Classification of anterior open bite using individualized cephalometry.
OBJECTIVE
The objective of this study was to describe the cephalometric characteristics of the open bite, and to classify the open bite according to individualized norms.


METHODS
The lateral cephalograms of 134 patients with an anterior open bite (min -0.5 mm) were analyzed. Patients were classified according to the inclination of the jaws, applying the principles of individualized cephalometry. The harmony box described by Hasund was used to define individualized norms for the inclination of the upper and lower jaws in each patient. The open bite was classified into four sub-types: (1) dental, (2) skeletal with enlarged ML-NSL angle, (3) skeletal with reduced ML-NSL angle, and (4) skeletal with deviations in upper and lower jaws. A skeletal open bite was found in 89 patients (66.4%). A dental open bite was found in 45 patients (33.6%).


RESULTS
A number of significant differences were found between these four groups using single-factor variance analysis and the Bonferroni a posteriori test, (p < or = 0.05, p < or = 0.01, p < or = 0.001). The most prominent variables were index value of anterior facial hight, total facial height ratio, gonial angle, and Y-axis. No significant differences were found for overbite, however.


CONCLUSIONS
It was possible to use individualized norms to classify the open bite into four sub-types. The demarcation between the four groups was supported statistically. The extent of the anterior open bite does not allow any conclusions as to the craniofacial pattern.
Bock
Jens Johannes
JJ
Martin-Luther-Universität Halle-Wittenberg, Universitätspoliklinik für Kieferorthopädie, Grosse Steinstr. 19, 06097 Halle/Saale, Germany. drbock@web.de
Bock
Franziska
F
Böhm
Bernhard
B
Fuhrmann
Robert A
RA
D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D024343:Open Bite / Q000145:classification* / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011861:Radiography, Dental / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity