Medial canthal region as an external reference point in orthognathic surgery.
OBJECTIVE
The aim of this investigation was to evaluate the effectiveness of using the medial canthal region (MCR) as an external reference point to determine the vertical dimension during maxillary repositioning as planned in model surgery and predictive tracing.


METHODS
The analyzed group consisted of 43 consecutive patients who underwent maxillary or bimaxillary orthognathic surgery. Before downfracture, the vertical height was established from the distance of the MCR to the incisal edge of the right upper central incisor (UCI). The vertical dimension was obtained with frequent measurements by use of calipers as desired during cephalometric tracing and model surgery. After rigid fixation, the vertical height was verified again. The UCI was traced from the postoperative cephalogram and predictive tracing onto a preoperative tracing. Repositioning of the maxilla and postsurgical movements of the UCI were registered at the horizontal and vertical planes. Comparison was made between the predicted maxillary position on the cephalometric tracing and the actual position, as well as between the planned maxillary position in model surgery and the actual position.


RESULTS
The mean difference between the planned UCI position on predictive tracing and postsurgical position was 0.30 mm (SD, 0.21 mm; P > .05) in the vertical plane. The variation between the planned maxillary position in model surgery and the actual position was 0.37 mm (SD, 0.31 mm; P > .05) in the vertical plane.


CONCLUSIONS
Good surgical accuracy in positioning the mobilized maxilla can be achieved by use of the MCR as an external reference point.
Oral and Maxillofacial Surgery Department, Santa Catarina Federal University, Florianópolis, Brazil. gil@ccs.ufsc.br
José Nazareno
JN
Gil
Felipe Eduardo Baires
FE
Campos
Jonathas Daniel Paggi
JD
Claus
Luiz Fernando
LF
Gil
Charles
C
Marin
Sérgio Fernando Torres
SF
de Freitas
D000293:Adolescent; D000328:Adult; D001860:Bone Plates; D001863:Bone Screws; D016025:Bone Transplantation; D002508:Cephalometry / Q000379:methods*; D005143:Eyelids / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D008953:Models, Anatomic; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D010027:Osteotomy / Q000379:methods; D019340:Osteotomy, Le Fort / Q000379:methods; D010347:Patient Care Planning; D012189:Retrospective Studies; D013165:Splints; D016896:Treatment Outcome; D014716:Vertical Dimension; D055815:Young Adult