Ectodermal dysplasias: Classification and organization by phenotype, genotype and molecular pathway

An international advisory group met at the National Institutes of Health in Bethesda, Maryland in 2017, to discuss a new classification system for the ectodermal dysplasias (EDs) that would integrate both clinical and molecular information. We propose the following, a working definition of the EDs building on previous classification systems and incorporating current approaches to diagnosis: EDs are genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. Genetic variations in genes known to be associated with EDs that affect only one derivative of the ectoderm (attenuated phenotype) will be grouped as non-syndromic traits of the causative gene (e.g., non-syndromic hypodontia or missing teeth associated with pathogenic variants of EDA "ectodysplasin"). Information for categorization and cataloging includes the phenotypic features, Online Mendelian Inheritance in Man number, mode of inheritance, genetic alteration, major developmental pathways involved (e.g., EDA, WNT "wingless-type," TP63 "tumor protein p63") or the components of complex molecular structures (e.g., connexins, keratins, cadherins).

Orofacial function and monitoring of oral care in amyotrophic lateral sclerosis

OBJECTIVE

The aim was to assess orofacial function and monitor oral care in patients with amyotrophic lateral sclerosis (ALS) to maintain oral comfort and oral health.

MATERIALS AND METHODS

A case series of 14 patients newly diagnosed with ALS accepted to participate in a quality improvement project. After initial examinations, baseline oral conditions were obtained and the patients were seen every 3 months. Nordic Orofacial Test-Screening (NOT-S) was used for evaluation of orofacial function.

RESULTS

Patients were grouped according to initial symptoms in a bulbar group and a spinal group with eight and six patients, respectively. The mean age at diagnosis was 62.8 years. All were dentate with a mean of 26.7 natural teeth. Most patients had very good oral and dental conditions. As expected, orofacial functions were differently affected in the two groups; at initial NOT-S registration, the mean total score was 5.6 (range 3-8 domains) in the bulbar group and 0.7 (0-2 domains) in the spinal group. At final registration, the corresponding figures were 6.1 and 3.2. Oral and dental aids were introduced according to need.

CONCLUSIONS

In the bulbar group, several orofacial functions became impaired at an early stage of disease development, and at final registrations many vital orofacial functions were severely compromised. The spinal group was less severely affected orally. However, all individuals irrespective of type of initial symptoms needed assistance in performing oral hygiene measures in the latter part of the disease period. Good oral health and oral comfort could be maintained in all participants and no other dental treatment was needed.

Further evidence for specific IFIH1 mutation as a cause of Singleton-Merten syndrome with phenotypic heterogeneity

Singleton-Merten syndrome (MIM 182250) is an autosomal dominant inherited disorder characterized by early onset periodontitis, root resorption, osteopenia, osteoporosis, and aortic valve or thoracic aorta calcification. The disorder can have significant intrafamilial phenotypic variability. Here, we present a mother and daughter with Singleton-Merten syndrome harboring a previously described pathogenic missense mutation, c.2465G>A p.(Arg822Gln), in IFIH1 (interferon induced with helicase C domain 1), encoding MDA5 (Melanoma Differentiation-Associated protein 5). These data confirm the pathogenicity of IFIH1 c.2465G>A p.(Arg822Gln) for Singleton-Merten syndrome and affirm the striking phenotypic heterogeneity of this disorder. In addition, we expand the Singleton-Merten phenotype by adding severe systemic lupus erythematosus (SLE) to the clinical picture. Investigations of known SLE genes as well as a single nucleotide polymorphism suggested to be involved in development of SLE were normal.

Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency

BACKGROUND

The WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis.

METHODS

In seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis.

RESULTS

Investigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I.

CONCLUSIONS

We conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of bi-allelic WNT10A mutations of importance for diagnosis, counselling and follow-up.

Profiles of orofacial dysfunction in different diagnostic groups using the Nordic Orofacial Test (NOT-S)--a review

OBJECTIVE

The Nordic Orofacial Test-Screening (NOT-S) was developed as a comprehensive method to assess orofacial function. Results from the screening protocol have been presented in 11 international publications to date. This study reviewed these publications in order to compile NOT-S screening data and create profiles of orofacial dysfunction that characterize various age groups and disorders.

MATERIALS AND METHODS

NOT-S results of nine reports meeting the inclusion criteria were reviewed. Seven of these studies not only provided data on the mean and range of total NOT-S scores, but also on the most common domains of orofacial dysfunction (highest rate of individuals with dysfunction scores), allowing the construction of orofacial dysfunction profiles based on the prevalence of dysfunction in each domain of NOT-S.

RESULTS

The compiled data comprised 669 individuals, which included healthy control subjects (n = 333) and various patient groups (n = 336). All studies reported differences between individuals with diagnosed disorders and healthy control subjects. The NOT-S data could measure treatment effects and provided dysfunction profiles characterizing the patterns of orofacial dysfunction in various diagnoses.

CONCLUSIONS

This review corroborates previous results that the NOT-S differentiates well between patients and healthy controls and can also show changes in individuals after treatment. NOT-S could be used as a standard instrument to assess orofacial dysfunction, evaluate the outcomes of oral habilitation and rehabilitation and improve comparability in clinical practice and research.

EDAR-induced hypohidrotic ectodermal dysplasia: a clinical study on signs and symptoms in individuals with a heterozygous c.1072C > T mutation

Background

Mutations in the EDAR-gene cause hypohidrotic ectodermal dysplasia, however, the oral phenotype has been described in a limited number of cases. The aim of the present study was to clinically describe individuals with the c.1072C > T mutation (p. Arg358X) in the EDAR gene with respect to dental signs and saliva secretion, symptoms from other ectodermal structures and to assess orofacial function.

Methods

Individuals in three families living in Sweden, where some members had a known c.1072C > T mutation in the EDAR gene with an autosomal dominant inheritance (AD), were included in a clinical investigation on oral signs and symptoms and self-reported symptoms from other ectodermal structures (n = 37). Confirmation of the c.1072C > T mutation in the EDAR gene were performed by genomic sequencing. Orofacial function was evaluated with NOT-S.

Results

The mutation was identified in 17 of 37 family members. The mean number of missing teeth due to agenesis was 10.3 ± 4.1, (range 4–17) in the mutation group and 0.1 ± 0.3, (range 0–1) in the non-mutation group (p < 0.01). All individuals with the mutation were missing the maxillary lateral incisors and one or more of the mandibular incisors; and 81.3% were missing all four. Stimulated saliva secretion was 0.9 ± 0.5 ml/min in the mutation group vs 1.7 ± 0.6 ml/min in the non-mutation group (p < 0.01). Reduced ability to sweat was reported by 82% in the mutation group and by 20% in the non-mutation group (p < 0.01). The mean NOT-S score was 3.0 ± 1.9 (range 0–6) in the mutation group and 1.5 ± 1.1 (range 0–5) in the non-mutation group (p < 0.01). Lisping was present in 56% of individuals in the mutation group.

Conclusions

Individuals with a c.1072C > T mutation in the EDAR-gene displayed a typical pattern of congenitally missing teeth in the frontal area with functional consequences. They therefore have a need for special attention in dental care, both with reference to tooth agenesis and low salivary secretion with an increased risk for caries. Sweating problems were the most frequently reported symptom from other ectodermal structures.

Rehabilitation of children with ectodermal dysplasia. Part 2: an international consensus meeting

A consensus meeting was arranged to provide an opportunity to discuss the residual nonconsensus questions following three rounds of a Delphi study. It was hoped that the nonagreements could be resolved to define a comprehensive protocol for the management of ectodermal dysplasia, particularly with respect to the use of dental implants in growing patients. An international panel of expert clinicians in pediatric dentistry, prosthodontics, and orthodontics was invited to be part of the Delphi study to develop agreement on clinical questions through a consensus of ideas. Each expert had been invited to form a study group or team within his or her home institution. As required by the Delphi protocol, a 90-part questionnaire was considered by the collaborating teams and progressed through three iterations with increasing agreement. This process is discussed in part 1 of the study. The residual nonconsensus questions, which represented 10% of the questionnaire, required collaborative interaction for resolution. The consensus meeting was held in London, England, over a 2-day period with support from Nobel Biocare and the British Dental Association.

Rehabilitation of children with ectodermal dysplasia. Part 1: an international Delphi study

PURPOSE

An international Delphi study was undertaken to determine by consensus an agreed approach to the management of children with dental manifestations of ectodermal dysplasia, including the use of dental implants. This was done using a questionnaire developed by an interdisciplinary team.

MATERIALS AND METHODS

The Delphi study questionnaire was built around 19 areas of clinical relevance and included 90 items. Topic areas included dental disability; initial diagnosis; global disability; oral health aspects of dental treatment (orthodontics, hypodontia, anodontia, implants); and case studies of selected treatment options. Eleven teams from six countries contributed to three iterations of the questionnaire. An algorithm was designed to standardize analysis of the questionnaire answers, all of which were blinded to ensure anonymity. The second and third rounds of the questionnaire excluded previously agreed-upon items but included the responses to the questions from the earlier rounds. The nonconsensus items inquired about the use of radiographs at initial diagnosis; sedation of an uncooperative child; use of a pretreatment questionnaire; the age range for specific treatments (eg, dentures, orthodontics, implants); specific uses of implants (eg, partial prostheses, overdentures, cantilevered prostheses); and case study 2. The residual nonconsensus questions were subsequently discussed at a 2-day meeting.

RESULTS

Among the 90 questions and partial questions, there was progressive consensus, with agreements in rounds 1, 2, and 3 of 61%, 21%, and 8%, respectively. At the conclusion of round 3, there was 90% agreement and it was considered that the nonconsensus items required in-depth face-to-face discussion at a consensus meeting, which is described in part 2 of the study.

CONCLUSION

The Delphi study provided an opportunity to engage specialist teams in recognized centers to integrate their clinical knowledge and draw on published data to develop a consensus of evidence-based responses.

Orodental manifestations in ectodermal dysplasia-a review

Oral signs and symptoms are present in most ectodermal dysplasias (EDs). The aim of this article is to summarize some of the literature on current knowledge of oral manifestations and orofacial function in EDs. The review will focus on the most common forms where dental manifestations can be crucial for a differential diagnosis of ED among individuals with hypodontia and oligodontia, and preferably where the investigations included persons who had a genetically verified diagnosis. Disturbances in tooth development are common and can appear as tooth agenesis, variations in size and shape of teeth, defects in the mineralized tissues, and problems in tooth eruption. Abnormalities in number, size, and shape of teeth, and reduced salivary secretion, present in isolated oligodontia as well as in hypohidrotic ED and incontinentia pigmenti. In some more rare EDs these symptoms appear in combination with clefts of lip and/or palate in some affected individuals. Leukokeratosis in the oral mucosa presents in 70% of genetically confirmed cases of pachyonychia congenita. Also, orofacial function is often affected in ED, due to malformations, an incomplete dentition, and low salivary secretion which can compromise chewing, swallowing, and speech. In conclusion, there is a clinical overlap in oral signs and symptoms between isolated oligodontia and the most common EDs. Studies with genetically confirmed diagnoses and larger cohorts, as well as multicenter collaboration and the establishing of international registries, would create a basis for refined diagnostics, where oral examinations should be an integrated part of clinical assessment.

WNT10A mutations account for ¼ of population-based isolated oligodontia and show phenotypic correlations

A large proportion (>50%) of patients with isolated oligodontia were recently reported with WNT10A mutations. We have analyzed a population-based cohort of 102 individuals diagnosed with non-syndromic oligodontia and a mean of 8.2 missing teeth. The cohort included 94 families and screening of WNT10A identified that 26 probands (27.7%) had at least one WNT10A variant. When we included the MSX1, PAX9, AXIN2, EDA, EDAR, and EDARADD genes, 38.3% of probands were positive for a mutation. Biallelic WNT10A mutations were strongly associated with a larger number of missing teeth (11.09) when compared to both monoallelic WNT10 mutations (6.82) and the group without mutations in WNT10A, MSX1, PAX9, AXIN2, EDA, EDAR, or EDARADD (7.77). Genotype-phenotype analysis of individuals with WNT10A mutations showed that premolars were the most common missing teeth. Furthermore, biallelic WNT10A mutations were associated with absence of maxillary and mandibular molars as well as mandibular central incisors. Maxillary central incisors were always present. Thus, our study indicates that WNT10A mutations are associated with both the type and numbers of missing teeth. Furthermore, we show that this population-based cohort of isolated oligodontia had a considerably lower frequency of mutated WNT10A alleles and a lower mean number of missing teeth when compared to patients recruited from dental specialist centers.

Orofacial dysfunction in ectodermal dysplasias measured using the Nordic Orofacial Test-Screening protocol

OBJECTIVE

To screen orofacial function in people with various ectodermal dysplasia (ED) syndromes and compare with a healthy reference sample.

MATERIAL AND METHODS

The ED group comprised 46 individuals (30 M and 16 F; mean age 14.5 years, range 3-55). Thirty-two had hypohidrotic ED, while 14 had other ED syndromes. The reference sample comprised 52 healthy individuals (22 M and 30 F; mean age 24.9 years, range 3-55). Orofacial function was screened using the Nordic Orofacial Test-Screening (NOT-S) protocol containing 12 orofacial function domains (maximum score 12 points).

RESULTS

The total NOT-S score was higher in the ED group than in the healthy group (mean 3.5 vs. 0.4; p<0.001). The dysfunctions most frequently recorded in the subjects with ED occurred in the domains chewing and swallowing (82.6%), dryness of the mouth (45.7%), and speech (43.5%). Those with other ED syndromes scored non-significantly higher than those with hypohidrotic ED (mean 4.6 vs. 3.0; p>0.05).

CONCLUSIONS

Individuals with ED scored higher than a healthy reference sample in all NOT-S domains, especially in the chewing and swallowing, dryness of the mouth, and speech domains. Orofacial function areas and treatment and training outcomes need to be more closely evaluated and monitored.

Isolated oligodontia associated with mutations in EDARADD, AXIN2, MSX1, and PAX9 genes

Oligodontia is defined as the congenital lack of six or more permanent teeth, excluding third molars. Oligodontia as well as hypodontia (lack of one or more permanent teeth) are highly heritable conditions associated with mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes. Here we define the prevalence of mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes, and the novel candidate gene EDARADD in a cohort of 93 Swedish probands with non-syndromic, isolated oligodontia. Mutation screening was performed using denaturing gradient gel electrophoresis and DNA sequence analysis. Analyses of the coding sequences of the six genes showed sequence alterations predicted to be damaging or potentially damaging in ten of 93 probands (10.8%). Mutations were identified in the EDARADD (n = 1), AXIN2 (n = 3), MSX1 (n = 2), and PAX9 (n = 4) genes, respectively. None of the 10 probands with mutations had other self-reported symptoms from ectodermal tissues. The oral parameters were similar when comparing individuals with and without mutations but a family history of oligodontia was three times more frequent for probands with mutations. EDARADD mutations have previously been reported in a few families segregating hypohidrotic ectodermal dysplasia and this is, to our knowledge, the first report of an EDARADD mutation associated with isolated oligodontia.

Implant-supported fixed dental prostheses in an edentulous patient with dystrophic epidermolysis bullosa

PURPOSE

This clinical report describes the use of implant-supported fixed dental prostheses (ISFDPs) in a severe case of dystrophic epidermolysis bullosa.

MATERIALS AND METHODS

The patient's appearance was characterized by reduced corporal growth and severe mutilation of the hands and feet. He was first examined at age 20. The severely decayed residual dentition had already been extracted by the time of examination. Conventional dentures were not possible due to severe microstomia and the fragility of the denture-bearing tissues. Even a modest manual touch was very painful and detached the epithelium of the oral mucosa. The first treatment was only possible under general anesthesia. To allow some prospect for oral rehabilitation, four implants were inserted in the maxilla and three in the mandible. Several years of steroid treatment had weakened the bony structures. Therefore, the diameter of the last drill used to prepare the bone for implant insertion was smaller than the diameter of the implants to improve primary stability. Complete FDPs with a shortened dental arch design served as superstructures. Several fractures in the screw-designed titanium abutments in the mandible necessitated insertion of three additional implants and an ISFDP with two occlusal units, which was screwed horizontally to a milled bar mesostructure.

RESULTS

Despite multiple fractures of the acrylic resin veneers caused by severe bruxism and the small occlusal surface, this rehabilitation proved successful until the patient died at age 25, as a consequence of his hereditary disease.

CONCLUSION

This treatment greatly improved the patient's oral function, nutrition, and psychosocial well-being. Int J Prosthodont 2010;23:42-48.

Oligodontia ectodermal dysplasia--on signs, symptoms, genetics, and outcomes of dental treatment

The general aim of this thesis was to broaden our knowledge of the signs and symptoms, genetics, and outcomes of dental implant treatment in individuals with oligodontia or ectodermal dysplasia. Article I is a population-based study in three Swedish counties of 162 individuals with oligodontia, which was a prevalence of 0.09%. The intent was to explore ways for dentists to assess symptoms from other ectodermal structures than teeth through a clinical interview and chair-side analyses. Thirty per cent had low salivary secretion rates while only 11% with no known syndrome reported symptoms from hair, nails, or sweat glands. These are, together with teeth, the ectodermal structures on which it is proposed that a clinical diagnosis of ectodermal dysplasia (ED) be based. Article II screened 93 probands with oligodontia for mutations in six genes known to cause oligodontia and hypohidrotic ED. Sequence alterations predicted to be damaging or potentially damaging were revealed in the AXIN2, MSX1, PAX9, and EDARADD genes in 14 (15%) of the probands. All mutations but one were novel. For the first time, EDARADD mutations were shown to cause isolated oligodontia. No individual who had reported ectodermal symptoms from hair, nails, or sweat glands had a mutation. Article III assessed orofacial function in individuals with different types of EDs using the Nordic Orofacial Test-Screening (NOT-S) protocol. Individuals with ED scored significantly higher in orofacial dysfunction than a healthy reference sample, especially in the Chewing and swallowing, Dryness of the mouth, and Speech domains. Article IV surveyed treatment outcome of dental implants in Swedish children up to age 16 years. In a 20-year period, only 26 patients were treated, 5 of whom had hypohidrotic ED and anodontia of the mandible. Individuals with ED had 64% failed implants compared to 6% among subjects with teeth missing due to trauma or agenesis. The main conclusions of this thesis were that (i) a check of whether one or more permanent incisors are missing will identify 65% of individuals with oligodontia and 84% of individuals missing nine teeth or more, (ii) evaluation of salivary secretion is indicated in children with oligodontia, (iii) a majority of individuals with oligodontia did not report other abnormal ectodermal organ function besides teeth, (iv) no clinical indicator discriminated between individuals with and without mutations in the tested genes, and more unidentified genes are involved in tooth morphogenesis, (v) EDARADD mutations are associated with isolated oligodontia, (vi) evaluation of orofacial function is indicated in individuals with ED, and many individuals with ED would benefit from orofacial skills training, (vii) dental implant placement is a rare treatment modality in children, (viii) individuals with hypohidrotic ED seem to present special challenges due to structural as well as direct effects of the mutations on bone, which seem to compromise osseointegration, (ix) central registers on signs and symptoms in individuals with rare disorders would help establish prevalences of various diagnoses and define treatment needs, and (x) quality registers for monitoring treatment outcomes of dental implants would promote early detection of risks and side-effects in individuals with rare disorders.

Implant failure in young children with ectodermal dysplasia: a retrospective evaluation of use and outcome of dental implant treatment in children in Sweden

PURPOSE

This study surveyed dental implant treatment in children up to age 16 years in Sweden between 1985 and 2005, with special reference to young children with ectodermal dysplasia (ED) and anodontia in the lower jaw.

MATERIALS AND METHODS

A questionnaire was sent to Swedish specialist clinics in oral and maxillofacial surgery and prosthetic dentistry. Also, the teams who had treated children with ED were asked to submit their records for these children for a discussion on reasons for implant failure.

RESULTS

Six out of 30 specialist centers (20%) in Sweden had treated 26 children with dental implants between 1985 and 2005. Twenty-one patients had received 33 implants to replace teeth missing from nonsyndromic agenesis or trauma at ages 14 or 15 years; 2 (6.1%) of these implants were lost. Five children with ED received 14 implants at 5 to 12 years of age; 9 (64.3%) of these implants were lost before loading.

CONCLUSIONS

Dental implant placement has been a rarely used treatment modality in Swedish children less than 16 years old in the last 20 years. The failure rate in children treated because of tooth agenesis was only slightly higher than that reported for adult individuals, whereas in young children with ED and anodontia in the mandible, implants seemed to present special challenges, and the failure rate was very high. The small jaw size and peroperative conditions, rather than ED per se, were thought to be the main risk factors. Centralizing implant operations in young children with ED and monitoring outcomes in implant registers are strongly advocated.

Development and evaluation of a comprehensive screening for orofacial dysfunction

The aim was to develop a comprehensive screening instrument for evaluation of orofacial dysfunction that was easy to perform for different health professionals without special equipment. The Nordic Orofacial Test--Screening (NOT-S), consisting of a structured interview and clinical examination,was developed with a picture manual illustrating the different tasks in the examination. It was first tested in a Swedish version, and later translated to other Nordic languages, and to English. The interview reflected six domains, (I) Sensory function, (II) Breathing, (III) Habits, (IV) Chewing and swallowing, (V) Drooling, and (VI) Dryness of the mouth, and the examination included six domains representing (1) The face at rest, and tasks regarding (2) Nose breathing, (3) Facial expression, (4) Masticatory muscle and jaw function, (5) Oral motor function, and (6) Speech. One or more "yes" for impairment in a domain resulted in one point (maximum NOT-S score 12 points). The mean NOT-S score (+/- SD) in 120 patients (3-86 yr), referred to five centers for specialized dental care or speech and language pathology in Sweden, Norway and Denmark, was 4.1 +/- 2.6, and 0.4 +/- 0.6 in 60 control subjects (3-78 yr). The screening was easy to administer and the time spent 5-13 min. The scores from the clinic-referred sample differed significantly from the controls, and the sensitivity of the screening was 0.96 and specificity 0.63. Repeated evaluations of videotapes of 200 patients by 3 examiners, speech-language pathologists and dentists, with at least two-week intervals, showed inter- and intraexaminer agreement on the points given in the domains at respectively 83% and 92-95% which increased after recalibration to 85% and 95-99%. Kappa values for interexaminer agreement on the NOT-S scores were 0.42-0.44 (i.e. fair), and the method error was 5.3%. To conclude, NOT-S gave a reliable and valid screening for orofacial dysfunction.

Signs and symptoms from ectodermal organs in young Swedish individuals with oligodontia

OBJECTIVES

The aim was to assess signs and symptoms from other ectodermal organs in addition to teeth in young individuals with oligodontia and to establish the prevalence of oligodontia.

SAMPLE AND METHODS

Children born 1981-94 reported by dental teams in the Public Dental Service to have oligodontia were asked to participate in a clinical study. The examinations comprised a structured interview on symptoms from ectodermal organs, and testing of salivary secretion.

RESULTS

One hundred and sixty-two individuals met the inclusion criteria, and 123 individuals (75.9%) participated in the clinical study. Half of the individuals had one to four signs or symptoms from ectodermal organs beside oligodontia. The most common sign was low salivary secretion. Twelve individuals (9.6%) with isolated oligodontia reported impaired function of the sweat glands, hair, or nails. The prevalence of oligodontia was 0.090%.

CONCLUSIONS

An early identification of individuals with oligodontia can be made in a majority of cases by checking that all permanent incisors have erupted at the age of 8 years. The validity in asking individuals about normal and abnormal function of ectodermal organs was found to be low. This indicates that there is a strong need to establish routine clinical criteria for dysplasia of ectodermal organs.

The management of ectodermal dysplasia and severe hypodontia. International conference statements

An international conference on ectodermal dysplasias and hypodontia, held in London in 2004, featured a session devoted to the management of the ectodermal dysplasias and severe hypodontia. This paper presents a set of statements prepared by an international specialist panel, including representatives of patient support groups, who presented and subsequently debated a series of papers on this subject. The following topics were explored: potential roles of patient support groups; core care standards, including the roles and composition of medical and dental multidisciplinary teams for treating these conditions; the format of a baseline data set for patients with an ED; and priorities for research in ectodermal dysplasias, with particular regard to laboratory and clinical studies, and research methodology. The statements are intended to form an international framework for developing patient care pathways, and collaborative research in this field.

Mutations in the gene encoding fibroblast growth factor 10 are associated with aplasia of lacrimal and salivary glands

Autosomal dominant aplasia of lacrimal and salivary glands (ALSG; OMIM 180920 and OMIM 103420) is a rare condition characterized by irritable eyes and dryness of the mouth. We mapped ALSG to 5p13.2-5q13.1, which coincides with the gene fibroblast growth factor 10 (FGF10). In two extended pedigrees, we identified heterozygous mutations in FGF10 in all individuals with ALSG. Fgf10(+/-) mice have a phenotype similar to ALSG, providing a model for this disorder. We suggest that haploinsufficiency for FGF10 during a crucial stage of development results in ALSG.

Implant-supported welded titanium frameworks in the edentulous maxilla: a 5-year prospective multicenter study

PURPOSE

This study evaluated the 5-year clinical and radiographic performance of fixed implant-supported maxillary prostheses with either welded titanium or conventional cast-gold alloy frameworks.

MATERIALS AND METHODS

Fifty-eight consecutive patients were provided with 349 osseointegrated Brånemark system implants in the edentulous maxilla at six different implant centers. Twenty-eight of the patients received, at random, prostheses with laser-welded titanium frameworks, and the remaining 30 patients had prostheses with conventional cast-gold alloy frameworks. Clinical and radiographic data were collected for 5 years after prosthesis placement.

RESULTS

The titanium and cast-gold framework groups exhibited similar cumulative survival and success rates (CSR). The 5-year implant CSR from time of placement was 91.4% and 94.0%, respectively, and from prosthesis delivery the rate was 94.9% and 95.6%, respectively. The corresponding 5-year prosthesis CSRs were 96.4% and 93.3%. One patient from each group lost all the implants and turned to complete dentures within the first year of function. Another patient with a cast-gold framework had the prosthesis replaced after 4 years, basically because of problems with the veneering material. No fractures of implant components were observed during the follow-up period. Bone loss was on average 0.59 mm (SD 0.97 mm) during 5 years, with no statistical difference between the two groups.

CONCLUSION

Welded titanium frameworks presented a similar favorable clinical performance as conventional cast-gold alloy frameworks in fixed implant-supported prostheses in the edentulous maxilla after 5 years in function. Implant failures were concentrated in only a few patients in each study group.

[Incontinentia pigmenti. A rare disease with many symptoms]

Incontinentia pigmenti, also known as Bloch-Sulzberger syndrome, is a rare multi-systemic disorder. The disease is characterised by abnormalities in ectodermal tissues including the skin, eyes, central nervous system and dentition. It is inherited as an X-linked dominant trait and is usually fatal for male fetuses. Thirty-eight Swedish patients from 16 families were identified. Thirty patients were examined clinically and their DNA were analysed for deletions in the NEMO-gene. The disease showed a large clinical variability even within families and the common deletion in the NEMO-gene was found present in 70% of the families.

The role of prosthodontists in habilitation and rehabilitation in rare disorders: the ectodermal dysplasia experience

PURPOSE

The aim of this article is to highlight the strong worldwide trend of enhancing the opportunities for individuals with rare disorders to get adequate information and treatment. Hypohidrotic ectodermal dysplasia is used as an example.

MATERIALS AND METHODS

The development in recent years of databases for rare disorders, the establishment of resource centers in dentistry, and the strong movement of user influence by the formation of patient organizations and exchange of information through the Internet are described. Reference is made to the recent Scandinavian consensus conference on ectodermal dysplasia.

RESULTS

Motives for the centralization of treatment planning to resource centers for persons with rare disorders, the compilation of treatment outcomes in databases, and the advocation of a multidisciplinary team approach in dentistry are presented.

CONCLUSION

The prosthodontic profession has a key position in the habilitation and rehabilitation of many different diagnoses of rare disorders.

Prosthetic habilitation of a young patient with hypohidrotic ectodermal dysplasia and oligodontia: a case report of 20 years of treatment

PURPOSE

The aim of this article is to describe the oral habilitation, over a period of 20 years, of a young patient with hypohidrotic ectodermal dysplasia and agenesis of 15 permanent teeth.

MATERIALS AND METHODS

Different clinical interventions were adapted to suit the patient's dental and psychologic stage of development. The prosthodontic treatment, which took place at different ages, comprised several treatment modalities: composite-retained onlay fixed partial dentures, a removable partial denture, tooth-supported and implant-supported fixed partial dentures, and laminate crown therapy.

RESULTS

The different phases of treatment were successful, and the patient is satisfied from a functional as well as a psychosocial point of view.

CONCLUSION

Extensive prosthodontic treatment in growing individuals should preferably be performed with a multidisciplinary team approach. In treatment that is planned and performed over long periods, this approach has the advantages of continuity and shared responsibility for therapy decisions.

Fixed prosthodontics in adults in Jönköping, Sweden in 1983 and 1993. An epidemiological study of prevalence and choice of material

The aim of the study was to assess the prevalence of fixed prostheses, i.e. single crowns and fixed partial dentures, in adults 20-80 years old in two cross-sectional studies carried out in 1983 and 1993 and to analyse whether the choice of material for fixed prostheses had changed during this time period. The material comprised 586 and 593 individuals. A descriptive analysis of number of individuals with fixed prostheses was made concerning the number of crowns and pontics, the distribution in the jaws, and the materials used. The prevalence of individuals with fixed prostheses was shown to increase with age both in 1983 and 1993. In 1993 the number of individuals with fixed prostheses was slightly lower than in 1983 (44 and 48 percent respectively). There was no difference according to gender. The proportion of individuals with fixed prostheses was lower or almost unchanged in the 20-, 30-, 40-, 50-, 60-, and 80-year-olds in 1993 compared to 1983. In the 70-year-olds, however, the proportion of individuals with fixed prostheses was considerably higher in 1993 compared to 1983. Most individuals with fixed prostheses had a small number of crowned teeth, and about half of the individuals had not more than four crowned teeth. Likewise most individuals with pontics had a small number of pontics. The distributions of crowned teeth and pontics in the jaws were similar in 1983 and 1993. Pontics and crowns were more frequent in the upper than in the lower jaw. Crowns made of porcelain or metal ceramic had increased by 1993 in the 30-80 year age groups, and the study thus confirms general clinical experience that porcelain and metal ceramic are more often the materials of choice in fixed prosthodontics in adults today.

Laser-welded titanium frameworks for implant-supported fixed prostheses: a 5-year report

The 5-year results from a multicenter study of implant-supported, laser-welded titanium frameworks are reported here as a complement to earlier reported 2-year results. Implant survival rates were satisfactory for patients with titanium frameworks and for a control group of patients with gold-alloy frameworks. At the 5-year review, more patients with titanium frameworks had lost implants than the patients with gold-alloy frameworks, but this difference was not statistically significant. More fractures of the titanium frameworks occurred, compared to the gold-alloy frameworks; again, this difference was not statistically significant. No significant differences in marginal bone levels were found between the 2 groups of patients. Slightly more fractures of artificial teeth occurred in patients with titanium frameworks than in patients with gold-alloy frameworks. Overall results for the titanium frameworks after 5 years in function are encouraging.

Laser-welded titanium frameworks supported by implants in the edentulous maxilla: a 2-year prospective multicenter study

PURPOSE

The aim of this study was to evaluate the clinical and radiographic performance of patients who received implants and fixed prostheses with laser-welded titanium frameworks.

MATERIALS AND METHODS

Fifty-eight consecutive patients were treated with 349 osseointegrated implants ad modum Brånemark in the edentulous maxilla at 6 implant centers. The patients were randomly arranged into 2 groups at the time of final impression. Twenty-eight patients received laser-welded titanium frameworks and 30 patients received conventional cast frameworks. Clinical and radiographic data were collected for 2 years in function.

RESULTS

The 2 groups of patients showed similar results. The 2-year overall cumulative implant survival rate from the time of implant placement and prosthesis insertion was 93.7% and 96.2%, respectively. The corresponding cumulative survival rate for prostheses was 96.6%. Two patients, 1 from each group, failed completely and resumed using conventional complete dentures. The only obvious factor that could possibly be related to the 2 complete failures was a smoking habit. However, it was not possible to significantly correlate implant failures to smoking habits in this study. No fractures were observed in the frameworks or implant components, and both groups experienced the same frequency of resin veneering material fractures. The overall average marginal bone loss was 0.4 mm (SD 0.8 mm).

CONCLUSION

Patients treated with implant-supported prostheses fabricated with laser-welded titanium frameworks in the edentulous maxilla presented comparable results to patients with conventional cast frameworks after 2 years in function.

A multidisciplinary approach to oral rehabilitation with osseointegrated implants in children and adolescents with multiple aplasia

Oral rehabilitation of children with extensive aplasia includes a number of dental considerations as well as attention to psychological and physical development. The well-documented results of the use of implants in adults have raised the question of the use of implants and the timing of this procedure in children and adolescents with multiple aplasia. Eight-years' experience of a multidisciplinary approach to oral rehabilitation of children with extensive aplasia is described. Special emphasis is placed on early diagnosis, careful therapy planning, and co-ordination and timing of different parts of the therapy. The specific considerations from the point of view of paediatric dentists, orthodontists, oral surgeons, and prosthodontists are presented. A system for integrating all these aspects and knowledge will be a guarantee for high professional standards and a successful outcome. To exemplify the multidisciplinary approach, three treated cases are presented.

Laser-welded titanium frameworks for fixed prostheses supported by osseointegrated implants: a 2-year multicenter study report

Nineteen prosthodontic clinics participated in a prospective study of fixed prostheses supported by osseointegrated implants (FPOIs) with laser-welded titanium frameworks. Ninety-three patients with 100 FPOIs were included and followed for 2 years. The results from this group were compared to another group that was examined retrospectively. In the retrospective group (control group), 91 patients received 96 FPOIs with cast frameworks, and these patients were treated shortly before the patients in the titanium-framework group (test group). The two groups were treated at the same centers. The results for both groups were good, with only 1.2% of loaded implants lost during the follow-up period (1.6% in the titanium-framework group; 0.7% in the control group). One framework in each group fractured. However, in complete maxillary cases, there were significantly more subjects in the titanium-framework group who were affected by implant losses compared to the control group. There was also a tendency towards more fractures of artificial teeth and acrylic resin in the titanium-framework group, compared to the control group. A possible explanation might be that dental technicians at the different centers were not used to the design of the titanium frameworks when the study began. Thus, the results from the first 2 years are promising, but further studies are needed to establish the long-term serviceability of laser-welded titanium frameworks.

The relative importance of tooth loss and denture wearing in Swedish adults

Having natural teeth is a matter of varying importance according to the priorities given to dental health status, compliance with recommendations and demand for dental care. The aim of this study was to assess the relative adjustment needed when one or more teeth are lost and when dentures are provided compared with other life events. The study was conducted as a mailed questionnaire to a sample of 311 20-70 year old subjects in the community of Jönköping. Seventy-five per cent of the sample, with a mean age of 43.2 years, responded. The Social Readjustment Rating Questionnaire, comprising 46 life events, was supplemented with two events concerning tooth loss and denture-wearing. The answers were given on a graphic rating scale with end points 'not difficult at all' and 'more difficult than anything' and coded by values 0 to 20. After calculation of mean values, the questions were rank ordered; the item with the highest mean was given the highest rank. 'Losing one or more teeth' was ranked 28.5 (means = 10.7) and 'getting dentures' 33 (means = 12.0) of the 48 life events investigated. This suggests that a majority of respondents perceived losing teeth and being provided with dentures as more important in terms of adjustment than events such as 'marriage', 'retirement' and 'changing work'. No significant differences in relation to age and sex were found.

Dental prophylaxis for youths in their late teens. II. Knowledge about dental health and diseases and the relation to dental health behavior

A study of the knowledge about dental health and diseases of youths in their late teens has been conducted. A 10-class questionnaire relating to dental caries and gingivitis/periodontitis was answered by three test groups (A, B, C) totalling seventy-eight 19-year-olds who, during a 3-year period, had undergone professional prophylaxis at different intervals. Nineteen young people of the same age without organized preventive measures since their last attendance at the public dental service constituted a control group (D). The test groups were found to have a significantly better knowledge of factors relating to gingivitis/periodontitis than the control group. In questions relating to caries there were no differences among the groups. Higher points were scored in knowledge of therapy and prevention than of the causes and symptoms of the dental diseases. Several regularly repeated sessions for professional prophylaxis did not lead to better knowledge than only a few. No consistent correlation was found for any of the groups between knowledge and both quantitative tooth cleaning, i.e. type and frequency of use of oral hygiene aids, and qualitative tooth cleaning, expressed as the occurrence of plaque and gingivitis. Nor were significant differences found in these respects between individuals with and without a caries increment during the observation period regardless of grouping.