Date of Completion


Embargo Period



Dr. John Agar; Dr. Mark Litt; Dr. Thomas Taylor; Dr. Flavio Uribe

Field of Study

Dental Science


Master of Dental Science

Open Access

Open Access


Materials and Methods:

Twenty models with class I occlusion of White, Black, Asian, and Asian-Indian racial background had mandibular overlays of 2mm, 3mm, 4mm, and 5mm thicknesses fabricated.

Each model had clinical measurements made from pro-nasale to soft tissue menton for each of the following OVD above their normal bite 0mm, 2mm, 3mm, 4mm, and 5mm.

The same models described above had frontal and profile facial digital images recorded in maximum intercuspation (MIP) and wearing each of the four mandibular overlays. The digital images of 8 models were selected and displayed to 60 judges (30 laypeople, 15 general dentists, and 15 prosthodontists.) Using a VAS, all subjects rated the esthetics of each model at each OVD.


Objectively, a systematic increase of 1.0mm in OVD reflected an increase of LFH by 0.63; this increase in LFH was uncorrelated with OVD (r=.123; p >.20).

Subjectively, ratings of facial esthetics, evaluated across judges with different background statuses (layperson, general dentist, prosthodontist), were not affected (p>0.70) up to 5.0mm above MIP. When model and subject gender were the same (p > 0.80) ratings of facial esthetics were not correlated, but when model and subject race were the same (p < .01) ratings were affected.


  1. Objectively, increased OVD did not correlated to similar increases in LFH.
  2. Subjectively, judges could not detect a difference in facial esthetics with changes up to 5.0mm above MIP irrespective of background status. Interactions between model and subject gender affected ratings, but interactions between model and subject race were uncorrelated.

Major Advisor

Dr. Avinash Bidra