Second Molar Eruption Patterns in Cleft Affected Patients

Background: Recent reports on the association between eruptive patterns of second molars and different malocclusion and facial types are ambiguous. Unilateral cleft lip and palate (UCLP) affected patients, due to their craniofacial defect, present with midface deficiency manifested by under developed and retruded maxilla. Objectives: We compared the association between the eruptive position and developmental stage of second molars found in UCLP affected patients and in skeletal Class I controls. Methods: Pretreatment panoramic radiographs of 87 UCLP affected patients and 38 skeletal Class I malocclusion controls, from the Orthodontic and Craniofacial Department of the Rambam Medical Campus and Technion, Haifa, Israel were evaluated. The developmental stage of second molars was recorded and their eruptive position was calculated in relation to the occlusal reference line taken from the panoramic roentgenograms. Results: Dental and chronologic ages were found to be similar for both groups. In patients 6-8.5 years old, no statistically significant difference was found between the groups. In patients older than 8.5, a statistically significant difference was found in all second molars with less development and more apically located in the cleft affected patients compared to the controls (p≤0.039). Conclusion: UCLP affected patients older than 8.5 years present with under developed and more apically located second molars possibly due to insufficient space for maxillary eruption. This finding might be further used as a forecasting method for the development of maxillary retrusion skeletal Class III malocclusion.