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Introduction: The purpose of this study was to investigate the success rate of midpalatal miniscrews used for orthodontic anchorage and the factors affecting clinical success., Methods: One hundred twenty-eight consecutive patients (101 female, 27 male; mean age, 23.4 years), who received a total of 210 miniscrews in the midpalatal suture area, were examined. Success rates were determined according to 10 clinical variables., Results: The overall success rates were 88.20% for the total number of patients and 90.80% for the total number of miniscrews. There were no significant associations among success rate and sex, total period of treatment with miniscrews, diameter of miniscrews, types of tooth movements, and variables that represent sagittal and vertical skeletal relationships (ANB, FMA, and Sn-GoGn). The operator's learning curve, patient's age, area (midpalatal or parapalatal), and splinting significantly influenced the success rates. After adjusting for other variables, only 1- splinting-showed a significant effect on the success rate., Conclusions: The joining of 2 miniscrews by splinting, placement of the miniscrew in the midpalatal suture, patient's age (especially >15 years), and operator's skill were factors influencing the clinical success of orthodontic miniscrews in the palate., (Copyright 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Many appliances are available to move maxillary molars distally. First molars have routinely been moved distally with nickel-titanium coil springs and nickel-titanium wire before the eruption of the second molars. However, when first molars are moved distally after the eruption of the second molars, they tend to move slowly, and anchorage loss increases. In adults, the midpalatal area is appropriate for placing titanium miniscrews for orthodontic anchorage. This case report demonstrates the ability of midpalatal miniscrews to control anchorage while distalizing the entire maxillary dentition in an adult, with improvements in lip profile resulting from the retraction of anterior teeth followed by a good response of the lips. This report suggests that absolute anchorage can be established by placing miniscrews in the palate and that miniscrew anchorage can serve as anchorage for the distal movement of an entire arch.

This article describes a method to treat Class II malocclusions with no patient cooperation. The technique involves converting the Class II molar relationship to a Class I in the initial phase of treatment by moving the maxillary molars distally with superelastic coils and wire. Anchorage is provided by a transpalatal bar attached to the first premolars and connected to 2 palatal miniscrews. Once the molars are positioned correctly, the palatal miniscrews are removed and miniscrews are inserted bilaterally in the buccal bone between the first molar and the second premolar. These miniscrews serve as the anchorage for the retraction of the premolars, canines and incisors.

Dental casts of 30 patients treated with extraction and 30 patients without extraction of four first premolars were randomly selected to determine changes in arch width as a result of treatment. Arch widths were measured from the cusp tips of the canines, premolars, and molars. Posttreatment arch widths were also measured in the midline at a constant arch depth from the most labial surfaces of the incisors. Standardized frontal photographs of the face taken during smiling of 12 extraction- and 12 nonextraction-treated subjects were evaluated. Fifty laypersons judged the esthetics of the smiles. Intercanine width increased less than one mm in both groups, and there was no difference between the two groups. The interpremolar and intermolar distance in both arches decreased significantly from 0.53 to 0.95 mm in the extraction sample, whereas the interpremolar and intermolar widths increased significantly from 0.81 to 2.10 mm in the nonextraction sample. When arch widths of both groups were measured from the most labial surfaces of the teeth at a constant depth, the average arch width of both arches was significantly wider in the extraction sample (1.8 mm wider in the mandible and 1.7 mm wider in the maxilla). The mean esthetic score and the number of teeth displayed during a smile did not differ between the groups. The results indicate that arch width is not decreased at a constant arch depth because of extraction treatment, and smile esthetics are the same in both groups of patients.

An undocumented criticism of extraction treatment is that it results in narrower dental arches when compared with nonextraction therapy. Anterior and posterior arch widths of the maxillary and mandibular arches of 25 patients treated by 4 first-premolar extraction and 25 patients treated without extractions were measured on posttreatment study models and compared statistically to determine whether the dental arches were narrower after extraction treatment, to test the accuracy of this view. Measurements were made in the canine and the molar regions from the most labial aspect of the buccal surfaces of the canines and the molars. In both groups, anterior and posterior arch widths were the same except for the mandibular intercanine dimension, which was 0.94 mm larger (P <.01) in the extraction group. This indicates that extraction treatment does not result in narrower dental arches than nonextraction treatment.

In the mixed dentition, arch length preservation, maintaining the leeway space, can often provide adequate space to resolve lower incisor crowding. Yet the frequency of this occurrence is not known. To obtain this information, lingual arches were placed in the mandibular arches of 107 consecutive mixed dentition patients with incisor crowding to preserve arch length and make the leeway space available to resolve the crowding. Arch length decreased only 0.44 mm whereas the intercanine, interpremolar, and intermolar dimensions increased between 0.72 and 2.27 mm. There was adequate space to resolve the crowding in 65 (60%) of the 107 patients. If perfect arch length preservation had occurred, there would have been adequate space to resolve the crowding in 73 (68%) of the 107 patients. The correlation between leeway space and tooth size-arch size discrepancy was only 0.44.

Molars can be moved distally approximately 1 mm/month with little to no patient cooperation by using intraarch compressed 100 gm NiTi coils or 100 gm looped NiTi wires against the molars supported by a removable modified Nance appliance. When the molars are moved posteriorly by these intraarch mechanisms, anchorage loss occurs and produces an increase in overjet that is generally within acceptable limits. Although molars can be moved posteriorly at any age, an advantageous treatment time is the late mixed dentition.

Class II nonextraction treatment, which commonly includes distal movement of the maxillary molars to correct the molar relationship, most often can be successful when treatment is started in the late-mixed dentition stage of development. At least two factors contribute to this success. One is that the molars can be distalized routinely at this age. The second is that the "E" space is available and can be used either to help correct the molar relationship or to resolve any crowding that may exist. This article describes and illustrates the treatment of a late mixed-dentition patient with this type of Class II nonextraction treatment that includes distal movement of the maxillary molars with a 100 g NiTi coil system and the maintenance of the "E" space with a lip bumper.

The leeway space provides adequate space to resolve crowding that is present in the mixed dentition in the majority of individuals. This space can be maintained by preserving arch length with a lingual arch as the primary teeth begin to exfoliate, unless conditions such as the premature loss of a primary canine require earlier intervention. A lip bumper can also be inserted after the eruption of the first premolars to preserve arch length.

The late mixed dentition stage of development, after the eruption of the first premolars, is a favorable time to start treatment to resolve crowding. This protocol offers the clinician choices. If nonextraction treatment is preferable, arch length preservation can provide the space for alignment in approximately 75% of all patients with crowding. If extraction treatment is indicated, the first premolars are available.

In 111 patients pretreatment and posttreatment condylar position was evaluated with corrected tomograms taken with the mandible in centric occlusion. Seventy-nine of the patients were treated by nonextraction procedures and 32 were treated by extraction procedures, 27 of the patients with the extraction of one or more premolars and 5 with the extraction of one or more anterior teeth. When the condylar positions before and after treatment were compared in the entire sample of 111 patients, in the nonextraction patients, in the extraction patients, and in extraction patients relative to nonextraction patients, no statistically significant differences were found. Thus condylar position was stable during treatment and did not behave differently under extraction and nonextraction conditions. On an individual basis, condylar retropositioning, as defined in this study, occurred in only nine of the 222 joints examined and was noted in patients treated both with and without extraction.

Japanese NiTi superelastic coils, exerting 100 gm of force, were compressed against the maxillary first molars and moved the molars distally 1 to 1.5 mm/month. Anchorage was obtained with a modified Nance appliance cemented onto the first premolars in conjunction with a fixed appliance.

Condylar position in 17 patients whose Class II treatment (14 with edgewise appliances and 3 with Begg appliances) included extraction of the maxillary first premolars and in 17 control patients was compared by means of corrected tomography. The condyles in both groups were in an anterior position, and there were no statistical differences between the groups. In addition, no statistical correlation was found when the posttreatment bite depth, interincisal angle, and maxillary incisor inclination were correlated with condylar position. Thus, as determined in this study, condylar position was unrelated to treatment, bite depth, interincisal angle, and maxillary incisor inclination.

Repelling magnets, which were anchored to a modified Nance appliance cemented on the first premolars, were activated against the maxillary first molars to move them distally. Eighty percent of the space created represented distal movement of the first molars.

By means of corrected tomography, the positions of the condyles in patients who had undergone four-premolar extraction treatment (20 edgewise and 7 Begg) were compared with the condylar positions of patients who had not yet received orthodontic treatment. No significant between-group differences in condylar position were noted. In addition, the relationship between bite depth and condylar position was examined and no significant correlation was found. Thus, as performed in this study, condylar position was unrelated to extraction treatment and to bite depth.

The purpose of this study was to determine if selected cephalometric changes noted in groups of growing patients with Class II, Division 1 malocclusions treated with the Fränkel function regulator (FR-2), the edgewise technique, and the light-wire (Begg) mechanism were different and characteristic of a specific technique. To this end, the changes in the SNA, SNB, N-S-Gn, and the SN-GoGn angles, face height (N-M), the anterior movement of pogonion, and the annualized mandibular growth increment (AR-Gn) in a group of patients treated with the FR-2 were compared to the changes noted in similar groups of patients treated by the edgewise technique and the light-wire mechanism. The methods used to compare the groups were an analysis of variance and a discriminant analysis. A reduction in the SNA angle was observed in all groups. It was -0.37 degrees with light wire treatment, -0.60 degrees with Fränkel appliance use, and -1.47 degrees with edgewise therapy. The SNB angle increased in all three groups, ranging from 0.29 degrees in the edgewise group to 0.56 degrees in the Fränkel group. In the light-wire group it was 0.34 degrees. The N-S-Gn angle in the Fränkel group remained essentially the same (0.06 degrees), while in the light-wire and edgewise groups it increased 0.81 degrees and 0.82 degrees. The SN-GoGn angle opened slightly in all groups, ranging from a low of 0.46 degrees with Fränkel therapy to 0.58 degrees with edgewise treatment to 1.25 degrees with the use of the light-wire appliance.(ABSTRACT TRUNCATED AT 250 WORDS)

The treatment of a patient with an asymmetric malocclusion (class II, division I--subdivision) was presented. The treatment involved the use of repelling magnets for the distalization of the upper right molar which was in a class II relationship. A fixed "Nance" appliance attached to the second premolars was used for anchorage. Magnets are relatively easy to insert, are well tolerated, and they can distalize molars rapidly without significant loss of anchorage. No cooperation was required during the distalization phase of treatment and the second premolar distalized spontaneously once the "Nance" appliance was removed.

The complete mandibular subapical osteotomy has been presented as a method for correction of Class II malocclusions. At this point, it holds some promise as a solution to the skeletal relapse seen in the surgical correction of Class II malocclusions with use of other techniques. The procedure is a straight-forward combination of the sagittal osteotomy as described by Obwegeser and the subapical osteotomy as described by Köle. Further investigation into the versatility of this procedure is recommended.

A statistical evaluation of condyle position and mandibular length changes in 10 patients after one year of Fränkel appliance therapy, finding the condyle forward on the eminence in 4 of them. Large variations were found in mandibular growth, with no significant difference from the means of patients treated with the Edgewise appliance.

In a vertically slotted 0.022 X 0.028 inch edgewise system, the use of a two-dimensional ribbon arch--0.022 X 0.016 inch from lateral incisor to lateral incisor and 0.016 X 0.022 inch from the canine to the molars--plus an uprighting spring on the canine maintained incisor position while unilaterally protracting a molar-premolar unit by means of sliding mechanics. Five degrees of labial crown torque was placed in the incisor portion of the wire and the uprighting spring exerted a force of 200 to 250 g. The intra-arch force applied to protract the molar--premolar unit was 300 to 350 g.

The response of the gingiva to an increased interdental space was studied by creating a diastema between the central incisors of rats and analyzing autoradiographically the incorporation of H3 proline in the gingiva to detect increased collagen production. In addition, conventional histologic methods were used to determine changes in the gingival architecture. The results indicate that the gingiva responds to an increased space in at least two ways. One is the production of more collagen fibers. The other involves the reorientation of the existing fibers in a horizontal plane as the gingival papilla becomes flattened.

By means of corrected tomography, the positions of the condyles in 19 click-free persons with Class II malocclusions characterized by a bite depth greater than 50%, no overjet, and an interincisal angle of greater than 140 degrees were compared with a positions of the condyles in 21 control subjects. Average condylar position in both groups was concentric and no significant differences between groups were found. In addition, no significant correlation was noted when condylar position was related to bite depth.