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Paper text:
amelogenesis imperfecta ( ai ) , a group of hereditary diseases affecting the tooth enamel in either quality or quantity , is associated with crown malformation and abnormal enamel density . the prevalence varies from 1:700 to 1:14 000 , according to the populations studied .
clinical features of patients with ai depend on the type of ai involved . ai has been classified on the basis of clinical , radiographic , and histologic appearance of the enamel defect and the mode of inheritance of the trait .
ai has been categorized as hypoplastic ( autosomal dominant / autosomal recessive / x - linked dominant ) , hypocalcified ( autosomal dominant / autosomal recessive ) , hypomaturation types ( autosomal recessive / x - linked recessive / autosomal dominant ) and hypoplastic - hypomaturation type .
hypoplastic ai represents 60 to 73% of all cases , hypomaturation ai represents 20 to 40% , and hypocalcification ai represents 7% .
hypoplastic form of ai is characterized by thin enamel with yellowish - brown color , rough or smooth and glossy , square - shaped crown , lack of contact between adjacent teeth , flat occlusal surfaces of the posterior teeth due to attrition , and with / without grooves and / pitting .
radiographically , in hypoplastic type , there is a presence of thin radiopaque layer of enamel with normal radiodensity .
hypocalcified form of ai is the most common type and is characterized by normal size and shape of crown , softer enamel which wears down rapidly and can be removed by a prophylaxis instrument , and become pigmented - dark brown colored .
radiographically , in hypocalcified form , thickness of enamel is normal but radiodensity of enamel is less than that of dentin .
hypomaturation form of ai is characterized by normal thickness of enamel but softer than normal but harder than hypocalcified type and may crack away from the crown , mottled - colored cloudy white / yellow / brown / snow capped .
histologically , in hypomaturation type , alterations in enamel rod and rod sheath structures had been noted in various studies . in hypoplastic - hypomaturation with taurodontism , the enamel is thin , mottled yellow to brown , and pitted .
a 17-year - old male patient presented with a complaint of yellow discoloration of his teeth since 8 to 9 years .
patient was giving positive history of discolored anterior deciduous teeth ; however , medical history and family history was unremarkable .
all the anterior and posterior teeth were affected with brownish discoloration ; while attrition present with posterior teeth .
height of the clinical crowns of upper and lower posterior teeth were reduced . in 11 , 14 , 21 , 22 , 24 ,
panoramic radiograph was taken which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] .
on the basis of clinical and radiographic features , final diagnosis of hypoplastic ai was made .
clinical photos showing amelogenesis imperfecta ( case 1 - case 4 ) opg - panoramic view of patients showing radiographic features of amelogenesis imperfecta ( case 1 - case 4 ) a 12-year - old male patient came with a complaint of yellow brown discoloration of his upper anterior teeth since 4 - 5 years .
on examination , brownish discoloration was present in 21 , 11 , 36 , 46 and chalky white discoloration was present in relation with all other teeth .
incisal edges of 33 , 34 , 43 , 44 were thin with dentin exposed .
enamel was softer in consistency with chipping of enamel on probing [ figure 1 ] . on the basis of clinical examination , provisional diagnosis of hypomaturation ai
panoramic radiograph was advised which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin and taurodontism of 16 , 26 [ figure 2 ] .
final diagnosis of hypoplastic - hypomaturation - ai with taurodontism of 16 , 26 was made .
a 22-year - old female patient came with a complaint of yellow discoloration of teeth since 12 - 13 years .
upper and lower posterior teeth showed yellowish brown discoloration with attrition [ figure 1 ] .
consistency of enamel in affected teeth was hard and chipping of enamel not present in any teeth .
on the basis of clinical examination , provisional diagnosis of hypoplastic ai was made and panoramic radiograph was advised which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] .
a 14-year - old male patient came with a complaint of yellow discoloration of teeth since 5 - 6 years . past dental history was suggestive of discolored deciduous teeth . medical history and
anterior as well as posterior teeth of all segments showed brownish discoloration [ figure 1 ] .
on the basis of clinical features , provisional diagnosis of hypoplastic type of ai was made .
panoramic radiograph advised to confirm the diagnosis which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] . on the basis of clinical and radiographic features , final diagnosis of ai of hypomaturation type
a 17-year - old male patient presented with a complaint of yellow discoloration of his teeth since 8 to 9 years .
patient was giving positive history of discolored anterior deciduous teeth ; however , medical history and family history was unremarkable .
all the anterior and posterior teeth were affected with brownish discoloration ; while attrition present with posterior teeth .
height of the clinical crowns of upper and lower posterior teeth were reduced . in 11 , 14 , 21 , 22 , 24 ,
panoramic radiograph was taken which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] .
on the basis of clinical and radiographic features , final diagnosis of hypoplastic ai was made .
clinical photos showing amelogenesis imperfecta ( case 1 - case 4 ) opg - panoramic view of patients showing radiographic features of amelogenesis imperfecta ( case 1 - case 4 )
a 12-year - old male patient came with a complaint of yellow brown discoloration of his upper anterior teeth since 4 - 5 years .
patient had mixed dentition present with deciduous molar root pieces . on examination , brownish discoloration was present in 21 , 11 , 36 , 46 and chalky white discoloration was present in relation with all other teeth .
incisal edges of 33 , 34 , 43 , 44 were thin with dentin exposed .
enamel was softer in consistency with chipping of enamel on probing [ figure 1 ] . on the basis of clinical examination , provisional diagnosis of hypomaturation ai
panoramic radiograph was advised which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin and taurodontism of 16 , 26 [ figure 2 ] .
final diagnosis of hypoplastic - hypomaturation - ai with taurodontism of 16 , 26 was made .
a 22-year - old female patient came with a complaint of yellow discoloration of teeth since 12 - 13 years .
upper and lower posterior teeth showed yellowish brown discoloration with attrition [ figure 1 ] .
consistency of enamel in affected teeth was hard and chipping of enamel not present in any teeth . on the basis of clinical examination , provisional diagnosis of hypoplastic ai
was made and panoramic radiograph was advised which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] .
a 14-year - old male patient came with a complaint of yellow discoloration of teeth since 5 - 6 years .
past dental history was suggestive of discolored deciduous teeth . medical history and family history was unremarkable .
anterior as well as posterior teeth of all segments showed brownish discoloration [ figure 1 ] .
chipping of enamel was not present in any tooth . on the basis of clinical features , provisional diagnosis of hypoplastic type of ai was made .
panoramic radiograph advised to confirm the diagnosis which showed presence of a thin layer of enamel with radiodensity of enamel more than dentin [ figure 2 ] . on the basis of clinical and radiographic features , final diagnosis of ai of hypomaturation type
during organogenesis , the enamel transitions from a soft and pliable tissue to its final form , this is almost entirely devoid of protein .
the final composition of enamel is a reflection of the unique molecular and cellular activities that take place during its genesis .
mutation or alteration in any of the genes encoding specific enamel proteins such as enamelin gene ( enam ) , amelogenin gene ( amelx ) , kallikrein 4 gene ( klk4 ) , matrix metalloproteinase 20 gene ( mmp-20 ) , and distal - less homeobox 3 gene ( dlx3 ) have been linked with ai .
studies showed that ai is familial and can be inherited as autosomal dominant , autosomal recessive , or x - linked dominant and x - linked recessive .
although both deciduous and permanent dentition are affected in ai , it is affected more commonly in permanent teeth than primary teeth and more commonly in incisor teeth and first molars in both upper and lower jaws . according to various studies of ai ,
many non - enamel anomalies have been found in association with ai , e.g. , : delayed tooth eruption , congenitally missing teeth , anterior open bite , taurodontism , pulpal calcifications , dentin dysplasias , root and crown resorption , hypercementosis , and root malformations .
various studies showed that oral complaints associated with ai are unaesthetic appearance , extensive loss of tooth structure , dental sensitivity , and loss of vertical dimension .
treatment planning for patients with ai is related to many factors : the age and socioeconomic status of the patient , the type and severity of the disorder , and the intraoral situation at the time the treatment is planned .
it includes removal of surface stains , reducing sensitivity , maintaining vertical dimension of occlusion , and the esthetics with adhesive techniques / overdentures / porcelain - fused - to metal crowns / fixed partial dentures / full porcelain crowns / inlay / onlay restorations are used for better esthetics of the patients .
preventive aspects in the primary and mixed dentition include dietary advice , fluoride supplements , and oral hygiene instructions .
restorative aspects in the primary dentition includes giving glass ionomer restorations and stainless steel crowns , in the mixed dentition stainless steel crowns .
amelogenesis imperfecta ( ai ) represents a group of developmental conditions , genomic in origin , which affect the structure and clinical appearance of enamel of all or nearly all the teeth in a more or less equal manner . 
 ai is a serious problem that reduces oral health - related quality of life and causes some physiological problems . 
 we presented here four case reports of ai ( hypoplastic and hypomaturation ) which we diagnosed on the basis of classical clinical and radiographic features .