This study compared the treatment timing and outcomes of Class II Division 1 malocclusion treated during early mixed dentition, late mixed dentition, and permanent dentition. The study found that treatment duration decreased as dental development progressed, with patients in early mixed dentition treated for 57 months, late mixed dentition for 33 months, and permanent dentition for 21 months. Treatment outcomes, as measured by PAR score reduction, also improved with later treatment timing. Patients treated exclusively with fixed appliances like Herbst or multibracket had shorter treatment times (19-24 months) and greater PAR score reductions than those treated with functional or combination appliances. Overall, the study concluded that late treatment of Class II Division 1 malocclusion during

1. EARLY TREATMENT SYMPOSIUM
Treatment timing and outcome
Hans Pancherz, DDS, Odont Dr
Giessen, Germany
H
ow efficient is
early Class II
Division 1 treat-
ment compared with later
treatment? In a study at
the University of Gies-
sen,1
we defined treatment
efficiency as a better result
in a shorter treatment time.
We used the peer assess-
ment rating (PAR) index
to evaluate the pretreat-
ment and posttreatment dental casts of 204 patients who
had been treated for Class II Division 1 malocclusion in
the early mixed (n ϭ 54), late mixed (n ϭ 104), and
permanent (n ϭ 46) dentition. We found that the duration
of treatment decreased with progressing dental develop-
ment: patients in the early mixed dentition were treated for
57 months, those in the late mixed dentition for 33
months, and those in the permanent dentition for 21
months. Patients treated exclusively with fixed appliances
(Herbst or multibracket) had shorter treatment times (19 to
24 months) than those treated with functional appliances
or a combination of functional and multibracket appli-
ances (38 to 49 months). The PAR score reduction
(improvement) increased with progressing dental devel-
opment: early mixed dentition patients, late mixed denti-
tion patients, and permanent dentition patients had PAR
scores of 64%, 73%, and 77%, respectively. Patients
treated exclusively with fixed appliances had a greater
PAR score reduction (77%) than those treated with func-
tional appliances or a combination of functional and
multibracket appliances (60% and 71%, respectively).
With respect to both duration and outcome, we
found that late treatment of Class II Division 1 maloc-
clusion (in the permanent dentition) was more efficient
than earlier treatment (in the early or late mixed
dentition). Furthermore, treatment with fixed appli-
ances was more efficient than treatment with removable
appliances.
REFERENCE
1. von Bremen J, Pancherz H. Efficiency of early and late Class II
Division 1 treatment. Am J Orthod Dentofacial Orthop 2002;
121:31-7.
Professor, Department of Orthodontics, University of Giessen, Germany.
Presented at the International Symposium on Early Orthodontic Treatment,
February 8-10, 2002; Phoenix, Ariz.
Am J Orthod Dentofacial Orthop 2002;121:559
Copyright © 2002 by the American Association of Orthodontists.
0889-5406/2002/$35.00 ϩ 0 8/1/124165
doi:10.1067/mod.2002.124165
559