Best clinical practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH): an updated European Academy of Paediatric Dentistry policy document.

AIM: To update the existing European Academy of Paediatric Dentistry (EAPD) 2010 policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with Molar-Incisor-Hypomineralisation (MIH).' METHODS: Experts, assigned the EAPD, worked on two different topics: (A) Aetiological factors involved in MIH, and (B) Treatment options for the clinical management of MIH. The group prepared two detailed systematic reviews of the existing literature relevant to the topics and following a consensus process produced the updated EAPD policy document on the 'Best Clinical Practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (MIH).' The GRADE system was used to assess the quality of evidence regarding aetiology and treatment which was judged as HIGH, MODERATE, LOW or VERY LOW, while the GRADE criteria were used to indicate the strength of recommendation regarding treatment options as STRONG or WEAK/CONDITIONAL. RESULTS: (A) Regarding aetiology, it is confirmed that MIH has a multifactorial aetiology with the duration, strength and timing of occurrence of the aetiological factors being responsible for the variable clinical characteristics of the defect. Perinatal hypoxia, prematurity and other hypoxia related perinatal problems, including caesarean section, appear to increase the risk of having MIH, while certain infant and childhood illnesses are also linked with MIH. In addition, genetic predisposition and the role of epigenetic influences are becoming clearer following twin studies and genome and single-nucleotide polymorphisms analyses in patients and families. Missing genetic information might be the final key to truly understand MIH aetiology. (B) Regarding treatment options, composite restorations, preformed metal crowns and laboratory indirect restorations provide high success rates for the posterior teeth in appropriate cases, while scheduled extractions provide an established alternative option in severe cases. There is great need for further clinical and laboratory studies evaluating new materials and non-invasive/micro-invasive techniques for anterior teeth, especially when aesthetic and oral health related quality of life (OHRQoL) issues are concerned. CONCLUSIONS: MIH has been studied more extensively in the last decade. Its aetiology follows the multifactorial model, involving systemic medical and genetic factors. Further focused laboratory research and prospective clinical studies are needed to elucidate any additional factors and refine the model. Successful preventive and treatment options have been studied and established. The appropriate choice depends on the severity of the defects and the age of the patient. EAPD encourages the use of all available treatment options, whilst in severe cases, scheduled extractions should be considered.

An update of treatment modalities in children and adolescents with teeth affected by molar incisor hypomineralisation (MIH): a systematic review.

PURPOSE: To systematically review the treatment modalities for molar-incisor hypomineralisation for children under the age of 18 years. The research question was, 'What are the treatment options for teeth in children affected by molar incisor hypomineralisation?' METHODS: An electronic search of the following electronic databases was completed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, LILACS, Google Scholar and Open Grey identifying studies from 1980 to 2020. The PRISMA guidelines were followed. The studies were screened, data extracted and calibration was completed by two independent reviewers. RESULTS: Of 6220 potential articles, 34 studies were included. Twenty studies investigated management of molars with fissure sealants, glass ionomer cement, polyacid modified resin composite, composite resin, amalgam, preformed metal crowns, laboratory-manufactured crowns and extractions. In four articles management of incisors with microabrasion, resin-infiltration and a combination of approaches was reported. Eight studies looked at strategies to mineralise MIH-affected teeth and/or reduce hypersensitivity. Two studies investigated patient-centred outcomes following treatment. Due to the heterogeneity between the studies, meta-analysis was not performed. CONCLUSION: The use of resin-based fissure sealants, preformed metal crowns, direct composite resin restorations and laboratory-made restorations can be recommended for MIH-affected molars. There is insufficient evidence to support specific approaches for the management of affected incisors. Products containing CPP-ACP may be beneficial for MIH-affected teeth.

An update of the aetiological factors involved in molar incisor hypomineralisation (MIH): a systematic review and meta-analysis.

PURPOSE: To systematically review the aetiological factors associated with molar incisor hypomineralisation (MIH). To this day, the aetiology remains unknown. Determining risk factors would allow risk assessment and enhance early diagnosis of MIH in young patients. The aim was to assess, evaluate and summarise the relationship between MIH and reported aetiological hypotheses. METHODS: Electronic database searches of MEDLINE, EMBASE, EBSCO, LILACS and Cochrane Library were conducted. Authors conformed to PRISMA guidelines. Studies were screened, data extracted, assessment of risk of bias and calibration was completed by two independent reviewers. Meta-analyses with heterogeneity calculations were performed. RESULTS: Of the potential 8949 studies, 64 studies were included in the qualitative analysis whilst 45 were included in the quantitative analysis. Prenatal factors: results are inconclusive as only unspecified maternal illnesses appear to be linked to MIH. Perinatal factors: prematurity (OR 1.45; 95% CI 1.24-1.70; p = 0.0002) and caesarean delivery (OR 1.45; 95% CI 1.09, 1.93; p < 0.00001) are associated with an increased risk of developing MIH. Birth complications are also highlighted. These three factors can lead to hypoxia, and children with perinatal hypoxia are more likely to develop MIH (OR 2.76; 95% CI 2.09-3.64; p < 0.0001). Postnatal factors: measles, urinary tract infection, otitis media, gastric disorders, bronchitis, kidney diseases, pneumonia and asthma are associated with MIH. Fever and antibiotic use, which may be considered as consequences of childhood illnesses, are also associated with MIH. Genetic factors: an increasing number of studies highlight the genetic and epigenetic influences in the development of MIH. CONCLUSION: Several systemic and genetic and/or epigenetic factors acting synergistically or additively are associated with MIH, revealing a multifactorial aetiology model. Peri- and postnatal aetiological factors are more likely to increase the odds of causing MIH than prenatal factors.

Molar incisor hypomineralisation (MIH) training manual for clinical field surveys and practice.

BACKGROUND: Despite clear assessment criteria, studies of molar incisor hypomineralisation (MIH) and hypomineralised second primary molars (HSPM) are marked by inconsistency in outcome measurements. This has detracted from meaningful comparisons between studies and limited interpretation. AIM: To provide a comprehensive manual as a companion to assist researchers in planning epidemiological studies of MIH and HSPM, with particular reference to outcome measurement. METHODS: This manual begins with a succinct review of the clinical problems and evidence for management of the conditions. The subsequent sections guide researchers through diagnosis of MIH and HSPM and implementation of both the long and short forms of a recently proposed grading system. MIH and HSPM can often be confused with fluorosis, enamel hypoplasia, amelogenesis imperfecta, and white spot lesions but can be distinguished by a number of unique clinical features. Based on the grading system, a standardised protocol is proposed for clinical examinations. Intra and inter-examiner reliability is of key importance when outcome measurement is subjective and should be reported in all epidemiological studies of MIH. The manual concludes with an exercise forum aimed to train examiners in the use of the grading system, with answers provided. CONCLUSION: The use of a standardised protocol, diagnostic and grading criteria will greatly enhance the quality of epidemiological studies of MIH.

A novel approach for building up infraoccluded ankylosed primary molars in cases of missing premolars: A case report.

BACKGROUND: In cases of infraoccluded primary molars associated with agenesis of premolars, any treatment plan occasionally includes retention of the primary teeth for space preservation and future implant placement if needed. In these cases, building up the crowns to the occlusal line is necessary to prevent various clinical problems. The present case report describes in detail a novel but simple clinical approach for retention and building up of the crown of infraoccluded primary molars. CASE REPORT/TECHNIQUE PRESENTATION: The technique is presented in a 14-year-old girl with nine missing permanent teeth. Orthodontic evaluation indicated space closure for five teeth and space maintenance in the remaining four second primary molars, three of them being infraoccluded. The technique included the following clinical steps: (a) elastic separators were placed proximally to the primary molars for few days to create space; (b) proximal minimal reduction of the crown width was performed; a direct hand composite resin core was made to increase crown height facilitating the selection of a preformed metal crown (PMC). The selected PMC was filled with self-curing composite resin and placed on the primary tooth following an acid etch and adhesive procedure; excess cervical material was removed; (c) after polymerisation, the PMC was carefully removed using cutting and hand instruments, revealing the composite resin fabricated crown which was adjusted for occlusion and polished. Radiographic evaluation confirmed the result. CONCLUSION: This simple method for infraoccluded primary molars crown building up to occlusion using conventional instruments and materials, appears to be a valuable clinical tool for paediatric dentists who frequently find themselves dealing with primary teeth that need to be retained and which can produce serious clinical problems if left untreated.

Εvaluation of a treatment protocol for unerupted maxillary central incisors: retrospective clinical study of 46 children.

AIM: To evaluate the clinical outcome of a treatment protocol performed in children with unerupted permanent maxillary central incisors, including surgical removal of any related obstruction and traction initiation in one stage, under fully repositioned flap, combined with pre- and post-operative orthodontics for space creation and final alignment. METHODS: Forty-six patients aged 7.3-12.7 years (mean = 9.44 ± 1.36) having 54 impacted maxillary central incisors were reviewed. The study group included 37 patients fully treated by us and nine referrals with eruption failure of impacted incisors following previous surgical removal of various obstructions. Detailed patient's clinical and radiographic data were recorded. RESULTS: Aetiology of unerupted incisors included 9 patients with odontomas, 24 with supernumerary teeth, 1 with skeletal lack of space, 1 with a dentigerous cyst, 4 with dilaceration, 1 with severe incisor MIH, 5 with luxation injuries to primary predecessors and 1 with coexisting dilaceration and odontoma. The total treatment time following the standardised protocol ranged from 5 to 21 months (mean 9.88 ± 3.10), while the time needed using different approaches (no pre-operative orthodontics or obstruction removal and then to wait over an assessment period) ranged from 12 to 18 months (mean 15 ± 2.12) and 17 to 30 months (mean 23.73 ± 5.14), respectively (p < 0.05). The time needed for full alignment depended on the inclination, the height of the impacted tooth (p = 0.001) and the patient's age (p = 0.002). Additionally, the absence of pre-operative orthodontics for space creation dramatically increased treatment time (p = 0.018). In contrast, the maturity of the impacted tooth and the developmental stage of the anterior teeth did not affect treatment time. Finally, when the location of the impacted tooth and the space availability allowed waiting for spontaneous eruption, treatment time was not statistically different from that of the main treatment protocol (p = 0.545). CONCLUSIONS: The studied treatment protocol appears ideal for successful results and minimum treatment time. Space creation followed by surgical removal of any obstruction together with orthodontic traction initiation produces excellent results, while waiting for spontaneous eruption is indicated only in cases of favourable patient's age and tooth location. Treatment initiation with operation in the absence of the required eruption space is not recommended, whereas in unfavourable cases obstruction removal without simultaneous orthodontic traction increases dramatically the total treatment time and requires an unnecessary second operation for traction.

Solitary median maxillary central incisor syndrome (SMMCI) with congenital nasal puriform aperture stenosis: literature review and case report with comprehensive dental treatment and 14 years follow-up.

BACKGROUND: Solitary median maxillary central incisor syndrome [SMMCI] is an extremely rare anomaly, especially when no other abnormalities are present. The defect is often found together with various nasal abnormalities and short stature with or without decreased levels of growth hormone. In more severe cases, SMMCI has been associated with holoprosencephaly, the CHARGE and the VACTERL association. Also, published sporadic cases have been related with rare variants of ectodermal dysplasia, chromosomal abnormalities, precocious puberty, hypothalamic hamartoma, congenital heart defects, physical/mental retardation, genital hypoplasia and ear abnormalities. For these reasons when the initial diagnosis is made by the paediatric dentist, ENT, neurological and paediatric evaluations are essential. CASE REPORT: A 4-year-old boy with SMMCI was referred for dental treatment. Clinical/radiographic examination revealed a symmetrical primary and permanent SMMCI, a skeletal Class I and a unilateral crossbite. Medical history indicated respiratory distress and surgery soon after birth due to congenital nasal puriform aperture stenosis. Gradual orthodontic treatment started at the age of 4 years and completed at the age of 13 years. Following maxillary expansion, upper lateral segments were moved backwards and anterior space was created for accommodating a second central incisor. Retainers with a supplementary acrylic incisor were provided for aesthetic and functional replacement until the age of 16 years, when a fixed Maryland ceramic bridge was placed. FOLLOW-UP: Two years recall, at the age of 18 years, revealed a satisfactory and stable aesthetic and functional result. CONCLUSION: Successful dental management of SMMCI patients is possible, following a detailed long-lasting treatment plan requiring multidisciplinary paediatric dental, orthodontic and prosthetic approach.

Attitudes, knowledge and utilization of fissure sealants among Greek dentists: a national survey.

AIM: This was to evaluate the attitudes and knowledge of Greek Dentists concerning fissure sealants (FS) and other preventive measurements, together with the extent and the reasons for using or not using FS in their clinical practice. METHODS: 1,221 general dental practitioners (GDPs) including 50 Paediatric Dentists (PD) were randomly selected from 35 local dental societies of Greece and asked to answer a telephone questionnaire regarding their attitudes to prevention, use of FS and variables influencing their placement. Non parametric Pearson's Chi square test and multifactorial logistic regression models were used for analysing the data. RESULTS: Although 87.6% of all Greek dentists believe and apply prevention, only 35.8% are using them routinely. Factors highly correlated with FS usage for all dentists were using fluoride regimens (p<0.001), being in practice for 5-14 years (p=0.004) and practicing in urban areas (p<0.001). By contrast, all PD were using FS, regardless of any parameter (p>0.01). Concerning the type of surfaces sealed, 45.6% of GDP used FS on intact surfaces and 41.1% on questionable, while only 15% of them sealed incipient caries. Overall, fewer GDPs compared with PD sealed premolars, primary teeth, questionable surfaces, incipient enamel caries and molars in high risk patients (p<0.001), while fewer PD sealed intact surfaces (p<0.001). The reasons mentioned for not using FS were: 76.3% that parents were unwilling to pay, 61.9% did not know how to use them, while 43.0% believed that oral hygiene was sufficient in order to reduce caries. CONCLUSIONS: Insufficient knowledge and lack of clinical practice guidelines for the use of FS by GDPs in Greece, leads to low usage rates. Appropriate professional and scientific authorities should join efforts to improve knowledge of GDP and instil confidence in using FS.

Treatment modalities in children with teeth affected by molar-incisor enamel hypomineralisation (MIH): A systematic review.

AIM: This was to review the literature concerning the treatment of permanent teeth with molar-incisor hypomineralised enamel (MIH), comment about possible shortcomings and propose areas of future research. METHODS: A search of MedLine, Scopus, ResearchGate, Isis and Google Scholar databases was conducted using all terms relevant to the subject. Relevant papers published in English were identified after a review of their titles, abstracts or full reading of the papers. RESULTS: Of 189 references initially found, 66 papers were included; 34 directly relevant to the subject. From the latter, only 14 concerned laboratory or clinical studies dealing with treatment for MIH. Since 2000 11 reviews evaluated, to a certain extent, treatment options for affected teeth. Analysis of the proposed treatment modalities indicated options for prevention, restorations, and adhesion to hypomineralised enamel, full coronal coverage and extraction followed by orthodontics. Based on these findings, a treatment decision plan is proposed. CONCLUSIONS: Although treatment approaches for MIH have started to be clearer, long-term clinical trials, supported by laboratory studies, should be conducted to further facilitate the clinical management of this dental defect.

Best Clinical Practice Guidance for clinicians dealing with children presenting with Molar-Incisor-Hypomineralisation (MIH): An EAPD Policy Document.

BACKGROUND: The European Academy of Paediatric Dentistry (EAPD) has long recognised the necessity of promoting further research and knowledge regarding the dental defect described as molar-incisor-hypomineralisation (MIH). Following the establishment by EAPD of the defect diagnostic criteria in 2003, the publication of various papers and a whole issue assigned to the defect in the European Archives of Paediatric Dentistry (2008), an Interim Seminar and Workshop on MIH was organized in Helsinki in 2009. RESULT: The outcome of this event is the present consensus paper on the prevalence, diagnosis, aetiology and treatment for children and adolescents presenting with MIH. A clear diagnostic proposal and a treatment decision-making guide are presented together with suggestions on aetiology and guidance for future research. CONCLUSION: MIH is an important clinical problem that often concerns both the general dental and specialist paediatric dentists; the present 'best clinical practice guidance' aims to further help clinicians dealing with the condition.

Retention of fissure sealants using two different methods of application in teeth with hypomineralised molars (MIH): a 4 year clinical study.

AIM: This was to evaluate the retention rate of fissure sealants applied to MIH molars with occlusal enamel opacities, using two different application methods after 4 years. METHODS: 54 children exhibiting molars with MIH aged 6-7 years, participated in the study. SELECTION CRITERIA: presence of at least 2 fully erupted caries-free maxillary or mandibular first permanent molars in the opposite sides of the mouth, both with occlusal enamel opacities without breakdown. Following parental consent, sealants were applied using a half-mouth experimental design. Group A: On a randomly assigned first molar on one side of the mouth sealants Fissurit were placed using a single bottle adhesive system (One-step prior to sealant application. Group B: Sealants were applied on the contra-lateral molar using the conventional etch and seal technique. Children were seen biannually when a preventive program was applied, without replacing any lost sealant. RESULTS: After 4 years, 47 sets of molars (94 teeth) were available for blind evaluation. Teeth in Group A presented a better retention rate; 70.2% were fully sealed, 29.7% partly sealed and none unsealed (lost sealant). Group B revealed 25.5% fully sealed, 44.6% partly sealed and 29.7% unsealed teeth. STATISTICS: Differences between groups A and B were statistically significant (p<0.001). Also both groups revealed a decreasing retention rate over the 4-year period (p<0.001). There was no difference in dental caries increment rate and enamel breakdowns at the end of the study (p>0.01). CONCLUSIONS: In hypomineralised molars with occlusal opacities sealants appear to have greater retention when applied using 5th generation adhesive systems prior to sealant.

Case report: Surgical luxation and elevation as treatment approach for secondary eruption failure of permanent molars.

BACKGROUND. Secondary eruption failure of permanent molars is a rare disturbance that usually causes serious clinical problems to the patient. Various treatment approaches have been proposed that depend on the age of the patient, the developmental stage of the root, the position of the tooth, the severity of infraocclusion and the presence of one or more affected teeth. Surgical luxation followed by elevation and stabilization of the luxated tooth has been proposed as a first-step treatment in cases of young patients with incomplete root formation and favourable position of the tooth. CASE REPORT. A boy initially aged 7.5 years old presented with localized secondary eruption failure of the mandibular right first permanent molar (46) and infra-occlusion. The medical and dental history of the child was uneventful, while there was no history of eruption failure or ankylosis in any other family member. TREATMENT. This included surgical luxation of the tooth, followed by elevation to the occlusal plane and immobilization to the adjacent primary molar. The splint was removed after 4 weeks. FOLLOW-UP. Three years follow-up revealed a successful result with no clinical or radiological pathology of the area. Root development of the affected tooth was arrested, but there was no sign of pulp necrosis. CONCLUSION. Favourable treatment outcome using surgical luxation and repositioning of the teeth in the present case of permanent molar with secondary eruption failure was observed.

Parental attitudes and perceptions affecting children's dental behaviour in Greek population. A clinical study.

AIM: This was to investigate the relationship of children's behaviour during dental treatment to parental dental attitudes and perceptions in a definitive population of Greek children in Athens. METHODS: 88 children aged 3-11 years and their parents, attending the Community Dental Centre for Children in Athens, participated. A questionnaire including demographic information, questions regarding parents' dental experience and anxiety (M-DAS test), as well as questions regarding expectant behaviour of each child and his/her dental anxiety level (parental version of the CFSS -Dental Subscale), was completed by the parents during the first examination appointment. During the two following operative sessions each child's behaviour was recorded and evaluated using the Frankl Scale. Collected data were statistically analyzed using a SPSS statistical program. RESULTS: No significant difference was found between a child's actual behaviour and gender, nationality, frequency of parent's dental visits, parental dental fear (M-DAS) and previous medical experience of the child (p>0.001). In contrast, age (p=0.005), previous child's dental fear (p=0.081), previous child's dental behaviour (p<0.0001), predicted by the parent behaviour (p<0.0001) and parental version of CFSS-DS (p<0.001), revealed statistically significant associations to child's behaviour during treatment. CONCLUSION: According to the present study in Greek children, children's behaviour during dental treatment is related to age, previous dental fear and experience and behaviour prediction by the parents. Parents' estimations regarding their children's fear and behaviour could be a useful predictor of child's level of cooperation during dental treatment.

Molar-incisor-hypomineralisation (MIH). Retrospective clinical study in Greek children. I. Prevalence and defect characteristics.

AIM: This was to evaluate the prevalence and the clinical characteristics of MIH in a group of Greek children. METHODS: During the years 2003--2005, all MIH cases diagnosed according to the recently set criteria were selected from the new patients clinic of a Community Dental Centre for Children (Athens). Age, gender and teeth involved were recorded. The severity of MIH was determined collectively by dividing the affected teeth in two groups; a) mild defect (demarcated opacities) and b) moderate/severe defect (enamel breakdown and atypical restorations). Evaluation of the distribution of the affected teeth within MIH cases was performed in a separate group of 225 affected children aged 8-12 years with their entire 12 'index' teeth erupted. RESULTS: From the 3,518, 5.5 to 12 year old children that were examined, there were 360 (10.2%) children with MIH, 211 (58.6%) females and 149 (41.4%) males, with 1,926 affected teeth, 1,231 molars and 695 incisors. In the molars group, maxillary molars were more frequently affected (87.8/90.3%) than mandibular (81.7/82.2%). In the central incisor group, maxillary teeth were also more frequently affected (50/55%) than mandibular (24.4/25%), while laterals were the least affected. In all there were 37.9% molars with moderate/severe defects as compared with 4.9% incisors, the remaining 62.1% and 95.1% respectively being mild. The various associations between the affected teeth were evaluated in the sub-group of 225 MIH children with all 'index' teeth erupted (1,286 affected teeth, 776 molars and 510 incisors), with mean number of affected teeth per child being 5.7; separately for molars 3.4 and for incisors 2.2. In these cases 28.4% of the children had only molars affected and 71.6% had both molars and incisors. In descending order the associations of affected teeth more frequently found were: 4 molars/2 incisors (23.5%), 4 molars/4 incisors (16.8%), 4 molars alone (15.1%) and 2 molars alone (9.7%), the remaining being much less. STATISTICAL ANALYSIS: As age increased the clinical severity of the affected teeth became more prevalent (p=0.0001), and when the total number of affected teeth was assessed the likelihood of having severe defect was also increased (p=0.001). CONCLUSION: The prevalence of the defect in the present study was 10.2% with maxillary teeth being more frequently affected. Severity increased with age. Mild defects were much more frequent, particularly in incisors. The total number of teeth affected and the most frequently found associations were, 4 molars/2 incisors, 4 molars/4 incisors, 4 molars alone and 2 molars alone.

Molar-incisor-hypomineralisation (MIH). A retrospective clinical study in Greek children. II. Possible medical aetiological factors.

AIM: This was to examine the potential medical aetiological factors involved in the development of MIH. METHODS: During the years 2003--2005, all MIH cases diagnosed according to set criteria were selected from the new patients clinic of a Community Dental Centre for Children (Athens). The age, gender and teeth involved were recorded. A control group of socio-demographically matched controls was also identified. The potential aetiological factors were retrieved through personal interview with the parents and from each child and mother's medical book. Only verified aetiological factors were recorded. Evaluation of the correlation of affected teeth and the timing of the insult was performed in a separate group of 225 affected children aged 8-12 with their entire 12 'index' teeth erupted. RESULTS: From the 3,518, 5.5 to 12 years old children examined, 360 (10.2%) had MIH. Aetiology of MIH: 44 children (12.2%), presented without any relevant medical history, the remaining 316 (87.8%) recorded various medical problems associated with MIH, compared with 18.9% for controls. Perinatal (163, 33.6%) and postnatal (162, 33.9%) problems were the most frequently found and prenatal the least (33, 8.6%). For 42 children (11.7%) problems occurred in more than one chronological period, mainly during both the perinatal and postnatal period (11.1%). The most common prenatal problem was repeated episodes of high fever (12/33), in the perinatal period birth by Caesarean section (92/163) and other birth complications (34/163). Various respiratory conditions (88/162), repeated episodes of high fever (31/162) and neonatal illness (28/162) were the commonly reported problems in the postnatal period. Many MIH cases presented with more than one medical problem during the peri-and postnatal period. STATISTICAL ANALYSIS: Children with MIH recorded 68.9% more frequent medical problems than controls (p<0.0001). A positive correlation (p<0.001) between the total number and type of affected teeth with the timing of the insult was observed in the 225 MIH children with all their 'index' teeth erupted. CONCLUSION: Children with MIH present with more medical problems than controls during their prenatal, perinatal and postnatal period. The majority of these illnesses may produce hypocalcaemia, hypoxia and pyrexia to the child or the mother. The number of affected teeth was associated with the timing of the possible insult; children with prenatal, perinatal and postnatal problems present more affected teeth in increasing order.