ABSTRACT
BACKGROUND: The causes of dental crowding are not fully understood, but it may result from an evolutionary trend towards reduced facial volume, without a proportional reduction in tooth sizes. Most previous studies conducted among modern humans have revealed a very low or non-existent correlation between tooth size and jaw size. Cross-comparison between dental age and facial skeletal age could help to provide better knowledge of the dynamic process of dental crowding. The primary objective of this research was to study the synchronism of dental maturation and skeletal facial growth in a sample of modern children living in France. The secondary objective was to assess the link between dentofacial asynchronism and dental crowding. RESULTS: The random sample comprised 28 subjects (16 girls, 12 boys). Mean chronological age was 13.5 years (± 2.1; range 9.2-17.6). Mean dental age was 14.2 years (± 2.8; range 7.5-17) and mean facial skeletal age was 12.8 years (± 2.6, range 7-22). In the estimations of dental age and facial skeletal age, there was no evidence of systematic bias. There were 10 subjects (9 girls, 1 boy) with asynchronous dentofacial development. Finally, there were 13 subjects (8 girls, 5 boys) with dental crowding. A significant association was found between delayed facial skeletal growth/advanced dental maturation and dental crowding (P = 0.01). CONCLUSIONS: Dental maturation and facial growth are not necessarily synchronous. Further understanding of the interactions between dental maturation and facial growth could have crucial implications in biological anthropology, as well as for the clinical practice of orthodontists. From an anthropological perspective, this study suggests that asynchronous dentofacial development could, at least partially, explain the frequency of dental crowding in modern populations.
Subject(s)
Facial Bones/growth & development , Malocclusion/epidemiology , Tooth/growth & development , Adolescent , Age Determination by Teeth , Child , Cross-Sectional Studies , Dentition , Facial Bones/anatomy & histology , Facial Bones/diagnostic imaging , Female , France/epidemiology , Humans , Male , Malocclusion/diagnostic imaging , Malocclusion/pathology , Retrospective Studies , Tomography, X-Ray Computed , Tooth/anatomy & histology , Tooth/diagnostic imagingABSTRACT
INTRODUCTION: The Cochrane Collaboration is an international scientific not-for-profit organization the purpose of which is to produce and distribute systematic reviews of randomized clinical trials. The aim of this paper is to list the different existing Cochrane systematic reviews in the field of dentofacial orthopedics (DFO) and to analyse their main features. MATERIAL AND METHODS: The choice of Cochrane systematic reviews based on dentofacial orthopedics was made from the exhaustive list published by the Cochrane Oral Health Group. RESULTS: A total of 12 systematic Cochrane reviews related to dentofacial orthopedics were listed. All concluded on the need to conduct randomized clinical trials using more appropriate methodologies and comprising larger samples. None of these systematic reviews offered clear proof supporting any one form of treatment or treatment modality. DISCUSSION: Despite the lack of relevant conclusions in the still meagre number of Cochrane systematic reviews related to DFO, it is essential for orthodontists to regularly consult the reviews in the framework of their daily evidence-based orthodontic practice. This is true too for orthodontic researchers as clinical DFO research needs to be extended with the setting up of methodologically unquestionable randomized clinical trials. However, there exist alternatives to randomized clinical trials offering a lower level of proof but which are better suited to the field of dentofacial orthopedics.
