Tooth movements associated with deep overbite correction in Class II division 1 malocclusions

The orthodontic profession has assumed much of the responsibility for the improvement in function of the teeth and jaws. Since function is closely associated with overbite, the correction of vertical overbite discrepancies comprises a major part of clinical orthodontics. This investigation was undertaken to describe the movements that teeth undergo during the correction of excessive overbites and to correlate these movements to the change in overbite. A total of 87 cases were selected from the records of the Indiana University School of Dentistry, Department of Orthodontics. The selected cases had an excessive pre-treatment overbite of 4.0 mm or more as seen cephalometrically and a satisfactory post-treatment result. In addition, they were clinically determined to be post-pubertal, indicating essentially no growth potential during the treatment period. Pre and post-treatment tracings of the cephalograms were made and measurements collected from the tracings. Superimpositions were prepared of the pre and post-treatment radiographs and the general trends that appeared were noted. The change in overbite was correlated to tooth movements of the Class II Division 1 correction using the Pearson test of correlation coefficients. The results indicate that the tooth movements most commonly seen in treatment to reduce excessive overbite occur mainly in the mandibular arch. In Class II Division 1 cases, the change was significantly correlated to the reduction in vertical height of the mandibular incisor and to the increase in the angulation of the mandibular incisor to the mandibular plane. Not all measurements recorded were significantly correlated to the change in overbite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Longitudinal study of combined orthodontic and surgical treatment of Class II malocclusion with deep overbite

Twenty-one patients who had undergone orthodontic treatment in combination with mandibular advancement surgery to treat Class II malocclusion and deep overbite were followed up. Median vertical relapse at the bony chin (after a mean followup of 16 months) was found to be 2.9 mm (44%). Sagittal advancement was found to have good stability; most of the patients exhibited some additional anterior movement of the chin during the follow-up period. At the same time, the entire mandible rotated counterclockwise and the gonial angle increased. Individual response to treatment varied greatly; two patients exhibited major horizontal relapse. Controlling the position of the mandibular proximal segment seemed to be the most important factor in posttreatment stability of this sample.     

Predictive value of morphologic parameters for successful correction of Class II Division 2 malocclusion.

The aim of this study was to assess the predictive value of pretreatment cephalometric parameters and apical base size for successful correction of Angle Class II Division 2 malocclusion. Pretreatment lateral cephalograms and pretreatment and posttreatment study casts of 96 subjects with Class II Division 2 malocclusions were examined to obtain 23 cephalometric parameters and to measure the size of the apical bases. Success of occlusal correction was evaluated as the percentage of change of peer assessment rating scores during treatment; percentage of change was the dependent variable in multivariate statistical analyses used to test the predictive value of the assessed parameters. Cephalometric parameters of pretreatment craniofacial morphology were insignificant as predictors of successful orthodontic correction of the malocclusions. Maxillary apical base size was the strongest predictor of occlusal correction and might serve as a valuable diagnostic predictor of successful treatment outcome.     

Mandibular displacement in Angle Class II, Division 2 malocclusion

The effect of the treatment of Angle Class II, Division 2 malocclusion was studied in 22 children by x-ray cephalometry and by recording the relation between the retruded and the intercuspal mandibular positions. The treatment was performed in three phases. In the first phase the upper incisors were proclined, and the deep bite was corrected with an upper removable plate. In the second phase the distal occlusion was corrected with an activator. The result was retained in the third phase with a second activator designed for retention. The relation between the retruded (RCP) and the intercuspal (ICP) mandibular positions was recorded with wax bites and dental casts mounted in a modified gnathothesiometer. The anteroposterior distance between RCP and ICP was large before the start of the treatment. The distance was unchanged after proclination of the upper incisors and correction of the deep bite but decreased after correction of the distal occlusion and increased again somewhat during the retention phase. The proclination of the upper incisors and the correction of the deep bite (phase one of the treatment) did not result in mandibular anterior positioning. This fact and the results of the recordings of the relation between RCP and ICP were interpreted as evidence that the mandible is not posteriorly displaced in Class II, Division 2 malocclusion.     

Pathognomonic cephalometric characteristics of Angle Class II Division 2 malocclusion

The Class II division 2 (Class II/2) malocclusion as originally defined by E.H. Angle is relatively rare. The orthodontic literature does not agree on the skeletal characteristics of this malocclusion. Several researchers claim that it is characterized by an orthognathic facial pattern and that the malocclusion is dentoalveolar per se. Others claim that the Class II/2 malocclusion has unique skeletal and dentoalveolar characteristics. The present study describes the skeletal and dentoalveolar cephalometric characteristics of 50 patients clinically diagnosed as having Class II/2 malocclusion according to Angle's original criteria. The study compares the findings with those of both a control group of 54 subjects with Class II division I (Class II/1) malocclusion and a second control group of 34 subjects with Class I (Class I) malocclusion. The findings demonstrate definite skeletal and dentoalveolar patterns with the following characteristics: (1) the maxilla is orthognathic, (2) the mandible has relatively short and retrognathic parameters, (3) the chin is relatively prominent, (4) the facial pattern is hypodivergent, (5) the upper central incisors are retroclined, and (6) the overbite is deep. The results demonstrate that, in a sagittal direction, the entity of Angle Class II/2 malocclusion might actually be located between the Angle Class I and the Angle Class II/1 malocclusions. with unique vertical skeletal characteristics.     

Biomechanics of deep overbite correction

Correction of deep overbite can be accomplished in different ways depending on the treatment goals chosen for individual patients. The 2 primary methods of correction are intrusion of anterior teeth or extrusion of posterior teeth. Successful intrusion of the incisors depends on careful control of the force system used. Low force magnitude, force constancy, a properly selected single point of force application, and control of force direction are all important factors to consider. The design of the intrusion arch may be continuous, or a 3-piece intrusion arch may be selected depending on the needs of the patient. Alternatively, extrusion of posterior teeth may be indicated in patients who are still actively growing and who have short vertical facial dimensions.     

Treatment of a Class II Division 1 malocclusion.

This case was presented as part of the American Board of Orthodontics case displays at the 1999 AAO meeting. It was selected to be submitted for the publication in the American Journal of Orthodontics and Dentofacial Orthopedics by the ABO.     

Category 5: Class II Division 1 malocclusion.

This case report was part of a display of cases sponsored by the ABO after the board-certification process. The Summary of Treatment and records are reprinted here with minimal editing and reformatting, so the presentation resembles the actual documents submitted to the board.     

Early treatment of a severe Class II Division 1 malocclusion

This case report shows the effects of functional therapy at an early age in a severe Class II, division 1 malocclusion. Favorable changes in the profile and in the lip seal were achieved. The dental irregularity was treated by fixed appliances and extraction therapy. The patient and her parents were pleased with the final outcome.