The relationship between craniofacial development and hypodontia in patients with Down syndrome.

BACKGROUND/OBJECTIVE: Hypodontia is often seen in people with Down syndrome (DS). In the normal population, persons with hypodontia have a shorter cranial base and a hypoplastic maxilla, leading to a skeletal Class III tendency and a reduced face height. The purpose of this study was to examine craniofacial morphology in patients with DS at different ages and the influence of hypodontia on their craniofacial morphology. MATERIALS AND METHODS: A comparative cross-sectional study was conducted in 63 children with DS (6-19 years old; 28 males and 35 females) at a Centre for Special Care Dentistry in Rotterdam, the Netherlands (CBT Rijnmond). Digital lateral cephalograms were obtained from all subjects and a cephalometric analysis was performed. The subjects were divided into a group with hypodontia (13 males and 25 females) and a group without hypodontia (15 males and 10 females). RESULTS: Significant results included a decrease in antero-posterior relationship of upper and lower jaw (ANB angle -0.331° per year, P = 0.044) and a decrease in vertical dimension (S-N_Go-Gn angle -0.72° per year, P = 0.039) over the years in subjects with hypodontia compared to subjects without hypodontia. CONCLUSION: The process of growth in DS patients is towards a reversed overjet. Hypodontia seems to have an additional effect on this development. The management of hypodontia as part of the complete treatment of dental development in DS children is important because it strongly influences the jaw relationship.

[Dissertations 25 years after date 35. Periodontal disease in Down syndrome: an immunological disorder]. / Proefschriften 25 jaar na dato 35. Parodontale afbraak bij syndroom van Down: een immunologisch probleem.

In Down syndrome the prevalence of periodontal disease is high. Twentyfive years ago in a series of controlled experiments, based on an experimental gingivitis model, clinical, histological and immunological characteristics of a group children with Down syndrome and matched control children were evaluated. In the Down syndrome children the gingival inflammation occurred earlier and was more extensive. On the tissue level the early response was characterized by a polymorphonuclear leucocytes response. Chemotaxis assays were performed to rule out impaired function. It was found that random migration for the peripheral blood-polymorphonuclear leucocytes and chemotaxis in both groups of children were comparable; hence such a factor cannot be responsible the early polymorphonuclear leucocytes' response in the children with Down syndrome. The most striking feature in the group with Down syndrome was the delayed and impaired response of lymphocytes during plaque development compared to the controls. This impaired lymphocyte function was also observed in a pilot study on 1 child with Down syndrome. It showed a less pronounced T cell suppressor function and a lack of immune regulation. The high level of gingival inflammation in children with Down syndrome must therefore be related to their impaired adaptive immunity.

['Emily goes to the dentist'. Oral care for individuals with Down syndrome]. / 'Emily gaat naar de tandarts'. Mondzorg voor mensen met het syndroom van Down.

This article is primarily based on an editorial letter in the Journal of Oral Health and Disability that describes the visits of a patient with Down syndrome named Emily. Oral health care for individuals with Down's syndrome and other people with learning disabilities in The Netherlands is discussed. Due to the syndrome related oral aspects and specificity, the authors argue strongly in favour of working multidisciplinary within oral health care centres. The dependency of persons with Down's syndrome necessitates an appeal to parents, relatives and carers to maintain oral health. Client-centred care is mandatory for an optimal oral health condition of this vulnerable group.

Nonspecific and specific immune responses in a child with Down's syndrome and her sibling. A case report.

In a child with Down's syndrome (DS) and her sibling, host immune responses were evaluated under experimental gingivitis conditions. The children live in the same environment under identical conditions. In the DS child an earlier and more extensive gingival inflammation than in her sibling had been observed. Investigation of nonspecific host defense mechanisms revealed identical results in both children for the phagocytosis and intracellular killing of Candida albicans by polymorphonuclear leukocytes in crevicular washings (CR-PMNs), in blood (PB-PMNs) and blood monocytes. Furthermore, CR- and PB-PMNs were able to secrete identical amounts of hydrogen peroxide upon stimulation. The chemotactic response of PB-PMNs in the DS child was impaired, however. The results of the studies performed on parameters of specific host defense mechanisms showed low blastogenic responses to phytohemagglutinin (PHA) and pokeweed (PWM) by lymphocytes of the DS child as compared with her sibling. Also a lack of immune regulation leading to prolonged helper/inducer cell activation on a local (gingival) and circulation level and a less pronounced T-cell depression in PB were shown. Together, these differences observed in specific and nonspecific host response mechanisms may be responsible for the earlier and more extensive gingival inflammation found in the DS child.

[Periodontal disease in Down's syndrome]. / Parodontale aandoeningen bij het syndroom van Down.

During the next decade the number of persons with Down's syndrome is expected to rise; in addition, a smaller proportion of them will be institutionalized. Therefore, the number of patients with this syndrome calling on the general dental practitioner for treatment will be increasing. Epidemiological investigations show a high prevalence and a rapid progression of periodontal disease in persons with Down's syndrome. These periodontal problems are related to their diminished immunological response. The severity of the disease is indicated by the fact that 70% of the edentulous persons with Down's syndrome in institutions lost their dentition because of extraction due to periodontal destruction. This constitutes a sharp contrast with the normal population, where this percentage is less than 1. Characteristic clinical symptoms of this disease entity are described and their therapeutic measures indicated. Preventive measures are advocated, including chemical plaque control when the general immunological resistance of the individual is diminished.

[Down syndrome--2. Orofacial aspects]. / Le syndrome de Down--2éme partie: Aspects oro-faciaux.

Because of the higher life expectancy and the ambulant care facilities, the general dentist will be more and more confronted with patients suffering from Down's syndrome. Of major importance are the associated heart and vascular diseases and hypothyroidism, accentuating even more the retarded growth. These patients also show a decrease in resistance, which frequently (50%) results into periodontal disease. Apart from the typical bone "growth" changes, the hypotonicity of the masticatory musculature and the tongue are key factors determining the typical expression. The eruption time and, to a lesser extent, the age of the final teeth is slowed down. When in addition hypothyroidism is observed, this results in a typical radiographic image of the mandible (apices against bottom corticalis). When merely considering the microdontics, the agenesis and the more favourable composition of saliva, caries should be less frequent. However, for techno-hygienic reasons this is often not the case. When the gingiva is affected by a rapidly progressing periodontal disease, it should be frequently cleaned, supported by a chemical plaque treatment. The author emphasizes that on no account prevention can be left to the patient. The patients always need to be helped. Finally the logopaedic purpose of the Castillo-Moralis palatal plate, as well as the functional use of the surgical tongue reduction, are discussed.

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.

Experimental gingivitis around deciduous teeth in children with Down's syndrome.

Epidemiological studies have shown that there is a high prevalence and rapid progression of periodontal disease in children with Down's Syndrome (DS). In this respect, DS children exhibit a markedly different response compared with healthy children. In order to understand the reasons for this difference, a controlled study was set up to determine the extent and the quality of the differences in the early periodontal tissue response towards dental plaque in the deciduous dentition of DS children and matched control children. In a preliminary investigation, the gingival health was estimated by determining the bleeding tendency. 9 healthy children were selected from a group of 14 and matched with 9 DS children with respect to plaque development, sulcus depth and age. The DS children had a higher bleeding tendency than the matched controls. In the DS children, moreover, a correlation was found between bleeding tendency and age. No such correlation was found in the controls. After a period of intensive oral hygiene, all cleaning of teeth was discontinued for 21 days. The amount of plaque according to the plaque index, the gingival health according to the gingival index, and the amount of crevicular leucocytes and gingival exudate were assessed at days 0, 7, 14 and 21. During the experimental phase of the study, the amount of plaque increased at a similar rate in both groups. In the DS children, the development of gingival inflammation started earlier and was more extensive. It increased after day 14, whereas in the control children, the gingival inflammation seemed to stabilize at this time. The results of the present experimental study thus confirm earlier results from epidemiological studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental gingivitis in a Down's syndrome child and sibling.

Biopsies were taken from a child with Down's syndrome and her sibling under experimental gingivitis conditions and analyzed with monoclonal antibodies. At first, plaque caused a shift from a predominance of T cells to a predominance of B cells. Later, a gradual increase of T cells and a looser arrangement of B cells were observed.

Absence of a specific subgingival microflora in adults with Down's syndrome.

BACKGROUND: Periodontal disease in Down's syndrome (DS) is generally characterized by a high degree of bone loss. Bone loss of 5 mm or more is observed in 70% of these subjects. Among DS subjects, considerable differences in disease progression occur. So far, no studies have been conducted in which specific properties of the subgingival microflora have been related to the condition observed. AIMS: To investigate (1) the subgingival microflora in DS subjects and other mentally retarded (control) individuals which were matched to the utmost and (2) to investigate the subgingival microflora of a "low-risk" and a " high-risk" group formed in DS subjects. MATERIAL AND METHODS: 17 DS subjects and 17 control subjects were matched with respect to age, plaque level and bleeding on probing. In addition, the DS group was divided in a "low-risk" group (0-2 teeth lost due to periodontal disease n=6) and a "high-risk"group (6-13 teeth lost due to periodontal disease n=11). Prevalence and proportions of the putative periodontal pathogens Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Peptostreptococcus micros, Fusobacterium nucleatum and Campylobacter rectus in the subgingival plaque were determined using anaerobic culture techniques. No differences in the prevalence of distinct suspected periodontopathic bacteria and bacterial subgingival composition between the DS group and the control group could be established. Also no differences in the prevalence of the seven investigated microbial species between the "low-risk" and the "high-risk" group were observed. CONCLUSIONS: Because of the lack of differences in microflora between the DS group and the control group, a specific effect of the microbiological composition in the periodontal status of subjects with DS can be excluded in this population. Host factors constitute the more likely explanation of the differences observed in DS.

Morphological aspects of the gingiva in children with Down's syndrome during experimental gingivitis.

In a previous investigation, children with Down's syndrome (DS) showed an earlier, more rapid and more extensive gingival inflammation than normal healthy control children. These differences in gingival inflammation may be the result of aberrant morphology of the gingiva related to the genetic disorder in DS children. The aims of the present study were (i) to describe the structural composition of "normal" gingiva in DS compared to control children, (ii) to analyse the histological changes in the gingiva during plaque development and (iii) to investigate whether the clinical findings could be supported by morphological observations. The study was carried out in 8 DS and 8 matched control children. Their ages ranged from 5-10 years. Gingival normality was guaranteed by strict oral hygiene procedures. During a period of 21 days in which oral hygiene was abolished, gingival biopsies were taken from buccal sites of deciduous teeth following a predetermined schedule on days 0, 7, 14 and 21. Results on day 0 showed no morphological differences between the DS and control children regarding oral epithelium, junctional epithelium or connective tissue. During the experimental phase of the study, the amount of plaque accumulation in the DS children gave rise to a more extensive gingival inflammation than in the control children. The gingival inflammation in the DS group started earlier and included: (1) an acute inflammatory response, (2) an increase of the junctional epithelium area, (3) an increase of the infiltrated connective tissue area (ICT) and (4) a decrease in collagen fibre density of about 35-40% compared to day 0. The same phenomena were not seen until 7 days later in the control group. Conversely, the development of a perivascular lymphocyte infiltrate (LI) in the DS children was delayed compared to the control group. This may be caused by the impaired delayed-type hypersensitivity response in DS children. The development of 2 separate infiltrates (ICT and LI) in this age group and the different temporal development of ICT (day 7 for the DS and day 14 for the control group) and LI (day 14 for the DS and day 7 for the control group) does suggest different immunological mechanisms for both areas and both groups.

Cellular aspects of and effects on the gingiva in children with Down's syndrome during experimental gingivitis.

In a previous experimental gingivitis study, it was shown that in children with Down's syndrome (DS), gingival inflammation started earlier, was more extensive and developed faster, than in normal healthy control children. In both groups, the start of the process was accompanied by an acute inflammatory response and an increase of the infiltrated connective tissue area (ICT). The purpose of the present study was to investigate how these facts were reflected at a cytological level. The study was carried out in 8 DS and 8 matched control children. Their ages ranged from 5-10 years. A "normal" healthy gingiva was attained after strict oral hygiene procedures. During a period of 21 days in which oral hygiene was abolished, gingival biopsies were taken on days 0, 7, 14, and 21. In both groups, junctional epithelium (JE) and ICT contained low numbers of polymorphonuclear leucocytes (PMNs). The start of the inflammation (day 7 for the DS and day 14 for the control children) was marked by a significant positive correlation between the numbers of PMNs in the JE and the ICT, and a significant increase of the numbers of PMNs in ICT. In ICT, a concomitant decrease in collagen fibre density was observed. In the control group, the decrease correlated with the numbers of PMNs in ICT, which suggests that this collagen breakdown is caused by PMN products. After the initial decrease, the collagen fibre density remained fairly constant in this group throughout the study. In the DS group, there was a tendency to a further decrease in the ICT3 area, correlated with the numbers of PMNs in ICT.(ABSTRACT TRUNCATED AT 250 WORDS)