DENTAL AND FACIAL CHARACTERISTICS IN DOWN'S SYNDROME (MONGOLISM)

Periodontal diseases in Down syndrome during childhood: a scoping review

BACKGROUND

Down syndrome (DS) is a genetic condition that involves the deregulation of immune function and is characterized by a proinflammatory phenotype leading to an impaired response to infections. Periodontitis is a highly prevalent chronic inflammatory disease. It has been shown that adults and teenagers with DS are more susceptible to this disease, but a similar correlation in DS children remains elusive. This systematic scoping review aims to address this knowledge gap by examining periodontitis in DS children, with a secondary objective of elucidating the underlying mechanisms involved.

METHODS

Our primary search was conducted via the PubMed/MEDLINE database and Google Scholar, covering the period from 1951-July 1st, 2024. Primary studies written in English or French were included. The excluded articles were reviews, in vitro or animal studies, studies on teenagers or adults, and studies involving patients with disabilities other than DS. The quality of evidence was assessed via the Newcastle‒Ottawa scale for observational studies and a published tool for evaluating the quality of case reports and case series.

RESULTS

The initial electronic database search yielded a total of 2431 articles. 58 full-text articles, comprising seven cross-sectional studies, 36 case‒control studies, seven cohort studies, and eight case reports and case series, were included in the review. Compared with healthy children or children with disabilities, DS children appear to have more severe periodontal inflammation. However, the evidence is inconclusive regarding the presence of bone loss, with studies divided on this issue. Local risk and etiopathogenetic factors do not seem to play a significant role in increased inflammation. Instead, this difference could be attributed to the general proinflammatory phenotype of children with DS.

CONCLUSIONS

DS children seem to have higher periodontal inflammation than other children, but no periodontal bone loss. Investigating periodontal inflammation in DS children could provide valuable insights into the deregulation of immune function in these patients.

Craniofacial and Airway Morphology in Down Syndrome: A Cone Beam Computed Tomography Case Series Evaluation

Background: Down syndrome (DS) is a genetic condition characterized by an extra copy of chromosome 21, resulting in various physical and cognitive features. This study aimed to comprehensively analyze the dental and craniofacial morphology of individuals with DS using Cone Beam Computed Tomography (CBCT). Methods: Six individuals with DS, comprising five males and one female aged 17 to 35 years, underwent CBCT scanning. Radiographic assessments included dentition, occlusion, paranasal sinuses, airway, skull bones, and suture calcification. Linear and angular cephalometric measurements were performed, and airway analysis was conducted using Dolphin 3D imaging software v.11. Results: The study revealed prognathic maxilla in five patients, prognathic mandible in four, and bimaxillary protrusion in two. Dental findings included microdontia, enamel hypoplasia, and congenitally missing teeth, with maxillary and mandibular third molars most commonly absent. Sinus abnormalities, delayed suture closure, and cervical spine anomalies were also observed. Conclusion: These findings contribute to a deeper understanding of DS-related craniofacial characteristics and emphasize the importance of considering these morphometric features in clinical management strategies for individuals with DS. This study's limited sample size underscores the significance of radiographic assessment in planning interventions such as cosmetic reconstructions, prosthetic rehabilitation, or orthodontic treatment for individuals with DS.

Oral Health Status of Down's Syndrome Patients in Aseer, Saudi Arabia

Introduction:

It was observed that compared to the general population, mentally challenged subjects have higher rates of poor oral hygiene. Gingivitis is a common finding with moderate or severe variety reported most commonly. Periodontal disease is the most significant oral health problem, which can even lead to mobility of tooth and tooth loss. It is essential to generate oral health precautionary agendas and familiarize it with them.

Materials and Methods:

Four Centres of rehabilitation in the Aseer region of Saudi Arabia were included and subjects of 3–24 year age group was examined. Written informed consent was obtained from directors of Centres. Caries, oral hygiene status, soft-tissue and hard-tissue lesions were evaluated and statistically analyzed.

Results:

Higher Decayed, Missing and Filled Teeth score was observed in the present study in contrast to many other studies. Periodontal disease was seen in higher age group with higher percentages. Poor oral hygiene was seen in 27.3% of males and 66.7% of females. Tongue lesions comprised 85.7%, which accounted for the major part of soft-tissue abnormality. Various occlusal abnormalities (75%) and developmental tooth disturbances (53.6%) constitute the higher portion in hard-tissue abnormality.

Conclusion:

Dentists should be conscious of the range of oral anomalies that can manifest in this group of the patients. The microbial or serological investigation was not done which could have explained the etiology behind these lesions. In spite of these confines, the survey result have provided information regarding the oral health status of Down's syndrome subjects and the necessity of focusing on oral health need.

Metabolic Diseases and Down Syndrome: How Are They Linked Together?

Down syndrome is a genetic disorder caused by the presence of a third copy of chromosome 21, associated with intellectual disabilities. Down syndrome is associated with anomalies of both the nervous and endocrine systems. Over the past decades, dramatic advances in Down syndrome research and treatment have helped to extend the life expectancy of these patients. Improved life expectancy is obviously a positive outcome, but it is accompanied with the need to address previously overlooked complications and comorbidities of Down syndrome, including obesity and diabetes, in order to improve the quality of life of Down syndrome patients. In this focused review, we describe the associations between Down syndrome and comorbidities, obesity and diabetes, and we discuss the understanding of proposed mechanisms for the association of Down syndrome with metabolic disorders. Drawing molecular mechanisms through which Type 1 diabetes and Type 2 diabetes could be linked to Down syndrome could allow identification of novel drug targets and provide therapeutic solutions to limit the development of metabolic and cognitive disorders.

Automatic Identification of Down Syndrome Using Facial Images with Deep Convolutional Neural Network

Down syndrome is one of the most common genetic disorders. The distinctive facial features of Down syndrome provide an opportunity for automatic identification. Recent studies showed that facial recognition technologies have the capability to identify genetic disorders. However, there is a paucity of studies on the automatic identification of Down syndrome with facial recognition technologies, especially using deep convolutional neural networks. Here, we developed a Down syndrome identification method utilizing facial images and deep convolutional neural networks, which quantified the binary classification problem of distinguishing subjects with Down syndrome from healthy subjects based on unconstrained two-dimensional images. The network was trained in two main steps: First, we formed a general facial recognition network using a large-scale face identity database (10,562 subjects) and then trained (70%) and tested (30%) a dataset of 148 Down syndrome and 257 healthy images curated through public databases. In the final testing, the deep convolutional neural network achieved 95.87% accuracy, 93.18% recall, and 97.40% specificity in Down syndrome identification. Our findings indicate that the deep convolutional neural network has the potential to support the fast, accurate, and fully automatic identification of Down syndrome and could add considerable value to the future of precision medicine.

Diagnostic performance of artificial intelligence to detect genetic diseases with facial phenotypes: A protocol for systematic review and meta analysis

BACKGROUND

Many genetic diseases are known to have distinctive facial phenotypes, which are highly informative to provide an opportunity for automated detection. However, the diagnostic performance of artificial intelligence to identify genetic diseases with facial phenotypes requires further investigation. The objectives of this systematic review and meta-analysis are to evaluate the diagnostic accuracy of artificial intelligence to identify the genetic diseases with face phenotypes and then find the best algorithm.

METHODS

The systematic review will be conducted in accordance with the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols" guidelines. The following electronic databases will be searched: PubMed, Web of Science, IEEE, Ovid, Cochrane Library, EMBASE and China National Knowledge Infrastructure. Two reviewers will screen and select the titles and abstracts of the studies retrieved independently during the database searches and perform full-text reviews and extract available data. The main outcome measures include diagnostic accuracy, as defined by accuracy, recall, specificity, and precision. The descriptive forest plot and summary receiver operating characteristic curves will be used to represent the performance of diagnostic tests. Subgroup analysis will be performed for different algorithms aided diagnosis tests. The quality of study characteristics and methodology will be assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Data will be synthesized by RevMan 5.3 and Meta-disc 1.4 software.

RESULTS

The findings of this systematic review and meta-analysis will be disseminated in a relevant peer-reviewed journal and academic presentations.

CONCLUSION

To our knowledge, there have not been any systematic review or meta-analysis relating to diagnosis performance of artificial intelligence in identifying the genetic diseases with face phenotypes. The findings would provide evidence to formulate a comprehensive understanding of applications using artificial intelligence in identifying the genetic diseases with face phenotypes and add considerable value in the future of precision medicine.

OSF REGISTRATION

DOI 10.17605/OSF.IO/P9KUH.

Down syndrome-A narrative review with a focus on anatomical features

Down syndrome (DS) is the most common aneuploidy of chromosome 21, characterized by the presence of an extra copy of that chromosome (trisomy 21). Children with DS present with an abnormal phenotype, which is attributed to a loss of genetic balance or an excess dose of chromosome 21 genes. In recent years, advances in prenatal screening and diagnostic tests have aided in the early diagnosis and appropriate management of fetuses with DS. A myriad of clinical symptoms resulting from cognitive, physical, and physiological impairments caused by aberrations in various systems of the body occur in DS. However, despite these impairments, which range from trivial to fatal manifestations, the survival rate of individuals with DS has increased dramatically from less than 50% during the mid-1990s to 95% in the early 2000s, with a median life expectancy of 60 years reported recently. The aim of this narrative review is to review and summarize the etiopathology, prenatal screening and diagnostic tests, prognosis, clinical manifestations in various body systems, and comorbidities associated with DS. Clin. Anat. 29:568-577, 2016. © 2015 Wiley Periodicals, Inc.

Dentofacial and cranial changes in down syndrome

Objectives

This study aimed to determine the prevalence of certain oral characteristics usually associated with Down syndrome and to determine the oral health status of these patients.

Methods

The cross-sectional study was conducted among patients attending a special education program at Faculty of Dentistry, Jamia Millia Islamia, Delhi, India. The study design consisted of closed-ended questions on demographic characteristics (age, sex, and education and income of parents), dietary habits, and oral hygiene habits. Clinical examination included assessment of oral hygiene according to Simplified Oral Hygiene Index (OHI-S), dental caries according to decayed, missing, and filled teeth (DMFT) index, periodontal status according to the Community Periodontal Index of Treatment Needs (CPITN), and malocclusion according to Angles classification of malocclusion. Examinations were carried out using a using a CPI probe and a mouth mirror in accordance with World Health Organization criteria and methods. Craniometric measurements, including maximum head length and head breadth were measured for each participant using Martin spreading calipers centered on standard anthropological methods.

Results

The majority of the patients were males (n = 63; 82%) with age ranging from 6–40 years. The Intelligence Quotient (IQ) score of the patients indicated that 31% had moderate mental disability and 52% had mild mental disability. 22% exhibited hearing and speech problems.12% had missing teeth and 15% had retained deciduous teeth in adult population. The overall prevalence of dental caries in the study population was 78%. DMFT, CPITN and OHI scores of the study group were 3.8 ± 2.52, 2.10 ± 1.14 and 1.92 ± 0.63 respectively. The vast majority of patients required treatment (90%), primarily of scaling, root planing, and oral hygiene education. 16% of patients reported CPITN scores of 4 (deep pockets) requiring complex periodontal care. The prevalence of malocclusion was 97% predominantly of Class III malocclusions. Further 14% presented with fractured anterior teeth primarily central incisor. The percentage means of cephalic index was 84.6% in the study population. The brachycephalic and hyperbrachycephalic type of head shape was dominant in the Down syndrome individuals (90%).

Conclusion

The most common dentofacial anomaly seen in these individuals was fissured tongue followed by macroglossia.

Distribution of permanent canine agenesis in Down syndrome: 15 cases from a Centre for Special Care Dentistry

The purpose of this study was to investigate the distribution of permanent canine agenesis in subjects with Down syndrome (DS). Subjects with canine agenesis were determined by means of panoramic radiographs from 150 DS subjects attending a center for special care dentistry. Our results confirm the high prevalence of agenetic canines in DS (21 canines, 14%). We found specific effects on the distribution both of phenotype and of location (jaw). In subjects with a mild expression of hypodontia (phenotype nonoligodontia) agenetic canines primarily occurred in the mandibula, whereas in subjects with severe hypodontia (phenotype oligodontia) agenetic canines virtually only occurred in the maxilla. In both phenotypes cooccurrence of an agenetic lateral incisor with an agenetic canine was observed in the maxilla. It was striking that canine agenesis in the mandibula did not cooccur with agenesis of other teeth. These results can be important for treatment planning.

Orthodontic treatment of children/adolescents with special health care needs: an analysis of treatment length and clinical outcome

BACKGROUND

The aim of this retrospective study was to analyse the treatment time and differences between the pre- and post-treatment peer assessment rating (PAR) index and aesthetic component (AC) of the index of orthodontic treatment need (IOTN) scores in children/adolescents with special health care needs (SHCNs), compared to non-special health care needs (NSHCNs) controls.

METHODS

Based on certain inclusion and exclusion criteria, medical records of SHCNs and randomly selected NSHCNs controls at the Department of Orthodontics, University Hospital Muenster were analysed retrospectively for the treatment time, number of appointments, chair time ("moderate" or "considerable"), PAR scores, and AC scores. Sample size calculation, descriptive statistics, and explorative analyses were performed using the Mann-Whitney U Test.

RESULTS

Twenty-nine children with SHCNs (21 boys, 9 girls; median age: 11 years, pre-treatment) and 29 children with NSHCNs (12 boys, 17 girls; median age: 12 years, pre-treatment) were enrolled in this study.The overall treatment time did not differ between the patient groups. However, more "considerable chair time" was needed for the SHCNs group compared to the control group (p < 0.05), whereas "moderate chair time" was more often needed in patients with NSHCNs (p = 0.001).The age of the patients at the first and last appointments showed significant statistical differences: children in the SHCNs group commenced orthodontic treatment earlier, by a median of 1 year, compared to children in the NSHCNs group.The SHCNs group had significantly higher pre- and post-treatment PAR scores (median 21/median 6) and AC scores (median 9/median 3) compared to NSHCNs patients (PAR: median 17/median 0; AC: median 5/median 1).However, the overall treatment time and the overall PAR and AC score reduction did not differ significantly between the SHCNs and NSHCNs groups.

CONCLUSIONS

While the overall treatment time and number of appointments did not differ, the overall chair time was higher in the SHCNs group. The pre- and post-treatment PAR and AC scores were significantly higher in the SHCNs group.

Evaluation of Oral Hygiene Status and Periodontal Health in Mentally Retarded Subjects with or without Down's Syndrome in Comparison with Normal Healthy Individuals

AIM

The aim of the study was to assess the oral hygiene status and periodontal status of Mentally Retarded, Down's syndrome and normal subjects.

MATERIAL AND METHODS

The study was undertaken at OPPORTUNITY SCHOOL at Vepery, Chennai, India. 150 subjects were selected. Among them 100 were Mentally Retarted, 50 were Down's Syndrome subjects. 50 healthy normal subjects were selected (Students from Madha School, Chennai, India) for comparison. All were screened for oral hygiene and periodontal status by OHI-S and CPITN index. Statistical analyasis was done by Pearsson correlation coefficient.

RESULTS AND CONCLUSION

The results showed that the Mentally Retarded and Down's Syndrome subjects had decreased prevalence rate of periodontitis.

Age assessment based on dental calcification in individuals with Down syndrome

It is important to estimate both chronological age (CA) and maturational age of an individual, in order to perform orthopedic treatment or surgery, and in cases of lost documentation. Use of dental age (DA) for these purposes has been widely studied; however, the literature is scarce with regard to individuals with Down syndrome (DS), a prevalent condition worldwide. In this study the chronology of dental maturation was evaluated by analyzing the DA of individuals with DS based on the Chronological Mineralization Table proposed by Nolla (1960). Thus, second molars were evaluated in 57 panoramic radiographs of male and female individuals with DS, between 5 and 16 years-old. These data were compared with a control group of 191 nonsyndromic individuals of the same age group. Correlation between CA and DA was ascertained using Pearson's correlation coefficient (r), and the difference between these variables was measured using Student's t-test for paired samples and the method proposed by Bland and Altman. The difference between DA and CA was compared between the control and DS groups using Student's t-test for independent samples (α=0.05). DA was slightly lower than the CA; however, this difference was only significant for females. The difference between DA and CA was not significant between individuals with DS and control group (both genders, p=0.945; males, p=0.542; females, p=0.381). We concluded that dental maturation in individuals with DS occurs similarly to that of nonsyndromic individuals.

Speech impairment in Down syndrome: a review

PURPOSE

This review summarizes research on disorders of speech production in Down syndrome (DS) for the purposes of informing clinical services and guiding future research.

METHOD

Review of the literature was based on searches using MEDLINE, Google Scholar, PsycINFO, and HighWire Press, as well as consideration of reference lists in retrieved documents (including online sources). Search terms emphasized functions related to voice, articulation, phonology, prosody, fluency, and intelligibility.

CONCLUSIONS

The following conclusions pertain to four major areas of review: voice, speech sounds, fluency and prosody, and intelligibility. The first major area is voice. Although a number of studies have reported on vocal abnormalities in DS, major questions remain about the nature and frequency of the phonatory disorder. Results of perceptual and acoustic studies have been mixed, making it difficult to draw firm conclusions or even to identify sensitive measures for future study. The second major area is speech sounds. Articulatory and phonological studies show that speech patterns in DS are a combination of delayed development and errors not seen in typical development. Delayed (i.e., developmental) and disordered (i.e., nondevelopmental) patterns are evident by the age of about 3 years, although DS-related abnormalities possibly appear earlier, even in infant babbling. The third major area is fluency and prosody. Stuttering and/or cluttering occur in DS at rates of 10%-45%, compared with about 1% in the general population. Research also points to significant disturbances in prosody. The fourth major area is intelligibility. Studies consistently show marked limitations in this area, but only recently has the research gone beyond simple rating scales.

Wideband energy reflectance findings in presence of normal tympanogram in children with Down's syndrome

OBJECTIVES

The prevalence of middle ear disorders in children with Down syndrome is higher than normal children due to the associated craniofacial abnormalities. The goal of this study is to evaluate middle ear function using wideband energy reflectance at ambient pressure in 14 young children with Down syndrome and matched control group (2½-5 years old; N=19 ears per group) who each have a normal 226Hz tympanogram.

METHODS

All children underwent otoscopic examination, hearing screening using play audiometry (500-4000Hz), and middle ear testing using 226Hz tympanometry and wideband energy reflectance. The chirp signals for the wideband energy reflectance were presented to the child's ear at 65dB SPL stimulus level and the recording was done over 220-8000Hz range. The measured energy reflectance represents the ratio of the sound energy reflected from the tympanic membrane to the incident sound energy transmitted to the middle ear at a specific frequency. Paired Samples t-test was computed for the mean, 95th, 75th, 25th, and 5th percentile data of each frequency of the two groups.

RESULTS

Despite the presence of normal tympanometric findings in both groups, results revealed abnormal wideband energy reflectance findings in 63% of the children with Down syndrome compared to the normal wideband energy reflectance findings in the control group. The mean energy reflectance ratio of the Down syndrome group was abnormally lower than that of the control at 5700-8000Hz (p<0.0005). The 5th and 95th percentile ratios of the Down syndrome group fell outside the 5th and 95th percentile of the control group (p<0.0005).

CONCLUSIONS

Abnormally low energy reflectance ratios above 4000Hz in the presence of normal tympanograms in the Down syndrome group may suggest associated congenital middle ear anomalies in children with DS. The present findings suggest that wideband energy reflectance has the potential to be of more practical value in children with DS than tympanometry. Further research with a larger number of Down syndrome children will illuminate the potential of wideband energy reflectance in diagnosing middle ear disorders in children with Down syndrome.

Patterns of tooth agenesis in patients with Down syndrome in relation to hypothyroidism and congenital heart disease: an aid for treatment planning

INTRODUCTION

The purposes of this study were to investigate the patterns of tooth agenesis (oligodontia and nonoligodontia), maxillary canine impaction, and tooth transposition in subjects with Down syndrome and to determine whether congenital heart disease and hypothyroidism are parameters in tooth agenesis.

METHODS

The study included 114 patients with Down syndrome. The data were quantified by using standardized records, clinical examinations, panoramic radiographs, and solo roentgenograms. The subjects were differentiated into oligodontia (6 or more teeth missing) and nonoligodontia (5 or fewer teeth missing).

RESULTS

In these patients with Down syndrome, 59.6% had missing teeth. Those in the nonoligodontia group showed a tendency toward a negative correlation between congenital heart disease and agenesis (P = 0.093; odds ratio = 0.49) but a slight positive correlation between hypothyroidism and agenesis (P = 0.060; odds ratio = 3.71). In the oligodontia group, there was a quantitatively and qualitatively different pattern, indicating another phenotype. When both mandibular central incisors were missing, there was a remarkable chance for oligodontia (P = 0.001; odds ratio = 38.8). In the mandible, symmetrical agenesis of the canines and lateral incisors was more frequent in the nonoligodontia group.

CONCLUSIONS

The oligodontia (with a different phenotype) and nonoligodontia groups had different patterns of agenesis. Maxillary canine impaction was not related to absence of the lateral incisors. Absence of both mandibular central incisors was a high predictor for oligodontia. Congenital heart disease and hypothyroidism are parameters involved in tooth agenesis.

Os distúrbios fonoarticulatórios na síndrome de Down e a intervenção precoce

TEMA: a criança com Síndrome de Down apresenta um atraso na aquisição e desenvolvimento dos aspectos fonoarticulatórios, atraso este, que tem sido atribuído a características físicas e ambientais que influenciam negativamente no processo de desenvolvimento. Caracterizar os aspectos fonoarticulatórios dos sujeitos com Síndrome de Down pode proporcionar uma melhor compreensão das alterações abordadas na reabilitação em suas diversas modalidades e contribuir na evolução terapêutica. Por esta razão decidiu-se focar com maior profundidade em um dos aspectos mais importantes da comunicação, a fonoarticulação. OBJETIVO: caracterizar as alterações fonoarticulatórias encontradas em indivíduos portadores da Síndrome de Down, por meio de uma revisão bibliográfica, enfocando a importância da intervenção precoce frente a tais circunstâncias. CONCLUSÃO: a falta de estimulação e o encaminhamento tardio irão interferir no desenvolvimento fonoarticulatório, assim, por meio da intervenção precoce, será possível a obtenção de melhores resultados, fazendo com que grandes problemas tornem-se alterações mínimas.

Skeletal age of individuals with Down syndrome

The aim of this study was to assess the skeletal age of Brazilian individuals with Down syndrome (DS) using the method of Greulich and Pyle. Forty subjects with DS between the ages of 6 and 16 years were studied and compared to a control sample of children without DS. The statistical analysis showed that at the age of 7 years the skeletal age (SA) of the individuals with DS was delayed in relation to their chronological age (CA) (SA < CA). On the other hand, at the age of 15 years, their SA was advanced in relation to their CA (SA > CA). An evaluation of the results suggests that the period of adolescent development for individuals with DS was shorter. These individuals reach the completion of bone maturation earlier compared to individuals without DS.

Cephalometric Evaluation of Children with Down Syndrome After Early Intervention with the Stimulating Plate

The aim of stimulating plate therapy in patients with trisomy 21 is to correct orofacial dysfunctions and prevent the establishment of subsequent morphological characteristics such as protrusion of the incisors and pseudoprognathia. This study investigated the effectiveness of this type of therapy in improving skeletal traits of patients with Down syndrome. The lateral cephalograms of 22 consecutive juveniles with Down syndrome, whose orofacial dysfunctions had been successfully treated with a stimulating plate according to Castillo Morales in infancy (17 months +/- 24 months), were examined 136 months on average (minimum of 78 months, maximum of 231 months) after initiation of treatment. In 16 of the 22 patients, the anomaly-typical bialveolar protrusion of the anterior teeth was diagnosed. The cephalometric results indicated larger values of cephalometric parameters concerning cranial base and maxilla, and markedly larger mandibular cephalometric values when compared to untreated children with Down syndrome. These results show that a stimulating plate may not always be indicated in patients with Down syndrome with a skeletal Class III pattern and minor orofacial findings.

Genotyping of Streptococcus mutans by using arbitrarily primed polymerase chain reaction in children with Down Syndrome

OBJECTIVE

The aim of this study was to compare the caries prevalence between Down Syndrome (DS) and non-DS children and to investigate the difference between the genotypes of Streptococcus mutans (S. mutans) colonized in both DS and non-DS groups.

DESIGN

Sixty children with DS and 64 non-DS children aged between 7 and 12 years old were included to this study. All erupted teeth were evaluated according to the criteria recommended by the World Health Organization. Unstimulated saliva samples were carried out from the children and cultivated on S. mutans selective Tryptone-yeast-cystine (TYC) agar with 0.2 U/ml bacitracin and 15% sucrose. Molecular typing of S. mutans strains was performed by using arbitrarily primed polymerase chain reaction (AP-PCR) with OPA-05 primer. All data were analysed by using SPSS (SPSS Inc., Chicago, IL, USA) 11.0 software program for windows.

RESULTS

The caries index scores were found significantly lower in DS individuals than the non-DS group (p < 0.05). The salivary S. mutans levels between DS and non-DS groups did not show significant difference (p > 0.05). The difference between dental caries and salivary S. mutans levels also was not statistically significant (p > 0.05). According to the results of the AP-PCR typing, all profiles of S. mutans which colonized in DS group were different from the control group. The relationship between these different profiles and dental caries prevalence was statistically significant (p < 0.05).

CONCLUSION

The profiles of S. mutans colonized in DS group might be a reason of low caries prevalence.

Age-related changes in anthropometric measurements in the craniofacial regions and in height in Down's syndrome

This cross-sectional study analyzed age-related changes in normal and abnormal measurements of the head and face in three age categories in 115 Down's syndrome patients 1 to 36 years old. The frequency of normal measurements significantly surpassed that of abnormal ones in each category. Clinically, the key task was to ascertain differences between the youngest and oldest patients. In age group 1 (1 to 5 years), normal measurements in three of the six craniofacial regions were significantly more frequent than abnormal ones. In age group 2 (6 to 15 years) the percentage of normal measurements significantly increased, influenced by higher growth rates in the period of maturation, which coincided with this category. In age group 3 (16 to 36 years) the percentage of normal measurements significantly increased in the head and ear but decreased in the other regions, significantly in the orbits. The frequency of both optimal and severely abnormal measurements changed significantly from age group 1 to 3 in only five measurements each, with no consistency in the direction of results. Abnormal measurements qualified as stigmata and were recorded in 40% (10 of 25) in five regions: three in the face; two in each of the head, orbits, and ears; and one in the nose. Marked epicanthi covering the endocanthion decreased from 35.0% in age group 1 to 8.7% in group 3. In age group 1, the frequency of normal body height (20.7%) in both sexes was significantly less than subnormal (70.3%) but significantly decreased in age group 2. Mean height in group 3 was enough to rule out short stature as a stigmata of Down's syndrome. The study was limited by small numbers, particularly in the variations of normal and abnormal, but the trend toward normality after maturation suggests that reconstructive surgery should be delayed until this time.

Down syndrome: lip lesions (angular stomatitis and fissures) and Candida albicans

BACKGROUND

The incidence of angular cheilitis (angular stomatitis, perleche, commissural fissures) appears to be increased in people with Down syndrome (DS). Lip fissures are also (in our clinical impression) a fairly regular feature, yet this is scarcely mentioned in the literature.

OBJECTIVES

To establish the incidence of angular cheilitis and lip fissures in a substantial group of patients with DS and to examine the relationship with Candida albicans.

PATIENTS AND METHODS

The prevalence of orofacial soft tissue lesions was investigated in a group of 77 DS patients. Swabs were taken from lip lesions, palate and tongue and inoculated on Sabouraud's agar discs for the isolation of C. albicans, identified with commercially available kits.

RESULTS

Lip fissures were seen in at least one-quarter of DS patients. Angular cheilitis was also found in a similar percentage.

CONCLUSIONS

C. albicans was isolated from a substantial proportion of lesions tested, and was present more frequently than in those without lip lesions, but it is uncertain whether this represents cause or effect.

Surface anatomy of the face in Down's syndrome: age-related changes of anthropometric proportion indices in the craniofacial regions

The purpose of the study was to determine the age-related changes in normal and abnormal proportion indices in Down's syndrome patients between 1 to 5, 6 to 15, and 16 to 36 years of age. Nine indices were analyzed in five craniofacial regions of 125 subjects: 70.2% to 79.0% were normal and 21.0% to 29.8% abnormal. Proportionate indices increased in frequency in all age groups in a much higher percentage than disproportionate ones. In the oldest group, the frequency of normal proportions significantly increased in the head and trended higher in the facial, orbital, and nasal regions, and lower in the ear. Disproportions showed a similar pattern, with a decreasing frequency in all regions except the ear. The variations of harmony and disharmony in normal proportions, and moderate and severe in disproportions, helped clarify the morphological changes influencing the craniofacial design. Among proportionate ratios, harmony ranged from 45% to 65.5% in age group 1 and from 30% to 87.5% in group 3. No cases of severe subnormal disproportions were seen in the nasal tip protrusion-nose width and nasal root depth indices in age group 1, and none in the cephalic index, midface-lower face depth, and nasal tip protrusion-nose width indices in group 3. The 20-year age range of group 3 helped show the post-maturation improvements of the face and the remedying effect of the extended growth rate on some initial facial disproportions.

Tooth wear in children with Down syndrome

BACKGROUND

Several studies have described the impact that dental caries and periodontitis may have on the dentitions of individuals with Down syndrome, but there are few reports about the effects of tooth wear. This investigation aimed to compare the aetiology, prevalence and severity of tooth wear in 49 cytogenetically confirmed Down syndrome children with 49 non-Down syndrome controls.

METHODS

This study involved three aspects: an oral examination, including obtaining dental impressions; a dietary analysis spanning three days; and a questionnaire seeking information about habits, medical problems and medications. Tooth wear severity was scored on a 4-grade scale (none-to-little; moderate; severe; very severe), while aetiology was classified as being due to attrition mainly, erosion mainly, or a combination of both. Double determinations established scoring method reliability and chi-square tests assessed associations between samples.

RESULTS

Tooth wear was significantly more frequent (p<0.01) in the Down syndrome than the non-Down syndrome sample (67.4 per cent cf 34.7 per cent), with more of the Down syndrome children showing severe to very severe wear (59.2 per cent cf 8.2 per cent). Significantly more Down syndrome children (p<0.05) displayed a multifactorial aetiology of tooth wear, i.e., both attrition and erosion (46.7 per cent cf 28.6 per cent), although no particular dietary link was established. Gastric reflux and vomiting were reported in over 20 per cent of the Down syndrome sample.

CONCLUSIONS

Given the potential consequences of high levels of tooth wear, associated with tooth grinding and an acidic oral environment in Down syndrome children, educational programmes aimed at increasing awareness of carers and health professionals are needed urgently.

Effect of Down syndrome on the dimensions of dental crowns and tissues

Abnormal growth in Down syndrome (DS) is reflected by variable reduction in size and simplification in form of many physical traits. This study aimed to compare the thickness of enamel and dentine in deciduous and permanent mandibular incisor teeth between DS and non-DS individuals and to clarify how these tissues contribute to altered tooth size in DS. Sample groups comprised 61 mandibular incisors (29 permanent and 32 deciduous) from DS individuals and 55 mandibular incisors (29 permanent and 26 deciduous) from non-DS individuals. Maximum mesiodistal and labiolingual crown dimensions were measured initially, then the crowns were sectioned midsagittally and photographed using a stereomicroscope. Linear measurements of enamel and dentine thickness were obtained on the labial and lingual surfaces of the crowns, together with enamel and dentine-pulp areas and lengths of the dentino-enamel junction. Reduced permanent crown size in DS was associated with a reduction in both enamel and dentine thickness. After adjustments were made for tooth size, DS permanent incisors had significantly thinner enamel than non-DS permanent teeth. The DS permanent teeth also exhibited significant differences in shape and greater variability in dimensions than the non-DS permanent teeth. Crown dimensions of deciduous incisors were similar in size or larger in DS compared with non-DS deciduous teeth. Enamel and dentine thicknesses of the deciduous teeth were similar in DS and non-DS individuals. The findings indicate that growth retardation in DS reduces both enamel and dentine deposition in the permanent incisors but not in the earlier-forming deciduous predecessors. The results are also consistent with the concept of amplified developmental instability for dental traits in DS.

Surface anatomy of the face in Down's syndrome: linear and angular measurements in the craniofacial regions

Measurements (23 projective linear, 2 angular) taken in the 6 craniofacial regions of 127 patients with Down's syndrome showed that 63.1% (1,836 of 2,908) were within normal limits and 36.9% (1,072) were outside them. Abnormal measurements were subnormal in 90.8% (973) and supernormal in 9.2% (99). All statistical summaries were based on z scores (adjusting for age and sex differences) classified into a small number of ranges to yield a simplified frequency distribution for each measurement. The purpose of the study was to identify the measurements closest to normal and those indicating the most severe degrees of sub- or supernormality. Approximately a quarter of normal measurements were classified as optimal, and half the subnormal or supernormal measurements were classified as severe. Intercanthal width had the highest frequency of optimal measurements (93.7%, 119 of 127), head circumference the smallest (28.6%, 36 of 126). Knowledge of the frequency of extreme abnormalities in the craniofacial regions will help during visual examination of patients with Down's syndrome. This study found the highest percentage of severely subnormal measurements in the orbital region (57.8%, 74 of 128) and the smallest in the labio-oral region (32.7%, 16 of 49). The measurement with the highest proportion of severely subnormal to all subnormal values was the palpebral fissure length (68%, 51 of 75), and the nose width had the smallest proportion (14.3%, 1 of 7).

Malocclusions and traumatic injuries in disabled schoolchildren and adolescents in Kuwait

The present study was carried out to determine the prevalence of malocclusion and traumatic injuries in disabled children and adolescents attending the special-needs schools in Kuwait. Included in the study were 818 children (438 males and 380 females), in the age groups of 3-20 years, who have visual impairment, hearing impairment, physical handicaps, or developmental disorders. The mean age of participants was 11.9 years. The survey was carried out according to the methods of WHO. The prevalence of severe malocclusion was 23.6%, and that of slight malocclusion was 37.0%. Children with Down syndrome (OR = 2.3; 95% CI = 1.51-3.52), those of increasing age (OR = 1.1; 95% CI = 1.01-1.10), and males (OR = 1.5; 95% CI = 1.05-2.07) had higher risk for the occurrence of severe malocclusion. Less than one-fifth of the subjects (16.9%) had traumatized anterior teeth. Severe malocclusion (OR = 1.8; 95% CI = 1.17-2.77) and increasing age (OR = 1.2; 95% CI = 1.13-1.26) were significant risk factors for the occurrence of traumatic injuries. We concluded that malocclusion and traumatic injuries are more prevalent among these subjects with disabilities than among the healthy population in Kuwait.

Normal formation and development defects of the human dentition

Oral health and systemic health are intimately related, and a thorough evaluation of the oral health of children is critical in providing appropriate health care. By understanding the normal sequence and patterns of tooth development, clinicians can readily identify children who deviate from normal dental development and provide appropriate interventions or make appropriate referrals. Developmental defects of the human dentition are not uncommon and can severely adversely affect the physical and psychological health of children. Despite the severity of some developmental defects of the dentition, the ability to diagnose and manage these conditions, in most cases, allows children the benefit of optimal oral health.

Oligodontia: a radiographic comparison of subjects with Down syndrome and normal subjects

Panoramic radiographs and clinical records were used to investigate developmentally absent permanent teeth in 98 subjects with Down syndrome (trisomy-21). This retrospective study was based on the records and panoramic radiographs of subjects from approximately five years of age (the age at which mineralization of the permanent tooth germ could be identified) through to their most recent records. The time period covered by records ranged from 6 to 28 years. The majority of subjects with Down syndrome (63%) exhibited oligodontia, and many subjects were missing two or more teeth (53%). The most frequently absent teeth were the lower lateral incisors (23.3%), the upper second premolars (18.2%), the upper lateral incisors (16.5%), and the lower second premolars (15.3%). In general, the distribution of the developmentally absent teeth was similar for teeth in homologous positions (i.e., left and right canines, etc.) on either side of the midline or between the maxilla and the mandible. The only significant exceptions to this pattern were seen with the central incisors and the second molar. This study's findings suggest a high risk of oligodontia in subjects with Down syndrome.

Sequence of eruption of deciduous dentition in a Chilean sample with Down's syndrome

The eruption of the deciduous teeth in Down's individuals is reportedly delayed, but the extent of delay in comparison to normal children has been little studied. The eruption characteristics of the deciduous teeth in a sample of Chilean individuals with Down's syndrome were compared with those of the normal Chilean population. The sample consisted of 255 Down's individuals (all with trisomy 21), 127 males and 128 females. Boys with Down's syndrome showed significantly delayed eruption in six teeth: in the maxilla the right central incisor and right and left lateral incisors, and in the mandible the right central incisor and right and left canines. Girls with Down's syndrome showed significant delays in the eruption of 11 teeth: in the maxilla the right and left lateral incisors, right and left canines and first left molar, and in the mandible the left central incisor, right and left lateral incisors and canines and second right molar. The chronological sequence of eruption in Down's children was not completely different from that of normal individuals. With a few exceptions no significant departures from Gaussian distribution were found in the age of eruption among both normal and Down's individuals. The variance was significantly larger in cases of Down's syndrome.

A comprehensive 30-month preventive dental health program in a pre-adolescent population with Down's syndrome: a longitudinal study

A comprehensive systematic preventive dental health program was implemented in a young population with Down's Syndrome during a 30-month period. Twenty children (nine boys and 11 girls), ages 8-13 (mean age, 11), participated in the study, which took place in three hostel-like apartments. The main goals of this program were to achieve good plaque control and subsequently prevent periodontal disease as well as to apply fissure sealants and fluorides in an attempt to prevent dental caries. The mean plaque and gingival indices as well as the percentage of bleeding sites decreased significantly (P < 0.01) following the administration of our oral health program. Caries experience, as indicated by DMFS, decreased from 1-35 to 1-05 surfaces per child, and the use of fissure sealants to prevent occlusal caries was proved to be 100% effective. It is concluded that if the children's efforts are integrated with those of a motivated dentist, dental hygienist, and staff, a well-planned preventive dental health program can lead to a high degree of success in the prevention of dental diseases in young populations with Down's Syndrome.

Tooth malalignments in Chilean children with Down syndrome

The present study analyzes the frequencies and types of anomalies in tooth alignment in a sample of 136 children with Down syndrome, 147 mentally-impaired individuals without Down syndrome, and 149 normal individuals. Patients with Down syndrome showed a higher frequency of malalignments in both the deciduous and permanent dentitions compared with the children in control groups. In the three groups studied, the frequency of malalignments was higher in the permanent than in the deciduous dentition. In the deciduous dentition, the frequency of malalignments in the three groups was similar in the maxilla and mandible, and in both boys and girls. In the permanent dentition, the frequency of malalignments was higher in Down and mentally-impaired girls without Down syndrome, while the frequency of malalignments in the mandible was only increased in mentally-impaired individuals who did not have Down syndrome. In the deciduous dentition, the Down group presented a higher frequency of malalignment in the upper central incisor, lateral incisor, and canine regions compared with the normal children. When comparing teeth of Down children with those of mentally-impaired individuals who did not have Down syndrome, differences in malalignment were observed only in upper central incisor and canine regions. In the permanent dentition, the Down group showed a higher number of tooth malalignments than the normals (13 out of 28 teeth). A comparison of Down with non-Down mentally-impaired individuals, revealed only 8 teeth out of 28 were different. The most frequent malalignments in the deciduous dentition in Down patients were mesiopalatal, mesiolingual, and mesiovestibular. In the permanent dentition, the most frequent malalignments were distopalatal or distolingual.

Tooth agenesis in Down syndrome

We studied the frequency and pattern of tooth agenesis in a Danish population with Down syndrome, trisomy 21 (46 females and 54 males). The control group consisted of a normal Danish population (2424 females and 2431 males) [Rølling, 1980: Scand J Dent Res 88:365-369; Ravn and Nielsen, 1973: Tandlaaegebladet 77:12-22]. We found that individuals with Down syndrome have an occurrence of agenesis that is some 10 times greater that in the general population with a higher frequency in males than in females. Agenesis occurred more frequently in the mandible than in the maxilla and most often on the left side. The highly significant differences were primarily found in the occurrence of agenesis of the mandibular central incisors, followed by the maxillary lateral incisors and second premolars and the mandibular second premolars. The main components in the pattern of agenesis observed in Down syndrome are supposed to be related to the peripheral nervous system and abnormal cartilagenous tissue. The present study on Down syndrome suggests that the dentition, with its many different anomalies, from agenesis to malformation, can be used as an indicator in evaluating different aspects in the patheogenetic of aneuploidy conditions.

[The significance of gingival invagination in orthodontic space closure. A clinico-radiological study]

23 extraction sites from group I (14 patients, average age 25 years, two months) which exhibited gingival invagination during orthodontic space closure with fixed appliances were compared with an equal number of extraction sites without gingival invaginations from group II patients (13 patients, average age 22 years, three months). Clinical analysis criteria were: interdental distance, treatment period, depth of gingival invagination, plaque index, gingival index, and probing depth. The marginal bone level at the teeth and the interdental bone height were measured by radiographs. Comparisons of the group I information with the information from group II obtained by applying the same analysis criteria revealed that, given proper oral hygiene, the presence of gingival invaginations (mean depth 2.7 +/- 1.1 mm) has no influence on the hygienic state and, the level of gingival inflammation in the invagination area. However, a marginal bone loss at the teeth mesial and distal to the extraction sites, a reduction of the interdental crestal bone height, and an extended time frame for orthodontic space closure must be expected.

The sequence of eruption of the permanent dentition in a Chilean sample with Down's syndrome

The eruption of the permanent teeth in Down's individuals is reportedly delayed. The extent of such delay in comparison to normal children has been little studied. The eruption characteristics of the permanent teeth in a sample of Chilean individuals with Down's syndrome were here compared with those of the normal Chilean population. The sample consisted of 240 Down's individuals (all with trisomy 21), 116 males and 124 females. The chronological sequence of eruption in Down's children was not completely different from the normal. The least affected teeth were upper and lower first molars and central and lateral incisors. Alterations of the eruption sequence were not necessarily a consequence of alterations in the time of eruption. Asymmetries between sides of the jaw were mainly in canines and premolars. Alterations in sequence timing and asymmetry seem to be age dependent, being less frequent between 7 and 9 yr of age and more frequent between 10 and 14 yr of age. This may also reflect the larger variances of age of eruption observed in Down's individuals. Despite this, Down's children maintained a certain similarity in sequence and symmetry in comparison to normals.

Caries experience, periodontal treatment needs, salivary pH, and Streptococcus mutans counts in a preadolescent Down syndrome population

The prevalence of dental caries and periodontal treatment needs in an institutionalized population with Down syndrome was examined and the relationship between caries prevalence, salivary pH, and salivary levels of Streptococcus mutans was studied. Thirty-two children with Down syndrome, aged 8 to 13, were compared with two control groups of similar age ranges: healthy children and non-Down mentally retarded (MR) children living in the same institution as the Down syndrome population. The gender ratio mixtures in each group also matched the study sample. Caries experience as indicated by decayed, missing, and filled surfaces (DMF-S) showed significantly lower mean scores for the Down syndrome group compared with both control groups. A similar pattern was found when evaluating the mean numbers of decayed surfaces. Streptococcus mutans counts, expressed as number of colony-forming units on mitis salivarius agar plates among the Down syndrome group, were the lowest, although not statistically significant compared with the counts of the healthy children. Both groups had bacterial counts which were significantly lower than those of the MR group. Significant differences between the two institutionalized groups and the healthy group were recorded for the salivary pH levels. The periodontal treatment needs as evaluated by the Community Periodontal Index of Treatment Needs showed significant difference between the MR group versus both the healthy population and the Down syndrome group. On the whole, 84% of the Down syndrome children were cariesfree.

[The time of eruption of the milk teeth in Down's disease]

In the literature, the time of emergence of milk teeth in patients with Down's disease is reported to be delayed. However, only a few authors can document this observation in controlled studies. This occasioned a fresh analysis of the time and sequence of the milk dentition. In 93 babies and infants with Down's disease, the time of emergence of 842 milk teeth was recorded. In the statistical analysis, mean and standard deviations were calculated: by means of analysis of variance, left-right differences and sex differences were tested. There are the following results: the emergence of milk teeth begins with an average time delay of six months. The first milk molars frequently emerge as the first or second tooth. Sex differences and differences between right and left with regard to the emergence of milk teeth cannot be demonstrated. Overall, the sequence of emergence is very variable. The delayed emergence of milk teeth must be regarded as a component of the general delay in development in Down's disease which in the region of the head affects both the growth of the jaw and the development of the motor activity of the mouth.

Efficacy of two treatment approaches to reduce tongue protrusion of children with Down syndrome

Five children with Down syndrome aged between 21 and 31 months, all of whom demonstrated habitual tongue protrusion, were randomly assigned to receive either oral-motor treatment or behavior modification. Tongue posture of all three children who received oral-motor treatment improved. For two of these the improvement leveled off after treatment had ended, but the third continued to show improvement. One of the two children receiving behavior modification showed improved tongue posture during treatment and maintained the improvement, but for the second there were insufficient data points to draw firm conclusions. Both forms of treatment appear to be effective, but further study is needed before definite conclusions can be made.

Periodontal disease in Down's syndrome: a review

Cross-sectional as well as longitudinal studies indicate that the prevalence of periodontal disease in persons with Down's syndrome (DS) under the age of 30 years is extremely high. It is even noted in the deciduous dentition. The progression of the disease is rapid, especially in the younger age groups. Severe periodontal breakdown with horizontal bone loss is often present in the lower anteriors. The large amount of plaque and calculus alone cannot explain the severity of periodontal disease in DS persons. Many contributing factors are reported. Abnormal capillary morphology, disorders in connective tissue and anatomical aspects of teeth are some of those considered to be of influence. Alteration in immunological response may also play a role in the progression of the disease process. Disorders in the polymorphonuclear leucocyte function and monocyte function have been reported in persons with DS. T-cell functioning declines after the first 10 years of life. T-cell lymphocyte counts are low and an immature subset of T-lymphocytes is present. This latter effect occurs especially in institutions where the immunological system is under stress. The altered immune response together with higher calculus scores may explain the difference in severity of periodontal disease between institutionalized DS children and those living at home.

Prevalence of malocclusion in mentally retarded young adults

Occlusal anomalies were recorded in 218 mentally retarded young adults, aged 13-19 yr. Down's syndrome was diagnosed in 37 cases. Among the Down's syndrome individuals 41% had mandibular overjet, 54% mesial molar occlusion, 38% frontal open bite and 65% crossbite. Also, the mentally retarded subjects without Down's syndrome had markedly increased frequencies of some of the anomalies when compared to normal individuals. Thus, 27% had extreme maxillary overjet, 6% mandibular overjet, 17% mesial molar occlusion, 23% frontal open bite and 29% crossbite. Orthodontic dental service for the mentally retarded has been neglected for a long time. Though many factors may contraindicate treatment, it should in many cases be possible to improve the dental situation for this group, thereby helping these patients to a better oral function.

Sex differences in lingual marginal ridging on the human maxillary central incisor

Although incisor dimensions are on average larger in males, at least one incisor trait, lingual marginal ridging, is significantly more common in females. This is documented for the upper central incisor in a collation of 38 samples of living populations representing six racial groups. Caucasian, Asian, Polynesian, Melanesian, and American Indian females each possess significantly higher frequencies than their male counterparts. American Blacks do not show a sex difference. Sex differences in the duration and rate of incisor crown development do not explain this dimorphism. Possible underlying genetic causes are reviewed, and the hypothesis is proposed that relevant portions of both X chromosomes in females are contributing to greater trait expression.

Oral hygiene, periodontal health and need for periodontal treatment among institutionalized mentally subnormal persons in Norway

Oral hygiene, periodontal health and periodontal treatment needs were studied in the dentulous patients (n = 328) of a sample selected to be representative of all institutionalized mentally subnormal persons in Norway aged 5--45. The average oral hygiene and periodontal health was poor except for patients in a few institutions where the nurses were trained to clean teeth regularly. Increased age, epilepsy, Down's syndrome and a high degree of mental deficiency were all elements that apparently contributed to impairment of periodontal health and to increased treatment requirements. The preventive programs used in some institutions seemed to be effective. Still better results, however, could probably be obtained by the use of dental hygienists.

Periodontal disease among children with Down's syndrome and their siblings

The prevalence and severity of periodontal disease were determined in a group of individuals with Down's syndrome and a group of their selected siblings. Prevalence and severity of the disease were measured by the PI of Russell and were greatest in the children with Down's syndrome--more than threefold greater. The siblings demonstrated an experience not unlike that of the US population.