Objective: Due to the lack of a universally accepted classification system, we are aiming to introduce a
modified comprehensive, precise and relatively simple classification system for primary diagnosis of cleft
lip and palate.
Methods: The proposed classification is based on the Kernahan's striped Y diagram with more details in
cleft extent and with the addition of severity scores to each cleft component. Clear definitions of cleft
extents and severity degrees were described based on 400 consecutive primary cases. Two medical
students were taught the classification then diagnosed photographs of 100 cases twice to test its
reliability.
Results: The students' results were 11% and 13% wrong diagnoses for student 1 and 2 in the first time, 8%
and 10% in the second time, respectively. The inter-rater reliability for the two students in the first and
second time was 0.716 and 0.878, respectively. The intra-rater reliability for student 1 and 2 were 0.826
and 0.755 respectively. The average duration to diagnose a case was less than a minute.
Conclusion: This classification is comprehensive and records many diagnostic variables with high reliability
and precision.