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OBJECTIVE: To compare treatment outcomes of growing and nongrowing Class II patients characterized by mandibular retrusion and increased vertical dimension. MATERIALS AND METHODS: Seventeen patients (mean age 9 years 5 months) were treated with a Bionator fabricated with posterior bite block and high-pull headgear, while 15 patients (mean age 23 years 6 months) received Le Fort I osteotomy for maxillary impaction and mandibular advancement. These groups were compared with 17 nontreated control subjects from the Bolton and Michigan growth studies. Lateral cephalograms taken for the functional group at T1 (initial records), T2 (completion of functional appliance treatment), and T3 (completion of comprehensive treatment) were compared with radiographs taken at T1 (initial records), T2 (immediate post surgery), and T3 (1 year post surgery) for the surgical patients. A null hypothesis of no difference in treatment outcomes between the functional and surgical groups was proposed. A mixed-design analysis of variance was used to compare changes within and between groups. Significance was set at P ≤ .002. RESULTS: In the functional appliance group, the mandible showed a more favorable growth direction and rotation. Both groups had stable results over time and finished treatment with similar cephalometric measurements. CONCLUSION: Both the functional appliances and orthognathic surgery resulted in similar dentoskeletal treatment changes. The control groups did not self correct either in the anteroposterior or vertical dimensions.

The SPEED appliance (Strite Industries Ltd., 298 Shepherd Ave., Cambridge, Ontario, N3C 1V1 Canada), invented by Dr. G. Herbert Hanson in the early 1970s, is a miniaturized self-ligating bracket with an active spring clip. This fully preadjusted edgewise appliance, which is available in both 0.018″ and 0.022″ slot size, has been in clinical use since 1977 and commercially available since 1980. During the past 25 years, the SPEED design has been highly refined. Refinements include the incorporation of a superelastic nickel titanium spring clip for greater precision of tooth movement throughout treatment, a "labial window" that enhances ease of opening the spring clip, and a horizontal auxiliary slot in the bracket body that facilitates segmental archwire mechanics. Although the SPEED bracket is compatible with virtually any archwire selection, specific archwires have been designed to fully exploit SPEED's inherent benefits. These include Supercable (Strite Industries Ltd.), a seven-stranded coaxial nickel titanium archwire, Hills Dual-Geometry archwire (Strite Industries Ltd.), and SPEED archwires. Whether traditional or specialty archwires are used, SPEED, with its highly flexible spring clip, creates a unique mechanical system that is ideally suited for ultra-precise orthodontic tooth movement.

Purpose: The objective of this study was to compare the treatment outcomes and stability of patients with Class II malocclusion treated with either functional appliances or surgical mandibular advancement. Material: The early-treatment group consisted of 30 patients (15 girls, 15 boys), with a mean age of 10 years 4 months (range, 7 years 5 months to 12 years 5 months), who received either Frankel II (15 patients) or Herbst appliances (15 patients). The surgical group consisted of 30 patients (23 female, 7 male), with a mean age of 27 years 2 months (range, 13 years 0 months to 53 years 10 months). They were treated with bilateral sagittal split ramus osteotomies with rigid fixation. Lateral cephalograms were taken for the early-treatment group at T1 (initial records), T2 (completion of functional appliance treatment), and Tf (completion of comprehensive treatment). In the surgical group, lateral cephalograms were taken at T1 (initial records), T2 (presurgery), T3 (postsurgery), and Tf (completion of comprehensive treatment). The average times from the completion of functional appliance treatment or surgery to the final cephalograms were 35.8 months and 34.9 months, respectively. A mixed-design analysis of variance was used to compare changes within and between groups. Results: In the functional appliance group, the mandible continued to grow in a favorable direction even after discontinuation of the functional appliance. Both groups had stable results over time. Both groups finished treatment with the same cephalometric measurements. Significant skeletal and soft tissue changes were noted in the treatment groups due to either functional or surgical advancement of the mandible. More vertical relapse was noted in the surgical group than in the functional group. Conclusions: This study suggests that early correction of Class II dentoskeletal malocclusions with functional appliances yields favorable results without the possible deleterious effects of surgery.

The mandibular anterior repositioning appliance (MARA) is a tooth-borne functional appliance for use in patients with Class II malocclusions; it positions the mandible forward into a Class I occlusion. The aim of this study was to investigate the MARA's dental and skeletal effects on anterior, posterior, and vertical changes in 30 Class II patients. The treatment group consisted of 12 boys with an average age of 11.2 years and 18 girls with an average age of 11.3 years. A pretreatment cephalometric radiograph was taken 2 weeks before treatment, and a posttreatment cephalometric radiograph was taken 6 weeks after removal of the MARA, with an average treatment time of 10.7 months. The mean and standard deviation were calculated for each cephalometric variable, and Student t tests were performed to determine the statistical significance of the changes. The results of the study showed that the MARA produced measurable treatment effects on the skeletal and dental elements of the craniofacial complex. These effects included a considerable distalization of the maxillary molar, a measurable forward movement of the mandibular molar and incisor, a significant increase in mandibular length, and an increase in posterior face height. The effects of the MARA treatment were then compared with those of the Herbst and Fränkel appliances. The treatment results of the MARA were very similar to those produced by the Herbst appliance but with less headgear effect on the maxilla and less mandibular incisor proclination than observed in the Herbst treatment group.

The aim of this study was to evaluate the reliability of crown and root length, crown-root ratio and angular measurements of teeth relative to constructed reference lines and to other teeth in the same region on consecutive (T1 and T2) panoramic radiographs (OPGs). This retrospective study employed 20 cases; ten with five implants in each jaw (age range between 20 and 60 years) and ten with a full permanent dentition (age range between 12 and 16 years). The consecutive pairs of OPGs ranged from 6 months to 3 years apart. Four variables were measured and compared: 1) the crown or coronal segment length and the root or apical segment length; 2) the crown-root ratio; 3) the angulations of teeth and implants relative to specific reference lines in each jaw; 4) the angle between teeth and implants in the same sextant. The results revealed that comparisons of measurements taken of the same structures at T1 and T2, there were no statistically significant differences (p>0.05) between vertical linear measurements. The crown-root ratios and coronal-apical segment ratios too, showed no significant differences (p>0.05). Whereas, angulations of teeth or implants relative to respective reference lines showed significant differences (p=0.001) for some of the teeth. These differences, however, were less than 5 degrees; a clinically acceptable range. Angles measured between teeth or implants in the same sextant showed no significant differences (p>0.05). These results seem to support the hypothesis, therefore, that the linear vertical measurements, ratio calculations and angular measurements can be used to compare crown and root lengths, crown-root ratios and tooth angulations on OPGs taken of the same patient at different times with consistent accuracy.

Although many improvements have been made in orthodontic surgical procedures for mandibular retrognathism, relapse continues to occur. This study was designed to compare the stability of rigid and nonrigid fixation between 2 groups of patients who had undergone mandibular advancement surgery via sagittal split ramus osteotomy. Retrospective cephalometric measurements were made on 54 randomly selected orthognathic surgical patients. The patients, 7 males and 47 females, were divided into 2 groups: 28 patients stabilized by means of rigid fixation and 26 patients fixated with interosseous wires. The age of the patients ranged from 15.3 to 49.7 years. Lateral cephalograms were used to evaluate each patient at 3 distinct intervals: 7.0 ± 2.0 days before surgery (T1), 34.4 ± 15.0 days postsurgery (T2), and 458 ± 202 days after sagittal split osteotomy (T3). Eighteen linear and angular measurements were recorded and differences between the 3 time periods were evaluated. Statistical analyses were performed to assess the differences in the 2 fixation types between and within each group at different time intervals. The following measurements showed statistically significant skeletal relapse over time, for the P value.0028: Co-Go, ANS-Xi-Pm, IMPA, overbite, and overjet. The remaining variables showed no statistically significant relapse. The only measurement that showed a statistically significant group difference between T1 and T2 was DC-Xi-Pm. Results of the study led to the following conclusions: there was statistically significant relapse in mandibular length, lower anterior face height, mandibular arc, lower incisor inclination, overbite, and overjet in each group, regardless of the type of fixation. The potential was greater for relapse in patients stabilized with transosseous wiring. Although multifactorial, relapse in overbite and overjet may be a combination of skeletal and dental changes. (Am J Orthod Dentofacial Orthop 2000;118:397-403).

The increased use of self-ligating bracket systems frequently raises the question of how they compare with conventional ligation systems. An in vitro and clinical investigation was undertaken to evaluate and compare these distinctly different groups, by using five different brackets. The Activa ("A" Company, Johnson & Johnson, San Diego, Calif.), Edgelok (Ormco, Glendora, Calif.), and SPEED (Strite Industries Ltd., Cambridge, Ontario) self-ligating bracket systems displayed a significantly lower level of frictional resistance, dramatically less chairtime for arch wire removal and insertion, and promoted improved infection control, when compared with polyurethane elastomeric and stainless steel tie wire ligation for ceramic and metal twin brackets.

Since its inception in 1975, the SPEED appliance has undergone many significant design improvements. This article is intended to describe the various integral components of the SPEED appliance and review the function of each.

OBJECTIVE: To determine if the long-term dentoskeletal changes in patients treated with tooth-borne functional appliances were comparable to each other and to matched controls. MATERIALS AND METHODS: The experimental sample consisted of 80 consecutively treated patients who were equally divided into Bionator, Herbst, Twin Block, and mandibular anterior repositioning appliance (MARA) groups. The control group comprised 21 children with untreated skeletal Class II malocclusions. Lateral cephalograms were taken for the treated group at T(1) (initial records), T(2) (completion of functional therapy), and T(3) (completion of fixed appliance therapy). A repeated measure analysis of variance (ANOVA) was used to assess the differences between and within groups. If ANOVA results were significant, Tukey-Kramer tests were used to determine where the significant differences occurred. RESULTS: (1) Temporary restriction of maxillary growth was found in the MARA group (T(2)–T(1)). (2) SNB increased more with the Twin Block and Herbst groups when compared with the Bionator and MARA groups. (3) The occlusal plane significantly changed in the Herbst and Twin Block groups. (4) The Twin Block group expressed better control of the vertical dimension. (5) The overbite, overjet, and Wits appraisal decreased significantly with all of the appliances. (6) The Twin Block group had significant flaring of the lower incisors at the end of treatment. (7) Over the long-term, there were no significant soft tissue changes among treated and untreated subjects. CONCLUSIONS: No significant dentoskeletal differences were observed long-term, among the various treatment groups and matched controls.

Introduction The aim of this retrospective cephalometric study was 3-fold: (1) to compare the effects and long-term stability of protraction facemask treatment with untreated Class III controls, (2) to compare the long-term stability of early protraction facemask treatment with later surgical maxillary advancement with LeFort I osteotomy, and (3) to determine whether early intervention with protraction facemask is an effective treatment modality or whether surgical treatment after cessation of growth should be advocated. Materials The sample consisted of 34 consecutively treated white patients with Class III malocclusions characterized by maxillary deficiency. The protraction sample consisted of 17 children (8 boys, 9 girls). The surgical sample consisted of 17 adults (10 men, 7 women). The protraction group was also compared with a control group of white subjects with untreated Class III malocclusions. Lateral cephalograms were taken at T1 (initial records), T2 (end of functional appliance treatment or 2 weeks postsurgery), and T3 (7 years 6 months postprotraction or 1 year 5 months postsurgery). Means and standard deviations were calculated for descriptive cephalometric measurements. ANOVA was used to assess the differences between and within the protraction and surgery groups at T1, T2, and T3. The Tukey studentized range test was performed to determine the source of the difference. In addition, paired t tests were used to compare the differences between the protraction group and the matched controls as well as between the surgery group and the matched controls. Results In the protraction group, there was continued favorable growth of the maxilla, even after the removal of the protraction facemask. From T2 to T3, the maxilla continued to move anteriorly in the protraction patients more so than in the control groups, which had decreases in the intermaxillary measurements (ANB angle and Wits appraisal) over time. The surgical group remained stable from T2 to T3 in all measurements studied. Conclusions The most striking findings of this study were the general similarity between the protraction and the surgical groups at T3 and the overall stability of both treatment modalities over time.

Combined orthodontic and surgical treatment of severe Class II dentoskeletal deformities with the use of the bilateral sagittal split ramus osteotomy is a routine procedure in orthodontic practices. However, an alternative surgical technique, the total mandibular subapical alveolar osteotomy, could be used for the same purpose. The aim of this investigation was to compare the stability of the sagittal split ramus osteotomy with the total mandibular subapical alveolar osteotomy in the correction of dentoskeletal Class II malocclusions. Forty patients that exhibited Class II dentoskeletal relationships were included in the study. Twenty of these patients had mandibular advancement with the sagittal split ramus osteotomy; the remaining 20 patients had advancement of the whole lower alveolar segment with the total mandibular subapical alveolar osteotomy. The cephalograms studied were taken before the surgical procedure (T1 = 4 weeks before operation), immediately after the procedure (T2 = 10 days after surgery), and 1 year later (T3). The statistical analysis used to assess the results between and within the groups over the different time periods was the analysis of variance. The regression analysis was used to test the interdependence of soft tissue response to hard tissue movement. The results of this study show that both procedures are equally stable when correcting Class II malocclusions. This was proved by the stability of the correction of overjet, B point, and incisor-mandibular plane angle. There were no statistically significant differences between or within the groups in the position of these landmarks over time. There was a statistically significant change in the position of pogonion from T1 to T2 (P

Previous studies on the effects of surgical and rapid palatal expansion have been largely based on general skeletal and dental findings ascertained from radiographs and casts. The aim of this study was to measure and compare the soft tissue changes of the face during the expansion process and to determine the stability of any changes 1 year later. The sample consisted of 44 patients with unilateral or bilateral posterior crossbites. Twenty-four of the patients required a surgically assisted expansion procedure, and a second group of 20 patients were treated with orthopedic expansion. Ten measurements were made from standardized frontal facial photographic slides at 5 intervals of treatment: initial, bond appliance, stop expansion, debond appliance, and 1 year retention. Differences over time between the surgical and nonsurgical groups were analyzed by a 2 way multivariate analysis of variance (MANOVA) and post hoc t tests. Differences between initial and 1 year retention were found in the nasal widths (P < .001) of both surgical and nonsurgical groups. Other significant changes and trends were discussed. (Am J Orthod Dentofacial Orthop 1999;116:563-71)

At the present time no reports are available on the stability between orthopedic and surgically assisted rapid palatal expansion. This study was designed to examine and compare the dental and skeletal changes over time for both orthopedic maxillary expansion and surgically assisted palatal expansion. The study was divided into two groups. Group one was orthopedically expanded and consisted of 14 males and 10 females. The ages ranged from 6 years to 12 years with a mean of 8.5 years. Group two received surgically assisted rapid palatal expansion and consisted of 12 males and 16 females with ages ranging from 13 years to 35 years and a mean age of 19.25 years. All 52 subjects were white, from the same geographic area, and were treated by the same two operators. Dental models and posterior anterior cephalograms were obtained immediately before and after expansion, at removal of the expansion device, and 1 year after removal of the appliance. A repeated measures analysis of variance test was applied to assess changes over time between groups. The surgical and nonsurgical techniques displayed similar trends over time although the surgical group contained a greater quantity of expansion. Both the orthopedic and the surgical groups showed stable results.

Forty patients with Class III maxillary deficiencies were each treated with a bonded maxillary palatal expansion appliance followed by protraction. Nineteen of the 40 patients were retained with a Frankel III appliance. This group was compared with 24 Class I patients treated solely with bonded expansion appliance mechanotherapy. To determine at which level protraction mechanics affects the maxilla, the Walker's analysis and other cephalometric measurements were used. The protraction group showed significant increases (p

In the SPEED bracket system the arch wire is retained in the arch wire slot by means of a built-in, escape-proof, flexible spring clip. Unlike the traditional edgewise bracket, it requires no ligature tie, thus ostensibly reducing the frictional force generated by the more-established elastomeric or steel-tie ligature systems. An in vitro study was designed to compare the level of force required to move four distinct arch wires a similar distance, on six occasions, through four ligated bracket systems and the self-ligated SPEED bracket. The results consistently demonstrated a significant decrease in the force level required for the SPEED bracket with all four arch wires when compared with elastomeric and steel-tie ligation in both metal and plastic bracket systems.