Occurrence of XXXX and need of orthodontic treatment in early mixed dentition.

@entity1 @entity3232 @entity235
This study analyzed the occlusions of 489 @entity1 at the onset of the mixed dentition period (mean age 5.1 years, range 4.0-7.8 years). These @entity1 participate in an ongoing clinical trial that is investigating the effects of orthodontic intervention in the early mixed dentition. The aim was to report the occlusal findings at the baseline. The frequencies of mesial step, flush terminal plane, and distal step were 19.1%, 47.8%, and 33.1%, respectively. The @entity235 relationship was Class I in 46.1%, Class II in 52.4%, and Class III in 1.5% of the sides examined. An asymmetrical @entity235 relationship was found in 30.1% of the @entity1 , significantly more often on the right side than on the left (P <.001). Overjet ranged from -2 to +10 mm with a mean of 2.9 mm. Overbite ranged from -5 to +8 mm with a mean of 2.8 mm. Excessive (> or =4 mm) overjet was found in 26.7% and overbite in 33.8% of the @entity1 ; in 15.5% of the @entity1 , both variables were 4 mm or more. Anterior crowding was detected in the maxillary arch in 11.6% and in the mandibular arch in 38.9% of the @entity1 . @entity1 showed mandibular crowding more often than @entity1 (P <.01). A posterior crossbite was found in 7.5% of the @entity1 , unilaterally in 6.4% and bilaterally in 1.1%. Scissors-bite was detected in 1.1% and an anterior crossbite in 2.2% of the @entity1 . The mean maximal opening was 40.3 mm. Joint sounds were registered in 5.2% of the @entity1 . The prevalence of @entity3232 was between 67.7% and 92.7%, depending on the values of unacceptable parameters used for each occlusal characteristic.
