The use of linear and angular measurements of maxillo-mandibular anteroposterior discrepancies.
OBJECTIVE
To extend the assessment of the clinical significance of the measurement of the anteroposterior discrepancy between maxilla and mandible on the bisector of the palatal plane to mandibular plane angle to a large group of randomly selected patients of both sexes, and to verify the correlation of this measurement to well established angular and linear assessments of anteroposterior discrepancy.


METHODS
Retrospective analysis of pre-treatment lateral cephalometric radiographs.


METHODS
The Laboratory of Functional Anatomy of the Stomatognathic Apparatus at Milan University, Italy. Three hundred and six orthodontic patients (165 males, 141 females) aged between 6 and 50 years.


METHODS
ANB angle; corrected ANB* angle which compensates for the position of the maxilla and rotation of the mandible relative to the cranial base; Wits appraisal; MM-Wits: linear distance between the projections of A and B points on the bisector of the palatal plane to mandibular plane angle.


RESULTS
The MM-Wits distance was significantly correlated to two angles (ANB and ANB*), as well as to the Wits appraisal. All the correlations performed did not show sex- or age-characteristic patterns. The correlation to the corrected ANB* was the best among the three, with a correlation coefficient of 0.915, MM-Wits (mm) = 1.497 x ANB* (degrees) -6.784. From the correlation, reference values for the new measurement have also been estimated, and found to be between -0.65 and -6.85 mm for skeletal Class I individuals.


CONCLUSIONS
It is recommended that the diagnosis of orthodontic anomalies should be performed taking into consideration more than a single anteroposterior appraisal.
Ferrario
V F
VF
Functional Anatomy Research Center (FARC), Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Italy. farc@imiucca.csi.unimi.it
Sforza
C
C
Miani
A
A
Tartaglia
G M
GM
D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D016009:Chi-Square Distribution; D002648:Child; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D007574:Jaw Relation Record; D008297:Male; D008310:Malocclusion / Q000175:diagnosis*; D008445:Maxillofacial Development; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012494:Sampling Studies