The influence of traumatic intrusion of primary teeth on their permanent successors in monkeys A macroscopic, polarized light and scanning electron microscopic study

Abstract

Primary maxillary and mandibular eentral incisors were experimentally intruded on 13 monkeys, in order to examine changes of the enamel in the permanent successors. To study the effect of removal of the displaced tooth, the left primary incisor was extracted 1 h after the trauma, whereas that on the right was left in the jaw. Six weeks later the animals were sacrificed. Maeroscopically, circumscribed areas of opaeities on labial enamel were noted. The SEM examination showed tbat non-affeeted parts of enamel had reached anatomical form, whereas imbibition studies and microradiographs demonstrated that the maturation process was far from complete. Arrest of enamel matur'ation was noted as corresponding to the extent of the surface opacity. In the SEM small areas displaying rupture of the surfaee enamel were seen. No differences were observed either maeroscopically or histologieally in relation to immediate removal or preservation of the intruded primary incisor.

Management and Sequelae of Intruded Anterior Primary Teeth: A Systematic Review

“…Torriani et al 38 concluded from their study on dogs that the morphological changes in a permanent tooth is an immediate effect to trauma during intrusion than as a sequelae to trauma. However, Thylstrup and Andreasen 39 had observed no histologic or morphologic differences in the primary teeth that were immediately extracted or left to passively re-erupt. The metaplastic changes in reduced enamel epithelium of permanent tooth bud following injury by an intruded primary incisor are less severe when the tooth is extracted immediately than when the tooth is left in place.…”

Enamel Changes and Dental Caries in 7-Year-Old Children Given Fluoride Tablets from Shortly after Birth

“…The distribution of localized enamel opacities within the dentition as well as the localization of these indicated that the ma jority have been caused by trauma to the primary incisors [Andreasen et al, 1971;Thylstrup and Andreasen, 1977]. This ex plains also why no difference was noted be tween the study groups.…”

“…How waterborne fluoride reduces the fre quency of these defects remains, however, obscure. Of interest in this context is the slightly enhanced porosity of enamel devel oped in optimally fluoridated areas [Fejerskov et al, 1977] which explains the clinical appearance of this enamel as being more perfectly mineralized or 'optimal' [Miller, 1965], Histologically enamel opacities ap pear as localized porous areas [Thylstrup and Andreasen, 1977]; minor opacities in particular may therefore be difficult to dis cern in areas where the frequency of 'opti mal' enamel is at a maximum.…”

Color Masking of Developmental Enamel Defects: A Case Series

“…6 The clinical manifestation of milder forms of fluorosis-induced enamel changes appears as narrow white lines following the perikymata, cuspal snowcapping, and a snowflaking appearance without defined bor-ders. 7,8 The main characteristic of this damage is the symmetrical involvement of homologous teeth and often the involvement of several groups of teeth. 1 The traumatic hypomineralized lesion is a consequence of a periodontal disturbance involving the primary tooth, affected by luxation (displacement) injuries, during the mineralization phase of the permanent tooth.…”

“…1,10 The histological characteristic of these lesions is similar to white spot demineralizations and fluorosis, since it involves subsurface hypomineralization under a relatively well-mineralized surface. 1,7 Molar incisor hypomineralization is defined as hypomineralization of systemic origin in at least one of the four permanent first molars, frequently associated with affected incisors. 11 The lesions often present a surface layer with increased mineral content, but the nature of MIH-affected enamel is highly variable regarding mineral content, hardness, and porosity.…”