Giorgio Fiorelli's List: pubblicazioni ortodonzia

• h can produce measurements as accurate as those from a digital image created with a flatbed scanner. Methods: Twenty pretreatment lateral cepha
• Results: Angular measurements were not significantly different between the photographed and scanned images, but linear measurements were. Conclusions: It is acceptable to use digital photographs of cephalograms if angular measurements are primarily required. However, these images might not be acceptable if linear measurements are needed.

• spring clip that can press against the archwire (active) and those with a passive system of ligation,
• a fad

  • a temporary fashion, notion, manner of conduct, etc., esp. one followed enthusiastically by a group.
• veneer

  • a superficially valuable or pleasing appearance
• Almost anyone can present selected cases to prove a point; this is not evidence or science but selective memory, wishful thinking, or pseudo-science
• for canine retraction, the archwire is relatively constrained at each end by the posterior and anterior teeth but is often cantilevered in vitro. This relative constraint affects the mechanical loading at the bracket-archwire interface and thus the frictional resistance.
• The ratio of the normal forces on an archwire constrained at both ends to that of a cantilevered archwire can vary from 3:1 to over 9:1.9
• limited to fragmented or small aspects of overall orthodontic treatment such as frictional resistance with nickel-titanium wires relating to initial alignment.
• comparisons of .022-in slot conventional brackets and passive slide SL brackets (Damon, SmartClip) with SL brackets with a spring clip (In-Ovation “R,” Time 2, Speed) are like comparing apples to oranges. The .022-in slot SL bracket with a spring clip is not a true .022 × .028-in slot. The horizontal gingival wall is reduced (in the In-Ovation “R,” it is .0195 in) and not .028 in, and therefore the spring clip invades the bracket slot (Fig 2). Consequently, this reduces the dimensions and size of the bracket slot.
• Moreover, these in-vitro studies dealing with frictional resistance with nickel-titanium archwires simulating early stages of treatment seem somewhat superficial.
• SL brackets show excellent performance in vitro with smaller wires that are used early in treatment. However, when larger wires are used such as .016 × .022 in and .019 × .025 in nickel-titanium in the austenitic phase, no differences were found between SL brackets and conventional brackets.11 In other words, SL brackets demonstrated low frictional resistance only up to certain size archwires in a .022-in slot.
• after the 20-week period, the SmartClip bracket was no more effective in reducing irregularity than a conventional twin bracket ligated with elastomeric modules or stainless steel ligatures with the 2 wires tested.
• superceded

  • abbandonato
• retrospective study
• Retrospective studies such as these are potentially biased despite apparent “matching” because many uncontrolled factors might affect the outcome. It is unclear what techniques were used or which variables were controlled and which were not. These include greater experience, modified appointment intervals, differing archwires, and altered wire sequences
• 58 consecutively treated patients over a 20-week period
• (1) conventional brackets achieved better irregularity index scores than the Damon 2 (although not clinically significant); (2) patients preferred the look of the conventional twin bracket over the Damon 2; (3) there were more bracket failures with the Damon 2; and (4) Damon 2 brackets were less painful initially, but they were substantially more painful when the second archwire was placed.
• split-mouth design
• Several investigators and many clinicians reported difficulties in finishing patients with self-ligating brackets.19
• This normal force is avoided by using a Damon or a SmartClip bracket or “passive” ligation only when the brackets and wire are ideally aligned (so no movement occurs). Any deflection of the archwire that engages the bracket due to rotation, tip, or torque creates a normal force and therefore classical friction. If this deflection is greater, eventually binding and notching occur; these cannot be avoided by any bracket design, SL or conventional.
• In-Ovation “R” bracket slot (specifications are for the .022-in slot) has a short horizontal wall of .0195 in and a conventional horizontal wall of .0285 in.
• . “The intended benefit of storing some of the force in the clip as well as in the wire is that, in general terms, a given wire will have its range of labio-lingual action increased and therefore produce more alignment than would a passive slide with the same wire.”13
• Damon SL brackets have a so-called “passive slide”
• dimensions of the slot in a vertical and horizontal plane are conventional.
• The passive slide or clips might have an advantage for initial alignment
• As an aside, force diminution is the reduction in the force produced by an archwire, deflected in its elastic limits, as it returns to its original shape.
• conundrum

  • a riddle, the answer to which involves a pun or play on words, as What is black and white and read all over? A newspaper.
    2. anything that puzzles.
• a possible ideal SL bracket could be a combination bracket with both a spring clip and a passive slide. It could also be tied conventionally. If low RS is desired, the passive slide could be used, but, if high RS is appropriate, then the active spring clip could be used.

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• the PDL is exposed to considerable strains, which, combined with its relative incompressibility, greatly increase the level of hydrostatic pressure. If hydrostatic pressure exceeds systolic pressure (120 mm of mercury or 16 kPa), necrosis can occur in the PDL region.

  • limite per la ialinizzazione del pdl
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• a better understanding of the stress-strain patterns in the initial stage of OTM
• both the translational and rotational directions

  • realmente non capisco la direzione
• The compressive strains induced in the PDL anticipate the direction of tooth movement as a consequence of orthodontic loading. More importantly, the adjacent dentition causes greater compressive stresses because the PDL is compacted by the rigidity of the neighboring dentin structure; this demonstrates the necessity of considering mutual influences between the teeth.
• Although in the single-tooth system magnitudes of only 6 kPa occur in the root apex, in the multi-tooth system they reach 32 kPa at the root apex in the central incisor, 4 kPa in the canine, and 0.8 kPa in the first premolar. These hydrostatic stress results for the root apex of the central incisor are much greater than the systolic pressure (16 kPa), and, therefore, this tooth is susceptible to root resorption. These preliminary findings necessitate further investigations into hydrostatic pressure during orthodontic treatment that might provide new methods to predict and prevent root resorption.

  • La forza è di soli 50g, quindi forze leggerissime andrebbero applicate per evitare ialinizzazione
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• The force system was measured for molar root movement springs that had adjustable alpha (anterior) and beta (posterior) moments.
• Without reactivation, the force system becomes unfavorable after approximately 5° of molar movement (rotation). With reactivations, a favorable force system through 20° of molar movement is maintained.
• Ideally, to keep the anterior unit stable during molar root correction, the center of resistance (CR) must be defined. The force-moment system should provide an M:F for translation of the anterior unit (about 10 mm from the bracket to the CR), against root movement of the molar (about 11 mm from the auxiliary tube to the CR).

  • occlusione necessaria
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• A 2-cantilever mechanism (1 for the anterior, 1 for the posterior unit) was previously proposed to manipulate the differential M:F.11
• the system impractical in a busy practice

  • Mi chiedo se lo ha mai provato, il buon Rodrigo,,,
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• to control and predict clinical tooth movement, it is necessary to know not only the initial force system, but also how the force system changes with tooth movement
• The ideal location of the center of rotation (CRot) is at the molar bracket.
• The desired force system at the molar was a distal crown-tipping moment of 2000 cN per millimeter with an M:F of 11 mm (anatomical average derived from published studies and adjusted for the molar auxiliary tube position). Ideally, the moment magnitude must not decrease significantly to maintain the rate of tooth movement. From these conditions, it follows that the total horizontal force acting at the molar must be total horizontal force (Ftx) = 2000 gf mm/11 mm = 181.8 gf.

  • Non sono proprio sicuro che si debba lavorarte ad un M/F di 11, secondo me è qualcosa di più (13-14).
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• The final template used for spring construction.

  • La curvatura fa sì che la parte orizzontale, dopo attivazione, rimanga lineare.
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• to restore the original force system, the anterior part of the wire would have to be reactivated about 1 mm occlusally for each 2.5° of molar rotation.
• Fx (gf)

  • la forza orizzontale prodotta dalla molla è 0 quando completamente attivata, perchè assume una forma lineare.
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• If the molar is not constrained mesially by other teeth, tension in the spring, caused by changes in spring curvature, could pull the molar crown mesially (negative Fx), slackening the ligature or changing the molar's CRot.
• The data show that alpha-beta springs require reactivations or new V-bends, after approximately 5° of molar rotation to prevent undesirable movement of the anchorage unit that can happen from excessively increasing M:F.
• The spring must be pulled distally so that there is a 3-mm overhang beyond the molar tube and then cinched back for comfort.

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• efficiency of changing archwires in 131
• Turnbull and Birnie2
• Pellegrini et al,3
• no advantage over conventional brackets with respect to the status of the periodontal tissues of the mandibular anterior teeth.
• Pandis et al5
• Overall, there was no difference in the time required to correct mandibular crowding. However, when moderate (<5 mm) and severe (>5 mm) crowding were examined separately, self-ligating brackets corrected moderate crowding 2.5 times faster than conventional appliances. This difference was insignificant for patients with the more severe crowding. There was increased proclination of the mandibular incisors associated with the correction of crowding for both bracket groups.
• Hamilton et al6
• retrospective case analysis of 800 patients
• he active self-ligating appliance offered no measurable advantage in treatment time. Patients spent comparable amounts of time in rectangular and round archwires. The number of debonded brackets and other emergency visits was significantly higher in patients treated with self-ligating brackets.
• Fleming et al7
• bracket type had little effect on incisor inclination, positional changes, intercanine widths, or other arch dimensions.
• Scott et al8
• ctive self-ligating brackets appeared to offer no measurable advantages in treatment time, number of visits, and time spent in initial alignment over the conventional bracket system used. Damon3 self-ligating brackets were no more efficient than conventional preadjusted brackets to achieve tooth alignment.

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• Although the horizontal continuity of the gingival contour, teeth, and upper lip has been considered essential for esthetics,21 asymmetries of up to 1.5 mm in the free gingival margin of the maxillary central incisors seemed to be acceptable and not perceived by the laypersons who participated in this study. Our results suggest that some therapeutic approaches to correct asymmetries of gingival margins of the maxillary central incisors between 0.5 and 1.5 mm, such as periodontal surgeries20, 21, 22 or orthodontic tooth movement complemented by composite restorations,19, 20, 23, 26 might reflect an exaggerated concern by dental specialists rather than an esthetic need.
• No studies about the esthetic impact of wear of a maxillary canine cusp were found in the literature. No group of raters in our study detected this type of smile asymmetry when evaluating the frontal photographs. However, this discrepancy might be perceivable on profile and oblique photographs, in which the canine tends to gain relative esthetic importance.
• 
  

  4.Midline shifts were perceived at 1.0 mm by orthodontists and 3.0 mm by prosthodontists; laypersons did not notice midline shifts.

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• There is some evidence of adaptive remodeling changes in the TMJ with age as a consequence of a unilateral posterior crossbite
• he concern is that, with correction of this occlusal problem, a sudden change in condylar position could occur that might be beyond the adaptive capabilities of some persons.
• it is important to differentiate between 2 types of skeletal asymmetries, as suggested by Obwegeser and Makek.37 According to them, asymmetries can be classified as either hemimandibular elongation or hemimandibular hyperplasia. Hemimandibular elongation can be characterized by elongation of either the condyle or the ramus in the vertical plane, or the mandibular body in the horizontal plane. Combinations of both vertical and horizontal elongations are possible. In contrast, hemimandibular hyperplasia is an enlargement of half of the entire mandible. As a result, there will be greater distances from the tooth apices to the lower border of the mandible on the affected side and typical “notching” of the mandibular lower border midline on the panoramic film. The clinical implication of this classification becomes evident when timing of treatment is discussed. A distinction between the 2 types of asymmetry is the timing of growth cessation.38 Hemimandibular elongation is characterized by excessive growth along normal growth axes, following more of a somatic growth curve, and therefore tends to stop when facial growth stops. Conversely, hemimandibular hyperplasia tends to grow longer, exhibiting latent or continued hyperplastic growth.

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• most accurate movement was lingual constriction (47.1%)
• The mean accuracy of tooth movement with Invisalign was 41%.
• Invisalign scores were significantly lower for correcting posterior torque, occlusal contacts, anteroposterior occlusal relationships, and overjet.
• In the first clinical trial, Bollen et al10 compared the effects of material stiffness and activation frequency on the ability to complete Invisalign treatment. The authors concluded that subjects with a 2-week activation frequency, no planned extractions, and low peer assessment rating score were more likely to complete their initial series of Invisalign aligners. The overall completion rate of initial aligners for patients who had 2 or more premolars extracted was only 29%. All subjects who completed their initial series of aligners required case refinement or conversion to fixed appliances.
• percentage of accuracy = 100% − [(|predicted-achieved|/|predicted|) × 100%
• The mean accuracy of Invisalign for all tooth movements was 41%
• All movements had large standard deviations (mean SD = 32.9).
• Maxillary and mandibular canines achieved approximately one third of the predicted rotation.

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• Conclusions: Digital orthodontic models are as reliable as traditional stone models and probably will become the standard for orthodontic clinical use. Storing alginate impressions in sealed plastic bags for up to 4 days caused statistically significant deformation of alginate impressions, but the magnitude of these deformations did not appear to be clinically relevant and had no adverse effect on digital modeling.

• diameter, 1.3 mm; length, 8 mm;
• diameter, 1.5 mm; length, 9 mm
• . Each screw was inserted 5 or 6 mm into the alveolar bone at an angle of 20 to 30 degrees to the long axis of the proximal tooth, and the head of the screw was adjusted to at least 2 mm above the mucosa.
• n the present study, the maxillary first molar was moved to the distal by approximately 3 mm in cephalometric evaluations,

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• digital imaging and communications in medicine (DICOM)
• successive
• digital imaging and communications in medicine (DICOM)
• digital imaging and communications in medicine (DICOM)
• digital imaging and communications in medicine (DICOM)
• onsists o

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• The maximum occlusal force was calculated by using one pressure-indicating film (Dental Prescale 50-H type R; Fuji Film Co Ltd, Tokyo, Japan) per clench.
• The average occlusal force (±SD) was 587.5 N (±264.1 N). The condyles of group II patients (N = 6) were found to be smaller than that of group I patients (N = 6).