LANDMARK POSITIONING ON MAXILLA OF CLEFT-LIP AND PALATE INFANT - A REALITY

In this study, we tested the precision of landmark positioning for a s et of landmarks that can be used for the edentulous cleft lip and pala te maxilla of the infant, by analyzing intraobserver and interobserver repositioning and measuring on a series of 121 (unilateral and bilate ral) study casts, To date, no data on interobserver and only minimal d ata on intraobserver reproducibility are available, We found intraobse rver reproducibility acceptable with total measurement errors ranging from 0.51 to 1.54 mm. Interobserver reproducibility was only slightly less with total measurement errors ranging from 0.63 to 1.57 mm, Total measurement errors were found to be relatively high for some variable s, Both the intra- and interobserver analyses show insight into expect ed precision of landmark positioning during placement of these points on casts. A learning effect for precise positioning has been demonstra ted in both analyses, The points with the highest precision overall ar e Q and Q', followed by the linear measurements PL and P'L', Quality o f regular study casts (impressions) is an important factor, with room for improvement. Reproducible landmark positioning on the cleft lip an d palate infant's maxilla, can only be a reality if the quality of the cast is optimal and the investigator is experienced, Intraobserver an d interobserver reproducibility are in the same range, which justifies the comparison of results from different studies and relieves future investigators of the need to have all measurements within a study cond ucted by the same investigator, Aspects of the biologic meaning of lan dmarks are also discussed.