eruption pattern, with sensitivity and specificity of 96.7% and82.35%, respectively. Ratio was the next best predictor, withsensitivity and specificity of 83.87% and 70.59%, respec-tively. Palatal plane angle, midsagittal plane distance, andorbital plane angle showed no statistically significant relation-ship to unerupted canine locaction.

0889-5406/2003/$30.00 � 0doi:10.1067/mod.2003.36

Shear bond strength of a self-etchingprimer in the bonding of orthodonticbracketsTanya N. PaskowskySchool of Dentistry, West Virginia University, Morgantown

Currently, most dental bonding procedures involve 3steps: acid etching, priming, and applying an adhesive resin.Recently, developments have been made in bonding systemsby combining the acid etch and the primer into 1 solution toeliminate a step in the bonding process. The purpose of thisstudy was to evaluate the effectiveness of a new self-etchingprimer (SEP). This was accomplished by using an in vitro testto compare shear bond strengths between the SEP andconventional bonding methods, and an in vivo test to comparebond failure rates between methods in orthodontic patients. Inthe in vitro study, 30 extracted human premolars were bondedwith Transbond SEP, and 30 premolars were bonded conven-tionally with Transbond XT. Shear bond strengths wereevaluated and compared with the Student t test. In the in vivostudy, brackets were bonded in 13 consecutive patients byusing a split-mouth protocol. Bond failure rates betweenmethods were compared over an 8-month period with thechi-square test. The in vitro findings showed no differencesbetween groups (P � .20). Brackets bonded with the SEP hadshear bond strengths of 8.43 � 2.81 MPa, and bracketsbonded with the XT had shear bond strengths of 8.70 � 2.10MPa. There was also no significant difference between bondingmethods in the failure rate of brackets in orthodontic patients.

0889-5406/2003/$30.00 � 0doi:10.1067/mod.2003.37

Treatment effects of the edgewiseHerbst appliance: a cephalometric andtomographic investigationRyan Van Laecken, Peter Ngan, Terry Dischinger,Mark Durkee, Chris Martin, and Thomas RazmusDepartment of Orthodontics, West Virginia University, Morgantown

The aim of this retrospective study was to identify thecontributions of skeletal and dental changes in the correctionof subjects with a Class II malocclusion treated with theedgewise Herbst appliance. This study included 32 subjects(18 females and 14 males) treated with the edgewise Herbstappliance by an author (T.D.). These patients were comparedwith a control group obtained from the Bolton-Brush Study atCase Western Reserve University. Cephalometric measure-ments were made on the radiographs taken at pretreatment(T1), posttreatment (T2), and 16 months after the removal ofthe Herbst appliance (T3). The position of the condylerelative to the glenoid fossa was determined by using hori-zontally corrected axis tomograms taken at T1 and T2. Datawere analyzed with ANOVA, Tukey-Kramer multiple com-parison tests, and a 2-tailed t test. After 8 months of treatmentwith the Herbst appliance (T1-T2), the overjet was improvedby 8.4 mm compared with the control group. This wascontributed by a restraint in forward movement of the maxillaat Point A by 1.4 mm and an increase in forward movementof the mandible by 1.7 mm compared with the control group.The maxillary incisors were moved lingually 1.7 mm, and themandibular incisors were proclined 3.6 mm compared withthe control group. The molar relationship was found to besuper Class I or Class III at the end of the Herbst treatment.In the vertical plane, the mandibular incisors were intruded1.7 mm, the occlusal plane was tipped clockwise 5.2°, and themandibular plane was unchanged compared with the controlgroup. At T2, the tomograms showed only 0.2 mm of forwardmovement of the condyle within the fossa after the Herbsttreatment. Sixteen months after the removal of the Herbstappliance (T2-T3), the maxilla was found to move forward1.2 mm, and the mandible relapsed backward 0.7 mmcompared with the control group. The maxillary incisorsmoved labially 1.7 mm, and the mandibular incisors movedlingually 3.3 mm compared with the control group. Verti-cally, the occlusal plane was tipped 3.2° counterclockwise,and the mandibular plane was unchanged. The net treatmenteffects (T1-T3) were a backward movement of the maxilla by1.3 mm, forward movement of the mandible by 1.0 mm,lingual movement of the maxillary incisors by 0.2 mm, andlabial movement of the mandibular incisors by 0.2 mmcompared with the control group. The net overjet correctionwas 2.7 mm compared with the control group, and 85% wascontributed by skeletal correction. These results suggest thatboth skeletal and dental changes contribute to Class IItreatment with the Herbst appliance, and the minimal changein the condylar position relative to the fossa suggests acombination of fossa remodeling and redirection of condylargrowth after Herbst treatment.

0889-5406/2003/$30.00 � 0doi:10.1067/mod.2003.40

All inquiries regarding information on reviews and abstracts should be directed to the respective authors. Forordering books, contact your local bookstore or write directly to the publishers. Articles or books for reviewin this department should be addressed to Dr Alex Jacobson, University of Alabama School of Dentistry,University Station, Birmingham, AL 35295.

American Journal of Orthodontics and Dentofacial OrthopedicsVolume 123, Number 1

Reviews and Abstracts 101