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SIMPLIFIED TAD MECHANICS FOR MOLAR UPRIGHTING
NICOLA DERTON
CONEGLIANO, ITALY
INTRODUCTION
Preprosthetic orthodontic treatment plays a fundamental
role for adult malocclusion correction. Mandibular molar
uprighting is a huge help to both the surgeon and the prosthodontist
because it creates ideal conditions for prosthetic
rehabilitation of edentulous areas. Conventional orthodontic
appliances, when used traditionally, can present some
problems that are detrimental to the malocclusion correction.
These problems can include: molar extrusion, undesirable
movements of an anchorage unit, a need for extended appliance
wear, the need for auxiliary devices and/or a long treatment
time. During the last several years, skeletal anchorage
miniscrews have proved to be a reliable, efficient, and simple
adjunct to any biomechanical system. The aim of this paper
is to illustrate, by means of a case report, the guidelines for a
simplified TAD approach to molar uprighting for prosthetic
rehabilitation prior to restoration.
CASE REPORT
An adult woman presented with a Class I malocclusion and
several missing teeth. (Figs. 1, 2, 3) The mandibular right
second molar exhibited mesial inclination. After consultation
with the prosthodontist, the plan that was developed was
to insert two implants in the mandibular left quadrant and
one implant in the mandibular right quadrant. Prior to implant
insertion in the mandibular right quadrant, the mesioangular
inclination of the mandibular right second molar had to
be corrected. (Figs. 4, 5) Because of insufficient bony support,
the orthodontic treatment plan called for TAD anchorage
in order to simplify the mechanics. To accomplish molar
uprighting, a 1.5 mm x 9 mm miniscrew (Spider C2HDC,
Fig. 3
Fig. 4 Fig. 5
Sarcedo Italy) was inserted distal to the mandibular second
molar and a metal button was bonded to the mesial surface
of the molar. The force from the TAD to the inclined tooth
was accomplished with an alastic chain. (Figs. 6, 7) To
enhance the stability of the TAD, it was inserted in an outer
oblique line to the retromolar area where thicker cortical
bone can be easily found. The TAD was screwed deep into
the bone in order to develop a vertical force vector system
that would result in an intrusive effect on the molar. (The
head of the TAD was more cervical than the application
point on the tooth.)
Fig. 6 Fig. 7
Fig. 1 Fig. 2
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