Avaliação experimental dos efeitos da fixação interna (Ti, 1,5mm), no crescimento craniofacial pós-natal de coelhos por meio de análise morfométrica indireta

The purpose of the present investigation is to verify whether the potential for postnatal craniofacial bonegrowth in rabbits is impaired by the use of titanium microplates and microscrews in areas of rapid bone growth.To this end, 20 animals in their seventh week of life were divided into two groups: in the experimental group,a microplate with four holes was fixed on the right-hand side transversely to the coronal cranial suture; in thecontrol group, only two screws were placed, one on either side of the right coronal suture at a distancecorresponding to the two outer holes on the microplate. The animals were killed and manually decapitated inthe 17th postoperative week. An evaluation of bone growth was performed through indirect morphometric measurements by the tridimensional analysis of the craniofacial volumes using computed tomography. Astatistically significant difference was found when the partial direct volumes of the two groups were compared.It is thus possible to state that the use of internal rigid fixation in regions of rapid growth in growing rabbitsproduces dimensional changes

Avaliação experimental dos efeitos da fixação interna (Ti, 1,5mm) no crescimento craniofacial pós-natal de coelhos, por meio de análise morfométrica direta

In order to investigate the influence of internal rigid fixation on postnatal craniofacial growth, twenty rabbitswere randomly divided into two groups - experimental and control. In the experimental group, in theseventh postnatal week, one 1.5-mm straight microplate was transversely fixed to the coronal cranial suture.In the control group, also in the seventh postnatal week, a microscrew was placed on each side of the righthandside of the coronal suture at a distance equal to that separating the outer holes of the microplate. Allthe animals were sacrificed, at the age of 24 weeks, in the 17th postoperative week and an evaluation ofbone growth was performed using direct morphometric measurements of the anteroposterior distance indry skulls. An anteroposterior shortening of the lambdoid frontal distance was observed, both by comparing the right and left sides in the same specimen and by comparing the same side in the two groups. The righthandside was found to be smaller in the experimental group. It is believed that internal rigid fixationthrough areas of rapid bone growth in the skulls of rabbits at the age of development is able to inducechanges in the size of the skull

Hiperdontia

The presence of fourth molars is a rare condition. The radiographic exam is fundamental for itsdetection, since in most cases the supernumerary teeth are impacted. A case of fourthmandibular molars is presented. Prevalence, diagnostic images and surgical treatment arediscussed