Abstract
To identify the effect of a Hotz plate on the occurrence of palatalized articulation, we investigated the relationship between a Hotz plate and the occurrence of palatalized articulation. Furthermore, characteristics of palatal morphology relating to palatalized articulation were analyzed three-dimensionally.
The frequency of palatalized articulation was assessed in 142 patients with unilateral complete cleft lip and palate (UCLP) who underwent palatoplasty and speech assessment at 4 years of age. Threedimensional (3D) analysis of palatal morphology was performed in 32 UCLP patients, who had dental casts of the maxilla taken at about 4 years of age. Patients were divided into four groups: NH (-) group, showing normal articulation without a Hotz plate; PH (-) group, showing palatalized articulation without a Hotz plate; NH (+) group, showing normal articulation with a Hotz plate; and PH (+) group, showing palatalized articulation with a Hotz plate. The numbers in each group were 10,5,10, and 7, respectively. All dental casts were measured using a non-contact 3D laser scanner SURFLASER, and the 3D data were analyzed using the software 3D-Rugle. The landmarks were identified on the 3D images, then measurements on the horizontal, frontal, and sagittal planes were obtained and compared among the groups. The results were as follows.
1. Palatalized articulation was observed in 16 (29.1%) of 55 patients without a Hotz plate, whereas it was observed in 12 (13.8%) of 87 patients with a Hotz plate. There was a significant difference between the two groups.
2. In 15 patients treated without a Hotz plate, morphological characteristics of the palate, including narrowness in the posterior region, asymmetry and shallowness in the anterior region, were recognized. These characteristics were more remarkable in the PH (-) group (5 patients) than in the NH (-) group (10 patients). These abnormal morphologies of the palate were considered to account for the palatalized articulation.
3. In 17 patients treated with a Hotz plate, there were no significant differences in palatal morphologies between the NH (+) group (10 patients) and the PH (+) group (7 patients).
4. In the 12 patients with palatalized articulation, these morphological characteristics that were observed in the PH (-) group (5 patients) were not remarkable in the PH (+) group (7 patients).
5. The above findings suggest that the Hotz plate improves abnormal palatal morphologies and may decrease the occurrence of palatalized articulation.
