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A Kindred Showing Hypocalcified Amelogenesis Imperfecta: Report of Case
A kindred showing hypocalcified amelogenesis imperfecta: report of case
J o s e p h S . G ia n s a n ti, D M D , M S D , A tla n ta
A N e g r o g irl c a m e to th e E m o r y U n iv e rs ity D e n ta l S c h o o l a n d re q u e s te d f u ll-m o u th e x tra c tio n s . S h e w a s f o u n d to h a v e a m e lo g e n e s is im p e rfe c ta of th e h y p o c a lc ifie d o r h y p o m in e ra liz e d typ e . C a lc u lu s d e p o s i t i o n w a s u n u s u a l l y s e v e r e ; it a p p a r e n t l y w a s a g g ra v a te d b y p o o r o ral h y g ie n e . In fo rm a tio n in d ic a te d th a t a m e lo g e n e s is im p e rfe c ta w a s p re s e n t in t h e t e e th o f o t h e r m e m b e r s o f t h e f a m ily .
The term amelogenesis imperfecta indicates an imperfect formation o f enamel. Although Schulze1 also uses this term to include enamel defects associated with systemic disease such as Morquio’s disease and oculodentodigital dys plasia, Darling2 and Witkop3 do not. The latter restrict the use of the term to indicate a heredi tary defect in enamel formation without clinical ly demonstrable alterations in other tissues. Am elogenesis imperfecta is an uncommon disease, having an incidence in children o f about 1:14,000 to 1:16,000.4 The two main categories of amelogenesis imperfecta are hypoplastic (hypoplastic-aplastic) and hypocalcified (hypomin eralized).1-2 Witkop3-4 adds a third type, hypomaturation, based on clinical, genetic, and struc tural differences between it and the hypocalci fied type. A number of subclassifications within the three main groups have been proposed. These are based on clinical or histologic differences, or in the mode o f transmission. These are listed and discussed by Schulze,1 and by Witkop and
Sauk5 in detail. These classifications are, in part, tentative, pending documentation of addi tional kindreds with amelogenesis imperfecta. We wish, therefore, to add the following kin dred of amelogenesis imperfecta discovered at Emory University School o f Dentistry.
R e p o rt of case A 17-year-old black girl came to the dental school and requested full-mouth extractions. Because o f the extreme degree of calculus deposition (Fig 1, 2) it was impossible to examine the teeth properly until a prophylaxis was performed. The enamel of the teeth was largely intact ex cept for three o f the maxillary incisors and focal areas of loss related to posterior occlusal con tact (Fig 3). The enamel appeared chalky, hav-
Fig 1 ■ Anterior view of patient's mouth before dental prophyl axis illustrating severe degree of calculus deposition and an terior open bite. JADA, V ol. 86, M a rc h 1973 ■
675
Fig 4 ■ Panoramic radiograph illustrating essentially normal tooth form and supporting structures. Fig 2 ■ Intraoral view before dental prophylaxis illustrates ex treme degree of calculus deposition on all surfaces of posterior teeth.
Fig 3 ■ Anterior view after dental prophylaxis.
ing none o f the translucency normally seen. With little effort the enamel could be penetrat ed with a sharp explorer, or scraped off with a scaler. The patient said that, from time to time, pieces of teeth “ chipped off.” There was an anterior open bite, right poster ior crossbite, and mandibular prognathism. The degree of open bite was definitely greater than the corresponding loss of enamel (Fig 3). Radiographs revealed an essentially normal morphologic structure of crown and root (Fig 4). The enamel was generally of normal thick ness, but there was a definite loss of contrast between the enamel and dentin (Fig 5). A few teeth exhibited a moth-eaten appearance (Fig 676
■ JADA, V o l. 86, M a rch 1973
6). The upper left canine was impacted. There was no evidence o f resorption of erupted or un erupted teeth. N o pulpal calcifications or stones were seen. The condition of the supporting structures of the teeth v/as found to be within normal limits. The findings of a physical examination, with particular reference to other possible abnormal ities, including those of hair and nails, were otherwise normal. The patient said that her deciduous teeth had had a similar condition. Further questioning re vealed that the patient’s mother, as well as other relatives, was also affected. The family was then investigated; the results are shown in Fig 7. For socioeconomic reasons, the teeth were extracted; there were no complications. A num ber o f these teeth were studied. Thin, undecalcified sections of teeth showed only an accentuation of the interprismatic sub stance and small, focal areas of hypoplasia. In one region a cuticle was present on the surface of the enamel. Decalcified sections revealed dentin and cementum that were within normal limits. An unusual amount of enamel matrix was preserved. Radiographs of undecalcified thin ground sec tions showed considerable loss of contrast be tween enamel and dentin when compared with radiographs of similar sections of a normal tooth.
D is c u s s io n This propositus and kindred manifest amelogenesis imperfecta of the hypocalcified or hypo-
Fig 5 ■ R adiograph of low er an terior incisors illustra ting poor contrast between enamel and dentin.
Fig 6 ■ R adiograph eaten appearance.
of
m axillary incisors
<§> • ^ E X A M IN E D PROFESSIONALLY ■ ^H A S TRAIT © ^ E X A M IN E D PROFESSIONALLY E r DOES NOT HAVE TRAIT <§>
CHILDREN
I
INFANT )
illu stra tin g
moth-
RELIABLY REPORTED TO HAVE TRAIT
o□'
RELIABLY REPORTED ’’NOT TO HAVE TRAIT
RELIABLY REPORTED NOT TO HAVE
TRAIT
TEETH NOT ERUPTED Fig 7 ■ Pedigree o f fa m ily in question.
mineralized type. Information obtained from the family members indicates that the decidu ous and the permanent teeth were consistently affected. The condition is transmitted as an auto somal dominant trait. Although there is no maleto-male transmission, several affected males
have had normal daughters, thereby ruling out a sex-linked dominant transmission. This is the most common type of amelogenesis imperfecta,5 and similar cases have been re ported by others.li2,4,6'13 Calculus deposition, as seen in this patient, G ia n s a n ti: H Y P O C A LC IFIE D A M E L O G E N E S IS IM P E R FE C TA ■
677
is extreme, but is typical o f this type of amelogenesis imperfecta.5 H owever, in this kindred, it was stated not to be significant except in the propositus. Since for all practical purposes, no oral hygiene was practiced by this patient, the degree o f calculus formation probably was di rectly related. The presence o f open bite and crossbite in this patient is interesting. Although Schulze1 described one type of amelogenesis imperfecta as occurring with and without open bite, it is a sex-linked dominant type o f hypoplastic amelo genesis imperfecta. This subclassification into the presence or absence o f open bite is not ac cepted by others because open bite is not infre quently associated with deficiencies of tooth structure or eruption with a frequency greater than chance.5 A review o f the published reports of this type of amelogenesis imperfecta reveals essentially the same type of malocclusion in som e,11,12 but not all. T hese findings seemingly would support Witkop’s contention that the presence of open bite in amelogenesis imperfecta does not war rant separate classification. The histologic findings in the teeth examined are consistent with amelogenesis imperfecta of the hypocalcified type; these have been de scribed in detail by others.5-6-8-10
S u m m a ry A girl was seen who had amelogenesis imper fecta o f the hypocalcified or hypomineralized type. Evidence clearly indicated an autosomal dominant mode o f transmission. The calculus
678 ■ JA D A , V o l. 86, M a rc h 1973
deposition, which was unusually severe in this patient, is believed to be aggravated by the poor oral hygiene. The presence o f malocclusion in this patient is discussed relevant to the justification for sep arate categorization; it is concluded that such a separation is not warranted.
Dr. Giansanti is a member of the department of oral pathology, Emory University School of Dentistry, 1462 Clifton Rd, NE, At lanta, 30322. 1. Schulze, C. Developmental abnormalities of the teeth and jaw. In Gorlin, R.J., and Goldman, H.M. Thoma's oral pathology. St. Louis, C. V. Mosby Co., 1970, Vol 2, p 130. 2. Darling, A.I. Some observations on amelogenesis imper fecta and calcification of the dental enamel. Proc R Soc Med (Odontol Sec) 49:759 Oct 1956. 3. Witkop, C.J., Jr. Heterogeneity in inherited dental traits, gingival fibromatosis and amelogenesis imperfecta. South Med J 64:Suppl 11:16 Feb 1971. 4. Witkop, C.J., Jr. Genetic diseases of the oral cavity. In Tiecke, R.W. Oral pathology. New York, McGraw-Hill Book Co., 1965, p 801. 5. Witkop, C.J., Jr., and Sauk, J.J. Dental and oral manifesta tions of hereditary disease. Presented at workshop sponsored by American Academy of Oral Pathology, 1971, p 9. 6. Weinmann, J.P.; Svoboda, J.F.; and Woods, R.W. Heredi tary disturbances of enamel formation and calcification. JADA 32:397 April 1945. 7. Witkop, C.J., Jr. Hereditary defects in enamel and dentin. Acta Genet (Basel) 7:236 No. 1, 1957. 8. Chaudhry, A.P., and others. Hereditary enamel dysplasia. J Pediatr 54:776 June 1959. 9. Toller, P.A. Clinical report on six cases of amelogenesis imperfecta. Oral Surg 12:325 March 1959. 10. Rushton, M.A. Surface of the enamel in hereditary enamel hypocalcification. Br Dent J 112:24 Jan 2, 1962. 11. Laird, W.R. Hereditary amelogenesis imperfecta. Dent Pract (Bristol) 19:90 Nov 1968. 12. Winter, G.B. Hereditary and idiopathic anomalies of tooth number, structure and form. Dent Clin North Am 13:355 April 1969. 13. Pindborg, J.J. Pathology of the dental hard tissue. Phil adelphia, W. B. Saunders Co., 1970, p 77.
J o s e p h S . G ia n s a n ti, D M D , M S D , A tla n ta
A N e g r o g irl c a m e to th e E m o r y U n iv e rs ity D e n ta l S c h o o l a n d re q u e s te d f u ll-m o u th e x tra c tio n s . S h e w a s f o u n d to h a v e a m e lo g e n e s is im p e rfe c ta of th e h y p o c a lc ifie d o r h y p o m in e ra liz e d typ e . C a lc u lu s d e p o s i t i o n w a s u n u s u a l l y s e v e r e ; it a p p a r e n t l y w a s a g g ra v a te d b y p o o r o ral h y g ie n e . In fo rm a tio n in d ic a te d th a t a m e lo g e n e s is im p e rfe c ta w a s p re s e n t in t h e t e e th o f o t h e r m e m b e r s o f t h e f a m ily .
The term amelogenesis imperfecta indicates an imperfect formation o f enamel. Although Schulze1 also uses this term to include enamel defects associated with systemic disease such as Morquio’s disease and oculodentodigital dys plasia, Darling2 and Witkop3 do not. The latter restrict the use of the term to indicate a heredi tary defect in enamel formation without clinical ly demonstrable alterations in other tissues. Am elogenesis imperfecta is an uncommon disease, having an incidence in children o f about 1:14,000 to 1:16,000.4 The two main categories of amelogenesis imperfecta are hypoplastic (hypoplastic-aplastic) and hypocalcified (hypomin eralized).1-2 Witkop3-4 adds a third type, hypomaturation, based on clinical, genetic, and struc tural differences between it and the hypocalci fied type. A number of subclassifications within the three main groups have been proposed. These are based on clinical or histologic differences, or in the mode o f transmission. These are listed and discussed by Schulze,1 and by Witkop and
Sauk5 in detail. These classifications are, in part, tentative, pending documentation of addi tional kindreds with amelogenesis imperfecta. We wish, therefore, to add the following kin dred of amelogenesis imperfecta discovered at Emory University School o f Dentistry.
R e p o rt of case A 17-year-old black girl came to the dental school and requested full-mouth extractions. Because o f the extreme degree of calculus deposition (Fig 1, 2) it was impossible to examine the teeth properly until a prophylaxis was performed. The enamel of the teeth was largely intact ex cept for three o f the maxillary incisors and focal areas of loss related to posterior occlusal con tact (Fig 3). The enamel appeared chalky, hav-
Fig 1 ■ Anterior view of patient's mouth before dental prophyl axis illustrating severe degree of calculus deposition and an terior open bite. JADA, V ol. 86, M a rc h 1973 ■
675
Fig 4 ■ Panoramic radiograph illustrating essentially normal tooth form and supporting structures. Fig 2 ■ Intraoral view before dental prophylaxis illustrates ex treme degree of calculus deposition on all surfaces of posterior teeth.
Fig 3 ■ Anterior view after dental prophylaxis.
ing none o f the translucency normally seen. With little effort the enamel could be penetrat ed with a sharp explorer, or scraped off with a scaler. The patient said that, from time to time, pieces of teeth “ chipped off.” There was an anterior open bite, right poster ior crossbite, and mandibular prognathism. The degree of open bite was definitely greater than the corresponding loss of enamel (Fig 3). Radiographs revealed an essentially normal morphologic structure of crown and root (Fig 4). The enamel was generally of normal thick ness, but there was a definite loss of contrast between the enamel and dentin (Fig 5). A few teeth exhibited a moth-eaten appearance (Fig 676
■ JADA, V o l. 86, M a rch 1973
6). The upper left canine was impacted. There was no evidence o f resorption of erupted or un erupted teeth. N o pulpal calcifications or stones were seen. The condition of the supporting structures of the teeth v/as found to be within normal limits. The findings of a physical examination, with particular reference to other possible abnormal ities, including those of hair and nails, were otherwise normal. The patient said that her deciduous teeth had had a similar condition. Further questioning re vealed that the patient’s mother, as well as other relatives, was also affected. The family was then investigated; the results are shown in Fig 7. For socioeconomic reasons, the teeth were extracted; there were no complications. A num ber o f these teeth were studied. Thin, undecalcified sections of teeth showed only an accentuation of the interprismatic sub stance and small, focal areas of hypoplasia. In one region a cuticle was present on the surface of the enamel. Decalcified sections revealed dentin and cementum that were within normal limits. An unusual amount of enamel matrix was preserved. Radiographs of undecalcified thin ground sec tions showed considerable loss of contrast be tween enamel and dentin when compared with radiographs of similar sections of a normal tooth.
D is c u s s io n This propositus and kindred manifest amelogenesis imperfecta of the hypocalcified or hypo-
Fig 5 ■ R adiograph of low er an terior incisors illustra ting poor contrast between enamel and dentin.
Fig 6 ■ R adiograph eaten appearance.
of
m axillary incisors
<§> • ^ E X A M IN E D PROFESSIONALLY ■ ^H A S TRAIT © ^ E X A M IN E D PROFESSIONALLY E r DOES NOT HAVE TRAIT <§>
CHILDREN
I
INFANT )
illu stra tin g
moth-
RELIABLY REPORTED TO HAVE TRAIT
o□'
RELIABLY REPORTED ’’NOT TO HAVE TRAIT
RELIABLY REPORTED NOT TO HAVE
TRAIT
TEETH NOT ERUPTED Fig 7 ■ Pedigree o f fa m ily in question.
mineralized type. Information obtained from the family members indicates that the decidu ous and the permanent teeth were consistently affected. The condition is transmitted as an auto somal dominant trait. Although there is no maleto-male transmission, several affected males
have had normal daughters, thereby ruling out a sex-linked dominant transmission. This is the most common type of amelogenesis imperfecta,5 and similar cases have been re ported by others.li2,4,6'13 Calculus deposition, as seen in this patient, G ia n s a n ti: H Y P O C A LC IFIE D A M E L O G E N E S IS IM P E R FE C TA ■
677
is extreme, but is typical o f this type of amelogenesis imperfecta.5 H owever, in this kindred, it was stated not to be significant except in the propositus. Since for all practical purposes, no oral hygiene was practiced by this patient, the degree o f calculus formation probably was di rectly related. The presence o f open bite and crossbite in this patient is interesting. Although Schulze1 described one type of amelogenesis imperfecta as occurring with and without open bite, it is a sex-linked dominant type o f hypoplastic amelo genesis imperfecta. This subclassification into the presence or absence o f open bite is not ac cepted by others because open bite is not infre quently associated with deficiencies of tooth structure or eruption with a frequency greater than chance.5 A review o f the published reports of this type of amelogenesis imperfecta reveals essentially the same type of malocclusion in som e,11,12 but not all. T hese findings seemingly would support Witkop’s contention that the presence of open bite in amelogenesis imperfecta does not war rant separate classification. The histologic findings in the teeth examined are consistent with amelogenesis imperfecta of the hypocalcified type; these have been de scribed in detail by others.5-6-8-10
S u m m a ry A girl was seen who had amelogenesis imper fecta o f the hypocalcified or hypomineralized type. Evidence clearly indicated an autosomal dominant mode o f transmission. The calculus
678 ■ JA D A , V o l. 86, M a rc h 1973
deposition, which was unusually severe in this patient, is believed to be aggravated by the poor oral hygiene. The presence o f malocclusion in this patient is discussed relevant to the justification for sep arate categorization; it is concluded that such a separation is not warranted.
Dr. Giansanti is a member of the department of oral pathology, Emory University School of Dentistry, 1462 Clifton Rd, NE, At lanta, 30322. 1. Schulze, C. Developmental abnormalities of the teeth and jaw. In Gorlin, R.J., and Goldman, H.M. Thoma's oral pathology. St. Louis, C. V. Mosby Co., 1970, Vol 2, p 130. 2. Darling, A.I. Some observations on amelogenesis imper fecta and calcification of the dental enamel. Proc R Soc Med (Odontol Sec) 49:759 Oct 1956. 3. Witkop, C.J., Jr. Heterogeneity in inherited dental traits, gingival fibromatosis and amelogenesis imperfecta. South Med J 64:Suppl 11:16 Feb 1971. 4. Witkop, C.J., Jr. Genetic diseases of the oral cavity. In Tiecke, R.W. Oral pathology. New York, McGraw-Hill Book Co., 1965, p 801. 5. Witkop, C.J., Jr., and Sauk, J.J. Dental and oral manifesta tions of hereditary disease. Presented at workshop sponsored by American Academy of Oral Pathology, 1971, p 9. 6. Weinmann, J.P.; Svoboda, J.F.; and Woods, R.W. Heredi tary disturbances of enamel formation and calcification. JADA 32:397 April 1945. 7. Witkop, C.J., Jr. Hereditary defects in enamel and dentin. Acta Genet (Basel) 7:236 No. 1, 1957. 8. Chaudhry, A.P., and others. Hereditary enamel dysplasia. J Pediatr 54:776 June 1959. 9. Toller, P.A. Clinical report on six cases of amelogenesis imperfecta. Oral Surg 12:325 March 1959. 10. Rushton, M.A. Surface of the enamel in hereditary enamel hypocalcification. Br Dent J 112:24 Jan 2, 1962. 11. Laird, W.R. Hereditary amelogenesis imperfecta. Dent Pract (Bristol) 19:90 Nov 1968. 12. Winter, G.B. Hereditary and idiopathic anomalies of tooth number, structure and form. Dent Clin North Am 13:355 April 1969. 13. Pindborg, J.J. Pathology of the dental hard tissue. Phil adelphia, W. B. Saunders Co., 1970, p 77.