Bone-anchored maxillary protraction in unilateral cleft lip and palate: a cephalometric appraisal.

OBJECTIVES: The aim of this study was to evaluate the cephalometric outcome of bone-anchored maxillary protraction (BAMP) in individuals with unilateral complete cleft lip and palate (UCLP). MATERIAL AND METHODS: The experimental group (EG) comprised 23 individuals (17 males and 6 females) with UCLP and a mean age of 11.7 years. At least 6 months after secondary alveolar bone grafting, Bollard miniplates were installed in the posterior region of the maxilla and in the anterior region of the mandible. Class III elastics were recommended to be worn for 24 hours/day for a mean time of 18 months. Cone beam computed tomography (CBCT) was obtained before (T1) and after treatment (T2). The control group (CG) consisted of 23 individuals with UCLP matched by initial age and gender with the EG and without any orthopaedic or surgical intervention performed between T1 and T2. The interval between T1 and T2 observations was 18 months for both groups. Twenty-one cephalometric variables were analysed. Intra- and intergroup comparisons were performed using paired and independent t-tests, respectively (P < 0.05). RESULTS: BAMP caused a greater maxillary protrusion (SNA) and a greater decrease of Class III maxillomandibular discrepancy (ANB and Wits appraisal) compared with the CG. BAMP also caused a counterclockwise rotation of the occlusal plane (Occ Plane to FH) and an improvement in the molar relationship compared with controls. CONCLUSIONS: BAMP therapy demonstrated a significant orthopaedic maxillary protraction and an improvement in the Class III skeletal pattern in UCLP.

Growth modification of the face: A current perspective with emphasis on Class III treatment.

A summary of the current status of modification of jaw growth indicates the following. 1. Transverse expansion of the maxilla is easy before adolescence, requires heavy forces to create microfractures during adolescence, and can be accomplished only with partial or complete surgical osteotomy after adolescence. Transverse expansion of the mandible or constriction of either jaw requires surgery. 2. Acceleration of mandibular growth in preadolescent or adolescent patients can be achieved, but slower than normal growth afterward reduces or eliminates a long-term increase in size of the mandible. Restraint of maxillary growth occurs with all types of appliances to correct skeletal Class II problems. For short-face Class II patients, increasing the face height during preadolescent or adolescent orthodontic treatment is possible, but it may make the Class II problem worse unless favorable anteroposterior growth occurs. For those with a long face, controlling excessive vertical growth during adolescence is rarely successful. 3. Attempts to restrain mandibular growth in Class III patients with external forces largely result in downward and backward rotation of the mandible. Moving the maxilla forward with external force is possible before adolescence; moving it forward and simultaneously restricting forward mandibular growth without rotating the jaw is possible during adolescence with intermaxillary traction to bone anchors. The amount of skeletal change with this therapy often extends to the midface, and the short-term effects on both jaws are greater than with previous approaches, but individual variations in the amount of maxillary vs mandibular response occur, and it still is not possible to accurately predict the outcome for a patient. For all types of growth modification, 3-dimensional imaging to distinguish skeletal changes and better biomarkers or genetic identification of patient types to indicate likely treatment responses are needed.

Three-dimensional analysis of maxillary changes associated with facemask and rapid maxillary expansion compared with bone anchored maxillary protraction.

INTRODUCTION: Our objectives in this study were to evaluate in 3 dimensions the growth and treatment effects on the midface and the maxillary dentition produced by facemask therapy in association with rapid maxillary expansion (RME/FM) compared with bone-anchored maxillary protraction (BAMP). METHODS: Forty-six patients with Class III malocclusion were treated with either RME/FM (n = 21) or BAMP (n = 25). Three-dimensional models generated from cone-beam computed tomographic scans, taken before and after approximately 1 year of treatment, were registered on the anterior cranial base and measured using color-coded maps and semitransparent overlays. RESULTS: The skeletal changes in the maxilla and the right and left zygomas were on average 2.6 mm in the RME/FM group and 3.7 mm in the BAMP group; these were different statistically. Seven RME/FM patients and 4 BAMP patients had a predominantly vertical displacement of the maxilla. The dental changes at the maxillary incisors were on average 3.2 mm in the RME/FM group and 4.3 mm in the BAMP group. Ten RME/FM patients had greater dental compensations than skeletal changes. CONCLUSIONS: This 3-dimensional study shows that orthopedic changes can be obtained with both RME/FM and BAMP treatments, with protraction of the maxilla and the zygomas. Approximately half of the RME/FM patients had greater dental than skeletal changes, and a third of the RME/FM compared with 17% of the BAMP patients had a predominantly vertical maxillary displacement.

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.

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.

Maxillary molar distalization with miniplates assessed on digital models: a prospective clinical trial.

INTRODUCTION: The purpose of this prospective study was to evaluate the effects of maxillary molar distalization in patients treated with a miniplate skeletal anchorage system. METHODS: Thirty-one miniplates were placed on the infrazygomatic crests of 17 nongrowing patients consecutively selected for Class II treatment with skeletal anchorage. Three weeks after surgery, a 150-g force was applied to distalize the molars. No appliances were placed in the mandible. Models made before treatment and after molar distalization were scanned. Linear measurements were made on the digitized casts. Molar movement was measured on the superimposed maxillary arches before and after distalization, coregistered on the untreated mandibular models. RESULTS: A molar hyper Class I relationship was reached in all patients 7.0 +/- 2.0 months after miniplate loading. The maxillary molars were moved distally a mean distance of 3.27 +/- 1.75 mm. In patients without contact between the maxillary and the mandibular incisors, overjet decreased by 0.99 +/- 1.32 mm. Intermolar width increased by 2.78 +/- 1.38 mm. CONCLUSIONS: Maxillary molar distalization with miniplates for skeletal anchorage is an efficient, noncompliance-dependent, and predictable treatment modality for patients with Class II molar relationship.

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.

Growth regulation of the rat mandibular condyle and femoral head by transforming growth factor-{beta}1, fibroblast growth factor-2 and insulin-like growth factor-I.

The mandibular condyle is a major growth site and is known to adapt to functional factors. Numerous studies have been performed on the effects of growth factors on the metabolism of primary cartilages, but only a few investigations have examined their action on primary and secondary cartilages. Therefore, the purpose of this study was to compare the effects of insulin-like growth factor-I (IGF-I), transforming growth factor-beta(1) (TGF-beta(1)), and fibroblast growth factor-2 (FGF-2) on the growth of secondary cartilage from the mandibular condyle and primary cartilage from the femoral head of new-born rats. In addition, synergy between these growth factors was investigated. The level of glycosaminoglycan (GAG) and DNA synthesis was analysed after 5 days in culture with the growth factors. The effects of TGF-beta(1) and FGF-2 on growth, tissue organization, and the GAG and collagen content were also evaluated. The stimulation of cell proliferation by the growth factors was higher in the mandibular condyles than in the femoral heads. The content of the matrix components was reduced more by FGF-2 in the mandibular condyles than in the femoral heads. Both TGF-beta(1) and FGF-2 antagonized the stimulatory effects of IGF-I on GAG synthesis in the two types of cartilage. In contrast, the total growth of mandibular condyles was not affected by TGF-beta(1) and FGF-2 while that of femoral heads was strongly reduced. This was mainly due to the inhibition of chondrocyte hypertrophy. These results show that in spite of the extensive effects of growth factors on the metabolism of mandibular condyles, their dimensional growth was not affected.