2024 Volume 49 Issue 1 Pages 1-9
Objective: Since its establishment in 1981, the Orthodontics department of the Chiba Dental Medical Center of Tokyo Dental College has been committed to providing orthodontic treatment to patients with cleft lip and/or palate who have occlusal abnormalities, in collaboration with other medical hospitals that cleft lip and palate patients with different techniques of lip and palatoplasty for malocclusion. This study investigated the prevalence of crossbite among cleft lip and palate patients, conducting a comprehensive clinical and statistical analysis of its dynamics. In addition, we investigated the evolution of crossbite in institutions that perform palatoplasty with different techniques while also assessing the role of our department within the local community.
Methods: Over the span of 40 years, from the establishment of Tokyo Dental College Chiba Hospital in 1981 to 2020, 1,254 patients with cleft lip and palate were admitted for treatment. This study examined 470 cases who underwent palatoplasty, i.e., isolated cleft palate, and unilateral or bilateral cleft lip and palate. All cases were at the stage of initiation of active orthodontic treatment. Using parallel study models, the incidence of crossbite was classified based on its position and the dimensions of the dental arch were calculated. Additionally, a comparative study was conducted between the two primary referral hospitals with different palatoplasty techniques to examine variations in crossbite occurrence associated with different palatoplasty techniques.
Results: When classifying patients based on the position of their crossbite, the percentage of Type 1 patients without crossbite increased, while the percentage of Type 6 patients with overall crossbite decreased from Phase 1 to 4. There were no significant changes in the length and width of the dental arch over time. Therefore, it was hypothesized that changes in the anteroposterior relationship between the maxillomandibular arch, rather than changes in the shape of the dental arches, play a role in decreasing crossbite. Regarding the position of crossbite incidence in relation to the palatoplasty method, a significant difference was noted only in Phase 2 of bilateral cleft lip and palate, where Type 6 had a notably high ratio, suggesting that two-stage palatoplasty had a better treatment outcome. However, no significant variations were observed in other cleft types suggesting no significant differences were observed in the classification of crossbites based on various palatoplasty techniques.
Conclusions: The incidence of crossbite in patients with cleft palate, as well as unilateral and bilateral cleft lip and palate, at the department has shown a decreasing trend over time. There was no relationship between the position of the crossbite and changes in the width or length of the dental arch. Furthermore, differences in palatoplasty did not affect the classification of crossbite.
