Objective To test the reliability of the modified Huddart-Bodenham (MHB) numerical scoring system and its agreement with the GOSLON Yardstick categorization for assessing the dental arch relationships in unilateral cleft lip and palate (UCLP) cases. Design A retrospective study. Setting Faculty of Dentistry, The University of Hong Kong. Patients Forty-one nonsyndromic UCLP consecutive patients attending the Joint Cleft Lip/Palate Clinic at Faculty of Dentistry in the University of Hong Kong were selected. Interventions Study models at 8 to 10 years old (T1) and 10 to 12 years old (T2) were obtained from each patient. Main Outcome Measures Models were rated with the MHB scoring system and GOSLON Yardstick index. The intra- and interexaminer reliabilities as well as correlation of both scoring systems were evaluated. Furthermore, to investigate the outcome measurements consistency, the MHB scoring system and GOSLON Yardstick were independently used to compare the dental arch relationships from T1 to T2, with the samples split into intervention and nonintervention groups. Results The MHB scoring system presented good intra- and interexaminer agreement, which were comparable to those of the GOSLON Yardstick. The correlation between the MHB scoring system and GOSLON Yardstick scores was good. Both scoring systems showed similar results when assessing the change in the dental arch relationships from T1 to T2. Conclusions The MHB scoring system can be used as an alternative method to the commonly used GOSLON Yardstick for assessing dental deformities in UCLP patients. Both scoring systems showed similar results in assessing the improvement in dental arch relationships.