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Hypoplastic Amelogenesis Imperfecta: Report of Case
Hypoplastic amelogenesis imperfecta: report of case
Stuart L. Fischman, DMD Ben C. Fischman, DDS, Buffalo
The case history of a 9-year-old girl with hypoplastic amelogenesis imperfecta is reported. Her family history is consistent with a sex-linked dominant mode of inheritance. Her father, female cousin, and other members of her kindred had discolored, soft teeth that they lost at an early age. Because all types of primary enamel defects are rare, especially the type reported here, this study is significant.
Many diseases affecting the enamel of the de ciduous and permanent dentitions have been described by the term hereditary amelogenesis imperfecta. W itkop1»2 and Darling3 have defined the specific entities classified as amelogenesis imperfecta. Prim ary conditions are those not associated with a generalized abnormality (such as ectodermal dysplasia). Primary amelogenesis imperfecta includes at least five distinct clinical and genetic types that may be classified on the basis of the predominant enamel defect as hypocalcification, hypoplasia, hypomaturation, pig mented hypomaturation, and a local hypoplastic type. As the mode of inheritance is of impor tance in classifying these conditions, an investi gation to determine the distribution of the anom aly within a family is desirable. The case history reported here is of the he reditary hypoplastic type of amelogenesis im perfecta. The enamel of the deciduous and the permanent dentitions is deficient in thickness, and the teeth are generally small. Radiographs characteristically reveal only a thin radiopaque tracing of enamel over the coronal dentin. 929
Fig. 1 ■ Intraoral radiographs of propositus,
Amelogenesis imperfecta as a sex-linked dom inant trait has been demonstrated in kindreds reported by Haldane;4 Weinman, Svoboda, and Woods;5 Rushton;6 Schultze;7 Hals;8 and Witkop.9 T oller10 reported a family with hereditary hypo plastic amelogenesis imperfecta in which the in heritance was through the father, but the con dition was not manifest in his generation. Chaudhry and others11 concluded that hereditary enamel dysplasia “Appears to be transmitted as a simple dom inant M endelian character without apparent sex linkage.” Other instances are reported in the literature, but many do not give sufficient clinical description or pedigree information to permit definite classification.
medical history were normal; other ectodermal structures (nails and hair) were normal, and there were no complications during pregnancy. Normal eating habits were reported, and there was no history of sensitivity of the teeth to ther mal extremes. The patient had a mouth odor, and in the morning she had gingival bleeding. Oral hygiene was fair, with a history of toothbrushing once a day. Radiographs made at this time (Fig. 1) re vealed an absence of enamel on the erupted and developing teeth. On close inspection (Fig. 2), a thin line of radiopaque enamel was visible on the first permanent molars.
Case h isto ry
The propositus in this report was a 9-year-old girl. Dental examination revealed a mixed den tition with a Class II molar relationship (Angle) and an inlocking of the right deciduous molars and canines. All of the teeth had rough surfaces and were yellow or tan in color. The molars showed considerable attrition and extended only a few millimeters above the gingiva, re sulting in a decreased vertical dimension. The rem ainder of the oral examination re vealed only a blunted uvula and generalized marginal gingivitis. Physical examination and 930 ■ JADA, Vol. 75, Oct. 1967
Fig. 2 ■ M ag n ifica tio n of m olar radiograph. Note th in region o f enamel on crowni.
Witkop 12’13 and R ushron14 described a pattern of vertical grooves of thin enamel separated by strips of thicker enamel on the teeth of females with this condition. They present this clinical feature as phenotypic evidence for the Lyon hypothesis. This striping was not clinically ap parent in the subject reported here, possibly be cause of oral environment factors. All types o f prim ary enamel defects are rare. W itkop15 estimated the frequency to be about one per 14,000 North American Caucasian children. This particular hypoplastic type of amelogenesis imperfecta is an additional rarity. *
EH Male EE-Died
O Female before usual age
for recognition o f trait.
\£ Reported
affected
® Observed affected
The authors th a n k Mr. M anfred Gygli, fo rm e rly c h ie f pho tographer, School of Dentistry, State U niversity o f New York at B uffalo, fo r reproduction o f radiographs and chart.
Fig. 3 ■ Fam ily h isto ry.
The family history is shown in Figure 3. A brother, 1 year older than the propositus, was examined and found normal. The teeth of the mother were similarly devoid of obvious develop mental anomalies. The patient’s father became edentulous in his early twenties, and his teeth were reported brown in color. His dentist had made a diagnosis of amelogenesis imperfecta. A female cousin was also observed to have poorly formed enamel before becoming edentulous at a young age. The other positive case histories re ported in the kindred are based on a combined history of discolored teeth, early loss of teeth, and a reported dental diagnosis of soft teeth. These cases were not documented by a profes sional observer.
Summary A girl with hereditary hypoplastic amelogenesis imperfecta is reported. H er family history is con sistent with a sex-linked dom inant mode of in heritance. That is, the affected fathers passed the trait to all of their daughters, and the affected mothers passed the trait to half their children of both sexes. The presence o f an abnormal gene on the X chromosome is postulated in this type o f anomaly.
Doctor S tuart Fischm an is an assistant professor in the de partm ent o f oral pathology a t th e State U n iversity o f New York at Buffalo, School of Dentistry, B uffalo, 14214. Doctor Pen Fischm an’s address is 825 Tonawanda Street, Buffalo. 1. W itkop, C. J., Jr. G enetics and dentistry. Eugen Quart 5:15 March, 1958. 2. W itkop, C. J., Jr. Dental genetics. JADA 60:564 May, 1960. 3. Darling, A. I. Some observations on amelogenesis im perfecta and c a lc ific a tio n o f th e dental enamel. Proc Roy Soc Med 49:759 Oct., 1956. 4. Haldane, J. B. S. Probable new sex-linked dom inant in man. J Hered 2 8 :58 Feb., 1937. 5. Weinmann, J. P.; Svoboda, J. F., and Woods, P. W. Hereditary disturbances o f enamel fo rm a tio n and ca lc ific a tio n . JADA 32:397 A pril, 1945. 6 . Rushton, M. A. Case of hereditary enamel hypoplasia. B rit Dent J 88:300 June 2, 1950. 7. Schultze, C. Erbbedingte S trukturanom alien menschlich e r Zahne. Acta Genet (Basel) 7:231 no. 1, 1957. 8 . Hals, E. D entin and enamel anomalies: h isto lo g ic ob servations. In W itkop, C. J. Jr. (ed.). G enetics and dental health. New York, M cGraw-Hill Book Co., 1962, p. 246. 9. W itkop, C. J., Jr. G enetics and den tistry. In Hammons, H. G. (ed.). H eredity counseling. New York, Paul B. Hoeber, 1959, p. 12. 10. Toller, P. A. C linical report on six cases o f amelo genesis im perfecta. Oral Surg 12:325 March, 1959. 11. Chaudhry, A. P., and others. Hereditary enamel dys plasia. J Pediat 54:776 June, 1959. 12. W itkop, C. J., Jr. Genes, chromosomes, and dentistry. JADA 68:845 June, 1964. 13. W itkop, C. J., Jr. Inborn errors o f m etabolism w ith par tic u la r reference to pseudohypoparathyroidism . J Dent Res (suppl.) 45:568, 1966. 14. Rushton, M. A. Hereditary enamel defects. Proc Roy Soc Med 57:53 Jan., 1964. 15. W itkop, C. J., Jr. H ereditary defects in enamel and dentin. Acta Genet (basel) 7:236, 1957.
Fischman—Fischman: HYPOPLASTIC AMELOGENESIS IMPERFECTA ■ 931
Stuart L. Fischman, DMD Ben C. Fischman, DDS, Buffalo
The case history of a 9-year-old girl with hypoplastic amelogenesis imperfecta is reported. Her family history is consistent with a sex-linked dominant mode of inheritance. Her father, female cousin, and other members of her kindred had discolored, soft teeth that they lost at an early age. Because all types of primary enamel defects are rare, especially the type reported here, this study is significant.
Many diseases affecting the enamel of the de ciduous and permanent dentitions have been described by the term hereditary amelogenesis imperfecta. W itkop1»2 and Darling3 have defined the specific entities classified as amelogenesis imperfecta. Prim ary conditions are those not associated with a generalized abnormality (such as ectodermal dysplasia). Primary amelogenesis imperfecta includes at least five distinct clinical and genetic types that may be classified on the basis of the predominant enamel defect as hypocalcification, hypoplasia, hypomaturation, pig mented hypomaturation, and a local hypoplastic type. As the mode of inheritance is of impor tance in classifying these conditions, an investi gation to determine the distribution of the anom aly within a family is desirable. The case history reported here is of the he reditary hypoplastic type of amelogenesis im perfecta. The enamel of the deciduous and the permanent dentitions is deficient in thickness, and the teeth are generally small. Radiographs characteristically reveal only a thin radiopaque tracing of enamel over the coronal dentin. 929
Fig. 1 ■ Intraoral radiographs of propositus,
Amelogenesis imperfecta as a sex-linked dom inant trait has been demonstrated in kindreds reported by Haldane;4 Weinman, Svoboda, and Woods;5 Rushton;6 Schultze;7 Hals;8 and Witkop.9 T oller10 reported a family with hereditary hypo plastic amelogenesis imperfecta in which the in heritance was through the father, but the con dition was not manifest in his generation. Chaudhry and others11 concluded that hereditary enamel dysplasia “Appears to be transmitted as a simple dom inant M endelian character without apparent sex linkage.” Other instances are reported in the literature, but many do not give sufficient clinical description or pedigree information to permit definite classification.
medical history were normal; other ectodermal structures (nails and hair) were normal, and there were no complications during pregnancy. Normal eating habits were reported, and there was no history of sensitivity of the teeth to ther mal extremes. The patient had a mouth odor, and in the morning she had gingival bleeding. Oral hygiene was fair, with a history of toothbrushing once a day. Radiographs made at this time (Fig. 1) re vealed an absence of enamel on the erupted and developing teeth. On close inspection (Fig. 2), a thin line of radiopaque enamel was visible on the first permanent molars.
Case h isto ry
The propositus in this report was a 9-year-old girl. Dental examination revealed a mixed den tition with a Class II molar relationship (Angle) and an inlocking of the right deciduous molars and canines. All of the teeth had rough surfaces and were yellow or tan in color. The molars showed considerable attrition and extended only a few millimeters above the gingiva, re sulting in a decreased vertical dimension. The rem ainder of the oral examination re vealed only a blunted uvula and generalized marginal gingivitis. Physical examination and 930 ■ JADA, Vol. 75, Oct. 1967
Fig. 2 ■ M ag n ifica tio n of m olar radiograph. Note th in region o f enamel on crowni.
Witkop 12’13 and R ushron14 described a pattern of vertical grooves of thin enamel separated by strips of thicker enamel on the teeth of females with this condition. They present this clinical feature as phenotypic evidence for the Lyon hypothesis. This striping was not clinically ap parent in the subject reported here, possibly be cause of oral environment factors. All types o f prim ary enamel defects are rare. W itkop15 estimated the frequency to be about one per 14,000 North American Caucasian children. This particular hypoplastic type of amelogenesis imperfecta is an additional rarity. *
EH Male EE-Died
O Female before usual age
for recognition o f trait.
\£ Reported
affected
® Observed affected
The authors th a n k Mr. M anfred Gygli, fo rm e rly c h ie f pho tographer, School of Dentistry, State U niversity o f New York at B uffalo, fo r reproduction o f radiographs and chart.
Fig. 3 ■ Fam ily h isto ry.
The family history is shown in Figure 3. A brother, 1 year older than the propositus, was examined and found normal. The teeth of the mother were similarly devoid of obvious develop mental anomalies. The patient’s father became edentulous in his early twenties, and his teeth were reported brown in color. His dentist had made a diagnosis of amelogenesis imperfecta. A female cousin was also observed to have poorly formed enamel before becoming edentulous at a young age. The other positive case histories re ported in the kindred are based on a combined history of discolored teeth, early loss of teeth, and a reported dental diagnosis of soft teeth. These cases were not documented by a profes sional observer.
Summary A girl with hereditary hypoplastic amelogenesis imperfecta is reported. H er family history is con sistent with a sex-linked dom inant mode of in heritance. That is, the affected fathers passed the trait to all of their daughters, and the affected mothers passed the trait to half their children of both sexes. The presence o f an abnormal gene on the X chromosome is postulated in this type o f anomaly.
Doctor S tuart Fischm an is an assistant professor in the de partm ent o f oral pathology a t th e State U n iversity o f New York at Buffalo, School of Dentistry, B uffalo, 14214. Doctor Pen Fischm an’s address is 825 Tonawanda Street, Buffalo. 1. W itkop, C. J., Jr. G enetics and dentistry. Eugen Quart 5:15 March, 1958. 2. W itkop, C. J., Jr. Dental genetics. JADA 60:564 May, 1960. 3. Darling, A. I. Some observations on amelogenesis im perfecta and c a lc ific a tio n o f th e dental enamel. Proc Roy Soc Med 49:759 Oct., 1956. 4. Haldane, J. B. S. Probable new sex-linked dom inant in man. J Hered 2 8 :58 Feb., 1937. 5. Weinmann, J. P.; Svoboda, J. F., and Woods, P. W. Hereditary disturbances o f enamel fo rm a tio n and ca lc ific a tio n . JADA 32:397 A pril, 1945. 6 . Rushton, M. A. Case of hereditary enamel hypoplasia. B rit Dent J 88:300 June 2, 1950. 7. Schultze, C. Erbbedingte S trukturanom alien menschlich e r Zahne. Acta Genet (Basel) 7:231 no. 1, 1957. 8 . Hals, E. D entin and enamel anomalies: h isto lo g ic ob servations. In W itkop, C. J. Jr. (ed.). G enetics and dental health. New York, M cGraw-Hill Book Co., 1962, p. 246. 9. W itkop, C. J., Jr. G enetics and den tistry. In Hammons, H. G. (ed.). H eredity counseling. New York, Paul B. Hoeber, 1959, p. 12. 10. Toller, P. A. C linical report on six cases o f amelo genesis im perfecta. Oral Surg 12:325 March, 1959. 11. Chaudhry, A. P., and others. Hereditary enamel dys plasia. J Pediat 54:776 June, 1959. 12. W itkop, C. J., Jr. Genes, chromosomes, and dentistry. JADA 68:845 June, 1964. 13. W itkop, C. J., Jr. Inborn errors o f m etabolism w ith par tic u la r reference to pseudohypoparathyroidism . J Dent Res (suppl.) 45:568, 1966. 14. Rushton, M. A. Hereditary enamel defects. Proc Roy Soc Med 57:53 Jan., 1964. 15. W itkop, C. J., Jr. H ereditary defects in enamel and dentin. Acta Genet (basel) 7:236, 1957.
Fischman—Fischman: HYPOPLASTIC AMELOGENESIS IMPERFECTA ■ 931