Orthodontic tooth movement in the prednisolone-treated rat

Adverse effects of corticosteroids on bone metabolism raise concerns as to whether steroid treatment may influence orthodontic movement. This study examined the effect of prednisolone on orthodontic movement using an established rat model. The corticosteroid treated group (N = 6) was administered prednisolone (1 mg/kg) daily, for a 12-day induction period; the control group (N = 6) received equivalent volumes of saline. On day 12, an orthodontic appliance was placed which exerted 30 g of mesial force to the maxillary first molar. Animals were sacrificed on day 24 and tooth movement was measured. Sagittal sections of the molars were stained with haematoxylin and eosin, and for tartrate-resistant acid phosphatase (TRAP) activity. While there were no significant differences in the magnitude of tooth movement between the 2 groups, steroid-treated rats displayed significantly less root resorption on the compression side and fewer TRAP-positive cells within the PDL space on the same side. This suggests steroid treatment suppressed elastic activity

Lathyrism and the half-life of collagen

Maturation of collagen in the periodontal ligament has often been designated as the cause of tooth eruption. The fact that collagen has a high turnover rate provided some sort of proof of this hypothesis. It is well known that lathyrogens decrease eruption rate. Experiments were performed, using Wistar rats, which looked into the relationship between collagen turnover and lathyrism. The collagen turnover was established in teeth not erupting after the administration of lathyrogens. These results were compared to those obtained after having stopped eruption by the placement of a goldcrown on the lower incisors. It was found that lathyrism, and therefore collagen maturation, did not influence turnover rate. Thus the supposition, that collagen is responsible for tooth eruption, becomes doubtful

A Family Case Report: Disturbances in Tooth form and Eruption of the Second Premolar

This report describes a family who demonstrated anomalies of tooth form and eruption of the lower second premolar. Observation of the second premolars remaining in the mother’s and father’s dentitions included ectopic eruption with impaction and substantial spacing between the first and second premolars. Four siblings were also examined - three boys aged 15, 14 and 12 years, and one girl aged 11 years. Anomalies of the second premolar recorded in the males and female include: congenital absence, ectopic eruption with impaction, delayed eruption and spacing. Associated anomalies included: congenital absence of other permanent teeth and spacing. It appears that the defect in tooth form and eruption is of a genetic origin, affecting both males and females. The condition(s) did not appear to be associated with a syndrome and the human papilloma virus lesions noted in all family members were not considered to be related to the dental defects. This family demonstrated two anomalies of the lower second premolar: congenital absence and disturbance in tooth eruption. The question raised by this case report is whether these two anomalies are inherited as separate traits or whether failure of tooth eruption is a variation in expression of the same geuetic factor that results in oligodontia

Prevalence of malocclusion traits in an Australian adult population

The prevalence of certain malocclusion traits in an Australian adult population was examined in a sample of 113 female and 103 male adult subjects aged between 18 and 64 years (average age = 38.1 years). If cross-sectional studies of younger population groups are to be used for research into the long-term physiological effects of malocclusion, it is essential to know if certain and specific malocclusion traits are stable over time. In this cross-sectional study, the prevalence of many malocclusion traits did not change; however, with advancing age, the incidence of posterior crowding, posterior rotations, posterior crossbite and anterior irregularity increased significantly

Marfan syndrome: a review of the literature and case report

Marfan syndrome (MFS) is a connective tissue disorder of variable inheritance that affects multiple organ systems. Cardiovascular, ocular, and skeletal abnormalities are cardinal features of the syndrome. Orofacially, MFS patients typically exhibit skeletal class II malocclusion, dolichofacial growth pattern, mandibular retrognathia, malar hypoplasia, high arched palate, dental crowding, and root anomalies. The purpose of this paper is to provide a review of the literature, as well as describe an 11-year-old female with MFS diagnosed at the age of 10.5 years. This report emphasizes the orofacial findings in MFS and highlights particularities of dental treatment when social deficits and intellectual disabilities are also implicated