China experts' consensus on preventive and interceptive orthodontic treatments of malocclusions of children.

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.

[Histological study of miniscrew implanted in lower mandibles of juvenile and adult Beagle dogs].

OBJECTIVE: To examine the histological discrepancies between juvenile and adult Beagle dogs at different concrescence times after miniscrew implants. METHODS: Miniscrew implants were performed in six juvenile Beagle dogs and six adult Beagle dogs. The space between the fourth premolar root and first molar root, and the spaces in distal and mesial of M1 root were picked up for the implants of the 48 miniscrews. The lower jaw specimens including the miniscrews were harvested 3 and 12 weeks after the implants for the histological examinations and bone implant contact (BIC) calculations. RESULTS: There was no miniscrew falling off or becoming loose. The miniscrews had favorable biological consistencies with the tissues around them. The osteoblasts and osteoclasts showed active functions in the peri-bones of the minisrews. The BIC became higher when the healing time was prolonged. The juvenile Beagle dogs had lower BIC than the adults 3 weeks after the implants. But the BIC of the juvenile dogs surpassed the adults 12 weeks after the implants. CONCLUSION: The osseointegration of the miniscrews is hindered by the poorer bone quality of the juvenile Beagle dogs. But the early osseointegration deficiency can be made up by the rapid development and growth of the bones of the juvenile dogs.

[Pancherz's analysis in evaluating the treatment effects of headgear-activator on skeletal Class II divison 1 malocclusion].

OBJECTIVE: To evaluate the effects of headgear-activator (HGAC) combination appliances on bone and dentition of juveniles with Class II division 1 malocclusion using Pancherz's analysis approach. METHODS: Fifteen patients (8 males of 10-13 years old and 7 females of 9-12 years old, average age was 11.2 years old, ANB > or = 5 degrees, overjet > or =6 mm, Class II molar relation) were treated with HGAC appliance for more than 14 hours everyday and for total of 8-10 months cephalograms were taken before and after the treatment. The data was analyzed with Pancherz's analysis and pare t test (SPSS 11.5 software). RESULTS: After the therapy, SNA and ANB angles reduced, the change of SNB angle was trivial, pg/OLP was forward movement. The axial inclination of the lower incisors increased and of the upper incisor reduced. Overjet of the incisors was improved, in which skeletal factor was improved to 44.64% and dentition factor was 55.36%. The first molar on the mandible was forward movement. Molar relationship was also improved, in which skeletal factor was improved to 65.65%, and dentition factor was 34.35%. CONCLUSION: HGAC can efficaciously treat Class II division 1 malocclusion with maxillary protrusion, stimulate modification of the mandibular condyle and fossa, and promote the development of the mandibles. Dentition was improved more than skeletal on overjet, and skeletal was improved more than dentition on molar relationship.