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.

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.

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.

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.

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.

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.