A standardized method to determine the proper working distance for dental magnification
utilizing neutral ergonomics positioning


Hind S. Hussein1a , Shelby Anderson1b , Melissa Matick1c , Avery Greene1d , Mark P. Zmiyiwsky1e ,
Nader F. Abdulhameed1f*

1Restorative Dentistry Department, School of Dental Medicine, Lake Erie College of Osteopathic Medicine, Bradenton, Florida, USA

aBDS, Assistant Professor; email:; ORCIDiD:
bDMD Student; email:; ORCIDiD:
cDMD Student; email:; ORCIDiD:
dDMD Student; email:; ORCIDiD:
eDDS. MSBE, Assistant Professor; email:; ORCIDiD:
fBDS. MS.PhD, Assistant Professor; email:; ORCIDiD:



Introduction Evaluate and compare the relationship between anatomic measurements of the dental clinician in a neutral ergonomics position with the proper working distance and test the hypothesis that working distance can be estimated using specific anatomical measurements of the operator.
Materials and Methods Specific measurements were obtained from 134 participants utilizing a neutral ergonomics position. Values were applied using the Pythagorean theorem to calculate a hypothesized working distance (HWD) from lateral epicanthus (E) to antecubital fossa (F) and antecubital fossa to the tip of the thumb (T). The actual working distance (ET) was measured from lateral epicanthus to tip of the thumb in a neutral ergonomics position in a simulated setting.
Results The results showed a significant positive correlation between (ET) and (HWD) and a positive correlation for all of the anatomic measurements taken in simulation: ET to height and HWD to height; (EF) and ET, EF and HWD; antecubital fossa to the thumb (FT) and ET, FT and HWD (p<0.00). There was a marginally significant difference when comparing vision types, corrective and non- corrective (p<0.058), with non-corrective vision having a higher actual working distance. There was a statistical difference when comparing gender and HWD with male participants ranking higher hypothesized and actual working distance.
Conclusion When applying the Pythagorean formula using anatomic landmark measurements, the HWD is repeatable for most operators and may contribute to a more standardized method to measure the accurate working distance that fits the ergonomics.


Ergonomics; Dental Education; Musculoskeletal Disorders; Dentist; Dental Hygienists.



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