clinical Features
usually presents on the buccal or occlusal surfaces of the molars and incisors
asymmetrical defects
the risk of defects to the incisors appears to increase when more first permanent molars have been affected

8. Clinical Features
the affected molars are sensitive to cold and appear to be more difficult to anaesthetise
the lesions on the incisors are usually not as extensive as those in the molars and present mainly a cosmetic problem
the remaining permanent dentition is usually not affected

9. Diagnosis
It is important to diagnose MIH, delineating it from other developmental disturbances of enamel

10. Diagnosis
Diagnostic criteria to establish the presence of MIH include:
the presence of a demarcated opacity (defect altering the translucency of the enamel)
posteruptive enamel breakdown (loss of surface enamel after tooth eruption, usually associated with a pre-existing opacity)
atypical restorations (frequently extend to the buccal or palatal smooth surfaces reflecting the distribution of hypoplastic enamel)

11. Diagnosis
Mild MIH
Demarcated opacities are in nonstress-bearing areas of the molar
No enamel loss from fracturing is present in opaque areas
There is no history of dental hypersensitivity
There are no caries associated with the affected enamel
Incisor involvement is usually mild if present

12. Diagnosis Moderate MIH Atypical restorations can be present
Demarcated opacities are present on occlusal/incisal third of teeth without posteruptive enamel breakdown
Posteruptive enamel breakdown/caries are limited to 1 or 2 surfaces without cuspal involvement
Dental sensitivity is generally reported as normal

13. Diagnosis Severe MIH Posteruptive enamel breakdown is present
There is a history of dental sensitivity
Caries is associated with the affected enamel
Crown destruction can advance to pulpal involvement
Defective atypical restoration
Aesthetic concerns are expressed by the patient or parent

14. Differential diagnosis
MIH can sometimes be confused with fluorosis or amelogenesis imperfecta

15. Differential diagnosis
It can be differentiated from fluorosis as its opacities are demarcated, unlike the diffuse opacities that are typical of fluorosis
fluorosis is caries resistant and MIH is caries prone
fluorosis can be related to a period in which the fluoride intake was too high

16. Differential diagnosis
Choosing between amelogenesis imperfecta (AI) and MIH:
only in very severe MIH cases, the molars are equally affected and mimic the appearance of AI
In MIH, the appearance of the defects will be more asymmetrical
In AI, the molars may also appear taurodont on radiograph
There is often a family history

17. Prevalence
The prevalence figures range from 3.6–25% and seem to differ between countries
The number of hypomineralized first permanent molars in an individual can vary from one to four
The frequency of MIH molars was not evenly divided among children

18. Aetiology Amelogenesis is a highly regulated process
The asymmetrical occurrence of MIH suggests that the ameloblasts are affected at a very specific stage in their development
Children with poor health during the first 3 years of life are more likely to be at increased risk for MIH

19. Aetiology Ameloblast cells are irreversibly damaged
Clinically these appear as yellow or yellow/brown opacities
These opacities are more porous
Ameloblasts have the potential to recover after the disturbance
These defects appear creamy yellow or whitish cream demarcated opacities

20. Aetiology Various causes of MIH have been implicated:
Environmental conditions
Respiratory tract infections
Perinatal complications
Dioxins
Oxygen starvation and low birth weight
Calcium and phosphate metabolic disorders
Childhood diseases
Antibiotics
Prolonged breast feeding
the aetiology of MIH still remains unclear

21. Restoration Children with MIH may have extensive treatment needs
By the age of nine, children with MIH were treated ten times as often as children without such molars
MIH children display more dental fear and anxiety
Children with MIH exhibited greater DMFS and dmfs

22. Restoration
MIH molars are fragile, and caries may develop easily in these molars
This is aggravated because children tend to avoid the sensitive molars when brushing
In order to minimize the loss of enamel and any damage due to caries, both preventive and interceptive treatment is required

23. Restoration
Besides normal brushing and education, prevention also includes fluoride varnish application and application of glass ionomer sealants
Sometimes the sensitivity of the teeth is decreased by these applications
In some cases of hypersensitivity the use of casein phosphopetide-amorphous calcium phosphate (CC-ACP) (Tooth Mousse) products have been advised as they remineralize and desensitize the tooth

24. Extraction
Extraction combined with orthodontic treatment, should be considered as an alternative treatment, especially if the molars have a poor longterm prospect.
The optimal time for extraction is indicated by the calcification of the bifurcation of the roots of the lower second permanent molar

25. Short-Term Treatment
The immediate treatment planning needs of young children with MIH must reflect:
Behavioural
Preventive
growth and development
restorative requirements
The objective is to:
maintain function
preserve tooth structure
plan for any required orthodontic care

26. Partially Erupted Molars
Prone to caries development and highly sensitive
Applying desensitizing agent in combination with fluoride varnish applications could be of some help in decreasing sensitivity
GI to cover the affected surfaces of a partially erupted molar can act as an interim method of:
decreasing sensitivity
reducing caries susceptibility
preserving tooth structure

27. Mild MIH: Short-Term Treatment
Prevention and maintaining the dentition
Teeth should be carefully monitored
applying fluoride varnish and placing sealants on the occlusal surfaces of molars
where the enamel is intact and the patient does not report any sensitivity, sealants are the current treatment of choice
60-second pretreatment with 5% sodium hypochlorite (NaOCl) to remove intrinsic enamel proteins may be beneficial

28. Moderate MIH: Short-Term Treatment
preventive measures previously outlined
intervention may be required
Anterior teeth with isolated demarcated opacities that are of aesthetic concern can be treated with NaOCl or other bleaching techniques, microabrasion, or resin restorations
Yellow or yellow/brown spots in incisors or molars can lighten and become less noticeable with bleaching, but whitish opacities may become more prominent after applying the bleach

29. Moderate MIH: Short-Term Treatment
For posterior teeth with enamel loss or decay limited to 1 or 2 surfaces that does not involve cuspal tooth structure, resin is the material of choice if the tooth can be adequately isolated
The outline of the restoration should be made in non-hypomineralized enamel, but it can be very difficult to find out where sound enamel begins, resulting in repeated restorations due to disintegration of adjacent enamel or opacities on other spots.

30. Moderate MIH: Short-Term Treatment
Two approaches have been described in determining the location of the cavity margin but neither is ideal
Fall the visibly defective enamel is removed
Only the very porous enamel is removed until good resistance is felt between the bur and the sound enamel
Existing, intact restorations on molars should be carefully monitored

31. Available adhesive dental materialsGI
RMGI
Compomer
RBC
Glass ionomers and resin-modified glass ionomers have poor wear resistance and are not recommended for placement in stress-bearing areas
The enamel-adhesive interface
Porous
Cracks
Decreased bond strength
Cohesive failure

32. Severe MIH: Short-Term Treatment
Treatment of children with severe MIH presents a tremendous challenge
Early intervention is necessary to prevent PEB
To minimize discomfort and decrease the likelihood of behaviour management problems, profound local analgesia is necessary
Some patients may benefit from the use of nitrous oxide sedation in conjunction with local anaesthesia

33. Stainless-steel crowns protect the tooth against
Once the molar has erupted, preformed stainless-steel crowns are the treatment of choice for severely hypoplastic molars
Stainless-steel crowns protect the tooth against
masticatory forces
protect enamel from acid attack
decrease sensitivity
increase the child’s OH compliance

34. Long-Term Treatment
Once children have a mature dentition and a more stable gingival to clinical crown height, full-coverage cast restorations should be considered to replace the interim stainless-steel crowns on molars
Anterior teeth can be managed with veneers or crowns should they be indicated for severe cases of enamel defects, and where aesthetic concerns continue to be an issue

35. Summary Early Diagnosis High risk prevention protocol
Make a decision regarding prognosis of the molars
Extract if prognosis is poor or if behaviour management will be an issue

36. Summary Replace missing tooth structure Regular recall
Use best available restorative material
SSC ideal
Regular recall
Delay aesthetic treatment of the incisors until the child requests treatment

37. Thank You