dc.description.abstract |
Introduction. In order to establish an accurate diagnosis and proper therapy planning in
orthodontics, it is necessary to perform the analysis of dental records. The only non-invasive
three-dimensional record that provides important information in orthodontics is the study cast.
The present study was conducted to determine the Linder Harth, Korkhaus and Bolton analyses
on dental casts before and after treatment, in two different cases with different approaches to
treatment plan.
Aim of the study. The aim of the present study is to determine the contribution of study casts in
orthodontic treatment planning.
Material and methods. Dental records of two patients were selected, one case treated with
extraction of upper first premolars and with non-extraction therapy in another one. These cases
were selected randomly, without malocclusion restriction, from the Chair of Pediatric Oromaxillo-
facial surgery, Pedodontics and Orthodontics, SUMPh Nicolae Testemitanu. Two sets of
dental casts with permanent dentition were examined in the transverse and sagittal plane. Manual
measurements were done with a digital caliper directly on the dental casts, and the obtained
values were compared to those defined by the formula.
Results. For the first case (with extraction of upper first premolars) in the pre-treatment stage,
for the maxillary arch, Linder Harth analysis showed that in the premolar arch the width is 3,6
mm less than the expected value and in the molar one 3,2mm less. Korkhaus analysis established
for the upper arch in the anterior segment a deficiency of 3mm and 5,5mm in the posterior one.
The Bolton's anterior ratio was 76% and the overall ratio 88%; this indicates maxillary tooth
material excess. For the second case (non-extraction case) in the pretreatment stage, for the
maxillary arch, Linder Harth analysis showed that in the premolar arch the width is 1,25mm less
than the expected value, but for the molar one with 4,1mm more. Korkhaus analysis established
for the upper maxillary, only in the anterior segment (-1,5mm) a relative narrow dental arch, but
for the posterior segment the values are within the normal range. The anterior ratio of Bolton is
80%, and indicates mandibular anterior excess.
Conclusions. The data collected and analyzed from these study casts in order to evaluate the
differences in pre-treatment and post-treatment stages, established the value and the contribution
of study casts in determination of best approach in treatment planning. Orthodontic treatment
planning is more than just deciding on extraction or non-extraction case. It requires an individual
approach, despite the great importance of biometric standards. |
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