Pii: S0300-5712(00)00023-3
نویسندگان
چکیده
Objective: The objective of this study was to investigate the relationship between age, gender and clinical crown length using a longitudinal study design. Method: Four hundred and fifty-six sets of study models initially obtained for a large prospective longitudinal cohort study of orthodontic needs were examined. Each set of models corresponded to subjects at three different ages: 11–12, 14–15 and 18–19 years old. The clinical crown height of the maxillary right central incisor (11), maxillary right canine (13), maxillary left lateral incisor (22) and mandibular left central incisor (31) was measured from gingival crest to the incisal edge using digital calipers. Results: Analysis revealed a significant p , 0:0001 age effect on crown length for all four teeth investigated. A significant gender effect was found in relation to the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor. Pairwise comparisons of the means for each age group for the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor revealed significant p , 0:0001 increases in clinical crown length between each assessment period. Conclusion: The findings of the present study indicate that, the process of passive eruption, resulting in increased clinical crown length appears to continue throughout the teenage years. This finding is considered to be of importance to the clinician making treatment decisions for teenagers and young adults requiring treatment in the anterior segments of the mouth. q 2000 Elsevier Science Ltd. All rights reserved.
منابع مشابه
Pii: S0300-5712(00)00048-8
Objectives: The aim of this study was to review the published work on the indications and efficacy for antibiotics in endodontic therapy. Data sources: Published works in the medical and dental literature. Study selection: Evaluation of published clinical trials in endodontic and other pertinent literature. Conclusions: Antibiotics are not routinely indicated in the practice of endodontics. The...
متن کاملPii: S0300-5712(00)00038-5
Objectives: The effects of trehalose on cariogenesis by mutans streptococci were investigated. Methods: Inhibited effect of trehalose on water-insoluble glucan (WIG) synthesis from sucrose by glucosyltransferase (GTase) of mutans streptococci was assayed. The acid fermentability of trehalose by mutans streptococci was determined by the measurements of pH, and amounts of lactic acid production. ...
متن کاملPii: S0026-2692(00)00023-9
In this paper we analyse the trade-offs for a terahertz imaging system and discuss implementation of a terahertz micro antenna array for imaging. We also describe applications of terahertz imaging and improvements in the signal processing. q 2000 Elsevier Science Ltd. All rights reserved.
متن کاملPii: S0925-7721(00)00023-7
It is shown that in any polygonal art gallery of n sides it is possible to place bn/3c point guards whose range of vision is 180◦ so that every interior point of the gallery can be seen by at least one of them. The guards can be stationed at any point of the art gallery. This settles an open problem posed by J. Urrutia. 2000 Elsevier Science B.V. All rights reserved.
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We present three mechanisms for maintaining consistent product views in a distributed product information data base. The mechanisms are used when one of the views makes a change to the product model and the other views must be updated to maintain consistency.
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