Dirk Wiechmann

Publications of Dirk Wiechmann

• The University Munster model surgery system for Orthognathic surgery. Part I - The idea behind.

  Authors: Ulrike Ehmer, Ulrich Joos, Stefanie Flieger, Dirk Wiechmann

  Head & face medicine. 05/2012; 8(1):14.

  ABSTRACT: BACKGROUND: We describe a procedure for diagnosis and planning for orthognatic surgery based on international standards. A special 2D planning based on lateral cephalograms (Axis OrbitalABSTRACT: BACKGROUND: We describe a procedure for diagnosis and planning for orthognatic surgery based on international standards. A special 2D planning based on lateral cephalograms (Axis Orbital Marker Lines System) realize a transmission to the SAM 2P articulator (3D) by means of the Axis Orbital Plane. METHODS: Former intraoperative measurement of the average height of the LeFort I osteotomy plane relative to the molar occlusal plane allow to construct a virtual osteotomy plane in the lateral cephalogram. This is the basis for the development of the Axis Orbital Marker Lines System (AO-MLS). RESULTS: The AO-MLS is presented graphically, and in detail, with construction guidelines. The system could be integrated into various lateral cephalometric analysis- and surgical prediction schemes. It forms the basis for a standardized transfer of the 2D planning to the 3D planning in the articulator, and vice versa. This procedure makes it possible to generate surgical planning protocols based on the model surgery, which represent the dislocations in the proximity of the real osteotomy planes. CONCLUSIONS: The Axis Orbital Marker Lines System (software component) in conjunction with the University Munster Model Surgery System (hardware system) increases the predictability of model operations in orthognathic surgery.

• Control of mandibular incisors with the combined Herbst and completely customized lingual appliance--a pilot study.

  Authors: Dirk Wiechmann, Rainer Schwestka-Polly, Hans Pancherz, Ariane Hohoff

  Head & face medicine. 03/2010; 6:3.

  The traditional Herbst appliance induces mandibular incisor proclination independent of the anchorage system used. The dental effects of the Herbst appliance as an element of a completely customizedThe traditional Herbst appliance induces mandibular incisor proclination independent of the anchorage system used. The dental effects of the Herbst appliance as an element of a completely customized lingual orthodontic (LO) appliance (Incognito, 3 M) has not been analyzed yet and the aim of this paper was to measure the effect of mandibular incisor proclination using this Herbst-LO device. Retrospective study. Inclusion criteria: a) Class II >or= 5 mm molar relationship; b) Herbst appliance >or= 9 months in situ; and c) finished active treatment. Incisor position was measured on digital models before treatment, on the digital target setup, and on digital models obtained at the day of debonding. All measurements were performed by one investigator. Twelve patients (8 females, 4 males) out of 632 cases treated with a lingual appliance were included in the study. The measurement error computed with Dahlberg's formula was 0.2 degrees . Seven cases had planned (target setup) mandibular incisor uprighting (ccr), and five cases had proclination (clockwise rotation). There was no statistical difference (p > 0.05) between planned incisor rotations of the target setup and achieved incisor rotations at the day of debonding. The overall mean difference was 2.2 degrees +/- 1.0 degrees. The Incognito-Herbst combination is the first Herbst device with full control over mandibular incisor movement. Using this system, anchorage loss or anchorage gain is independent of the Herbst treatment. It depends only on the planned tooth position of the individual target setup.

• Herbst appliance in lingual orthodontics.

  Authors: Dirk Wiechmann, Rainer Schwestka-Polly, Ariane Hohoff

  American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics. 10/2008; 134(3):439-46.

  INTRODUCTION: The aims of this article were to outline a technique for attaching Herbst telescopes to a customized lingual orthodontic (LO) appliance and to demonstrate the treatment phases andINTRODUCTION: The aims of this article were to outline a technique for attaching Herbst telescopes to a customized lingual orthodontic (LO) appliance and to demonstrate the treatment phases and outcome with a case report. METHODS: The interface between the LO appliance and the telescopes consists of a computer-aided design/computer-aided manufacturing (CAD/CAM), custom-made labial pivot base connected to the custom-made bands of the maxillary molars and mandibular canines. The individual CAD depiction of the interface ensures an optimal 3-dimensional tube-and-plunger position for correct and smooth function of the telescope mechanism. Because of the lingual location of the brackets, a small buccal tooth-to-telescope distance can be achieved, increasing patient comfort. Various options of anchorage are possible with only 1 device. After bite jumping, the telescopes and pivot bases can be removed easily without debonding the bands or removing the archwires. RESULTS: Experience from the first patient suggests that the Herbst-LO appliance facilitates treatment control during all phases, decreases the risk of interface breakage and mandibular incisor flaring, and might reduce overall treatment time. CONCLUSIONS: These initial clinical observations justify further research to provide evidence about the efficacy of Herbst-LO appliances.

• Prediction of oral discomfort and dysfunction in lingual orthodontics: a preliminary report.

  Authors: Dirk Wiechmann, Joachim Gerss, Thomas Stamm, Ariane Hohoff

  American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics. 04/2008; 133(3):359-64; quiz 476.e1.

  INTRODUCTION: The purpose of this prospective study was to examine the influence of malocclusion on the amount of discomfort of patients who were treated with Incognito lingual brackets (T.O.P.INTRODUCTION: The purpose of this prospective study was to examine the influence of malocclusion on the amount of discomfort of patients who were treated with Incognito lingual brackets (T.O.P. Service, Ormco, Amersfoort, the Netherlands; ibraces in North and South America, Lingualcare, Dallas, Tex). METHODS: Twenty-one female patients (mean age, 24.8 years; SD 10.7) participated in the investigation and completed a standardized questionnaire before and the day after placement of the appliance. One experienced orthodontist, blinded to the results of the questionnaires, evaluated their initial cephalograms and casts with respect to the parameters SNA, SNB, and ANB angles; overjet; overbite; maxillary and mandibular anterior contact-point displacement; crossbite; open bite; and missing teeth. RESULTS: Malocclusion measured on the casts had no significant impact on the amount of discomfort or dysfunction reported by the patients. The SNA (r = -0.619, P = .003) and SNB (r = -0.615, P = .003) angles, however, correlated significantly with the restriction of tongue space; patients with an SNB angle that was smaller than 1 SD from the norm were significantly more prone to experience severe restriction of tongue space (P = .003). CONCLUSIONS: The SNA and SNB angles are predictors for the level of tongue-space restriction after placement of lingual brackets: the smaller the angles, the more prone the patients are to experience discomfort.

• The influence of lead thyroid collars on cephalometric landmark identification.

  Authors: Dirk Wiechmann, Alain Decker, Ariane Hohoff, Johannes Kleinheinz, Thomas Stamm

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 10/2007; 104(4):560-8.

  OBJECTIVE: To investigate whether the application of thyroid collars (TCs) affects cephalometric landmark identification. STUDY DESIGN: A randomized and observer-blinded diagnostic study with headOBJECTIVE: To investigate whether the application of thyroid collars (TCs) affects cephalometric landmark identification. STUDY DESIGN: A randomized and observer-blinded diagnostic study with head films taken from 2 groups was undertaken, with 1 group wearing TCs during radiography (n = 100) and 1 group not wearing TCs (n = 100). The interobserver reproducibility of 15 landmarks was evaluated using 1-way analysis of variance and independent samples t test to compare the groups. RESULTS: The total mean error radius of the non-TC group (1.28 +/- 1.47 mm) was smaller (P < or = .001) than that of the TC group (1.57 +/- 1.58 mm). Three landmarks located on the hyoid bone and on the second and third cervical vertebrae were identified as the main confounding factors. CONCLUSIONS: Personal lead shielding of the thyroid gland affects landmark identification, but the overall clinical effect is negligible. Thyroid collars should be routinely applied during cephalometric radiography if cephalometric analyses are limited to structures above the second cervical vertebra.

• Success rate of mini- and micro-implants used for orthodontic anchorage: a prospective clinical study.

  Authors: Dirk Wiechmann, Ulrich Meyer, André Büchter

  Clinical oral implants research. 05/2007; 18(2):263-7.

  OBJECTIVES: Whereas micro-implants have become a useful alternative as orthodontic anchorage elements in orthodontics, less is known about the clinical effectiveness of micro-implants. The aim ofOBJECTIVES: Whereas micro-implants have become a useful alternative as orthodontic anchorage elements in orthodontics, less is known about the clinical effectiveness of micro-implants. The aim of this prospective clinical study was to evaluate the success rate of micro-implants used for orthodontic anchorage. MATERIAL AND METHODS: A total of 133 mini-implants (79 Abso Anchor, 54 Dual Top implants) placed in 49 patients to support orthodontic tooth movements were examined in the study. The majority of the implants were placed in the maxilla (82), followed by the vestibular (42) and lingual (nine) aspect of the mandible. RESULTS: An overall cumulative survival rate of 86.8% (102/133) was found by Kaplan-Meier analysis. The failure rate between Dual Top implants (13%) and Abso Anchor implants (30.4%) differed significantly (P=0.0196; log-rank test). The cumulative failure rate of implants was found to be significantly higher when implants were placed in the lingual aspect of the mandible compared with the other localizations (P=0.0011; log-rank test). Clinical evaluation revealed successful dental movements when implants remained stable during the orthodontic therapy. CONCLUSIONS: The present results confirm the effectiveness of orthodontic micro-implants used as anchorage elements.

• Load-related bone modelling at the interface of orthodontic micro-implants.

  Authors: André Büchter, Dirk Wiechmann, Christoph Gaertner, Marc Hendrik, Martin Vogeler, Hans-Peter Wiesmann, Josef Piffko, Ulrich Meyer

  Clinical oral implants research. 01/2007; 17(6):714-22.

  The purpose of this study was to determine the interface reaction of two different titanium micro-implant systems activated with different load regimens. A total of 200 micro-implants (100 AbsoThe purpose of this study was to determine the interface reaction of two different titanium micro-implant systems activated with different load regimens. A total of 200 micro-implants (100 Abso Anchor and 100 Dual Top) were placed in the mandible of eight Göttinger minipigs. Two implants each were immediately loaded in the opposite direction by various forces (100, 300 or 500 cN) through tension coils. Three different distances between the neck of the implant and the bone rim (1, 2, 3 mm) were used. The loads provided by superelastic tension coils (which are known to develop a virtually constant force) led to a range of tip moments 0-900 cN mm at the neck of implants. Non-loaded implants were used as a reference. Bone tissue responses were evaluated by histology, histomorphometry and scanning electron microscopy after 22 and 70 days of loading. Implant loosening was present in the groups where the load reached 900 cN mm. No movement of implants through the bone was found in the experimental groups, for any of the applied loads. A direct bone-to-implant contact to various extents was observed at differently loaded implants. Ultrastructural analysis confirmed the clinical and histological finding that implants (except when loaded at 900 cN mm) were well osseointegrated after 22 days. An increase in the bone-to-implant contact ratio was observed during the experimental period in the coronal part of the implants in most experimental groups. The difference reached a level of statistical significance at 500 cN mm (Abso Anchor) and 600 cN mm (Dual Top). We conclude that micro-implants can not only be loaded immediately without impairment of implant stability but many enhance bone formation at the interface when the load-related biomechanics do not exceed an upper limit of tip moment at the bone rim.

• Mini- and micro-screws for temporary skeletal anchorage in orthodontic therapy.

  Authors: Axel Berens, Dirk Wiechmann, Rupert Dempf

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 12/2006; 67(6):450-8.

  OBJECTIVE: Mini- and micro-screws are of increasing interest in orthodontic therapy in cases where maximum anchorage is requested. In this study we aimed to identify the criteria that influence theOBJECTIVE: Mini- and micro-screws are of increasing interest in orthodontic therapy in cases where maximum anchorage is requested. In this study we aimed to identify the criteria that influence the clinical success of micro-implants. MATERIAL AND METHODS: 239 micro-implants were inserted for skeletal anchorage in 85 patients undergoing orthodontic therapy. The survival rates of the first 133 implants were analyzed and those results were later applied in treating subsequent patients. RESULTS: In so doing, we were able to reduce the loss rate from 23% to 5%. Using thicker implants on the labial side of the lower jaw and the lingual side of the upper jaw was an important factor in reducing failure rates. We found the lower jaw's lingual side to be an inadequate region for inserting micro-implants. Thinner micro-implants were selected for the upper jaw's labial side. CONCLUSION: By following these guidelines, practitioners may find mini- and micro-screws to offer reliable orthodontic support.

• Objective growth monitoring of the maxilla in full term infants.

  Authors: Ariane Hohoff, Thomas Stamm, Ulrich Meyer, Dirk Wiechmann, Ulrike Ehmer

  Archives of oral biology. 04/2006; 51(3):222-35.

  OBJECTIVE: To develop a non-invasive method for longitudinal maxillary volume measurements and to provide first normative data. DESIGN: Thirty-four healthy infants served as a gold standard for aOBJECTIVE: To develop a non-invasive method for longitudinal maxillary volume measurements and to provide first normative data. DESIGN: Thirty-four healthy infants served as a gold standard for a growing population sample. Alginate impressions were taken of the upper jaw within the first week after birth, and consecutively at different stages of development. The plaster casts were digitised by an optical scanner generating a high resolution polygon mesh of each object. The digital models were aligned to a reference coordinate system with an iterative, landmark-independent procedure. Biometric linear and volume measurements were obtained by using feature-dependent calculations independent of landmark placements. Intra-investigator reproducibility was tested by repeated alignments and measurements of 30 randomly selected casts. To assess the effect of mesh resolution, the reproducibility test was repeated with low resolution models. The method was proved to be valid on the defined gold standard consisting of 96 consecutive edentulous casts. RESULTS: Feature-dependent, linear distances are less error prone (0.56-2.66%) compared to subjectively determined measurements (0.88-3.65%). The same applies to feature-dependent volume calculations (4.34%) compared to subjectively determined volumes (4.95%). Mesh resolution shows an effect (p<or=0.001) only on two linear measurements: palatal depth and palatal length. Growth of the individuals in the population sample was evidently confirmed by the maxillary volume measurements (asymptotic pattern) and by comparisons of head circumference (proportional pattern). CONCLUSION: The described method is non-invasive, precise and without any risk for the infant. Maxillary volume calculation could serve as an important biometric measurement for bone growth evaluation.

• Comparison of the initial orthodontic force systems produced by a new lingual bracket system and a straight-wire appliance.

  Authors: Lars-Michael Fuck, Dirk Wiechmann, Dieter Drescher

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 10/2005; 66(5):363-76.

  BACKGROUND AND AIM: Over the last few years, lingual appliances have become an established orthodontic treatment technique. Many studies have concentrated on various esthetic aspects, on laboratoryBACKGROUND AND AIM: Over the last few years, lingual appliances have become an established orthodontic treatment technique. Many studies have concentrated on various esthetic aspects, on laboratory and clinical procedures, and on patient comfort and compliance. The orthodontic force systems of these appliances, however, have not yet been investigated. The aim of this study was thus to determine the forces and moments produced by a new lingual bracket system during the leveling phase of orthodontic treatment and to compare those with the corresponding force system of a labial straight-wire appliance. MATERIAL AND METHOD: The intra-oral situation of ten patients undergoing orthodontic treatment was replicated in measurement casts fitted with lingual and labial brackets. Special care was taken to precisely reproduce each patient's interbracket geometry. We measured each tooth's force systems as generated by a leveling arch inserted into the lingual and labial brackets. RESULTS: The resulting force systems of both appliances were found to be quite similar with regard to the magnitude of most force and moment components. Only the first molars were subjected to considerably greater single forces with the lingual appliance. Tipping moments were found to be significantly smaller with the lingual technique, whereas the rotational moments were significantly smaller with the labial appliance. All in all we noted significant differences between the two techniques only in certain areas which upon closer examination were distributed over only a few tooth types. CONCLUSIONS: The initial force systems produced by the new lingual bracket system proved to be comparable with those delivered by a conventional straight-wire appliance. The actual levels of forces and moments, however, were found in certain cases to be too heavy with both techniques. We therefore recommend the development of leveling wires producing considerably lighter forces and moments.

• Load-related implant reaction of mini-implants used for orthodontic anchorage.

  Authors: André Büchter, Dirk Wiechmann, Stefan Koerdt, Hans-Peter Wiesmann, Josef Piffko, Ulrich Meyer

  Clinical oral implants research. 09/2005; 16(4):473-9.

  The purpose of this study was to determine the clinical and biomechanical outcome of two different titanium mini-implant systems activated with different load regimens. A total of 200 mini-implantsThe purpose of this study was to determine the clinical and biomechanical outcome of two different titanium mini-implant systems activated with different load regimens. A total of 200 mini-implants (102 Abso Anchor and 98 Dual Top) were placed in the mandible of eight Göttinger minipigs. Two implants each were immediately loaded in opposite direction by various forces (100, 300 or 500 cN) through tension coils. Additionally, three different distances between the neck of the implant and the bone rim (1, 2 and 3 mm) were used. The different load protocols were chosen to evaluate the load-related implant performance. The load was provided by superelastic tension coils, which are known to develop a virtually constant force. Non-loaded implants were used as a reference. Following an experimental loading period of 22 and 70 days half of the minipigs were sacrificed, and implant containing bone specimens evaluated for clinical performance and implant stability. Implant loosing was found to be statistically dependent on the tip moment (TM) at the bone rim. Clinical implant loosing were only present when load exceeded 900 cN mm. No movement of implants through the bone was found in the experimental groups, for any applied loads. Over the two experimental periods the non-loaded implants of one type of implant had a higher stability than those of the loaded implants. Dual Top implants revealed a slightly higher removal torque compared with Abso Anchor implants. Based on the results of this study, immediate loading of mini-implants can be performed without loss of stability when the load-related biomechanics do not exceed an upper limit of TM at the bone rim.

• Digital design and manufacturing of the Lingualcare bracket system.

  Authors: Magali Mujagic, Coralie Fauquet, Catherine Galletti, Christian Palot, Dirk Wiechmann, James Mah

  Journal of clinical orthodontics : JCO. 07/2005; 39(6):375-82; quiz 370.

• Accuracy of third-order bends of nickel-titanium wires and the effect of high and low pressure during memorizing heat treatment.

  Authors: Thomas Stamm, Ariane Hohoff, Dirk Wiechmann, Jan Sütfeld, Dirk Helm

  American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics. 10/2004; 126(4):476-85.

  This study evaluated the accuracy of third-order bends of nickel-titanium wires and determined the effect of high and low pressure for maintaining the wire shape during memorizing heat treatment. AThis study evaluated the accuracy of third-order bends of nickel-titanium wires and determined the effect of high and low pressure for maintaining the wire shape during memorizing heat treatment. A computer-aided bending machine was used to incorporate 200 randomly determined torsional angles between 0 degrees and 60 degrees into 30 linear 0.016 x 0.022-in NeoSentalloy F80 (GAC International, Central Islip, NY) wires. The torsional bendings were randomized into 2 groups. Bends assigned to group 1 (n = 100) received heat treatment of 1.6 MPa (16 bar) pressure, and bends assigned to group 2 (n = 100) received heat treatment of 50 MPa (500 bar) pressure. Cross-sectional cuts from the bent wires were prepared by using standard metallurgical techniques, and the torsional angles were analyzed under computer control. The results of our study show that third-order bends </= 30 degrees can be made with adequate clinical accuracy with an error of 1.89 degrees +/- 1.75 degrees (0 degrees to 10 degrees ) and 3.57 degrees +/- 1.57 degrees (20 degrees to 30 degrees ), irrespective of the pressure applied. With bends > 30 degrees but </= 40 degrees , the method with the higher pressure offers fundamentally greater precision than that with the lower pressure. With torque bends > 40 degrees , the bending error with both methods is clinically unacceptable. In addition to the variability in the dimension and composition of nickel-titanium wires, the scale of the incorporated plastic deformations makes a substantial contribution to the bending error. As far as permitted by the clinical situation, then, the bend should be distributed over the maximum possible wire length. Third-order bends in the first rectangular pseudoelastic nickel-titanium wires represent an efficient means of effecting torque at an early stage. This individualization allows the full therapeutic potential of these archwires to be exploited right from the initial phase of treatment.

• Customized brackets and archwires for lingual orthodontic treatment.

  Authors: Dirk Wiechmann, Volker Rummel, Andrea Thalheim, Jean-Stefane Simon, Lital Wiechmann

  American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics. 12/2003; 124(5):593-9.

  After 20 months of clinical testing and more than 600 bonded arches, brief interim conclusions can be drawn on treatment with a new lingual bracket system, one that differs fundamentally fromAfter 20 months of clinical testing and more than 600 bonded arches, brief interim conclusions can be drawn on treatment with a new lingual bracket system, one that differs fundamentally from conventional appliances in both design and manufacture. The demand for maximum individuality is met by using state-of-the-art computer-aided design/computer-aided manufacturing technology to fuse the 2 normally separate processes of bracket fabrication and bracket positioning. Both the brackets and the pertinent archwires are customized. Additional advantages of the system include direct and thus simplified rebonding in the event of bracket loss, more precise finishing, and enhanced patient comfort.

• Apical root resorption after lingual orthodontic therapy.

  Authors: Ulrike Fritz, Peter Diedrich, Dirk Wiechmann

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 11/2003; 64(6):434-42.

  PURPOSE: Apical root resorptions are among the undesirable side effects of orthodontic therapy. The aim of the present study was to investigate radiologically whether and to what extent resorptionsPURPOSE: Apical root resorptions are among the undesirable side effects of orthodontic therapy. The aim of the present study was to investigate radiologically whether and to what extent resorptions occur in patients treated solely with a fixed lingual appliance, as well as the pathogenetic relevance of the extent and direction of the therapeutically induced apical movement. PATIENTS AND METHODS: The collective comprised 33 female and seven male patients with a mean age of 24.2 +/- 8.4 years. Permanent lower premolars were extracted in five, and permanent upper premolars in 22 patients. In total, 456 upper and lower incisors and canines were assessed. In order to evaluate the relative change in root length and the sagittal and vertical apical movements, pre- and posttherapeutic panoramic radiographs and/or lateral cephalograms were analyzed. RESULTS: After completion of orthodontic treatment the mean root length was 96.3%, corresponding to a resorption rate of 3.7%. The resorption rates of teeth 11, 12 and 21 differed significantly from those of teeth 31, 32 and 43. Upper incisors presented increased mean resorption rates < or = 10%. Only 18% of the 456 teeth analyzed were affected by pronounced resorptions > 10%. 82% of the teeth were resorption-free. A patient-related evaluation revealed that 26 of the 40 patients had no resorptions > 20%, while 14 had between one and four affected teeth. No significant relationship between extent of resorption and parameters such as age, gender, active treatment time, Angle class, or extent and direction of apical movement was recorded. CONCLUSIONS: The results suggest that lingual orthodontic therapy resulted in only slight root resorptions. Pronounced root shortenings were observed in some patients whose individual predisposition may constitute the main risk factor for the occurrence of root resorptions.

• Effects of a mechanical interdental cleaning device on oral hygiene in patients with lingual brackets.

  Authors: Ariane Hohoff, Thomas Stamm, Nicola Kühne, Dirk Wiechmann, Stephan Haufe, Carsten Lippold, Ulrike Ehmer

  The Angle orthodontist. 11/2003; 73(5):579-87.

  This study was aimed at determining the influence of a battery-operated interdental cleaning device (icd) (WaterPik Flosser) on the oral hygiene of 32 female right-handed patients (mean age 25.9This study was aimed at determining the influence of a battery-operated interdental cleaning device (icd) (WaterPik Flosser) on the oral hygiene of 32 female right-handed patients (mean age 25.9 years) with lingual brackets in the upper (n = 29) and or in the lower arch (n = 25). Approximal plaque index (API) and bleeding on probing (BOP) were recorded at the lingual surfaces by a single blinded examiner before application (t0), on average 38.6 days after (t1), and again on average 46.0 days after (t2) the application of the icd. The patients used the icd once a day in the second and fourth quadrants only (icdq). In all quadrants (icdq and non-icd quadrants [n-icdq]), oral hygiene was performed with a manual toothbrush. Of the patients enrolled in the study, 96.9% found the icd subjectively very helpful to moderately helpful for cleaning their teeth and 65.6% had the subjective impression that their teeth were cleaner with the appliance. Despite those positive subjective assessments, an objective comparison of the icdqs with the n-icdqs revealed no statistically significant differences in the mean changes in API and BOP from t0 to t1, from t0 to t2, or from t1 to t2. Because there were spectacular improvements in API in all quadrants, the improvements could be interpreted as an outcome of the instruction and motivation given to the patients, the increasing awareness of oral hygiene, and the greater skill in using the toothbrush in the course of time.

• A new bracket system for lingual orthodontic treatment. Part 2: First clinical experiences and further development.

  Authors: Dirk Wiechmann

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 10/2003; 64(5):372-88.

  BACKGROUND AND METHOD: Almost 20 months of practical application of a new lingual bracket system have revealed some clinically relevant advantages and disadvantages deriving from the original design.BACKGROUND AND METHOD: Almost 20 months of practical application of a new lingual bracket system have revealed some clinically relevant advantages and disadvantages deriving from the original design. Numerous modifications in the design of the bracket bodies and bases have contributed towards further optimization of the appliance. The efficiency of the appliance is discussed, taking five treated cases as examples. RESULTS AND CONCLUSIONS: The initial demands for low bracket loss rates and simplified rebonding, controlled finishing and enhanced patient comfort have been largely met by the customized design and the flexibility in the manufacture of the new appliance. However, in the triad of orthodontist, patient and appliance that is of such great importance to any orthodontic therapy, any future ideal appliance will still offer no guarantee of a successful treatment outcome.

• Evaluation of the parameters underlying the decision by adult patients to opt for lingual therapy: an international comparison.

  Authors: Ariane Hohoff, Dirk Wiechmann, Didier Fillion, Thomas Stamm, Carsten Lippold, Ulrike Ehmer

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 04/2003; 64(2):135-44.

  BACKGROUND: The present study is the first instance of patients having been questioned on the criteria applied in their decision for therapy with lingual brackets and on the sources of informationBACKGROUND: The present study is the first instance of patients having been questioned on the criteria applied in their decision for therapy with lingual brackets and on the sources of information available to them within the framework of an international comparison prior to the start of therapy by means of a standardized questionnaire. PATIENTS AND METHOD: 68 patients (19 male, 49 female; mean age 32.4 years, range 19.8 to 60.0 years, SD 9.7) were interviewed. RESULTS: Therapy with lingual brackets was more important to the patients in the present study for professional than for private reasons: The further the patients were from the typical "braces age", the more important was treatment with an invisible appliance from the professional standpoint. The patients' educational level had no influence on the decision for a fixed lingual appliance. There was no significant difference between the German and the French patients in the decision-making criteria of adult patients and the sources of information available to them in the context of the lingual technique. CONCLUSION: The information available through the media on the lingual technique is inadequate in both countries.

• A new bracket system for lingual orthodontic treatment. Part 1: Theoretical background and development.

  Authors: Dirk Wiechmann

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 06/2002; 63(3):234-45.

  BACKGROUND AND METHOD: This paper presents a new lingual bracket system differing fundamentally both in design and in manufacturing methods from existing appliances. Using state-of-the-art CAD/CAMBACKGROUND AND METHOD: This paper presents a new lingual bracket system differing fundamentally both in design and in manufacturing methods from existing appliances. Using state-of-the-art CAD/CAM technology, the two normally separate processes of bracket production and bracket positioning are fused into one unit. In this process, the demand for maximum individuality with simultaneously minimized space requirements is put consistently into practice. RESULTS AND CONCLUSION: Improved patient comfort, simplified rebonding in the event of bracket loss, and enhanced finishing precision are the improvements resulting for the course of treatment. In addition, bracket manufacture by a Rapid Prototyping technique permits direct transfer to clinically purposeful further developments.

• Lingual technique--patients' characteristics, motivation and acceptance. Interpretation of a retrospective survey.

  Authors: Ulrike Fritz, Peter Diedrich, Dirk Wiechmann

  Journal of orofacial orthopedics = Fortschritte der Kieferorthopädie : Organ/official journal Deutsche Gesellschaft für Kieferorthopädie. 06/2002; 63(3):227-33.

  AIM: The aim of the present study was to collect personal data of patients treated solely with fixed lingual appliances. In addition, motivation and appliance acceptance were to be assessed. PATIENTSAIM: The aim of the present study was to collect personal data of patients treated solely with fixed lingual appliances. In addition, motivation and appliance acceptance were to be assessed. PATIENTS AND METHODS: The collective comprised 98 patients from our orthodontic clinic (C) and from an orthodontic practice (P). In addition to personal data such as gender, age, profession and marital status, the questionnaire covered the following parameters: initial source of information, motivation, phonetic-functional impairment, and subjective assessment of the treatment outcome. RESULTS: Statistical analysis of the personal data revealed a characteristic type of patient with a preference for lingual treatment: females below 40 years of age, whose preference for the lingual technique was based primarily on esthetic considerations. The main impairment (65%) due to the lingual appliance was reported to be injury to or irritation of the tongue and the restricted functional space for the tongue. The phonetic-functional adaptation period was 1-3 weeks. 99% of the patients were content or very content with the treatment outcome. 87% would recommend the lingual technique without reserve to relatives and friends. The majority of the patients would have refused orthodontic treatment with the labial technique. CONCLUSION: The results indicate that treatment with a fixed lingual appliance appeals to a characteristic patient group. In general, the level of acceptance among patients was positive and impairments during the adaptation period were tolerated after 1-3 weeks. The lingual technique should be integrated into routine orthodontic practice.