Model surgery with a passive robot arm for orthognathic surgery planning.
OBJECTIVE
The aims of the study were to assess the degree of accuracy of model surgery performed manually using the Eastman technique and to compare it with model surgery performed with the aid of a robot arm.


METHODS
Twenty-one patients undergoing orthognathic surgery gave consent for this study. They were divided into 2 groups based on the model surgery technique used. Group A (52%) had model surgery performed manually, whereas group B (48%) had their model surgery performed using the robot arm. Patients' maxillary casts were measured before and after model surgery, and results were compared with those for the original treatment plan in horizontal (x-axis), vertical (y-axis), and transverse (z-axis) planes.


RESULTS
Statistical analysis using Mann-Whitney U test for x- and y-axis and independent sample t test for z-axis have shown significant differences between both groups in x-axis (P =.024) and y-axis (P =.01) but not in z-axis (P =.776).


CONCLUSIONS
Model surgery performed with the aid of a robot arm is significantly more accurate in anteroposterior and vertical planes than is manual model surgery. Robot arm has an important role to play in orthognathic surgery planning and in determining the biometrics of orthognathic surgical change at the model surgery stage.
Theodossy
Tamer
T
Oral and Maxillofacial Surgery, University College London Hospitals NHS Trust, Mortimer Market, London WC1E 6AU, UK. tamertheodossy@hotmail.com
Bamber
Mohammad Anwar
MA
D002508:Cephalometry; D003725:Dental Articulators; D004867:Equipment Design; D006801:Humans; D007574:Jaw Relation Record; D008437:Maxilla / Q000601:surgery*; D008953:Models, Anatomic; D003765:Models, Dental; D010347:Patient Care Planning; D012371:Robotics / Q000295:instrumentation*; D018709:Statistics, Nonparametric