Amelogenesis imperfecta Report
of two
cases
T
he term a.ntf3Zogenesi.s imperfects has been applied to many disturbances of the enamel, including such conditions as hppoplasia, dysplasia, hypocalcification, hypomaturation, altered pigmentation, am1 defevts involving hereditary and genetic linkage. Amelogenrsis impcrfecta is generally accepted as a hereditary defect in enamel, with no apparent clinica.lly demonstrable changes in any of the other- r~toclermal tissues. In the western hemisphere, it is found to occur in the human tlentition in the approximate ratio of 1 :15,000. Amclogenesis impcrfecta may vary from a complete lack of enamel to an immature matrix, with the remaining tooth components within normal proportional limits, cscept in cases of attrition, \vhcrc the dentin map be slightly or markedly reduced. Clinical features most commonly ohset~vctl in amclogcncsis imperfecta arc (1) either the tlcciduous, permarrcrrt, or both tlentitions may he affcrtccl, (2) the numhcr of teeth affeetcd may vary in rach given (~tsv, (3) the remaining cnamcl is hard, with normal to yellow tliscoloration, (4) the cnamcl will usually fravturc readily from the underlying dentin, (5) the teeth nsually do not mcvt at the contact points, and (6) in the consideration of a differential diagnosis, rickets, the vontlitions t,o 1-W high fcvcr, ant1 psenclo~iy~~o~arat,h~roicIistti arc ilnlOIlg consitlrrcd. Case
Reports
Two sisters, 6 xnd 9 years of age, presenter1 wit11 :L callief wmplaint of dentin sensitivity xrld mantlihlxr (lcntitions. Tn l&h cases, sonw and poor clinical :Ippearanw of the maxillary degree of irurginxl gingivitis was observed, :~ntl tllis w:w thought to be the result of limited or31 hygiene. 502
Amelogenesis imperfecta
Volume 39 Number 3
Fig. 1. Intraoral photograph mandibular central incisors.
Fig. 8. X-ray dentition. PATIENT
picture
of Patient
of Patient
A showing
A illustrating
a lack of enamel
formation
a lack of enamel in the erupting
503
in the
permanent
A
Patient A, 6 years of age, was seen during the mixed-dentition stage, mith a normal eruption pattern. The clinical appearance of the mandibular central incisors was similar to that of her sister; however, there was no apparent sensitivity to temperature changes or percussion. Radiologic findings revealed a generalized lack of enamel formation (Figs. 1 and ‘2 -1. PATIENT
This dentition,
6
g-year-old patient was the eldest child with only the permanent teeth being
of a second marriage. She had a mixed hypoplastic. The enamel on the occlusal
Oral Surg. March, 1975
Fig. 3. Intraoral photograph of Patient B showing the frail appearance of the maxillary lateral incisors and the pitted rough appearance of the permanent anterior dentition.
Fig. 4. X-ray picture permanent dentition.
of Patient
B illustrating
the lack
of
enamel
formation
in the
surfaces of the permanent first molars was missing. The remaining enamel on the maxillary and mandibular incisors was thin, yellow, and rough in appearance. The incisal third of the permanent anterior teeth seemed to be very frail and terminated in a series of sharp points. The permanent dentition was sensitive to thermal change and percussion. The degree of sensitivity manifested itself in the patient’s inability to maintain her oral hygiene (Figs. 3 and 4). OTHER FAMILY
MEMBERS
The family history revealed that the mother of the two girls had had several anterior crowned because of a lack of enamel.
teeth
Volume 39 Number 3
Amelogen,esis imperf ecta, 505
DISCUSSION
The present cases of amelogenesis imperfecta present an example of classic mendclian heredity. The trait is passed on via one of the parents, with approximately a 50 per cent inheritance probability for every child of the affected person. SUMMARY
This article documents a familial occurrence of hypoplastic amelogenesis imperfecta. The deciduous dentition may or may not be affected. The low rate of caries irmidence and the absence of any other ectodermal defects are to be noted. REFERENCES
1. Weinmann, J. P., Svoboda, J. F., and Woods, R. W.: IIereditary Disturbances of Enamel Formation and Calcification, J. Am. Dent. Assoc. 32: 397-418, 1945. 2. Burzynski, N. J., Gonzalez, W. E., Jr., and Snawder, K. D.: Autosomal Dominant Smooth Hypoplastic Amelogenesis Imperfecta, ORAL SUSG. 36: 818-823, 1973. Reprint requests to: Dr. J. S. Druck 235 Dixon Rd. Weston, Ontario, Canada