Autotransplantation of maxillary second premolars to mandibular recipient sites where the primary second molars were impacted, predisposes for complications.

OBJECTIVE: The aim of the study was to elucidate whether ankylosis of a transplanted permanent tooth can be predicted based on an evaluation of the primary and permanent dentitions. MATERIALS AND METHODS: The study comprised 162 maxillary second premolars and 49 third molars transplanted to the mandibular second premolar region in 157 patients treated in the period 1980-2003. SELECTION CRITERIA: panoramic radiograph available; agenesis of the mandibular permanent premolar/s; persistence of the primary molar at the recipient site. The 211 transplanted teeth were observed for a period of between 1-29 years. RESULTS: Seven per cent (95% confidence interval, CI = 3-11%) of the transplanted second premolars ankylosed during the first 10 years after operation. The success rate for transplantation of the third molar to the mandibular second premolar region was significantly lower (p = 0.001), as 40% (95% CI = 24-57%) of the third molars had ankylosed 10 years after operation. A significant association (p = 0.022) was found between ankylosis of a second premolar and infra-position of the primary second molar located at the recipient site. The infraposition group had 13% (CI = 4-23%) ankylosis after 10 year, whereas the non-infraposition group had 5% (CI = 1-9%) ankylosis after 10 years. CONCLUSIONS: The present study concludes that there is an increased risk of ankylosis of the transplanted permanent tooth if the primary tooth at the recipient site is in infraposition. This observation may be decisive for treatment planning, especially in young individuals in whom excessive growth of the alveolar process is expected from the cephalometric analysis.

Association between third mandibular molar impaction and degree of root development in adolescents.

OBJECTIVE: To compare the root development and the growth rate of the mandibular third molar (M3 inf) in individuals where the M3 inf erupted vs individuals exhibiting M3 inf impaction. MATERIALS AND METHODS: Serial standardized intraoral radiographs (Eggen technique) were taken annually of the mandibular third molar region from 132 subjects (71 male and 61 female) from 15 to 20 years of age. Based on the films, 264 lower third molars were classified into an eruption and an impaction group. Root development was recorded according to a quantitative method described by Haavikko (1970), and the eruption status was analyzed using logistic regression. RESULTS: In total, 155 (59%) of the M3 inf erupted, and 109 (41%) were impacted at age 20. In 44 (33%) patients both M3 inf were impacted, in 21 (16%) patients one tooth was erupted and the contralateral tooth impacted, and in 67 (51%) patients both M3 inf were erupted. The more mature a tooth was at age 15, the higher was the probability of eruption (odds ratio: 3.89, P < .001). The growth rate of the root development stage was statistically significantly associated with the probability of eruption (odds ratio: 10.50, P  =  .041). CONCLUSIONS: Delayed mandibular third molar root development is associated with impaction. Radiographs taken at age 15 may predict the risk of impaction and thereby guide decision making for the orthodontist or the oral and maxillofacial surgeon.

Development of an interactive dental trauma guide.

Diagnosis and treatment of traumatic dental injuries is a complex task and the diagnostic process of reaching a correct diagnosis and treatment can sometimes be very difficult. Traumatic dental injures often occur as combination injuries between one of the 6 luxations and the 9 fracture types resulting in 54 trauma scenarios of which many have specific requirements for treatment The situation is further complicated by the fact that the two dentitions have very different treatment demands. As a result it's impossible even for experienced practitioners to provide evidence-based treatment on the basis of personal experience alone. Based on 60 clinical studies of 4000 cases with long-term follow-up treatment and prognosis has been determined for almost all fractures and luxation and their combinations. Information on treatment and prognosis relating to these 4000 cases will now in the future be available on the internet at: "www.DentalTraumaGuide.org". We hope that the Dental Trauma Guide can help improve the knowledge about dental traumatology worldwide and hereby improve the quality of treatment.