The Characteristic of Transverse Dental Arch Relationship Study in Unilateral Cleft and Palate versus Noncleft in Thai Northeastern Population.

Objectives:  To evaluate and compare the transverse dental arch relationship of patients with unilateral cleft lip and palate (UCLP) versus the noncleft controls in Northeastern region of Thailand.

Materials and methods:  A cross-sectional study involving 80 participants comprising 40 nonsyndromic children with UCLP and 40 healthy noncleft children of similar age (mean age: 11 years). The study was conducted at the Faculty of Dentistry, Khon Kaen University, Thailand. Each participant underwent assessments for Angle's classification, overjet, overbite, and transverse dental arch width, along with the evaluation of the modified Huddart/Bodenham (MHB) index using three-dimensional digital dental casts. Comparisons between groups were performed using paired sample t-tests and nonparametric Mann-Whitney tests, with a significance level established at p < 0.05.

Results:  The sample was categorized into two groups: the early mixed dentition group (ages 7-10 years) and the late mixed dentition group (ages 11-14 years). In the antero-posterior plane, individuals with UCLP and those without cleft presented with class II Angle's classification. In the transverse plane, the maxillary transverse arch width was notably narrower in UCLP cases compared with noncleft cases, with more pronounced differences observed in the late mixed dentition group. However, there was no statistically significant difference in mandibular transverse width between the two groups. The mean MHB index scores were -9.35 in the early mixed dentition group and -12.63 in the late mixed dentition group, indicating a more severe score in the latter. When compared with the noncleft control group, both UCLP groups showed significantly lower MHB index scores.

Conclusion:  In comparison to noncleft individuals, the majority of UCLP cases exhibited class II angles with negative overjet. A significantly smaller transverse arch width was observed in the maxilla of UCLP patients, with no significant variances noted in the mandible. Analysis using the MHB index indicated greater total arch constriction in UCLP cases, particularly in the anterior tooth region. Furthermore, the severity of these findings was observed to escalate with age.