• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.352-358
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• 2021

Molar-incisor malformation (MIM) is characterized by malformation in the root with a normal crown. While MIM mostly occurs in the permanent first molar, it has also been reported in the maxillary central incisor and the primary second molar (PSM), but anatomical analysis of the primary teeth with MIM has not been studied to date. In this case report, a patient with MIM was reported, and an extracted PSM with MIM was analyzed with micro computed tomography (CT). A cervical constriction morphology of the cementoenamel junction (CEJ) can be observed in extracted PSM. In micro CT analysis, characteristics such a mineralized plate (cervical mineralized diaphragm) in the CEJ area, complex root canal morphologies, a calcified mass inside the pulp chamber, and constricted pulp chamber of crown portion were observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.370-377
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• 2017

Molar-incisor malformation (MIM) is a recently described dental anomaly characterized by root malformation in permanent first molars accompanied sometimes by abnormal root forms in primary second molars or enamel defects in maxillary central incisors. This report presents three cases of MIM along with a review of previous studies. Three patients exhibited abnormal root forms in the permanent first molars, with varying degrees of deformation. Two of the patients experienced medical events at birth. One of the patients was a monozygotic twin, whose twin sister exhibited normal dentition without any significant abnormalities. The present report also reviews recently reported cases of MIM in literature. In the management of MIM-associated clinical issues, consideration of microscopic features and accompanying characteristics might facilitate early diagnosis and comprehensive treatment planning.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.337-343
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• 2020

Molar-incisor malformation (MIM) is a new type of root anomaly reported recently. The characteristics of MIM are dysplastic root formations, constriction of pulp chambers and presence of calcified matrices at the level of cementoenamel junction in permanent first molars and primary second molars. In some cases, permanent maxillary incisors are also affected. The permanent first molars of the patient in this case report were affected with MIM. Generalized pulp stones were observed in overall primary dentition. Micro-computed tomography (micro-CT) imaging and scanning electron microscope-energy dispersive X-ray spectrometer analysis were performed on the extracted mandibular first molar and maxillary primary second molar of the patient. Micro-CT images revealed the discontinuity of enamel directly connected to an accessory canal of the root.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.181-189
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• 2022

Molar incisor malformation (MIM) has been introduced as a new type of dental anomaly. Currently, the morphological and histological characteristics of MIM are known; however, its etiology has not been clearly identified. To date, the long-term prognosis of first permanent molars (FPM) affected by MIM has rarely been reported, and few treatment guidelines have been established. The purpose of this case report was to present guidelines for the extraction of FPM affected by MIM, depending on the presence of the third molar. In patients with a third molar, spontaneous mesial shift of the posterior molars might be induced by extracting the FPM at an appropriate time, that is, when the second permanent molar is at an early furcation stage of the tooth. However, it is recommended that FPM be preserved for as long as possible if a third molar does not exist. When an FPM needs to be extracted, it is suggested to consider space maintenance.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.121-130
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• 2022

Molar-incisor malformation (MIM) is a newly reported dental anomaly with molar root deformity and incisor crown defects. MIM-affected teeth may cause severe pain with no apparent tooth caries. Since the affected molars clinically appear normal, radiographs are recommended for accurate diagnosis on the first visit. Since MIM-affected patients are in mixed dentition, timely and appropriate interventions are needed to avoid unnecessary pain and complicated clinical issues. This report was written to describe two patients who had MIM in early mixed dentition and report their 2-year follow-ups.