| Summary: | Thesis (M.Dent)--University of the Witwatersrand, Faculty of Health Sciences, 1998. === This study was undertaken to investigate the observation that in
some subjects w ith early-onset periodontitis there is a peculiar
tapering slenderness of root form. This study compares the degree
of taper of the roots of maxillary second premolars, and of the distal
roots of mandibular first molars of patients with early-onset
periodontitis {experimental subjects), with that of the corresponding
roots of control subjects. It seeks to determine whether the degree
of taper is ascribable to a particular part of the root; whether
differences if any are related to gender or to race; and whether the
molars or the premolars would be better diagnostic aids to, and
predictors of disease.
Periapical radiographs of tw enty teeth of each type were selected
for the experimental am control groups. Accurate large scale
tracings of the root outlines were made from radiographs. Using the
mesiodistal widths of the roots at the cemento-enamel junction in
the case of the premolars, and at the root bifurcation in the case of
the distal roots of the molars as baseline measurements, the degrees
of taper of the roots were determined.
Statistical comparison of the degrees of taper of roots from
experimental subjects with those of the roots of control subjects
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showed strong evidence of a sharper degree of taper in the former;
this was more pronounced for the premolars than for the molars.
The degree of taper was more marked in the apical half of the roots
of experimental molars; but in experimental premolars the increased
taper was evident throughout the entire length of the root.
In the case of the experimental molar roots, there is a relationship
between race and the degree of taper: this highlights the desirability
of future studies examining the root forms of racially segregated
groups. There is no relationship between gender and the tapering of
the experimental molar roots.
For premolars the increased taper of experimental teeth is related
neither to race nor to gender. Prediction and diagnosis of disease is
more reliable with premolars than with molars, because the latter
taper more sharply only along a portion of their roots.
In an affected individual, the maxillary second premolar appears to
be a reliable predictor and an indicator of early-onset periodontitis.
The distal root of the mandibular first molar likewise is a predictor
and an indicator of early-onset periodontitis; but as its degree of
taper is less pronounced and occurs only in the apical half of the
root, its reliability in these roles may be diminished.
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