Jill Gehrig, Rebecca Sroda, Darlene Saccuzzo - Fundamentals of Periodontal Instrumentation and Advanced Root Instrumentation (2016, LWW) - libgen.lc

32 Fundamentals of Periodontal Instrumentation & Advanced Root Instrumentation
Te mple
piece
Line of
sight
Fig ure 1-55. Declination Angle. The d eclination angle is the
angle ormed between the temple piece o spectacle-mounted
magnif cation system and the clinician’s actual line o sight.
3. Important Considerations or Preclinical Periodontal Instrumentation
A. Limitations on What Can Be Seen with Magnif cation
1. Limited Field o Vision with Magnif cation. The feld o view is the total
size of the object that can be viewed through the loupes. The most popular
magni cation strengths for periodontal instrumentation are 2.0×, 2.5×, and
2.6× (55). The lowest level of magni cation required should be selected. Lower
magni cation levels increase the depth of eld and minimize the blind zone.
2. Blind Zone with Magnif cation. The blind zone is an area of vision between the
unmagni ed peripheral eld of vision and the magni ed center of the eld of
vision.
a. The blind zone presents the most dif culty when an instrument is being
moved into or out of the magni ed eld of view. Injury to the patient or the
clinician is a possibility as the instrument is moved through the blind spot.
Most clinicians simply move the loupes aside until a stable fulcrum has been
established with the instrument.
b. The lowest magni cation should be selected to minimize the size of the
blind zone.
B. Criteria or Use o Magnif cation Loupes in Preclinical Setting
1. Ability or Student Sel -Assessment
a. When learning the skills of clinician position, patient position, clock
positions, mirror use, and nger rests it is vital that the student clinician
is able to continuously self-assess the positioning of his or her body, arms,
hands, and ngers.
b. Sel -assessment o these skills during the learning process means that the
student clinician must have a visual f eld that includes the patient’s head
and the clinician’s arms, hands, and f ngers as well as the oral cavity.
c. Figure 1-56 shows the minimum eld of vision needed by the student
clinician while practicing and mastering the fundamental skills of patient
position, clock positions, mirror use, and nger rests.
d. Magni cation loupes limit the clinician’s eld of vision to the oral cavity
(60). Figure 1-57 shows the clinician’s eld of vision using with 2.5×
magni cation loupes. Once a clinician has mastered the fundamental skills
of patient position, clock positions, mirror use, and nger rests, the loupes
provide a eld of vision that is adequate for instrumentation.
e. This magnif ed f eld o vision, however, is too restrictive to permit sel -
evaluation o skills when acquiring the undamental preclinical skills o
positioning and f nger rests.