Vol. 8, No 1, 2001 pp. 39 - 45
UC 616.31
BIOMECHANICAL ANALYSIS OF FORCES AND MOMENTS
GENERATED IN THE MANDIBLE
Aleksandar Igić1, Ratko Pavlović2, Antoan
Steas3, Stevan Igić1
1Department of Prosthetic Dentistry, Medical Faculty, University
of Niš, Yugoslavia
2Department of Mechanical Engineering, Mechanical
Faculty, University of Niš, Yugoslavia
3Department of Prosthetic Dentistry, School of dentistry,
University of Thessaloniki, Greece
Summary. The forces generated during the function of the stomatognatic
system act to the jaw bones in different directions depending on action
of muscles which do definite action. The objective of this study
is to determine distribution of the forces and their moments in some parts
of a toothless mandible during simulation of one-sided ridge loading in
the region of the lateral teeth. The chosen researching method is
a combination of the clinical and the analytical (mechanically-mathematics)
parts. The obtained resellers show that the forces are unevenly distributed
along the jaw both on the left and right side, by which they are of the
higher intensity on the side where the loading acts. The force
FtB perpendicular to the mandible base, acting in the cranial
direction, retains the constant value on the regions
without loading, but in the loading zone it changes the action direction.
The forces acting to fosse articulates are of unequal intensities
and they are higher in the balances joint.
There is an explicit asymmetry of moment MfN between the left and right
side of the jaw, both in side and action direction.
The jaw torsion moment
retains approximately the same values on the working side, while
on the balance side it changes the action direction, by which
that change is performed in short region. Moment MfB
is nearly symmetrically distributed in relation to the medial
jaw plane.
Key words: Forces, moments, lower jaw
BIOMEHANIČKA ANALIZA SILA I MOMENATA GENERISANIH
U MANDIBULI
Kratak sadržaj: Sile koje se formiraju u toku funkcije žvakanja
deluju na vilične kosti u različitim pravcima u zavisnosti od delovanja
mišića koji vrše odredjenu akciju. Cilj ove studije je da utvrdi distribuciju
sila i njihovih momenata u pojedinim delovima bezube mandibule pri simulaciji
jednostranog opterećenja grebena u predelu bočnih zuba. Izabrani metod
istraživanja je kombinacija kliničkog i analitičkog (mehaničko-matematičkog)
dela. Dobijeni rezultati pokazuju da su sile neravnomerno raspodeljene
duž tela vilice sa leve i desne strane, pri čemu su većeg intenziteta na
strani gde dejstvuje opterećenje. Sila FtB upravna na bazu mandibule, koja
deluje u kranijalnom pravcu, zadržava konstantnu vrednost na delovima gde
nema opterećenja, a u zoni opterećenja menja smer dejstva. Sile koje deluju
na fossu articularis su nejednakih intenziteta i veće su u balansnom zglobu.
Postoji izražena asimetrija momenta MfN između leve i desne strane vilice,
kako po veličini tako i po smeru dejstva. Moment uvijanja vilice zadržava
približno iste vrednosti na radnoj strani, dok na balansnoj strani menja
smer dejstva, pri čemu se ta promena odvija na kratkom prostoru. Moment
MfB je skoro simetrično raspodeljen u odnosu na medijalnu ravan vilice.
Ključne reči: Sile, momenti, donja vilica
