USING ENDOSSEOUS DENIAL IMPLANTS FOR PATIENTS WITH ECTODERMAL DYSPLASIA A L B E R T D. G U C K E S , D.D .S ., M .S .D .; J A IM E S. B R A H IM , D .D .S ., M .S .; G E O R G E R. M C C A R T H Y , D .D .S .; SU SAN F. R U D V , R.N., B .S .N .; L Y N D O N F. C O O P E R , D .D .S ., PH.D.
ABSTRACT
Congenitally m issing teeth and poorly developed or absent alveolar ridges are signs often associated with various types o f ectoderm al dysplasia. E ndosseous dental im plants may be used to support fixed mandibular prostheses in p atients w ith ectoderm al dysplasia. A natom ical factors and age considerations require careful atten tion to treatm ent planning.
ctodermal dysplasia is a genetic birth defect in which at least two structures derived from the ectoderm develop abnormally. Noticeable oral findings may include anodontia, hypodontia, misshapen teeth, taurodontia, supernumerary teeth, neonatal teeth, natal teeth, retained primary teeth, enamel hypoplasia and lack of an alveolar ridge.1The pattern of congenitally missing teeth and dental abnormalities in these patients varies but usually results in significant edentulous spaces and smaller than normal teeth.2 At least 121 subtypes of ED are inherited through all Mendelian modes.3 Birth prevalence is estimated between 1in 10,000 and 1 in 100,000 .4The frequency of the various abnormalities in ED shows the dissimilar penetrance among affected individuals. Recent research findings have established the feasibility of accurate carrier detection and prenatal diagnosis, and even raised the hope of eventual treatment or prevention of some of the disorder’s systemic manifestations.5,6 ED is usually divided into two types based on the number and function of the sweat glands: hypohidrotic, where the sweat glands are absent or significantly decreased, and hidrotic, where the sweat glands are normal. The hypohidrotic type is considered more severe and is associated with heat intolerance, frequent high fevers, otolaryngological problems7and more associated dental defects.8 Clinicians can readily recognize the dental (80 percent of cases), hair (91 percent of cases), nail (75 percent) and sweat gland (42 percent) abnormalities associated with the most commonly occurring ectodermal dysplasias.9Diagnosis of hypohidrotic ED is often based on frequent episodes of severe pyrexia, the lack of hair and absent tooth germs. Peeling skin at birth, eczema and asthma or frequent respiratory infections maybe additional clues. Facial characteristics maybe striking, subtle or almost absent. Extraoral signs may include decreased or absent sweat glands, sparse and fine or coarse and curly hair, abnormally developed nails, prominent forehead, depressed midface, protuberant lips, marbled pattern of skin pigmentation, atrophic rhinitis, epistaxis, saddle nose deformity, hearing loss and decreased production of body fluids including saliva.1012 If ED is suspected, referral may be advisable for definitive diagnosis and genetic counseling, and to identify resources for the patient and JADA, Vol. 122, October 1991
59
In an ongoing clinical trial of endosseous screw-type titanium implants, both edentulous patients (ages 37 to 76) and ED patients (ages 13 to 69) have comparable successful results for clinical immobility of fixtures at secondstage surgery (Table l ).20In our experience, unique anatomical, physical, social and psychological conditions of ED patients mandate careful evaluation and planning before treatment. TREATMENT PLANNING CONSIDERATIONS
Figure 1. A 15-year-old male hidrotic ED patient with two retained primary teeth and poorly formed mandibular permanent anterior teeth. These teeth would be difficult to use to support a fixed prosthesis because of poor root form.
family; for instance, the National Foundation for Ectodermal Dysplasia (219 East Main, P.O. Box 114, Mascoutah, 111. 62258). Prosthetic dental treatment for ED has usually consisted of various combinations of over dentures, complete or partial removable dentures and fixed partial dentures.13,14However, the rapid acceptance of oral endos seous titanium screw-type implants has provided a new method for treatment of edentulous spaces in both children and adults.1616 Problem solving is fundamental to the practice of prosthetic dentistry. ED patients present many oral problems to challenge the dentist; some shared with nonED edentulous patients and some unique to the ED condition. The two groups often have poor esthetics and decreased occlusal vertical dimension and alveolar bone. It is also difficult for both groups to chew, maintain proper nutrition and adapt to dentures. ED patients have unique prob lems related to age or oral condi 60
JADA, Vol. 122, October 1991
tions: poor body image, unrealistic treatment expectations, im maturity, decreased alveolar bone development, abnormal cranio facial development (especially in females) and problems adapting to a fixed prosthesis.1719Endosseous implants can be of significant help in providing prosthetic treatment.
Lack of alveolar bone is often associated with congenitally missing teeth. The edentulous ridge is usually of minimal height and width. The mandibular ridge frequently has a knife-edge contour, often with a concave lingual profile, which can prevent ideal implant fixture placement. Teeth can pose a dilemma because of their positions and poorly formed or partially resorbed roots. The long-term documented success of endosseous titanium screw-type
Figure 2. Labial position and inclination of implant fixtures required unesthetic location of retention screw access holes. Temporary restorations are in place.
implants has made our group more willing to recommend extracting poorly formed teeth if they unduly complicate treatment. Age and psychological factors are also important. Parental concerns related to esthetics and diet are usually the motivation for dental treatment in young ED patients (up to age 7 or 8). The children themselves begin to take an interest in their facial esthetics as they approach puberty. A young person’s concern with oral and facial esthetics can be closely associated with psychological development and should not be ignored.1921 TREATMENT PLANNING GUIDELINES
** Plan orthodontic treatment to position permanent teeth to facilitate prosthesis support or to enhance occlusion. *■* Treat with conventional prostheses before placing implants to determine optimal tooth and fixture position and to assess the patient’s esthetic and functional expectations. Though this adds treatment cost and time, it ensures adequate interim prostheses during the entire treatment. Treatment may extend 18 months or more so that extraction or graft sites can heal before placing implants. Recent publications reporting the immediate placement of implants into extraction sites or in combination with bone grafts have demon strated the possibility of short ening the treatment period.22-23 mmConsider extracting the teeth early when their prognosis or use in the treatment plan is question able. The long-term success rates of endosseous dental implants are high. An endosseous titanium screw-type implant may be better suited to support a prosthesis than a retained Primary or permanent tooth with poor root form or a
Figure 3. Despite a severe labial inclination of the implant fixtures, angulated abutments facilitated the placement of retention screw access holes on the lingual and occlusal surfaces of the prosthesis.
Figure 4. Panoramic radiograph of patient referred fo r prosthetic treatment. Implants were placed before referral, when the child was 3 years of age. Maxillary teeth are developing.
partially resorbed root. " Consider bone grafting to facilitate placement of implant fixtures in the most useful position. The clinical integration rates of fixtures in the mandible of ED patients approaches that of non-ED denture patients. The fixture position, however, is often dictated by the mandibular alveolar ridge anatomy in ED
patients, and may present esthetic problems or cause labial or buccal mucosa irritation because of the position of the prosthesis retention screw access holes. Angulated abutments can be used with unfavorably aligned or positioned fixtures, although the stress distribution may differ from a conventional abutment.24'25Sophist icated radiological techniques may JADA, Vol. 122, October 1991
61
TA B LE 1
PATIENT TYPE
IMPLANTS UNCOVERED
IMPLANTS CLINICALLY IMM OBILE— SECONDSTAGE SURGERY
SUCCESS %
Non-ED edentulous
I6 l
153
95
Ectodermal dysplasia
61
55
90
Frequency of failure in ectodermal dysplasia and non-ED edentulous groups did not differ by analysis (x% with continuity correction = 1.246, df: 1, P= 0.2643).
determine optimal fixture position and bone grafting need.26 *■ Consider postponing implant placement in children younger than 13. Though it is possible to. place implants in very young children (Figure 4), currently there is no compelling reason to do so. Children seem to adapt readily to removable prostheses. Because osseointegrated implants do not have an associated periodontal ligament, a fixture in an acceptable position at age 7 or 8 may not be in a favorable position at age 16.27In addition, there is little long-term clinical exper ience using implants in the restricted anatomical conditions often found in young Dr. Guckes is deputy clinical director and children with chief, Patient Care ED. Another and Clinical factor is the Investigations Section, National additional Institute of Dental expense of Research, Building 10, Room 1N-13, frequently National Institutes of remaking an Health, Bethesda, Md. 20892. Address implantrequests for reprints supported to Dr. Guckes. prosthesis as the 62
JADA, Vol. 122, October 1991
child matures. If future research on young (less than 12 years old) patients with congenitally missing teeth indicates that loading the jaws with endosseous oral implants contributes to normal growth and development, or prevents atrophy of alveolar bone, earlier use of implants can be justified. SUMMARY
Despite anatomical constraints associated with minimal alveolar bone and abnormal craniofacial development, dental implants may be successfully employed to sup port and retain prosthetic teeth in patients with ectodermal dysplasia. However, the unique anatomical, physical, social and psychological conditions of ED patients mandates careful evalu ation and planning. T his p a p e r w as p resen ted in 1991 a t th e Scientific F ro n tie rs in Clinical D entistry Sym posium , National In stitu te for D ental Research, Bethesda, Md. Dr. B rahim is a sen io r staff oral a n d m axillofacial surgeon, NIDR; Dr. McCarthy is a sen io r staff dentist, NIDR; Ms. Rudy is a clinical co o rd in ato r for oral and m axillofacial surgery a n d ENT, W arren G ran t Magnuson C linical Center; Dr. Cooper is a staff fellow in th e Clinical Investigations and P atien t Care B ranch, NIDR, NIH. 1. W itkop CJ, B rearley LJ, G entry WC, Jr. Hypoplastic enam el, onycholysis, and hypohidrosis in h erited as an autosom al d o m in a n t trait. A review of ectoderm al dysplasia syndrom es. Oral S urg Oral Med Oral Pathol 1975;39:71-86.
2. Nakata M, Koshiba H, Eto K, Nance WE. A genetic study of an o d o n tia in X-linked hypohidrotic ectoderm al dysplasia. Am J Hum G enet 1980;32:908-19. 3. N ew ton F-M, Pinheiro M. Ectoderm al dysplasias: som e recollections and a classification. In: Salinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:3-14. 4. M yrianthopoulos NC. M alform ations in children from one to seven years: a rep o rt from th e collaborative perin atal project. New York: Alan R. Liss; 1985:98. 5. Z onana J, Clarke A, Sarfarazi M, e t al. X-linked h ypohidrotic ectoderm al dysplasia: localization w ithin the region Xqll-21.I by linkage analysis and im plications for c a rrie r detectio n and prenatal diagnosis. Am J Hum G enet 1988;43:75-85. 6. Blecher SR, K apalanga J, L alonde D. Induction of sw eat glands by ep id erm al grow th facto r in m u rin e Xlinked a n h id ro tic ectoderm al dysplasia. (Letter). N ature 1990;345:542-4. 7. Siegel MB, Potsic WP. Ectoderm al dysplasia: the otolaryngologic m anifestations and m anagem ent. In t J P ed iatr Otorhinolaryngol 1990;19:265-71. 8. Anton-Lam precht I, S chleierm acher E, Wolf M. A utosomal recessive anh id ro tic ectoderm al dysplasia: rep o rt of a case a n d discrim ination of diagnostic features. In: Salinas CF, Opitz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:183-95. 9. Holbrook KA. S tru ctu ral abnorm alities of the epiderm ally derived appendages in the skin from p a tients w ith ectoderm al dysplasia: insight into developm ental errors. In: Salinas CF, Optiz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:1544. 10. Freire-Maia N, Pinherio M. Ectodermal dysplasias: a clinical and genetic study. New York: Alan R. Liss; 1984:33-5. 11. New ton F-M, P inheiro M. Selected conditions w ith ectoderm al dysplasia. In: Salinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:109-21. 12. Gorlin RJ. Selected ectoderm al dysplasias. In: Salinas CF, Opitz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:123-48. 13. B olender CL, Law DB, A ustin LB. Prosthodontic tre a tm e n t of ectoderm al dysplasia. (A case rep o rt) J P ro sth et D ent 1964;14:317-25. 14. S naw der KD. C onsiderations in den tal tre a tm e n t of c h ild ren w ith ectoderm al dysplasia. JADA 1976;93:1177-9. 15. Adell R, Lekholm U, Rockier B, B ranem ark P-I. A 15y ear study of osseointegrated im plants in th e tre a tm e n t of th e ed en tu lo u s jaw. In t J Oral Surg 1981;10:387-416. 16. Ekstrand K, Thom sson M. Ectoderm al dysplasia with partial anodontia: p ro sth etic tre a tm e n t w ith im plant fixed prosthesis. J D ent Child 1988;55:282-4. 17. Bixler E, Saksena SS, W ard RE. Characterization of th e face in hypohidrotic ectoderm al dysplasia by cephalom etric a n d anthropom etric analysis. In: S alinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:197-203. 18. Levin SL. Dental and oral abnorm alities in selected ectoderm al dysplasia syndrom es. In: S alinas CF, O pitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:205-27. 19. Levant BA. W hat den tists should know about dentofacial deform ity. A ust D ent J 1988;33:273-9. 20. Guckes AD, B rahim JS, R udy SF, M cCarthy GR. Use of titan iu m screw im plants in individuals w ith ectoderm al dysplasia. (Special Issue, Abstract no. 1771) J D ent Res 1991;70. 21. Albina JE , Tedesco LA, Conny DJ. P atien t perceptions o f dental-facial esthetics: shared concerns in o rthodontics and prosthodontics. J P ro sth et D ent 1984;52:9-13. 22. Block MS, K ent JN. Placem en t o f im plants in e xtraction sites-4 -y ear experiences. (Special Issue, A bstract no. 60) J D ent Res 1991;70. 23. Lew D, Hinkle RM, Unhold GP, Shroyer JV III, Stutes RD. R econstruction of the severely atrophic edentulous m andible by m eans of autogenous bone grafts and sim ultaneous p lacem en t of osseointegrated im plants. J Oral Maxillofac Surg 1991;49:228-33. 24. Kallus T, H enry P, Jem tT , Jo rn e u s L. Clinical evaluation o f angulated a b utm ents for th e B ranem ark system : a pilot study. In t J Oral Maxillofac Im plants 1990;5;39-45. 25. Clelland NL, Gilat A, Goehring DP. Photo-elastic stress com parison of angulated ab u tm en ts for an im plant. (Special Issue, A bstract no. 1548) J D ent Res 1991:70. 26. Schwarz MS, R othm an SLG, C hafetz N, R hodes M. C om puted tom ography in dental im plantation surgery. D ent Clin North Am 1989;33:555-97. 27. Enlow DH, P oston WB. Facial growth. Philadelphia: Saunders; 1990:131-2.
ABSTRACT
Congenitally m issing teeth and poorly developed or absent alveolar ridges are signs often associated with various types o f ectoderm al dysplasia. E ndosseous dental im plants may be used to support fixed mandibular prostheses in p atients w ith ectoderm al dysplasia. A natom ical factors and age considerations require careful atten tion to treatm ent planning.
ctodermal dysplasia is a genetic birth defect in which at least two structures derived from the ectoderm develop abnormally. Noticeable oral findings may include anodontia, hypodontia, misshapen teeth, taurodontia, supernumerary teeth, neonatal teeth, natal teeth, retained primary teeth, enamel hypoplasia and lack of an alveolar ridge.1The pattern of congenitally missing teeth and dental abnormalities in these patients varies but usually results in significant edentulous spaces and smaller than normal teeth.2 At least 121 subtypes of ED are inherited through all Mendelian modes.3 Birth prevalence is estimated between 1in 10,000 and 1 in 100,000 .4The frequency of the various abnormalities in ED shows the dissimilar penetrance among affected individuals. Recent research findings have established the feasibility of accurate carrier detection and prenatal diagnosis, and even raised the hope of eventual treatment or prevention of some of the disorder’s systemic manifestations.5,6 ED is usually divided into two types based on the number and function of the sweat glands: hypohidrotic, where the sweat glands are absent or significantly decreased, and hidrotic, where the sweat glands are normal. The hypohidrotic type is considered more severe and is associated with heat intolerance, frequent high fevers, otolaryngological problems7and more associated dental defects.8 Clinicians can readily recognize the dental (80 percent of cases), hair (91 percent of cases), nail (75 percent) and sweat gland (42 percent) abnormalities associated with the most commonly occurring ectodermal dysplasias.9Diagnosis of hypohidrotic ED is often based on frequent episodes of severe pyrexia, the lack of hair and absent tooth germs. Peeling skin at birth, eczema and asthma or frequent respiratory infections maybe additional clues. Facial characteristics maybe striking, subtle or almost absent. Extraoral signs may include decreased or absent sweat glands, sparse and fine or coarse and curly hair, abnormally developed nails, prominent forehead, depressed midface, protuberant lips, marbled pattern of skin pigmentation, atrophic rhinitis, epistaxis, saddle nose deformity, hearing loss and decreased production of body fluids including saliva.1012 If ED is suspected, referral may be advisable for definitive diagnosis and genetic counseling, and to identify resources for the patient and JADA, Vol. 122, October 1991
59
In an ongoing clinical trial of endosseous screw-type titanium implants, both edentulous patients (ages 37 to 76) and ED patients (ages 13 to 69) have comparable successful results for clinical immobility of fixtures at secondstage surgery (Table l ).20In our experience, unique anatomical, physical, social and psychological conditions of ED patients mandate careful evaluation and planning before treatment. TREATMENT PLANNING CONSIDERATIONS
Figure 1. A 15-year-old male hidrotic ED patient with two retained primary teeth and poorly formed mandibular permanent anterior teeth. These teeth would be difficult to use to support a fixed prosthesis because of poor root form.
family; for instance, the National Foundation for Ectodermal Dysplasia (219 East Main, P.O. Box 114, Mascoutah, 111. 62258). Prosthetic dental treatment for ED has usually consisted of various combinations of over dentures, complete or partial removable dentures and fixed partial dentures.13,14However, the rapid acceptance of oral endos seous titanium screw-type implants has provided a new method for treatment of edentulous spaces in both children and adults.1616 Problem solving is fundamental to the practice of prosthetic dentistry. ED patients present many oral problems to challenge the dentist; some shared with nonED edentulous patients and some unique to the ED condition. The two groups often have poor esthetics and decreased occlusal vertical dimension and alveolar bone. It is also difficult for both groups to chew, maintain proper nutrition and adapt to dentures. ED patients have unique prob lems related to age or oral condi 60
JADA, Vol. 122, October 1991
tions: poor body image, unrealistic treatment expectations, im maturity, decreased alveolar bone development, abnormal cranio facial development (especially in females) and problems adapting to a fixed prosthesis.1719Endosseous implants can be of significant help in providing prosthetic treatment.
Lack of alveolar bone is often associated with congenitally missing teeth. The edentulous ridge is usually of minimal height and width. The mandibular ridge frequently has a knife-edge contour, often with a concave lingual profile, which can prevent ideal implant fixture placement. Teeth can pose a dilemma because of their positions and poorly formed or partially resorbed roots. The long-term documented success of endosseous titanium screw-type
Figure 2. Labial position and inclination of implant fixtures required unesthetic location of retention screw access holes. Temporary restorations are in place.
implants has made our group more willing to recommend extracting poorly formed teeth if they unduly complicate treatment. Age and psychological factors are also important. Parental concerns related to esthetics and diet are usually the motivation for dental treatment in young ED patients (up to age 7 or 8). The children themselves begin to take an interest in their facial esthetics as they approach puberty. A young person’s concern with oral and facial esthetics can be closely associated with psychological development and should not be ignored.1921 TREATMENT PLANNING GUIDELINES
** Plan orthodontic treatment to position permanent teeth to facilitate prosthesis support or to enhance occlusion. *■* Treat with conventional prostheses before placing implants to determine optimal tooth and fixture position and to assess the patient’s esthetic and functional expectations. Though this adds treatment cost and time, it ensures adequate interim prostheses during the entire treatment. Treatment may extend 18 months or more so that extraction or graft sites can heal before placing implants. Recent publications reporting the immediate placement of implants into extraction sites or in combination with bone grafts have demon strated the possibility of short ening the treatment period.22-23 mmConsider extracting the teeth early when their prognosis or use in the treatment plan is question able. The long-term success rates of endosseous dental implants are high. An endosseous titanium screw-type implant may be better suited to support a prosthesis than a retained Primary or permanent tooth with poor root form or a
Figure 3. Despite a severe labial inclination of the implant fixtures, angulated abutments facilitated the placement of retention screw access holes on the lingual and occlusal surfaces of the prosthesis.
Figure 4. Panoramic radiograph of patient referred fo r prosthetic treatment. Implants were placed before referral, when the child was 3 years of age. Maxillary teeth are developing.
partially resorbed root. " Consider bone grafting to facilitate placement of implant fixtures in the most useful position. The clinical integration rates of fixtures in the mandible of ED patients approaches that of non-ED denture patients. The fixture position, however, is often dictated by the mandibular alveolar ridge anatomy in ED
patients, and may present esthetic problems or cause labial or buccal mucosa irritation because of the position of the prosthesis retention screw access holes. Angulated abutments can be used with unfavorably aligned or positioned fixtures, although the stress distribution may differ from a conventional abutment.24'25Sophist icated radiological techniques may JADA, Vol. 122, October 1991
61
TA B LE 1
PATIENT TYPE
IMPLANTS UNCOVERED
IMPLANTS CLINICALLY IMM OBILE— SECONDSTAGE SURGERY
SUCCESS %
Non-ED edentulous
I6 l
153
95
Ectodermal dysplasia
61
55
90
Frequency of failure in ectodermal dysplasia and non-ED edentulous groups did not differ by analysis (x% with continuity correction = 1.246, df: 1, P= 0.2643).
determine optimal fixture position and bone grafting need.26 *■ Consider postponing implant placement in children younger than 13. Though it is possible to. place implants in very young children (Figure 4), currently there is no compelling reason to do so. Children seem to adapt readily to removable prostheses. Because osseointegrated implants do not have an associated periodontal ligament, a fixture in an acceptable position at age 7 or 8 may not be in a favorable position at age 16.27In addition, there is little long-term clinical exper ience using implants in the restricted anatomical conditions often found in young Dr. Guckes is deputy clinical director and children with chief, Patient Care ED. Another and Clinical factor is the Investigations Section, National additional Institute of Dental expense of Research, Building 10, Room 1N-13, frequently National Institutes of remaking an Health, Bethesda, Md. 20892. Address implantrequests for reprints supported to Dr. Guckes. prosthesis as the 62
JADA, Vol. 122, October 1991
child matures. If future research on young (less than 12 years old) patients with congenitally missing teeth indicates that loading the jaws with endosseous oral implants contributes to normal growth and development, or prevents atrophy of alveolar bone, earlier use of implants can be justified. SUMMARY
Despite anatomical constraints associated with minimal alveolar bone and abnormal craniofacial development, dental implants may be successfully employed to sup port and retain prosthetic teeth in patients with ectodermal dysplasia. However, the unique anatomical, physical, social and psychological conditions of ED patients mandates careful evalu ation and planning. T his p a p e r w as p resen ted in 1991 a t th e Scientific F ro n tie rs in Clinical D entistry Sym posium , National In stitu te for D ental Research, Bethesda, Md. Dr. B rahim is a sen io r staff oral a n d m axillofacial surgeon, NIDR; Dr. McCarthy is a sen io r staff dentist, NIDR; Ms. Rudy is a clinical co o rd in ato r for oral and m axillofacial surgery a n d ENT, W arren G ran t Magnuson C linical Center; Dr. Cooper is a staff fellow in th e Clinical Investigations and P atien t Care B ranch, NIDR, NIH. 1. W itkop CJ, B rearley LJ, G entry WC, Jr. Hypoplastic enam el, onycholysis, and hypohidrosis in h erited as an autosom al d o m in a n t trait. A review of ectoderm al dysplasia syndrom es. Oral S urg Oral Med Oral Pathol 1975;39:71-86.
2. Nakata M, Koshiba H, Eto K, Nance WE. A genetic study of an o d o n tia in X-linked hypohidrotic ectoderm al dysplasia. Am J Hum G enet 1980;32:908-19. 3. N ew ton F-M, Pinheiro M. Ectoderm al dysplasias: som e recollections and a classification. In: Salinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:3-14. 4. M yrianthopoulos NC. M alform ations in children from one to seven years: a rep o rt from th e collaborative perin atal project. New York: Alan R. Liss; 1985:98. 5. Z onana J, Clarke A, Sarfarazi M, e t al. X-linked h ypohidrotic ectoderm al dysplasia: localization w ithin the region Xqll-21.I by linkage analysis and im plications for c a rrie r detectio n and prenatal diagnosis. Am J Hum G enet 1988;43:75-85. 6. Blecher SR, K apalanga J, L alonde D. Induction of sw eat glands by ep id erm al grow th facto r in m u rin e Xlinked a n h id ro tic ectoderm al dysplasia. (Letter). N ature 1990;345:542-4. 7. Siegel MB, Potsic WP. Ectoderm al dysplasia: the otolaryngologic m anifestations and m anagem ent. In t J P ed iatr Otorhinolaryngol 1990;19:265-71. 8. Anton-Lam precht I, S chleierm acher E, Wolf M. A utosomal recessive anh id ro tic ectoderm al dysplasia: rep o rt of a case a n d discrim ination of diagnostic features. In: Salinas CF, Opitz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:183-95. 9. Holbrook KA. S tru ctu ral abnorm alities of the epiderm ally derived appendages in the skin from p a tients w ith ectoderm al dysplasia: insight into developm ental errors. In: Salinas CF, Optiz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:1544. 10. Freire-Maia N, Pinherio M. Ectodermal dysplasias: a clinical and genetic study. New York: Alan R. Liss; 1984:33-5. 11. New ton F-M, P inheiro M. Selected conditions w ith ectoderm al dysplasia. In: Salinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:109-21. 12. Gorlin RJ. Selected ectoderm al dysplasias. In: Salinas CF, Opitz JM, Paul NW, eds. Recent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:123-48. 13. B olender CL, Law DB, A ustin LB. Prosthodontic tre a tm e n t of ectoderm al dysplasia. (A case rep o rt) J P ro sth et D ent 1964;14:317-25. 14. S naw der KD. C onsiderations in den tal tre a tm e n t of c h ild ren w ith ectoderm al dysplasia. JADA 1976;93:1177-9. 15. Adell R, Lekholm U, Rockier B, B ranem ark P-I. A 15y ear study of osseointegrated im plants in th e tre a tm e n t of th e ed en tu lo u s jaw. In t J Oral Surg 1981;10:387-416. 16. Ekstrand K, Thom sson M. Ectoderm al dysplasia with partial anodontia: p ro sth etic tre a tm e n t w ith im plant fixed prosthesis. J D ent Child 1988;55:282-4. 17. Bixler E, Saksena SS, W ard RE. Characterization of th e face in hypohidrotic ectoderm al dysplasia by cephalom etric a n d anthropom etric analysis. In: S alinas CF, Opitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:197-203. 18. Levin SL. Dental and oral abnorm alities in selected ectoderm al dysplasia syndrom es. In: S alinas CF, O pitz JM, Paul NW, eds. R ecent advances in ectoderm al dysplasias. New York: Alan R. Liss; 1988:205-27. 19. Levant BA. W hat den tists should know about dentofacial deform ity. A ust D ent J 1988;33:273-9. 20. Guckes AD, B rahim JS, R udy SF, M cCarthy GR. Use of titan iu m screw im plants in individuals w ith ectoderm al dysplasia. (Special Issue, Abstract no. 1771) J D ent Res 1991;70. 21. Albina JE , Tedesco LA, Conny DJ. P atien t perceptions o f dental-facial esthetics: shared concerns in o rthodontics and prosthodontics. J P ro sth et D ent 1984;52:9-13. 22. Block MS, K ent JN. Placem en t o f im plants in e xtraction sites-4 -y ear experiences. (Special Issue, A bstract no. 60) J D ent Res 1991;70. 23. Lew D, Hinkle RM, Unhold GP, Shroyer JV III, Stutes RD. R econstruction of the severely atrophic edentulous m andible by m eans of autogenous bone grafts and sim ultaneous p lacem en t of osseointegrated im plants. J Oral Maxillofac Surg 1991;49:228-33. 24. Kallus T, H enry P, Jem tT , Jo rn e u s L. Clinical evaluation o f angulated a b utm ents for th e B ranem ark system : a pilot study. In t J Oral Maxillofac Im plants 1990;5;39-45. 25. Clelland NL, Gilat A, Goehring DP. Photo-elastic stress com parison of angulated ab u tm en ts for an im plant. (Special Issue, A bstract no. 1548) J D ent Res 1991:70. 26. Schwarz MS, R othm an SLG, C hafetz N, R hodes M. C om puted tom ography in dental im plantation surgery. D ent Clin North Am 1989;33:555-97. 27. Enlow DH, P oston WB. Facial growth. Philadelphia: Saunders; 1990:131-2.
