Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2019  |  Volume : 37  |  Issue : 3  |  Page : 282--285

Analysis of bone mineral density and content in children with molar incisor hypomineralization using dual-energy X-ray absorptiometry scan: A pilot study


Morankar Rahul1, Goyal Ashima1, Gauba Krishan2, Singla Veenu3,  
1 Oral Health Sciences Centre, Unit of Pedodontics and Preventive Dentistry, PGIMER, Chandigarh, India
2 Oral Health Sciences Centre, PGIMER, Chandigarh, India
3 Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh, India

Correspondence Address:
Dr. Morankar Rahul
Assistant Professor, PGIMER Satellite Centre, Sangrur, Punjab, Ex Senior Resident, Oral Health Sciences Centre, Unit of Pedodontics and Preventive Dentistry, PGIMER, Chandigarh - 160 012
India

Abstract

Aim: The objective was to evaluate the bone mineral density (BMD) and bone mineral content (BMC) in children affected with molar incisor hypomineralization (MIH) using dual-energy X-ray absorptiometry (DEXA) scan. Materials and Methods: The study comprised a total of 30 children aged 6–10 years. Fifteen children were affected with MIH (moderate and severe variety) diagnosed using the European Academy of Paediatric Dentistry 2003 criteria, and remaining 15 children not affected with MIH serve as a control group. DEXA scan was done in all the selected children under standard conditions. Results: A positive association was seen between childhood illness and MIH. The mean subtotal BMC (grams) in MIH and control group was 633 ± 80.05 and 670.33 ± 166.41, respectively, whereas mean subtotal BMD (g/m2) was 1.00 and 0.87 ± 0.35, respectively, with no statistically significant difference between two groups. BMD and BMC at the lumbar spine and thoracic spine locations were also did not vary significantly between MIH-affected children and controls. Conclusion: Childhood illnesses were more common in MIH-affected children compared to controls. Bone maturation parameters (BMD, BMC) do not differ between MIH affected and control children.



How to cite this article:
Rahul M, Ashima G, Krishan G, Veenu S. Analysis of bone mineral density and content in children with molar incisor hypomineralization using dual-energy X-ray absorptiometry scan: A pilot study.J Indian Soc Pedod Prev Dent 2019;37:282-285


How to cite this URL:
Rahul M, Ashima G, Krishan G, Veenu S. Analysis of bone mineral density and content in children with molar incisor hypomineralization using dual-energy X-ray absorptiometry scan: A pilot study. J Indian Soc Pedod Prev Dent [serial online] 2019 [cited 2019 Nov 22 ];37:282-285
Available from: http://www.jisppd.com/text.asp?2019/37/3/282/268182


Full Text



 Introduction



Enamel is a highly mineralized tissue of ectodermal origin with inability to repair postmineralization. It is laid down by specialized cells called ameloblasts which are highly sensitive and even minimal insults during the period of enamel formation can lead to either quantitative (hypoplasia) or qualitative (hypomineralization/hypomaturation) enamel defects.[1],[2]

Molar–incisor hypomineralization (MIH) is a defect of systemic origin that affects one or more permanent first molars and frequently affects permanent incisors.[3] MIH is a clinical condition that has been a source of concern for the clinicians worldwide owing to its global presence and associated clinical challenges. Non availability of an effective and predictable restorative modality for this condition, in addition to the associated hypersensitivity, pain, and behavioral problems have made clinical management very challenging.[4]

MIH-affected teeth typically represent a poor mineralization of the enamel. The affected enamel is with low Ca:Pratio and high carbon content.[5],[6] Fluoride content is highly variable, and surface layers may show higher fluoride content owing to its posteruptive absorption from saliva. The affected enamel also has higher than normal amounts of sodium, potassium, and magnesium. A normal, unaffected tooth has a higher concentration of minerals at surface compared to dentinoenamel junction, while in a MIH-affected tooth, this order is reversed.[6] The content of protein in MIH-affected enamel is higher than a normal enamel.[7]

The minerals such as calcium and phosphorus are essential for the process of enamel maturation.[8] Enamel formation of permanent first molar starts in the third trimester prenatally. It is completed by the age of about 2.5–3 years.[9] Bone formation is a continuous process and is quite similar to enamel formation with regard to the predominance of calcium and phosphorus minerals.[10] MIH, which is a qualitative defect of enamel formation, has been suggested to be indirectly associated with the bone mass of an individual.[11] The present investigation was planned with an objective to evaluate the bone maturation parameters (bone mineral density [BMD] and content) in children affected with MIH.

 Materials and Methods



The study sample consists of a total of 30 children, 15 diagnosed with MIH and 15 unaffected controls selected from children aged 6–10 years, attending the Outpatient Unit of Pediatric and Preventive Dentistry. Inclusion criteria for samples were MIH-affected children (moderate and severe variety), age ranges between 6 and 10 years, and those giving consent for their participation in the study.

Ethical clearance was obtained from the Institute Ethics Committee (INT/IEC/2017/747) before the commencement of the study. The parents were informed about the objectives of the study, and written informed consent was obtained from all the participants. They were explained about the possible risk associated with dual-energy X-ray absorptiometry (DEXA) scan and benefits of preventive assessment of BMD and bone mineral content (BMC), as it can help to assess the risk of developing osteoporosis and bone fracture. European Academy of Paediatric Dentistry 2003 criteria was used to diagnose the children affected with MIH by a calibrated evaluator, and only those having moderate and severe variety of MIH were selected.[12]

Measurement of bone mineral density and content

The selected children in two groups were matched with respect to mean age, height, weight, and gender. DEXA scan was carried out for all the patients at the department of radiodiagnosis and imaging, PGIMER, Chandigarh, under standard conditions (Hologic, Horizon DXA system, Auto whole body fan beam, version 13.4.2., USA). BMD was measured over a projected area (bone area) in the scan. BMC (bone mass) was derived multiplying BMD by bone area. The subtotal (total body except head) results are recommended by the International Society for Clinical Densitometry for the evaluation of childhood skeletal disorders.[13] Therefore, subtotal BMD and BMC were measured for all the selected children. In addition, BMD and BMC were also determined at lumbar spine and thoracic spine locations. Children with less than normal BMD and BMC for their age were further referred to the Advanced Pediatric Centre, PGIMER, Chandigarh, for needful.

Statistical analysis

MS Excel (Microsoft corporation, Redmond, WA, USA) was used to enter information in a database. SPSS version 21.0, IBM Corp., Armonk, NY, USA, software was used for statistical analysis. Qualitative data were described as frequencies and rates/proportions analyzed for its association with the groups using Chi-square test. Quantitative data were presented as mean ± standard deviation and analyzed using Student's t-test or Fisher's exact test where indicated. All statistical tests were performed at a significance level of P= 0.05.

 Results



The results revealed that MIH and control group children did not differ significantly in terms of mean age (years), height (cm), weight (kg), and gender [Table 1]. There was a positive association between childhood illness (birth to first 3 years of life) and MIH [Table 2]. BMD and BMC did not differ significantly between MIH and control group [Table 3].{Table 1}{Table 2}{Table 3}

 Discussion



Enamel and bone both are made up of hydroxyapatite, and their maturation is quite similar to each other with calcium and phosphorus being the principal minerals. Despite the availability of vast amount of research, the sight into etiological factors of MIH is still unclear. Van der Tas et al. in their study found a positive association between decreased bone mass and dental hypomineralization.[11] Thus, the present study was carried out with an aim to evaluate the BMD and BMC in children affected with MIH, a qualitative defect of enamel formation.

A thorough clinical history of the selected children revealed that more number of children affected with MIH had childhood illness in the first 3 years of life compared to controls. Enamel formation of permanent first molar and incisor starts at 8 months intrauterine and is completed by the age of 2.5–3 years, therefore, an insult to ameloblasts during enamel formation due to a medical condition or any other contributing factor leads to a formative defect in these teeth.[13] They can also affect the overall growth of the child resulting in delayed bone growth and maturation which may reflect in its mineral content and density. Therefore, both enamel as well as bone formation may get affected due to childhood medical conditions.

The subtotal BMD and BMC, that is, total body minus head better reflects an overall BMD and BMC of a young child, as the head is disproportionately larger in young child and may mask deficits at other skeletal sites.[14] An analysis of thoracic and lumbar spine for mineral content and density also gives very reliable and consistent results.[15] In the present study, the selected children in MIH and control group did not differ significantly in terms of mean age (years), height (cm), weight (kg), and gender which can significantly affect the bone formation and maturation. There was no statistically significant difference between MIH and the control group children, with respect to bone maturation parameters. This can be attributed to duration of period over which bone is formed compared to enamel formation. Bone formation is a continuous process characterized remodeling throughout the life, whereas enamel is formed over a small period of time and is not characterized by any repair mechanism. Therefore, enamel is more prone to developmental disturbances compared to the bone.

This cross-sectional analysis has not found any difference in BMD and BMC between MIH and control children. This can be attributed to the age group (6–10 years) of selected samples, as the present study was not assessing the bone maturation during the critical period of enamel formation in MIH-affected children. These children may have a bone development problem in the past, but it may not be persistent at present. In other words, if there had been a systemic event, the bone may have recovered, or possibly was never affected. Hence, the best way to study the effect of bone-related parameters on enamel maturation would be a prospective trial which is difficult to carry out.

 Conclusion



Bone maturation parameters (BMD and BMC) do not differ between MIH affected and control children. Childhood illnesses in the first 3 years of life were more common in MIH-affected children compared to controls.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Clarkson J. A review of the developmental defects of enamel index (DDE). Int Dent J 1992;42:411-26.
2Suckling GW. Developmental defects of enamel – Historical and present-day perspectives of their pathogenesis. Adv Dent Res 1989;3:87-94.
3Weerheijm KL, Jälevik B, Alaluusua S. Molar-incisor hypomineralisation. Caries Res 2001;35:390-1.
4Lygidakis NA, Dimou G, Marinou D. Molar-incisor-hypomineralisation (MIH). A retrospective clinical study in Greek children. II. Possible medical aetiological factors. Eur Arch Paediatr Dent 2008;9:207-17.
5Jälevik B, Klingberg G, Barregård L, Norén JG. The prevalence of demarcated opacities in permanent first molars in a group of Swedish children. Acta Odontol Scand 2001;59:255-60.
6Fearne J, Anderson P, Davis GR. 3D X-ray microscopic study of the extent of variations in enamel density in first permanent molars with idiopathic enamel hypomineralisation. Br Dent J 2004;196:634-8.
7Mahoney EK, Rohanizadeh R, Ismail FS, Kilpatrick NM, Swain MV. Mechanical properties and microstructure of hypomineralised enamel of permanent teeth. Biomaterials 2004;25:5091-100.
8Smith CE. Cellular and chemical events during enamel maturation. Crit Rev Oral Biol Med 1998;9:128-61.
9Alaluusua S. Aetiology of molar-incisor hypomineralisation: A systematic review. Eur Arch Paediatr Dent 2010;11:53-8.
10Zhu K, Prince RL. Calcium and bone. Clin Biochem 2012;45:936-42.
11van der Tas JT, Elfrink ME, Vucic S, Heppe DH, Veerkamp JS, Jaddoe VW, et al. Association between bone mass and dental hypomineralization. J Dent Res 2016;95:395-401.
12Weerheijm KL, Duggal M, MejÁ re I, Papagiannoulis L, Koch G, Martens LC, et al. Judgement criteria for molar incisor hypomineralisation (MIH) in epidemiologic studies: A summary of the European meeting on MIH held in Athens, 2003. Eur J Paediatr Dent 2003;4:110-3.
13Takahashi K, Correia Ade S, Cunha RF. Molar incisor hypomineralization. J Clin Pediatr Dent 2009;33:193-7.
14Gordon CM, Bachrach LK, Carpenter TO, Crabtree N, El-Hajj Fuleihan G, Kutilek S, et al. Dual energy X-ray absorptiometry interpretation and reporting in children and adolescents: The 2007 ISCD pediatric official positions. J Clin Densitom 2008;11:43-58.
15Bonnick SL. New applications for DXA. In: Bone Densitometry in Clinical Practice: Application and Interpretation. 3rd ed. New Jersey: Humana Press, Springer Publication; 2010. p. 347.