The premature loss of primary first molars: space loss to molar occlusal relationships and facial patterns.

OBJECTIVE

To investigate space changes with the premature loss of primary first molars and their relationship to permanent molar occlusion and facial forms.

MATERIALS AND METHODS

Two hundred twenty-six participants (ranging in age from 7 years 8 months to 8 years 2 months; 135 female, 91 male) met all inclusion criteria designed to study space loss as a result of the premature loss of the primary first molar. After 9 months, space loss was evaluated in relationship to molar occlusion and facial form. Statistical evaluation was performed with the paired t-test and with a two-way analysis of variance for independent groups.

RESULTS

Patients with leptoprosopic facial form and end-on molar occlusions all exhibited a statistically significant difference when compared to controls in terms of space loss (P < .001). The mandibular extraction site for individuals with a mesoprosopic/euryprosopic facial form and end-on molar occlusion displayed space loss as well (P < .05). All patients with a leptoprosopic facial form and Class I molar occlusion displayed space loss in the maxilla (P < .05) and the mandible (P < .001) respectively, that was statistically significant when compared to that of the control. Individuals within the mesoprosopic/euryprosopic group and with Class I molar occlusions showed no significant difference in space loss.

CONCLUSIONS

The relationship between the first permanent molar occlusion and facial form of the child has an influence on the loss of space at the primary first molar site.