[Anterior open bite: a formula for the differential diagnosis].
BACKGROUND
The differentiation between dental and skeletal anterior open bite, both with distinct etiologies and characteristics, is necessary to establish adequate orthodontic and speech-language treatment procedures.


OBJECTIVE
To establish a formula for the differential diagnosis of dental anterior open bite and skeletal anterior open bite based on a cephalometric analysis of the angles that measure the mandibular plane inclination (NS.GoGn), the vertical and anteroposterior mandibular growth (NSGn), and the Facial Axis angle.


METHODS
78 lateral radiographies, of individuals with ages varying from 6 to 13 years, were analyzed and divided into two groups: dental anterior open bite and skeletal anterior open bite.


RESULTS
There was a significant difference between the groups regarding the measurements of the angles: for the group with skeletal anterior open bite the NS.GoGn and the NSGn angles were bigger and the Facial Axis angle was smaller when compared to the group with dental anterior open bite. The adjustment to the linear function resulted in a formula that determines the type of anterior open bite with only 3.5% of error.


CONCLUSIONS
It was possible to establish a high precision formula for the differential diagnosis between dental and skeletal open bite, based on the angle measurements of NS.GoGn NSGn and Facial Axes. The presented formula for the differential diagnosis has research and clinical applicability.
Alimere
Heloísa Canesin
HC
Motricidade Oral pela Universidade de Ribeirão Preto (Unaerp). heloalimere@bol.com.br
Thomazinho
Adílson
A
de Felício
Cláudia Maria
CM
D017677:Age Distribution; D000465:Algorithms; D002508:Cephalometry; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D024343:Open Bite / Q000175:diagnosis*