Three-dimensional analysis of maxillary protraction with intermaxillary elastics to miniplates.

INTRODUCTION: Early Class III treatment with reverse-pull headgear generally results in maxillary skeletal protraction but is frequently also accompanied by unfavorable dentoalveolar effects. An alternative treatment with intermaxillary elastics from a temporary anchorage device might permit equivalent favorable skeletal changes without the unwanted dentoalveolar effects. METHODS: Six consecutive patients (3 boys, 3 girls; ages, 10-13 years 3 months) with Class III occlusion and maxillary deficiency were treated by using intermaxillary elastics to titanium miniplates. Cone-beam computed tomography scans taken before and after treatment were used to create 3-dimensional volumetric models that were superimposed on nongrowing structures in the anterior cranial base to determine anatomic changes during treatment. RESULTS: The effect of the intermaxillary elastic forces was throughout the nasomaxillary structures. All 6 patients showed improvements in the skeletal relationship, primarily through maxillary advancement with little effect on the dentoalveolar units or change in mandibular position. CONCLUSIONS: The use of intermaxillary forces applied to temporary anchorage devices appears to be a promising treatment method.

Superimposition of 3-dimensional cone-beam computed tomography models of growing patients.

INTRODUCTION: The objective of this study was to evaluate a new method for superimposition of 3-dimensional (3D) models of growing subjects. METHODS: Cone-beam computed tomography scans were taken before and after Class III malocclusion orthopedic treatment with miniplates. Three observers independently constructed 18 3D virtual surface models from cone-beam computed tomography scans of 3 patients. Separate 3D models were constructed for soft-tissue, cranial base, maxillary, and mandibular surfaces. The anterior cranial fossa was used to register the 3D models of before and after treatment (about 1 year of follow-up). RESULTS: Three-dimensional overlays of superimposed models and 3D color-coded displacement maps allowed visual and quantitative assessment of growth and treatment changes. The range of interobserver errors for each anatomic region was 0.4 mm for the zygomatic process of maxilla, chin, condyles, posterior border of the rami, and lower border of the mandible, and 0.5 mm for the anterior maxilla soft-tissue upper lip. CONCLUSIONS: Our results suggest that this method is a valid and reproducible assessment of treatment outcomes for growing subjects. This technique can be used to identify maxillary and mandibular positional changes and bone remodeling relative to the anterior cranial fossa.

Modified miniplates for temporary skeletal anchorage in orthodontics: placement and removal surgeries.

PURPOSE: Skeletal anchorage systems are increasingly used in orthodontics. This article describes the techniques of placement and removal of modified surgical miniplates used for temporary orthodontic anchorage and reports surgeons' perceptions of their use. PATIENTS AND METHODS: We enrolled 97 consecutive orthodontic patients having miniplates placed as an adjunct to treatment. A total of 200 miniplates were placed by 9 oral surgeons. Patients and surgeons completed questionnaires after placement and removal surgeries. RESULTS: Fifteen miniplates needed to be removed prematurely. Antibiotics and anti-inflammatories were generally prescribed after placement but not after removal surgery. Most surgeries were performed with the patient under local anesthesia. Placement surgery lasted on average between 15 and 30 minutes per plate and was considered by the surgeons to be very easy to moderately easy. The surgery to remove the miniplates was considered easier and took less time. The patients' chief complaint was swelling, lasting on average 5.3 +/- 2.8 days after placement and 4.5 +/- 2.6 days after removal. CONCLUSIONS: Although miniplate placement/removal surgery requires the elevation of a flap, this was considered an easy and relatively short surgical procedure that can typically be performed with the patient under local anesthesia without complications, and it may be considered a safe and effective adjunct for orthodontic treatment.

Patients' and orthodontists' perceptions of miniplates used for temporary skeletal anchorage: a prospective study.

INTRODUCTION: Temporary skeletal anchorage is a relatively recent addition to orthodontic treatment. Surgical miniplates, modified with intraoral attachments, provide an alternative to miniscrews for skeletal anchorage. In this study, we wanted to determine patients' and providers' perceptions of miniplate use during orthodontic treatment. METHODS: Consecutive patients having miniplates placed as part of their treatment completed questionnaires about their experiences during surgery and orthodontic treatment. A total of 200 miniplates were placed for 97 patients. The 30 orthodontists treating these patients also completed questionnaires concerning miniplate success, handling complexity, and whether these devices simplified treatment. RESULTS: The success rate was 92.5%. The devices were well tolerated by the patients. After a year, 72% of the patients reported that they did not mind having the implant, and 82% said that the surgical experience was better than expected, with little or no pain. The most frequent problems were postsurgical swelling, lasting 5 days on average, and cheek irritation experienced initially by more than a third of the patients, but it lessened over time. The clinicians reported that these devices were easy to use and greatly simplified orthodontic treatment. CONCLUSIONS: Miniplates are well accepted by patients and providers and are a safe and effective adjunct for complex orthodontic treatments.

A study of military recruitment strategies for dentists: possible implications for academia.

Results of the annual American Dental Education Association surveys of dental school seniors show approximately 10 percent of graduates enter federal government services while less than 1 percent enter dental academia. To examine this difference, this study sought the perceptions of senior dental students and junior military dental officers regarding their choice of a military career in order to determine how military recruitment strategies influenced their career decisions. Official documents explaining military recruitment efforts were requested from the military services and summarized. In-depth telephone interviews were conducted to gather perception data from the students and dental officers on successful strategies. By employing several strategies, the military was able to inform potential recruits about the benefits of being a dentist in the military. The opportunity to have the military finance a student's dental education was a successful military recruitment tool. Other enticing factors included guaranteed employment upon graduation, prestige associated with serving in the military, access to postgraduate training, minimal practice management responsibilities, and opportunities to continue learning and improve clinical skills without significant financial implications. It was concluded that dental education can use the same strategies to highlight the benefits of an academic career and offer many similar incentives that may encourage students to consider a career path in dental education.

Systematic review of the experimental use of temporary skeletal anchorage devices in orthodontics.

INTRODUCTION: Our aim was to review the experimental literature to determine what is known about functional and morphological tissue reactions around orthodontically loaded temporary skeletal anchorage devices. METHODS: The PubMed electronic database and the reference citations in published articles were searched to the end of April 2006. The inclusion criteria were animal studies about orthodontically loaded skeletal anchorage consisting of metallic bone plates or screw implants of 2.2 mm diameter or less. Data on healing time, force application, stability, side effects, and osseointegration were collected by 2 independent readers. RESULTS: Eight articles met the selection criteria. The healing times ranged from 0 to 12 weeks, and the amount of force varied from 25 to 500 g. Implant stability was generally achieved without severe side effects. Direct bone-screw contact was reported to be 10% to 58%, and osseointegration increased with loading time. Nevertheless, no significant difference in bone-screw contact was found between loaded and unloaded screw implants, or between tension and pressure sides of loaded implants. CONCLUSIONS: This review highlights some positive experimental findings that apply in clinical practice. However, questions concerning optimal force systems, surgical techniques and placement, and healing times remain. Future research should be well controlled and based on standardized protocols to test specific hypotheses.

Bond strengths and adhesive remnant index of self-etching adhesives used to bond brackets to instrumented and uninstrumented enamel.

PURPOSE: This study evaluated bond strengths of orthodontic brackets to instrumented and uninstrumented enamel using self-etching adhesive systems when compared to a total-etch adhesive system. The adhesive remnant index (ARI) was also determined after debonding. METHODS: 140 bovine incisors were included in acrylic resin, and divided randomly in two groups: instrumented vs. uninstrumented enamel. For the instrumented enamel, specimens had their facial enamel ground flat to 600-grit. In each group, specimens were subdivided into four experimental subgroups according to the adhesive technique used: Transbond Plus, Adper Prompt L-Pop, iBond, and Adper Single Bond, applied following manufacturers' instructions. Orthodontic brackets were bonded to the treated instrumented or uninstrumented enamel with Transbond XT light-cured resin-based composite cement, and the bond strength was tested in shear mode after 7 days. One group where no etch and no adhesive were used served as a control. ARI scores were determined after debonding. RESULTS: There was no statistically significant difference in mean bond strengths between instrumented and uninstrumented enamel for any of the adhesive systems (P > or = 0.05). No significant differences were observed for bond strengths among the adhesives tested (P = 0.308), and all experimental groups resulted in mean bond strengths significantly higher than the controls (P < 0.05). Statistically significant differences were identified when ARI scores were compared, with less adhesive remnants being observed for iBond (uninstrumented enamel) and the control groups (P < 0.05).

Implantable devices as orthodontic anchorage: a review of current treatment modalities.

UNLABELLED: Recently, there has been a dramatic increase in the use of implantable devices as direct adjuncts to orthodontic treatment. Whereas the use of conventional dental implants has been researched extensively, the body of literature associated with the more recent uses of implantable devices in orthodontics is relatively small. Currently, a limited number of such devices are used to aid in orthodontic treatment. The options include conventional titanium endosseous dental implants, palatal implants, titanium miniscrews (also known as micro- or mini-implants), and mini-bone plates. Integration of dental implants or implantable devices into contemporary orthodontic practice has the following possible advantages: serving as a means of increasing orthodontic anchorage, virtually eliminating patient compliance issues with regard to wearing of appliances, decreasing overall treatment time, and occasionally permitting orthodontic treatments previously thought to be impossible without surgery. CLINICAL SIGNIFICANCE: This article is a review of the currently available options for use of implantable devices as sources of temporary skeletal anchorage in orthodontics.

Outcomes in a 2-phase randomized clinical trial of early Class II treatment.

In a 2-phased, parallel, randomized trial of early (preadolescent) versus later (adolescent) treatment for children with severe (>7 mm overjet) Class II malocclusions who initially were developmentally at least a year before their peak pubertal growth, favorable growth changes were observed in about 75% of those receiving early treatment with either a headgear or a functional appliance. After a second phase of fixed appliance treatment for both the previously treated children and the untreated controls, however, early treatment had little effect on the subsequent treatment outcomes measured as skeletal change, alignment, and occlusion of the teeth, or length and complexity of treatment. The differences created between the treated children and untreated control group by phase 1 treatment before adolescence disappeared when both groups received comprehensive fixed appliance treatment during adolescence. This suggests that 2-phase treatment started before adolescence in the mixed dentition might be no more clinically effective than 1-phase treatment started during adolescence in the early permanent dentition. Early treatment also appears to be less efficient, in that it produced no reduction in the average time a child is in fixed appliances during a second stage of treatment, and it did not decrease the proportion of complex treatments involving extractions or orthognathic surgery.

External apical root resorption in Class II malocclusion: a retrospective review of 1- versus 2-phase treatment.

External apical root resorption (EARR) is an imperfectly understood problem of orthodontic treatment. The records of 138 children with Class II malocclusion (overjet > 7 mm) participating in a randomized clinical trial of early orthodontic treatment were reviewed. The patients were treated in either 1 phase with fixed appliances only (n = 49) or 2 phases with headgear (n = 49) or bionator (n = 40) followed by fixed appliances. The 3 groups were similar in age, sex, and malocclusion severity at enrollment. The records examined included anamnestic data, clinical examination records, panoramic radiographs before and after fixed appliance therapy, and posttreatment periapical radiographs. All radiographs were reviewed and scored independently by 2 examiners for maxillary incisor root development, morphology, and EARR. Of the 532 incisors scored, 11% of central and 14% of lateral incisors demonstrated moderate to severe (>2 mm) EARR. The proportion of incisors with moderate to severe EARR was slightly greater in the 1-phase treatment group. There was no difference in the incidence of EARR between teeth that had had trauma and those that had not, and there was only a slight increase in frequency of root resorption in teeth with unusual root morphology. Significant associations exist among EARR, the magnitude of overjet reduction, and the time spent wearing fixed appliances. However, not all incisors in a child respond in the same way, so other variables must play a role in determining the root response to orthodontic forces.

Incisor trauma and early treatment for Class II Division 1 malocclusion.

This study investigated incisor trauma in children with overjets greater than or equal to 7 mm who were enrolled in a clinical trial of 2-phase early orthodontic treatment for Class II malocclusion. In phase 1, children were randomly assigned to treatment in the mixed dentition with either modified bionator or combination headgear or to a group in which treatment was delayed until the permanent dentition. All children received comprehensive treatment during phase 2 if necessary. At the start of the trial, 29.1% of the patients had already had some incisor trauma. This was not significantly related to dental developmental age. During the trial, there was an increase in trauma in all 3 groups, but the magnitude of this increase was not significantly greater in the group for which treatment was delayed until the permanent dentition. This might suggest that orthodontic intervention aimed at reducing trauma should begin very soon after the eruption of the maxillary incisors. However, the injuries tended to be minor, and the expected cost of treatment related to incisor trauma was small compared with the expected additional cost of a 2-phase orthodontic intervention.

Measuring orthodontic treatment satisfaction: questionnaire development and preliminary validation.

OBJECTIVES: The aims of this study were to develop a reliable self-report measure of consumer satisfaction with orthodontic treatment, and to preliminarily assess its validity. METHOD: Transcripts of qualitative interviews with patients, their parents, and practicing orthodontists together with items from existing dental satisfaction questionnaires were used to develop a pool of 41 items assessing satisfaction with various aspects of orthodontic care. These items were paired with five-point Likert scales (1 = strongly disagree, 5 = strongly agree) and were administered to 299 parents of children who had completed orthodontic treatment at two university-based clinics. RESULTS: Factor analyses and reliability analyses identified three main subscales with high reliabilities: 13 items assessing satisfaction with treatment process (Cronbach's alpha = .92), seven items assessing satisfaction with psychosocial effects of treatment (Cronbach's alpha = .87), and five items assessing satisfaction with overall treatment outcome (Cronbach's alpha = .79). Relationships among these three subscales and pre- and posttreatment variables were examined in a subset of 86 parents/patients. Forward stepwise regression with backward overlook revealed no significant relationships between any satisfaction subscale and demographic variables. Posttreatment overjet was inversely related to parental satisfaction with orthodontic treatment process (R2 = .13; P < .001), and parent satisfaction with treatment outcome (R2 = .28; P < .0001). Improvement in esthetics as measured by improvement in IOTN Aesthetic Component scores was positively related to satisfaction with psychosocial outcomes (R2 = .28; P < .0001). CONCLUSIONS: The present instrument is reliable and can be used to assess three dimensions of parental satisfaction with their child's orthodontic treatment. Relationships between visible orthodontic outcome variables and parent satisfaction provide preliminary validity support for the instrument.

Understanding orthodontic treatment satisfaction from the patients' perspective: a qualitative approach.

OBJECTIVES: To apply qualitative research methods to develop hypotheses about orthodontic treatment process and outcome, as well as treatment satisfaction. DESIGN: Four focused interviews with 4-8 adolescents in retention. SETTING AND SAMPLE POPULATION: UNC orthodontic clinic; 22 patients in retention. RESULTS: Patients expressed dissatisfaction with some aspects of the treatment process, but were generally satisfied with the treatment outcome. Patients were aware of differences between clinic versus private treatment. From these discussions, we infer that there may be important differences between patients' and orthodontists' perceptions of the treatment process. CONCLUSIONS: Qualitative methods are useful tools for exploring orthodontic treatment from the patients' perspective and can be used to suggest important future areas of research.

Surgical versus orthodontic correction for Class II patients: age and severity in treatment planning and treatment outcome.

Treatment options for Class II malocclusion include orthognathic surgery. Treatment choices are particularly difficult for young patients because of the uncertainty regarding future growth. Surgical treatment has generally been considered necessary for older patients with more severe Class II problems. The treatment records of more than 500 patients with Class II malocclusion were reviewed. Patients were grouped according to their initial treatment plan (surgery or orthodontics) and treatment outcome (overjet [OJ] reduced to < 4 mm or not). Discriminant function analyses using data from the patient's pretreatment cephalogram were used to determine whether age, in combination with malocclusion severity, could predict the choice of treatment, and whether a simple set of pretreatment variables could predict the success or failure of OJ reduction. The derived equations were tested in a similar group of growing Class II children. Although the data showed clinicians use patient's age in determining treatment choice, age did not seem to be associated with treatment outcome. The majority of the variability that determined the success or failure of OJ reduction was not explained by patient's age or malocclusion severity. These findings suggest other factors, including psychosocial variables, need to be explored if we are to gain a better understanding of why treatments succeed or fail.

Benefit of early Class II treatment: progress report of a two-phase randomized clinical trial.

Preadolescent children with overjet greater than 7 mm were randomly assigned to observation only, headgear (combination), or functional appliance (modified bionator) and were monitored for 15 months. Of the 166 patients who completed this first phase of the trial, 147 continued to a second phase of treatment. The data from the first 107 patients to complete phase 2 are available and form the basis of this progress report. During phase 1, on average there was no change in the jaw relationship of untreated children, but 5% showed considerable improvement and 15% demonstrated worsening. Both early-treatment groups had a significant average reduction in ANB angle, more by change in maxillary dimensions in the headgear group and mandibular growth in the functional appliance group. There were wide variations in response, however, with only 75% of the treated children showing favorable skeletal response. Failure to respond favorably could not be explained by lack of cooperation alone. The preliminary results from phase 2 show that, on average, time in fixed appliances was shorter for children who underwent early treatment, but the total treatment time was considerably longer if the early phase of treatment was included. Only small differences were noted in anteroposterior jaw position between the groups at the completion of treatment, and the changes in dental occlusion, judged on the basis of Peer Assessment Rating scores, were similar between groups. Neither the severity of the initial problem nor the duration of treatment was correlated with the occlusal result. The number of patients who required extraction of permanent teeth was greater in the early functional appliance group than in the headgear or control group. The option of orthognathic surgery was presented more often in the cases of children who did not undergo early treatment, but surgery was accepted or was still being considered almost as frequently in the previous headgear group as in the controls, less often in the patients previously treated with functional appliances.

Bias and variability in clinical research.

Two of the practical problems facing investigators attempting to compare alternative orthodontic treatments are bias and variability. Since the subjects receiving treatments are usually different people, observed differences can be due to differences in people rather than differences in the treatments. If the groups being evaluated differ in any systematic way, they are said to be biased. Treatment comparisons between biased groups are difficult to interpret since bias can exaggerate, nullify or reverse true differences. The random assignment of patients to alternative treatments breaks any systematic connection between treatment and any variable that might favor one treatment over another; thus, making it safer to attribute differences in outcome to the treatments given rather than the people studied.

Early treatment of Class II, division 1 malocclusion--comparison of alternative treatment modalities.

The purpose of this paper was to compare the findings from three randomized clinical trials that investigated alternative treatments of Class II, division 1 malocclusion in young children. The trials were conducted at the University of North Carolina, the University of Florida, and the University of Pennsylvania. The appliances investigated in each center were a functional appliance versus a headgear. Variations in the specific aims and the working hypotheses were noted. The types of appliances, length of treatment, and methods of evaluation were also different. A general comparison of selected clinically relevant findings reveals similarities and differences in conclusions, but underlines the importance of assessing each study on the basis of its original hypothesis. The separate and combined contribution of these studies to the state of knowledge and research is discussed.

Influences on the outcome of early treatment for Class II malocclusion.

In the first phase of a randomized clinical trial of early versus late Class II treatment, statistically significant differences were observed between the treatment and observation groups. However, there were wide variations in response. The change in jaw relationship (categorized as the annualized reduction in ANB angle) was favorable or highly favorable in 76% of the headgear, 83% of the functional appliance, and 31% of control (observation only) groups. The patient's initial skeletal severity, age/maturity at the outset of treatment, growth pattern, and cooperation with treatment were examined as possible influences on early growth modification treatment. Correlations between the annualized change in the ANB angle and any of the possible influences were close to zero and not statistically significant. We conclude that there is little to be gained from precisely timing early treatment to specific age/maturity markers and that a favorable reduction in Class II skeletal problems can occur for patients in a broad range of skeletal severity and growth patterns. Cooperation, measured as the number of hours of reported wear, or the clinical assessment of compliance, explained little of the variation in treatment response. The wide variation in growth seen in the untreated patients highlights the importance of well-controlled studies if clinicians are to improve their ability to select children with the greatest chances of a favorable treatment response.

The effect of early intervention on skeletal pattern in Class II malocclusion: a randomized clinical trial.

Early treatment for Class II malocclusion is frequently undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. Because the majority of previous studies of growth modification for Class II malocclusion have been based on retrospective record reviews, the efficacy of such an approach has not been well established. In this controlled clinical trial, patients in the mixed dentition with overjet > or = 7 mm were randomly assigned to either early treatment with headgear, or modified bionator, or to observation. All patients were observed for 15 months with no other appliances used during this phase of the trial. The three groups, who were equivalent initially, experienced statistically significant differences (p < 0.01) in skeletal change. There was considerable variation in the pattern of change within all three groups, with about 80% of the treated children responding favorably. Although patients in both early treatment groups had approximately the same reduction in Class II severity, as reflected by change in the ANB angle, the mechanism of this change was different. The headgear group showed restricted forward movement of the maxilla, and the functional appliance group showed a greater increase in mandibular length. The permanence of these skeletal changes and their impact on the subsequent treatment remains to be evaluated.