The relationship between vertical facial morphology and overjet in untreated Class II subjects.

OBJECTIVE

To evaluate the association between vertical facial morphology and overjet in untreated Class II subjects.

MATERIALS AND METHODS

The lateral cephalograms of 140 untreated Class II subjects (68 males and 72 females) between 8 and 11 years of age were divided into three groups based on their overjet value as measured on study casts: Group I normal overjet (less than 3 mm), Group II increased overjet (more than 3 mm but less than or equal to 6 mm), and Group III extreme overjet (more than 6 mm). Mean values and standard deviations of 28 variables measured on lateral cephalograms were calculated. Differences between the three groups were tested using one-way analysis of variance (ANOVA), followed by Bonferroni tests. Additionally, cephalometric differences between groups and available normal values for the Syrian population were evaluated using an independent t-test.

RESULTS

Subjects with normal overjet showed a horizontal facial pattern and posterior inclination of the maxilla, whereas increased overjet subjects exhibited a neutral facial pattern. In contrast, subjects with extreme overjet had a vertical facial pattern and anterior inclination of the maxilla. The mandible was retrognathic and the maxilla was normally positioned in the three groups.

CONCLUSIONS

A positive association was found between the overjet and the tendency toward a hyperdivergent pattern.