molar - incisor hypomineralization ( mih ) is a clinical condition of systemic origin characterized by qualitative enamel defects of the first permanent molars and frequently associated with affected incisors . for a patient to be diagnosed as suffering from mih , at least one permanent first molar the term molar hypomineralization has been used , sometimes , to distinguish children in whom the incisors are not affected . due to the developmental history of the permanent first molars and upper and lower anterior teeth , the search for an etiology has focused around the time of birth and early childhood . several researchers have discussed possible causes , prenatal ( maternal infections , metabolic disturbances , etc . ) , natal ( complicated delivery ) and postnatal ( neonatal viral infections , prolonged antibiotic and other medication usage ) . however , there is currently insufficient evidence to establish etiological factor(s ) relevant to mih and it has been suggested that mih is caused by not one but many different factors which may act together , increasing the risk . the defect is clinically presented as demarcated enamel opacities of different color in the affected teeth , occasionally undergoing posteruptive breakdown due to soft and porous enamel . this may result in atypical cavities or even complete coronal distortion , requiring extensive restorative treatment . post - eruptive breakdown of the defective enamel creates areas more conducive to plaque retention which , combined with improper oral hygiene maintenance by the patient because of profound hypersensitivity of the affected teeth , might collectively result in increased caries susceptibility . the importance of recognizing and managing mih can not be overemphasized . early identification of the condition and its prompt management is crucial for successful , longterm outcomes in affected children . failure to address mih and its related problems such as dental caries can lead to further and severe destruction of tooth structure and ultimately , result in loss of the affected teeth or in rare cases , give rise to a life - threatening situation due to severe infection . this paper presents an untreated case of severe mih that led to pulpal involvement of one of the affected teeth and consequently , to submandibular and submental space infection . a 12-year - old boy reported to our paediatric dental service with the complaint of pain and swelling in the lower face and jaw since five days , associated with fever and inability to open the mouth or swallow food . the pain and swelling originated in the region of the right lower back tooth and eventually spread to the left side of the mandible . he had , a few days earlier , consulted a local dental practitioner for the same problem but was only prescribed medication for pain . examination revealed a diffuse swelling which involved the submental and submandibular areas bilaterally and extended from the angle of the mandible of one side to the other . the swelling was hard and tender , and the overlying skin was stretched , shiny , and reddened ( figure 1 ) . mouth opening was restricted to less than two centimeters , which allowed only a limited intraoral examination . it was observed that the mandibular first permanent molars were hypomineralized and badly destructed ( figure 2 , picture taken on third day ) and the labial surface of the maxillary left central incisor showed the presence of a small , demarcated , opaque - white patch of hypomineralization ( figure 3 ) , findings that are characteristic of mih . the molar hypomineralization was of the severe type ( post - eruptive enamel breakdown ) and the incisor hypomineralization of the mild type ( whitecream opacity without enamel breakdown ) . the oral hygiene of the patient was poor and halitosis was present ; however , this could be due to an inability , caused by restricted mouth opening to perform adequate oral hygiene procedures . orthopantomograph revealed radiolucencies closely approximating the pulps in both mandibular first permanent molars , periapical radiolucency in relation to the mesial root and widened periodontal space around the distal root of the right mandibular first permanent molar ( figure 4 ) . a diagnosis of space infection involving the submandibular and submental spaces bilaterally was made from the clinical and radiographic findings . since the child was highly anxious , he was first counseled along with his parents . the dentoalveolar abscess is poly - microbial comprising various facultative anaerobes and strict anaerobes and a vast majority of dental abscesses respond to surgical treatment , such as drainage of pus and elimination of the source of infection , with antibiotic use limited to severe spreading infections . therefore , following routine blood investigations the patient was put on intravenous analgesics , fluids and empiric antibiotic therapy with amoxicillin and metronidazole . after 24 h the patient 's mouth opening was found to have increased sufficiently to allow emergency access opening of the right first permanent molar . by the second day , the swelling was reduced and mouth opening was improved considerably permitting complete cleaning of the root canals . the boy was discharged after three days with instructions to continue oral antibiotics for four days more totaling a course of seven days . at his next appointment four days later , the boy appeared fine , the swelling having diminished completely and the mouth opening to normal limits . excavation of caries in the left first permanent molar revealed no pulpal involvement ; hence , indirect pulp capping was done . stainless steel crowns were placed on both mandibular first permanent molars ( figure 5 ) and sealants on maxillary first permanent molars . the incisor hypomineralization was very mild and since it did not present a major esthetic problem , it was decided that no treatment was required for the same . the decline of dental caries worldwide has encouraged researchers and clinicians to observe and recognize other problems that were overlooked in the past . the last couple of decades has seen the recognition and acknowledgement of non - fluoride - associated developmental dental defects as an increasing clinical problem . these defects , characterized by discolored opacities or as a total absence of enamel , are observed to most commonly affect the first permanent molars with or without involvement of the permanent incisors . during the last decade the presence of enamel defects can considerably affect a child 's overall well - being . defective molars may be profoundly sensitive to routine oral hygiene procedures as well as more susceptible to plaque accumulation and dental caries . research has found that , by nine years of age , mih - affected children have undergone dental treatment on their permanent first molars nearly ten times as often as healthy children . this greater incidence of dental caries combined with compromised , defective enamel results in substantial dental morbidity and presents challenges to the clinician . not surprisingly , behavior management problems and dental fear and anxiety are common in affected than unaffected individuals . serious complications seldom arise out of mih if the condition is detected and managed early . however , severe , untreated cases are more often than not associated with dental caries . destruction of the coronal tooth structure may result in tipping of the adjacent teeth or supraeruption of the opposing tooth , necessitating orthodontic intervention . on rare occasions , severe infection involving a mih - affected tooth considering the high prevalence , it becomes imperative that the condition be identified early and appropriate treatment instituted as soon as possible . by this , not only is the further destruction of the tooth structure prevented , the occurrence of complications such as the one seen in the present case becomes virtually impossible . the available treatment modalities for teeth with mih are extensive , ranging from prevention to restoration to extraction . the decision on which treatment should be based is complex and dependent on a number of factors such as the severity of the condition , dental age of the child , presence of carious lesions , occlusion , aesthetics , orthodontic condition and patient / parent compliance . knowledge of the clinical appearance of mih and its diagnosis as soon as the first permanent molars erupt play an important role in planning treatment , maintenance and prognosis . because of the different degrees of involvement in a single patient 's mouth , assessment of each of the affected teeth is necessary for providing effective treatment . it is also important to raise public awareness regarding dental enamel malformations that can increase the caries risk of the individual .
complications arising because of untreated molar - incisor hypomineralization ( mih ) have received little mention in the dental literature . however 
 , this can be an area of concern , with severe consequences in rare cases . 
 hence , early recognition and prompt management of mih is essential for long - term oral health of affected individuals . 
 this paper describes an untreated case of severe mih that resulted in infection of facial spaces .