Results for Nite-Guide preventive and interceptive procedure

Several occlusal dimensions were measured initially at 5.1 years of age and again at the termination of the study at 8.4 years.

The most important of these dimensions were crowding of the mandible and maxilla, overbite, overjet, open-bite, mandibular length (condylion-grathion) and the need for treatment at the end of the study (as a percentage).

All of the initial measures had no statistical differences, while both groups at the termination of treatment exhibited significant differences at the 0.001 level of significance.

Mandibular crowding had a 98 percent correction from 48 percent to a 1 percent incidence. The maxillary crowding improved 82 percent from 11 percent to 2 percent while the control increased 256 percent (9 to 32 percent incidence).

Both overbite and overjet were treated optimally to 2.1 mm and 1.9 mm. Two millimeters is the ideal recommended measure at this early age (8.4 years) in order to accommodate future jaw growth (Bergersen, 1990, 1995).

Open-bite had a 98 percent correction while the control sample had a 20 percent increase. The Class II canine relation had an 87.5 percent improvement while the control group remained unchanged.

The need for further treatment for overbite and open-bite at the end of
Nite-Guide use was 2 percent compared to 74 percent for the control sample. Mandibular crowding was 1 percent (treated) versus 47 percent (control), and maxillary crowding was 2 percent (treated) versus 32 percent (control).

The conclusion of these results at the termination of the study were expressed as “… little treatment need was left in the treatment group compared with the control group …” (Keski-Nisula et al, 2008).

In a second report from the same study (Keski-Nisula et al, 2008), the most meaningful conclusion was that the mandibular length (condylion-grathion) grew
54.2 percent greater than the control sample (11.1 mm vs. 7.2 mm) or 3.9 mm greater during a three-year period (5.1 to 8.4 years). This represents a very large orthopedic growth factor in correcting overjets and proper intercuspation and also results in little or no overjet relapse in these cases (Bergersen, unpublished research).

Ninety-three percent of 5- to 7-year-old children are candidates for this treatment procedure (Keski-Nisula et al, 2003). Ninety-three percent of children wore the appliance as directed while sleeping, while 62 percent kept the appliance in all night after one week (Methenitou et al, 1990).

It was found that only one hour of passive wear each night was sufficient to obtain a successful result in overbite and overjet (Methenitou et al, 1990).

Research shows that the mean lower arch increase as a result of the incisal eruption is 3.21 mm (Lewis & Lehman, 1929; Korkhaus & Lehmann, 1931; Baume, 1950; Moorrees, 1959).

The mean maximum lower arch enlargement was 5.1 mm (Lewis & Lehman, 1932, 5.5 mm; Baume, 1950, 4.6 mm). The mean maximum upper arch increase was 6.8 mm (Lewis & Lehman, 1932, 7.0 mm; Baume, 1950, 6.5 mm).

The maximum arch increase in a study of 43 individuals using the Nite-Guide technique (Methenitou et al, 1990) was 6.9 mm in the lower and 8.9 mm in the upper arch.

This is a 35.3 percent increase in the mandible and 30.9 percent increase in the maxilla over the above maximum in the literature. This is the approximate mean widths of an upper lateral and central incisor respectively (G.V. Black, 1902).

Note: This article was published in Ortho Tribune U.S. Edition, Vol. 8 No. 2, AAO Preview 2013 issue.