Edwin M. Ongkosuwito

Dental development in hemifacial microsomia

Hemifacial microsomia (HFM) is a congenital disorder marked by facial asymmetry. Whether facial asymmetry accounts for asymmetrical dental development is unknown. There are few data on dental development relative to mandibular development or severity of HFM, or on development over time. We hypothesized that when mandibular development was severely disturbed, local dental development was also affected. We compared dental development scores between affected and non-affected mandibular sides in patients with HFM (n = 84) and compared these data with those collected from Dutch control children (n = 451). Logistic functions were constructed for dental age over time for all four Pruzansky/Kaban types. The results showed a tendency toward delayed dental development in Pruzansky/Kaban types IIb and III at younger ages. The temporary delay of tooth formation in patients with severe forms of HFM and the distribution of agenic teeth suggest an interaction between mandibular and dental development.

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.

Muscle fibrosis in the soft palate: Delivery of cells, growth factors and anti-fibrotics

The healing of skeletal muscle injuries after major trauma or surgical reconstruction is often complicated by the development of fibrosis leading to impaired function. Research in the field of muscle regeneration is mainly focused on the restoration of muscle mass while far less attention is paid to the prevention of fibrosis. In this review, we take as an example the reconstruction of the muscles in the soft palate of cleft palate patients. After surgical closure of the soft palate, muscle function during speech is often impaired by a shortage of muscle tissue as well as the development of fibrosis. We will give a short overview of the most common approaches to generate muscle mass and then focus on strategies to prevent fibrosis. These include anti-fibrotic strategies that have been developed for muscle and other organs by the delivery of small molecules, decorin and miRNAs. Anti-fibrotic compounds should be delivered in aligned constructs in order to obtain the organized architecture of muscle tissue. The available techniques for the preparation of aligned muscle constructs will be discussed. The combination of approaches to generate muscle mass with anti-fibrotic components in an aligned muscle construct may greatly improve the functional outcome of regenerative therapies for muscle injuries.

Dental development in Down syndrome and healthy children: a comparative study using the Demirjian method.

OBJECTIVE In children with Down syndrome, the timing of dental eruption is important for orthodontics treatment planning. Aim of this study was to determine whether tooth eruption and development of the dentition in children with Down syndrome are impaired. MATERIAL AND METHODS Dental development was scored on orthopantomograms (OPTs) of 95 children with Down syndrome. The dental age was determined at the left mandibular side according to the Demirjian method and by converting the assigned scores to the dental maturity score. Dental development scores of control children and DS children were compared with a mixed model linear regression analysis. RESULTS The model showed statistically significant changes relating to increasing age (P<0.001) and gender (P<0.05). In this comparison, the total DS group (with and without hypodontia) was not statistically significantly different from the control group. There was also no significant difference between the total sample of DS children and the control group after using the Nyström imputation (with and without hypodontia). CONCLUSION The findings showed that dental development in DS children is similar to the development of control children and that a relationship exists between hypodontia and dental development. The clinically observed late eruption is probably not due to late dental development but due to the other processes that take place during eruption, such as the possible impaired processes at the apical side and the occlusal side of an erupting element.

Accuracy of a computed tomography scanning procedure to manufacture digital models.

Introduction: Accurate articulation of the digital dental casts is crucial in orthodontic diagnosis and treatment planning. We aimed to determine the accuracy of manufacturing digital dental casts from computed tomography scanning of plaster casts regarding linear dimensions and interarch relationships and to test whether eventual differences in interarch relationships between plaster and digital casts would affect orthodontic diagnostics. Methods: Plaster casts with the wax bites of 2 patients were used to create digital dental casts with a computed tomography scanner. This was repeated 4 times with a 1‐week interval. Linear distances were measured on plaster and digital models twice by 2 observers. Next, the 4 digital models of each patient were scored twice by 5 observers for interarch variables. Results: Digital vs plaster measurements showed high Pearson correlation coefficients (>0.954), whereas the mean difference was small (<0.1 mm) and not significant. The interarch scorings, however, showed significant differences for all variables, except overjet for model 1. Conclusions: We found substantial interarch inaccuracies of the digital models. These inaccuracies are probably due to a lack of built‐in “collision control” in the software and manual articulation of the digital models by a human operator. HighlightsInterarch measurements are essential for diagnosis and treatment planning.Accurate articulation of digital study models is crucial.Research on the accuracy of interarch variables vs digital is scarce.This study demonstrated substantial interarch inaccuracy of digital models.Interarch inaccuracies are due to manual articulation and lack of “collision control.”