ODONTOLOGIA MESTRADO EM ORTODONTIA EFEITOS ... - Unicid

Guerreiro FS. Effects of diet consistency on the mandibular growth in rats:
Histomorphometric analysis. [Dissertação] São Paulo: Universidade Cidade de
São Paulo, 2009.
ABSTRACT
The purpose of this study was to investigate the association between
masticatory hypofunction and the growth pattern and internal bone structure of
the mandible. The sample was composed of 24 male Wistar rats (Albinus
norvegicus) 21 days old. The animals were randomly divided into two groups
(12 rats per group), according to the consistency of the diet: solid (Control
Group - GC) or powdered (Experimental Group - GE). After 50 days of the
experiment, the animals were submitted to euthanasia and their mandibles were
removed, separated into two halves and processed for histomorphometric
analysis. A qualified examiner performed the evaluations twice. The following
characteristics were assessed: mandibular growth by means of linear and
angular measurements taken from photographs, bone density, estimated in the
mandibular ramus region, based on an aluminum stepwedge recorded on the
digital radiographs obtained from the left hemimandibles and the area of the
cortical and trabecular bone tissue in the region of the second molar on the left
side, in 5 µm-thick serial cuts, stained with Cason’s trichrome. The means with
reference to the two groups were compared by the Mann-Whitney test (α =
0.05). The results showed that the consistency of the softer diet promoted
mandibles with smaller macroscopic dimensions, presenting a shorter