Assessment of osteointegrative response around dental implants using technetium 99-methylene diphosphate scintigraphy: a comparison of two implant surfaces in a rabbit model.

PURPOSE: To compare the metabolic activity at the bone-implant interface of implants with machined and rough surfaces using bone scintigraphy during the in vivo process of osseointegration in a rabbit model, as well to establish a correlation between activity index (AI) and the bone-implant contact percentage (%BIC). MATERIALS AND METHODS: Twenty-four implants were placed (12 with a machined surface and 12 with a rough titanium oxide surface) in 12 New Zealand White rabbits. Preoperatively and during the postoperative period (at 15 days and at monthly intervals), animals underwent bone scintigraphy with technetium 99m-methylene diphosphate (Tc-99m-MDP), and the AI for each implant was calculated by planar and pinhole collimator scintigraphy. A total of 240 AIs were obtained; after animal sacrifice at 105 days postsurgery, the %BIC was measured by scanning electron microscopy in 10 samples of each implant surface type. RESULTS: The activity-time curve showed a similar morphology for both implant types and both scintigraphy techniques. The maximum mean AI appeared after 15 days of implantation and was higher in machined implants. Significant differences were not found in the %BIC according to implant type. A significant correlation between the mean activity registered in the first postoperative scintigraph and the mean %BIC at the end of the study was observed for machined implants only. CONCLUSIONS: Tc-99m-MDP is useful for the assessment of osseous metabolic activity associated with different microsurfaces. The association between mean AI and %BIC was only demonstrated for machined implants in the first postoperative scintigraphy image.

An epidemiological study of dental agenesis in a primary health area in Spain: Estimated prevalence and associated factors

Objectives: To evaluate the prevalence of dental agenesis and its possible association with other developmental dental anomalies and systemic entities.Setting and Sample Population: Descriptive transversal study, for which 1518 clinical records, of patients visited by the Odontological Service of the Primary Health Centre of Cassà de la Selva (Girona-Spain) between December 2002 and February 2006 were reviewed. The data were recorded in relation to the oral and dental anomalies and the associated systemic entities, between the ones referred as concomitant in literature. Results: Values of 9.48% (7.25% excluding the third molars) for dental agenesis and 0.39% for oligodontia were obtained. The presence of dental agenesis concomitant with some other forms of oral and dental anomalies was observed. Attention must be drawn to the fact that a greater number of concomitant systemic entities were observedin those patients that presented a severe phenotypical pattern of dental agenesis.Conclusions: The results of the present study do not differ from the ones reported in studies of similar characteristics among Occidental and Spanish populations. The relationship observed between certain systemic entities and developmental dental anomalies suggest a possible common genetic etiology (AU)

Oral findings in Midline Syndrome: A case report and literature review

We describe a female patient with a midline syndrome. The patient presents agenesis of the corpus callosum, encephalocele,iris coloboma, hypertelorism, submucosal cleft palate and dental anomalies. Despite being very characteristic,her phenotypical traits do not coincide exactly with those reported to date in the literature. The karyotype and the molecular cytogenetic study do not show mutations. We identify the presence of dental anomalies in the mother and other family members, not being identified MSX1 and PAX9 mutations that could the related with their etiology. Despite the fact that dental agenesis has been related to a large number of other malformation syndromes and congenital conditions, dental anomalies have only rarely been mentioned when reporting midline syndromes. These dental phenotypical traits, present in the patient and her family, could be considered part of themidline syndrome in carriers as well as in the patients (AU)