Pancherz Analysis Research Articles

In-office distalizer as Motion Carriere versus Herbst appliance: a comparative study by superimpositions on 156 cases

Among the class II dental supported therapeutic devices, the Carriere Motion Appliance (Henri Schein) was introduced in 2004 followed by in-office adjustments. The objective of this study was to evaluate, by superimpositions, the dento-skeletal effects of the in-office distalizer (D) close to the Carriere Motion Appliance compared to the reference treatment: the Herbst appliance (B). A retrospective intention-to-treat study was conducted. Patients had to be in class II, 1 bilateral, have growth potential, two successive lateral cephalograms. The criteria evaluated were cephalometric, mainly from the Pancherz analysis. Statistical tests were performed with a threshold of 5%. Overall, 116 patients treated with D and multi-attachment appliance (MA) and 40 patients treated with B and MA were included. D and B slow maxillary advance, stimulate mandibular advance and correct the skeletal Class II. They normalize the molar class by distalizing the maxillary arch (palato-position of the maxillary incisors, retreat of the maxillary first molar) and by mesializing the mandibular arch (vestibulo-position and vestibulo-version of the mandibular incisors by 5 to 6°, advance of the mandibular first molar). They provide good control of facial divergence, but with a clockwise tilt of the occlusal plane. Randomized trials are needed to confirm our results. With similar adverse effects, the in-office distalizer may be an interesting alternative because of its smaller volume, comfort and easy manufacture.

Efficacy of invisible advancement correction for mandibular retraction in adolescents based on Pancherz analysis

Mandibular retraction is the main etiological mechanism of class II malocclusion in China and the subsequent distal molar relationship can cause functional discomfort in mastication, breathing and the temporomandibular joint. The use of mandibular advancement (MA) devices has recently emerged as an adolescent mandibular retraction treatment; however, current studies regarding the effect thereof are relatively few, and there is lack of sufficient clinical support. To investigate the clinical effect of invisalign MA on the treatment of mandibular retraction in adolescents. This study included 30 adolescent patients who underwent treatment with the MA appliances from December 2017 to June 2021. The lateral cephalometric data before and after treatment were collected and imported into Dolphin Imaging software. The changes were measured by linear measurement superimposed with lateral cephalometric trajectory based on the Pancherz technology. There was no significant difference in the length and position of maxilla before and after the treatment. The position of the mandible moved 3.13 mm, the length increased 4.14 mm, the mandibular ramus length increased 4.09 mm, the body length increased 4.25 mm, and the position of the condyle moved 1.03 mm forward after treatment. Additionally, changes in the incisor sagittal position and labial inclination were observed. The position of the upper incisor point moved back 1.33 mm, without statistical difference, the inclination and tooth angle decreased by 3.44° and 4.06°, respectively; the position of the lower incisor point was moved 2.98 mm, and the inclination and tooth angle increased by 2.62° and 1.23°, respectively. Furthermore, changes in the incisor overjet and molar relationship were seen. Overjet decreased by 4.31 mm, of which 1.78 mm was due to dental factors, accounting for 41.3% of the effect as opposed to 58.7% due to skeletal factors. Molar relationship improved 3.87 mm, with 1.34 mm due to dental factors, and dental and skeletal factors were accounted for 34.6% and 65.4% of the effect, respectively. For adolescent patients with mandible retraction, invisalign MA can effectively promote the mandible growth, and it was proven to be mainly due to skeletal effects.

Validity and reproducibility of a tripoding method in point registration-based 3D superimposition software compared to a conventional cephalometric method

Abstract Objective: The present study aimed to assess the validity and reproducibility of a tripoding reference method for digital study cast superimposition to measure maxillary tooth movement. Methods: This retrospective study used 30 treated orthodontic cases which required premolar extractions. Pre- and post-treatment cephalograms were conventionally superimposed, while digitised study casts were superimposed using point registration-based software (Materialise 3-matic Research 12.0) and a tripoding method. This method involved superimposing the digital study casts using the medial two-thirds of the third palatal rugae, and the bilateral depression of the greater palatine foramen as references. Incisor and molar orthodontic tooth movements in the vertical and horizontal planes were measured using the Pancherz analysis for cephalograms and Materialise 3-matic software for the digitised study casts. Validity and agreement were assessed by a paired t test and a Bland-Altman analysis while reproducibility was assessed by an intraclass correlation coefficient (ICC) and a paired t test. Clinical significance was set at 2 mm. Results: The paired t tests found no statistically significant differences (p > 0.05) in tooth movements between the cephalometric and digitised cast measurements, and between the same measurement methods. However, the Bland-Altman analysis showed the 95% limits of agreement were greater than 2 mm but less than 4.3 mm for all measurements. The ICC showed all measurements had good to excellent reproducibility. Conclusion: The tripoding method is a valid and reliable method to superimpose the maxillary study casts for measuring incisor and molar orthodontic movements but it is not interchangeable with the Pancherz analysis.

Sydney Magnoglide- Influence of magnetic forces for class II corrections - Preliminary results of a pilot study

Objective: To investigate the influence of magnetic forces on the skeletal and dentoalveolar effects for the correction of Class II malocclusion using the Sydney Magnoglide design with or without magnets. Study Design: An Inter university Prospective Randomized Controlled Clinical Trial Place & Duration of Study: Universities of Sydney and University of Queensland, Australia from March 2011 to August 2012. Methodology: Final sample size comprised of 12 subjects in Sydney magnoglide magnetic version at University of Sydney compared to 13 in the non-magnetic version at University of Queensland, Brisbane, Australia. A strict selection criteria was followed to ensure comparable groups hence the sample size. Lateral cephalograms were taken prior to treatment and immediately after functional correction. Pancherz analysis utilized. Comparisons performed with Student’s t-tests significance set at (P <0.05). Results: The two groups were fairly homogenous reducing the selection bias. Overall treatment was successful for all patients treated either with the magnetic or non-magnetic Sydney Magnoglide. Conclusion: Based on the statistical results and the limitations of the current study the non-magnetic and the magnetic Sydney Magnoglide appliance seem to be equally effective in this pilot study.

Comparison of Dentoskeletal Changes, Esthetic, and Functional Efficacy of Conventional and Novel Esthetic Twin Block Appliances among Class II Growing Patients: A Pilot Study.

A twin block appliance used for correction of skeletal Class II malocclusion suffers from undesirable dental effects and bulkiness. To overcome these limitations and the need for more esthetic appearance of this appliance, an esthetic twin block was designed and used in patients. This study aimed to compare dentoskeletal changes and esthetic and functional efficacy in patients treated with conventional and newly designed esthetic twin block (CTB and ETB) appliances using cephalometric measurements and a questionnaire. A pilot study with a 2-arm parallel-randomized double-blind clinical trial was conducted on 24 patients (20 males, 4 females) in the age group of 11-13 years. Subjects were treated with CTB (group 1 [G1]: n=12; mean age=11.67±0.49 years) and ETB (group 2 [G2]: n=12; mean age=11.75±0.62 years) appliances. A modified Pancherz analysis was performed to evaluate skeletal and dental changes. The esthetic and functional efficacy was evaluated by a questionnaire using Likert scale. Wilcoxon and Mann-Whitney U tests were employed for intra and intergroup comparisons respectively (p<0.05). In G1, a significant increase in lower incisor inclination was observed (p<0.05) whereas it was insignificant in G2. The changes were predominantly skeletal in G2 whereas they were both skeletal and dental in G1. ETB was found to be esthetically and functionally acceptable in all the patients while CTB patients were esthetically conscious, lacked confidence and had discomfort and difficulty in eating, chewing and speaking. ETB had greater skeletal effects with a reduced tendency of lower incisor proclination, was esthetically acceptable, and functionally more comfortable than the CTB.

Influence of Vertical Facial Growth Pattern on Herbst Appliance Effects in Prepubertal Patients: A Retrospective Controlled Study.

Introduction The Herbst device is widely used for correction of class II malocclusions; however, most of the researches carried out on the Herbst appliance in literature do not take into account patients with a different mandibular divergence. The aim of this study was to investigate the effects of Herbst on dental and skeletal structures and to evaluate possible influence of vertical facial growth patterns. Methods A retrospective study was conducted on lateral cephalograms of 75 growing patients (mean age: 9.9 ± 1.9 years) with class II malocclusion treated with Herbst. Subjects were divided into 3 groups using the mandibular divergence index (SN and GoMe angle). Cephalometric parameters were evaluated using the modified SO (sagittal occlusion) Pancherz's analysis. A statistical analysis was conducted to evaluate differences among groups using ANOVA. Results Our study showed differences in response to treatment depending on patient's facial vertical growth pattern. Cranial base angle and mandibular rotation were significantly different (p < 0.05) between hypodivergent patients and normodivergent patients and between hypodivergent and hyperdivergent subjects. Conclusion Hypodivergent patients increased their mandibular divergence during treatment to a greater extent than normodivergents; moreover, hyperdivergent patients exhibited a decreased mandibular divergence at the end of the treatment.

Effects of the Forsus Fatigue-resistant Device on Skeletal Class II Malocclusion Correction

To test the hypothesis that skeletal and dentoalveolar effects are both important in skeletal class II malocclusion corrected with the Forsus fatigue-resistant device (FRD). A total of 35 patients (16 females and 19 males; age 12.0 ± 0.6 years) with skeletal class II malocclusion treated with the Forsus FRD were included. Lateral cephalometric radiographies before and after treatment were collected. Cephalometric analysis and superimpositions were applied. Pancherz's analysis was performed to discover the skeletal and dentoalveolar effects on all patients and 60% contribution was set as a milestone to classify. Statistical comparisons were performed by paired t testing (p < 0.05). The mean treatment period of the Forsus FRD was 6.4 ± 0.2 months. All patients (AG) have been corrected to class I molar relationship in three mechanisms: 15 patients in the skeletal group (SG), 10 patients in the dentoalveolar group (DG), and 10 patients in the skeletal and dentoalveolar group (SDG). Four groups showed a significant change in skeletal sagittal relationship improvement (p < 0.05). The AG, SG, and SDG showed a significant improvement in the growth of the mandible (Co-Go, Go-Pog, and Co-Gn, p < 0.05). The DG showed a significant improvement in the growth of the mandibular body (Go-Pog, p < 0.05). Three mechanisms were found in skeletal class II malocclusion corrected with the Forsus FRD. Skeletal and dentoalveolar effects are both important in skeletal class II malocclusion corrected with the Forsus FRD. And skeletal and dentoalveolar effects played differential roles in different cases. The mechanism of skeletal class II correction with Forsus FRD may divide into mandibular growth, dentoalveolar effects, and both.

“Spontaneous” correction capacity of skeletal Class II malocclusions in growing patients after upper and lower arch coordination using fixed appliances: A prospective controlled clinical study

ObjectiveTo determine the effect of arch coordination on the dentoskeletal jaw base relationship and the mandibular growth pattern in growing skeletal Class II patients. Materials and MethodsLeveling, aligning, and upper/lower arch coordination were done in 30 Class II/1 growing patients with preadjusted edgewise fixed appliances. After arch coordination was achieved without transverse discrepancy and occlusal interferences, the 6-month experimental passive observation period was started. The records were compared with 30 untreated patients who served as controls. The initial (T0) and post-coordination+observation (T1) cephalograms of two groups were analyzed and compared using standard cephalometric parameters, Pancherz analysis, and cranial base superimposition. ResultsSagittal maxillary growth in the treated group was slightly restricted, in turn resulting in a decrease in profile convexity. Mandibular sagittal growth did not differ between groups, but the mandible rotated posteriorly in the treated and anteriorly in the control group. The upper incisors were retroclined and retruded in the treated group, resulting in overjet reduction. The lower incisors were intruded in the treated group, leading to overbite reduction. The cephalometric superimposition over the stable structures of the anterior cranial base showed higher prevalence for the forward rotation with forward pogonion position and increased vertical dimension in the control group. ConclusionsUpper and lower arch coordination alone does not seem to affect mandibular growth; however, because of a posterior rotation of the mandible, it does affect the direction of mandibular growth in some patients, although not in the desired therapeutic direction. (ClinicalTrials.in.th: TCTR20170706003).

Impact of force magnitude on effectiveness in cervical headgear therapy: a cephalometric analysis.

The main aim of this study was to study the impact of different force magnitudes on effectiveness in cervical headgear (CHG) therapy. Forty patients were treated with CHG with light (L; 300 g) or heavy (H; 500 g) force in this controlled clinical trial. Patients were asked to wear CHG for 10 hours/day for 10 months. The inner bow of the CHG was expanded (3-4 mm) and the long outer bow bent (10-20 degree) upward in relation to the inner bow. Adherence to instructions and force magnitude in CHG use was monitored by electronic module (Smartgear, Swissorthodontics, Switzerland). Lateral cephalograms were taken before (T1) and after (T2) the treatment and studied with modified Pancherz analysis using a Planmeca Romexis Ceph module (Planmeca, Finland). In both groups, skeletal and dental effects were seen. The only statistically significant difference in cephalometric analysis was the inclination of upper incisors at T1 (P = 0.010) and at T2 (P = 0.011). In both groups, a reduction in Sella-Nasion- point A (SNA) angle was found: L group T1 82.7degree (SD ± 3.6degree), T2 82.0degree (SD ± 3.5 degree) and H group T1 82.6 degree (SD ± 4.7 degree), T2 81.5 degree (SD ± 4.5 degree), but no statistically significant difference between the groups. Children in the L group used CHG statistically significantly more than those in the H group (10.0 ± 1.5 hour, and 8.3 ± 2.1 hour, respectively, P = 0.002). Children with lower force CHG seem to adhere better to instructions for CHG use. After 10 months of use, no statistically significant differences were found in dental or skeletal outcome. However, in the H group, the outcome was achieved with less daily hours of use.

Evaluation of Skeletal and Dental Effects of Modified Jasper Jumper Appliance and Delaire Face Mask with Pancherz Analysis.

The aim of this study was to evaluate the skeletal and dental changes in Class III patients treated with Modified Jasper Jumper appliance and Delaire face mask before the growth peak. A study sample comprising 16 patients with functional Class III malocclusion treated with Modified Jasper Jumper appliance and 17 patients treated with Delaire face mask was compared with a control group comprising 13 patients. Pancherz analysis was used as the analysis method. In both treatment groups forward movement of maxillary base and incisors and an increase in the overjet while no positional change in the mandibular base was observed. In the Modified Jasper Jumper group, 4.63 mm overjet correction was due to 51.4% skeletal and 48.6% dental changes; 4.77 mm Class III molar correction was due to 49.9% skeletal and 50.1% dental changes. In the Delaire face mask group, 5.17 mm overjet correction was due to 70.6% skeletal and 29.4% dental changes and 4.87 mm Class III molar correction was due to 75% skeletal and 25% dental changes. It was shown that both appliances were skeletally and dentally effective. Therefore, Modified Jasper Jumper therapy may be an alternative treatment modality for patients with poor cooperation, who are not ideal recipients for Delaire face mask.

Comparison of efficacy between modified forsus appliance and activator appliance in the treatment of class II patients with madibular retrusion

Objective To evaluate and analyze the effects between with modified Forsus appliance and activator in the treatment of class Ⅱ madibular retrusion.Methods 70 children with class Ⅱ malocclusion and mandibular retrusion were selected and divided into two groups:35 patients treated with this modified Forsus appliance (group A) and other 35 treated with activator (group B).Cephalometric radiographs were taken and analyzed at the pre-treatment time (T0) and the post-treatment time (T1) with the Pancherz analysis.Results The course of treatment was obviously different:the course of group A was (21.4±2.0) months,and group B was (27.3±2.5) months; the treatment course of group A was shorter than that of group B.After treatment,profiles of the two groups were obviously improved.The trends were similar in overjet and the molar relationship,SNB and ANB,with significant differences.But there was no significant difference between the results of the two groups.The change of occlusal plane was notably in group B.Conclusions Both the modified Forsus appliance and activator appliance combined with straight wire appliance can effectively stimulate the mandibular growth,balance the jaw relationship,and correct the class Ⅱ mandibular retrusion.But the modified Forsus appliance can effectively treat the class Ⅱ patients with the shorter course.And the same time,it can take effect continually without depending on the coordination of the patients. Key words: Forsus appliance; Activator; Pancherz analysis; Mandibular retrusion

Skeletal and dental outcomes of a new magnetic functional appliance, the Sydney Magnoglide, in Class II correction

The purpose of this prospective study was to evaluate the dentoskeletal effects of a new magnetic functional appliance, the Sydney Magnoglide (Macono Orthodontic Lab, Sydney, Australia), after both active treatment with the appliance and comprehensive fixed appliance therapy, compared with a group of untreated Class II controls. Thirty-four consecutively treated Class II Division 1 patients treated with the Sydney Magnoglide followed by fixed appliances were compared with 30 untreated Class II controls with the same initial dentoskeletal Class II features and matched for age and sex. Lateral cephalograms were taken before treatment, immediately after functional appliance therapy, and after comprehensive fixed appliance therapy. Cephalometric analyses included the Pancherz analysis and linear and angular measurements. The comparisons were made with Student t tests (P<0.05). There were 3 dropouts, for a final sample for statistical analysis of 31 subjects. There was no statistically significant difference between the treated and control groups before treatment. Treatment with the Sydney Magnoglide and comprehensive fixed appliance therapy normalized the overjet and corrected the Class II relationship in all treated subjects. The ANB angle showed a reduction of 1.0°, as opposed to an increase of 0.3° in the untreated controls, and was associated with a statically significant improvement in the SNB angle (P<0.05). There was a significant gain of 2.3 mm in mandibular length in the treated group compared with the control group (P<0.01). The outcomes of this prospective study demonstrate that the compliance-free Sydney Magnoglide is an effective functional appliance for Class II correction.

Comparison of sagittal and vertical dental changes during first phase of orthodontic treatment with MBT vs ROTH prescription

The present study was to evaluate and compare anchorage loss in sagittal, vertical dimension in incisal, molar segments and distal tipping of upper canine after first phase of orthodontic mechanotherapy utilizing MBT and ROTH philosophies. Thirty patients with class I dentoalveolar malocclusion requiring extraction of all first premolars were randomly assigned into group I and group II. Set of two lateral cephalograms (T1) and (T2) were obtained with appliance in place and after sufficient leveling and aligning respectively. Linear measurements were recorded on the tracings using Pancherz analysis. A Wilcoxon t-test was use to assess the linear changes. In group I sample, upper and lower incisors retroclined during T1 - T2; by mean (SD) value of 2.267 (1.0032) mm, 2.4 (0.98) mm, respectively. Group II sample showed upper incisor proclination by -0.4 (1.404) and lower incisal retroclination by 0.06 (1.48). Upper and lower molars in group I remained stationary and group II upper and lower molars moved mesially by -1.133 (0.351) and -0.002 (0.005). In group I, upper and lower incisors extruded by -0.867 (0.611) and -0.67 (0.703), respectively, and group II the upper and lower incisors extruded by -0.9 (0.507) and -0.133 (0.639). Upper canine tipped distally during T1 - T2 in group I by -0.33° (2.609) and group II there was a change in distal tip of upper canine by -3° (3.184). Results from this random clinical trial showed that MBT technique effectively addressed perceived inadequacies of ROTH philosophy.

La contention est-elle justifiée après traitement interceptif de classe II ?

Indication of intermediate retention after early treatment of class II malocclusion has not been yet assessed by comparative studies. Therefore, it is up to the practitioner to analyse the need for retention in the time period between the two phases. Does wearing a retainer indeed decrease the chance of relapse between phase one and phase two? We performed a retrospective comparative study consisting of 90 subjects in mixed dentition with class II molar relationships with an increased overjet (> or = 5 mm) treated in the J.-J. Aknin office with DAC appliance. The sample was divided into two groups: 31 patients wearing retention represented by a removable Hawley plate and 59 children in supervision without retention. Three lateral head-films were made at the beginning and the end of early treatment and before the resumption of the second phase treatment. Studied cephalometrics parameters were assessed according to superimposing Pancherz's analysis. A statistical analysis was performed. Results showed a significantly lower relapse of incisor's protrusion in the group wearing an upper retainer. Results' interpretation was in accordance with the assessment of confusion's factors and selection's criteria. Besides, this study was carried out in intention-to-treat and retention's effectiveness in proportion with patient's compliance. Nevertheless, the study was performed in real conditions. In conclusion, and without randomised trial, results show that retention seems to decrease maxillary incisor movements. It is therefore justified in cases presenting with important class II especially with procumbent incisors.

Comparison of Protraction Facemask Response Using Banded and Bonded Expansion Appliances as Anchorage

Protraction headgear has been used in combination with various fixed appliances as anchorage to correct Class III malocclusions with maxillary deficiency. The objective of this study was to compare the treatment response of maxillary protraction in combination with either the banded or the bonded rapid palatal expansion appliance. The sample consisted of pre- and posttreatment cephalometric radiographs of 20 patients treated with the banded expansion appliance, 20 patients treated with the bonded expansion appliance, and 20 control patients with no treatment who were matched in sex, age, and skeletal morphology. The average treatment time for the bonded group was 10 ± 2.1 months and the banded group was 9.5 ± 1.9 months. Traditional cephalometric measurements as well as the Pancherz analysis were used to describe the dental and skeletal changes in response to treatment. Data were analyzed using the analysis of variance (ANOVA) and paired <i>t</i> test. There were no significant differences in the forward movement of the maxilla between the banded and bonded expansion groups. The forward movement of the maxilla was 1.0 mm and 1.7 mm greater than in the control group, respectively. The full coverage of the occlusal surface by acrylic did not increase the efficiency of forward maxillary movement. Loss of anchorage was found in both treatment groups. The skeletal and dental contributions to the correction of overjet and overbite were quite similar in the two treatment groups. Maxillary expansion and protraction was accompanied by vertical displacement of the maxilla, increase in lower face height, and vertical eruption of posterior molars, irrespective of the type of anchorage appliance.

Lower second molar extraction in correction of severe skeletal class III malocclusion.

The purpose of this study was to evaluate dentoskeletal and soft-tissue profile changes after extraction of lower second molars and treatment using the Tip-Edge technique in severe Class III subjects. Thirteen patients with severe skeletal Class III malocclusion (four males, nine females), diagnosed as requiring orthognathic surgery, but who rejected surgical therapy, were included in the study. The average age was 13.2 +/- 0.8 years. Lateral cephalometric films taken at the beginning and the end of treatment were analyzed using the Pancherz analysis and a traditional cephalometric analysis. The arithmetic mean and standard deviation were calculated for each variable. Paired t-test was performed to evaluate significant treatment change. After active treatment, dramatic overjet change was noted, with an average value of 5.5 mm (P < .001). Inclination of lower incisors was decreased 12.0 degrees when measured to the mandibular plane (P < .001). Inclination of upper incisors was increased by 2.1 degrees to the SN plane (P > .05). A negative value of the distance between upper and lower lip position to Sn-Pg' at the beginning of treatment changed to a positive value (P < .001). The results of this preliminary study suggest that success in the treatment of some severe Class III deformity in the permanent dentition can be achieved with fixed appliances and extraction of lower second molars. A remarkable soft-tissue change was noted after the treatment, and concave facial profiles changed to straight profiles.

Preliminary investigation of nonsurgical treatment of severe skeletal Class III malocclusion in the permanent dentition.

The purpose of the study was to analyze the effects of nonsurgical treatment on subjects with a severe skeletal Class III deformity and to directly evaluate dental and facial profile changes. Eighteen patients with severe skeletal Class III malocclusions (5 males, 13 females), diagnosed as indication for orthognathic surgery, were included in the study. The average age was 13.7 +/- 2.5 years. All the cases were treated with Tip-Edge straight-wire technique or Begg light wire technique. Lateral cephalometric films taken at the beginning and at the end of treatment were analyzed with the Pancherz analysis and traditional cephalometric analysis. The arithmetic mean and standard deviation were calculated for each variable and paired t-test was performed. A mean reduction of 6.5 mm in the overjet was noted (P < .001), with skeletal changes and dental changes contributing 20% and 80% to the overjet correction, respectively. The inclination of the upper incisors to the SN plane was increased 5.9 degrees (P < .01). The inclination of the lower incisors to the mandibular plane was decreased 6.6 degrees (P < .001). The difference between the distance of the upper lip and lower lip to Sn-Pg' at the beginning of treatment changed from a negative value to a positive value with a significant difference (P < .001). Successful treatment effects can be obtained with nonsurgical therapy in severe skeletal Class III malocclusions in the permanent dentition. A remarkable soft tissue change was noted after the treatment, and the concave facial profile changed to a straight profile (see two case reports).

Treatment effects of simple fixed appliance and reverse headgear in correction of anterior crossbites

The aim of this study was to compare the skeletal and dental changes contributing to the correction of Class III malocclusion using a 2 × 4 appliance and reverse headgear in the mixed dentition. Seventeen consecutive patients (mean age, 9.7 years) with pseudo-Class III malocclusions and an anterior functional shift and straight or concave facial profile were treated with a simple fixed appliance. Another 20 consecutive patients (mean age, 8.5 years) with Class III incisor relationship and straight or concave facial profiles, were treated with reverse headgear. Lateral cephalometric films taken at the beginning of treatment, the end of the treatment, and 1 year after the active treatment, were analyzed with the modified Pancherz analysis. After active treatment, the overjet correction, 5.2 mm and 6.5 mm on average, respectively, were achieved using the 2 × 4 and reverse headgear. The overjet correction by the 2 × 4 appliance was due to dental changes only. In the reverse headgear group, 60% of the overjet correction was due to dental changes and 40% due to skeletal changes. During the 12 months follow-up period, the overjet was unchanged in the 2 × 4 group (1.6 mm) and decreased in the reverse headgear group, the difference being statistically significant ( P < .05). The change of jaw relationship was similar between the 2 × 4 and reverse headgear groups. During the follow-up period, a decrease in overjet in the reverse headgear group was mainly due to forward growth of the mandible and proclination of lower incisors. The overjet in the 2 × 4 group was unchanged due to dental compensation (1.6 mm). To conclude there was a similar amount of overjet correction in the 2 × 4 and reverse headgear groups. Overjet correction by the simple fixed appliance was produced by dental changes whereas in the reverse headgear group, it was produced by both dental and skeletal changes. (Am J Orthod Dentofacial Orthop 2000;117:691-9)