The University Münster Model Surgery System for Orthognathic Surgery. Part II -- KD-MMS.

BACKGROUND: Model surgery is an integral part of the planning procedure in orthognathic surgery. Most concepts comprise cutting the dental cast off its socket. The standardized spacer plates of the KD-MMS provide for a non-destructive, reversible and reproducible means of maxillary and/or mandibular plaster cast separation. METHODS: In the course of development of the system various articulator types were evaluated with regard to their capability to provide a means of realizing the concepts comprised of the KD-MMS. Special attention was dedicated to the ability to perform three-dimensional displacements without cutting of plaster casts. Various utilities were developed to facilitate maxillary displacement in accordance to the planning. Objectives of this development comprised the ability to implement the values established in the course of two-dimensional ceph planning. RESULTS: The system - KD-MMS comprises a set of hardware components as well as a defined procedure. Essential hardware components are red spacer and blue mounting plates. The blue mounting plates replace the standard yellow SAM mounting elements. The red spacers provide for a defined leeway of 8 mm for three-dimensional movements. The non-destructive approach of the KD-MMS makes it possible to conduct different model surgeries with the same plaster casts as well as to restore the initial, pre-surgical situation at any time. Thereby, surgical protocol generation and gnathologic splint construction are facilitated. CONCLUSIONS: The KD-MMS hardware components in conjunction with the defined procedures are capable of increasing efficiency and accuracy of model surgery and splint construction. In cases where different surgical approaches need to be evaluated in the course of model surgery, a significant reduction of chair time may be achieved.

The University Münster model surgery system for orthognathic surgery. Part I--the idea behind.

BACKGROUND: We describe a procedure for diagnosis and planning for orthognathic 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 Münster Model Surgery System (hardware system) increases the predictability of model operations in orthognathic surgery.

Orofacial findings in conjunction with infantile cerebral paralysis in adults of two different age groups--a cross-sectional study.

OBJECTIVES: The objective of this cross-sectional study was to assess differentiated malocclusion symptoms and dental findings such as caries prevalence in patients suffering from infantile cerebral paralysis (CP, ICP), as well as the amount of dental and orthodontic treatment. SUBJECTS AND METHODS: Sixty-two patients suffering from infantile cerebral paralysis (ICP) aged from 18 to 78 years were included in the study and assigned to one of two groups according to age. The analysis was carried out on study models that had been measured using a caliper gauge and an electronic model-measuring procedure. Clinical caries status and sociological data were evaluated and statistically analyzed. RESULTS: While the group of older patients underwent no orthodontic treatment, we observed a statistically-significant increase in orthodontic treatment in the younger group with infantile cerebral paralysis. The model analysis revealed a mean overjet of 4.8 mm (SD+/-3.9 mm). There was a tendency toward open bite in terms of the vertical relation, with the mean overbite measuring 1.6 mm (+/-3.7 mm). Comparing the two age groups, we noted that greater age correlated significantly with reduced dental crowding symptoms in the lower jaw, contrary to the more common development of crowding in the normal population. The resulting value of the palatal height index was 40.8%, with no differences between the age groups. Compared to the index of 42.0% (according to the average data in the literature), those participating in this study and suffering from ICP had a flatter palatal vault. Our study parameter "dental intervention per year" revealed that 2/3 of the patients had three dentist appointments per year with no significant difference between the age groups. The ICP patients' mean DMF/T index value was 13.4, which appears to be generally lower than the published values concerning disabled persons in Germany and the healthy population. CONCLUSIONS: We observed an overall correlation between the frequency of malocclusions and severity of mental retardation. The amount of orthodontic treatment was significantly higher in the younger group (32.3%) than the older group (0%). In diagnostic terms, orthodontic treatment should follow the general guidelines, namely, the recommendation of removable devices as treatment appliances, and multidisciplinarily speaking, modified sequences of myofunctional therapy in consideration of the individual compliance prognosis and parental cooperation. In the multidisciplinary coordination of rehabilitation under general anesthesia, specific orthodontic measures may be undertaken (such as taking impressions, limited fixed appliance insertions, controlled extractions). An early treatment start in combination with the appropriate orthodontic device is desirable because of the improved, trainable reflex pattern. The dental therapy results are generally positive due to the fact that our patients met a tight dental recall schedule.

Analysis of condylar differences in functional unilateral posterior crossbite during early treatment--a randomized clinical study.

OBJECTIVE: The analysis of potential discrepancies in condyle position among different occlusal relations (centric relation and maximum intercuspidation) is a key diagnostic component when treating children with unilateral posterior crossbite. Due to strict requirements imposed by ethics committees, and new regulations regarding the use of X-rays, radiological examinations (axial cephalometric radiographs or postero-anterior cephalometric radiographs) are not feasible. Thus the aim of this study was to apply an alternative procedure for the assessment of condylar deviations. PROBANDS AND METHODS: : We employed ARCUS digma, a measuring system based on ultrasound technology, to record condylar differences occurring in 65 children (6.9+/-2.0 years of age) with functional unilateral posterior crossbite in late deciduous and early mixed dentition. After randomization, 31 patients underwent early orthodontic treatment (bonded palatal expansion appliance and U-bow activator), whereas 34 patients remained untreated. Examinations were carried out at the beginning (T1) and after 12 months of treatment (T2). A three-dimensional (3D) assessment of deviations between maximum intercuspidation and centric position was carried out. Statistical analysis was performed using the SPSS 12.0 software program. RESULTS: Initially, the electronic position analysis revealed no significant differences between the control and therapy groups. A mean condylar deviation of > 2 mm was noted at T1 in the sagittal, frontal and transversal planes for crossbite and the noncrossbite sides. This difference was reduced in the therapy group, a finding that proved statistically highly significant (p<0.001). We also observed a highly significant (p<0.001) difference between the control and therapy groups at T2. CONCLUSION: The Münster concept for early treatment of functional unilateral posterior crossbites in late deciduous and early mixed dentition significantly improved the treated patients' occlusion in comparison to a randomized control group, which exhibited no spontaneous self-healing tendencies.

The spectrum of Apert syndrome: phenotype, particularities in orthodontic treatment, and characteristics of orthognathic surgery.

In the PubMed accessible literature, information on the characteristics of interdisciplinary orthodontic and surgical treatment of patients with Apert syndrome is rare. The aim of the present article is threefold: (1) to show the spectrum of the phenotype, in order (2) to elucidate the scope of hindrances to orthodontic treatment, and (3) to demonstrate the problems of surgery and interdisciplinary approach.Children and adolescents who were born in 1985 or later, who were diagnosed with Apert syndrome, and who sought consultation or treatment at the Departments of Orthodontics or Craniomaxillofacial Surgery at the Dental School of the University Hospital of Münster (n = 22; 9 male, 13 female) were screened. Exemplarily, three of these patients (2 male, 1 female), seeking interdisciplinary (both orthodontic and surgical treatment) are presented. Orthodontic treatment before surgery was performed by one experienced orthodontist (AH), and orthognathic surgery was performed by one experienced surgeon (UJ), who diagnosed the syndrome according to the criteria listed in OMIM. In the sagittal plane, the patients suffered from a mild to a very severe Angle Class III malocclusion, which was sometimes compensated by the inclination of the lower incisors; in the vertical dimension from an open bite; and transversally from a single tooth in crossbite to a circular crossbite. All patients showed dentitio tarda, some impaction, partial eruption, idopathic root resorption, transposition or other aberrations in the position of the tooth germs, and severe crowding, with sometimes parallel molar tooth buds in each quarter of the upper jaw.Because of the severity of malocclusion, orthodontic treatment needed to be performed with fixed appliances, and mainly with superelastic wires. The therapy was hampered with respect to positioning of bands and brackets because of incomplete tooth eruption, dense gingiva, and mucopolysaccharide ridges. Some teeth did not move, or moved insufficiently (especially with respect to rotations and torque) irrespective of surgical procedures or orthodontic mechanics and materials applied, and without prognostic factors indicating these problems. Establishing occlusal contact of all teeth was difficult. Tooth movement was generally retarded, increasing the duration of orthodontic treatment. Planning of extractions was different from that of patients without this syndrome.In one patient, the sole surgical procedure after orthodontic treatment with fixed appliances in the maxilla and mandible was a genioplasty. Most patients needed two- jaw surgery (bilateral sagittal split osteotomy [BSSO] with mandibular setback and distraction in the maxilla). During the period of distraction, the orthodontist guided the maxilla into final position by means of bite planes and intermaxillary elastics.To our knowledge, this is the first article in the PubMed accessible literature describing the problems with respect to interdisciplinary orthodontic and surgical procedures. Although the treatment results are not perfect, patients undergoing these procedures benefit esthetically to a high degree.Patients need to be informed with respect to the different kinds of extractions that need to be performed, the increased treatment time, and the results, which may be reached using realistic expectations.

In-vitro investigations on suitability of light-cured resins for interocclusal splints: part I: mechanical properties.

OBJECTIVE: It was the aim of the present study to investigate the material properties of different resins and their suitability for the fabrication of occlusal and intermaxillary splints. MATERIAL AND METHOD: We subjected auto-polymerized resins (Palapress, Orthocryl, Steady-Resin M) and light-polymerized resins (Acrylight, Primosplint, Triad TranSheet Colorless and Pink) to investigation. The Targis Power light oven was used to polymerize the light-cured resins. After the auto-polymerized resins had been mixed by hand and filled into the forms, they were polymerized for 15 minutes in a high-pressure polymerization machine (Palamat) at 2 bar. The parameters examined were flexural strength, water adsorption, and polymerization shrinkage. Tests carried out according to DIN EN ISO 1567 served to determine flexural strength, flexural modulus, and water adsorption. Polymerization shrinkage was determined via the buoyancy test. RESULTS: The resins' flexural strength ranged from 60 to 101 MPa. Flexural moduli lay between 1.3 and 5.3 GPa. The water adsorption noted in light-cured resins amounted to 2.1-4.6 mass percent. Palapress and Steady-Resin displayed the lowest water adsorption with 2.0 mass percent. The light-polymerized resins revealed significantly less shrinkage (p < 0.05) than the autopolymerized resins tested in this study. CONCLUSION: Our results demonstrate that the light-cured resins-with the exception of Acrylight -easily match and even exceed the material properties of the cold-polymerized resins regarding flexural strength, flexural modulus, water adsorption and polymerization shrinkage. The light-cured resins examined thus seem suitable for use as splint material.

In-vitro investigation on suitability of light-cured resins for interocclusal splints : part II: surface hardness.

OBJECTIVE: The aim of the present study was to determine the surface hardness of light- and auto-cured resins for the fabrication of occlusal splints employing Vickers hardness measurements. MATERIALS AND METHOD: In this study we used three auto-polymerized resins (Palapress, Orthocryl, Steady-Resin M) and four light-polymerized resins (Acrylight, Primosplint, Triad Tran- Sheet Colorless and Triad TranSheet Pink). The Vickers hardness measurement was carried out by means of a universal Durimet indenter applying a test load of 50 g for 30 seconds. The light-cured resins were polymerized in a Tagris Power light oven for 10 and 15 minutes each. Three separate test series were carried out (the hardness of plates under optimal conditions and of occlusal splints was measured, and the curing of light-polymerizing materials in layers of varying depth was evaluated). Data underwent statistical analysis via ANOVA and the Scheffé test. RESULTS: The microhardness determined in each case amounted to values between 10.4 HV 0.5 and 39.3 HV 0.5. The Vickers hardness determined for the plates that had been produced under optimal conditions demonstrated that their surface was significantly (p < 0.05) harder than that of cylinders and splints. The hardness values of the light-cured material Triad TranSheet Pink (39.3 HV 0.5) were significantly higher (p < 0.05) than those of all other resins. In all auto-polymerized resins, the surface hardness of the samples we examined (in the form of plates and splints) was significantly lower (p < 0.05) than that of the light-cured materials Triad TranSheet Pink and Colorless. CONCLUSION: The results we have obtained so far concerning surface hardness indicate that, in the fabrication of occlusal splints, light-cured resins may represent an alternative to auto-polymerizing materials.

Objective growth monitoring of the maxilla in full term infants.

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 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

Palatal development of preterm and low birthweight infants compared to term infants - What do we know? Part 1: The palate of the term newborn.

BACKGROUND: The evidence on prematurity as 'a priori' a risk for palatal disturbances that increase the need for orthodontic or orthognathic treatment is still weak. Further well-designed clinical studies are needed. The objective of this review is to provide a fundamental analysis of methodologies, confounding factors, and outcomes of studies on palatal development. One focus of this review is the analysis of studies on the palate of the term newborn, since knowing what is 'normal' is a precondition of being able to assess abnormalities. METHODS: A search profile based on Cochrane search strategies applied to 10 medical databases was used to identify existing studies. Articles, mainly those published before 1960, were identified from hand searches in textbooks, encyclopedias, reference lists and bibliographies. Sources in English, German, and French of more than a century were included. Data for term infants were recalculated if particular information about weight, length, or maturity was given. The extracted values, especially those from non-English paper sources, were provided unfiltered for comparison. RESULTS: The search strategy yielded 182 articles, of which 155 articles remained for final analysis. Morphology of the term newborn's palate was of great interest in the first half of the last century. Two general methodologies were used to assess palatal morphology: visual and metrical descriptions. Most of the studies on term infants suffer from lack of reliability tests. The groove system was recognized as the distinctive feature of the infant palate. The shape of the palate of the term infant may vary considerably, both visually and metrically. Gender, race, mode of delivery, and nasal deformities were identified as causes contributing to altered palatal morphology. Until today, anatomical features of the newborn's palate are subject to a non-uniform nomenclature. CONCLUSION: Today's knowledge of a newborn's 'normal' palatal morphology is based on non-standardized and limited methodologies for measuring a three-dimensional shape. This shortcoming increases bias and is the reason for contradictory research results, especially if pathologic conditions like syndromes or prematurity are involved. Adequate measurement techniques are needed and the 'normal palatal morphology' should be defined prior to new clinical studies on palatal development.

Palatal development of preterm and low birthweight infants compared to term infants - What do we know? Part 2: The palate of the preterm/low birthweight infant.

BACKGROUND: Well-designed clinical studies on the palatal development in preterm and low birthweight infants are desirable because the literature is characterized by contradictory results. It could be shown that knowledge about 'normal' palatal development is still weak as well (Part 1). The objective of this review is therefore to contribute a fundamental analysis of methodologies, confounding factors, and outcomes of studies on palatal development in preterm and low birthweight infants. METHODS: An electronic literature search as well as hand searches were performed based on Cochrane search strategies including sources of more than a century in English, German, and French. Original data were recalculated from studies which primarily dealt with both preterm and term infants. The extracted data, especially those from non-English paper sources, were provided unfiltered for comparison. RESULTS: Seventy-eight out of 155 included articles were analyzed for palatal morphology of preterm infants. Intubation, feeding tubes, feeding mode, tube characteristics, restriction of oral functions, kind of diet, cranial form and birthweight were seen as causes contributing to altered palatal morphology. Changes associated with intubation concern length, depth, width, asymmetry, crossbite, and contour of the palate. The phenomenon 'grooving' has also been described as a complication associated with oral intubation. However, this phenomenon suffers from lack of a clear-cut definition. Head flattening, pressure from the oral tube, pathologic or impaired tongue function, and broadening of the alveolar ridges adjacent to the tube have been raised as causes of 'grooving'. Metrically, the palates of intubated preterm infants remain narrower, which has been examined up to the age of the late mixed dentition. CONCLUSION: There is no evidence that would justify the exclusion of any of the raised causes contributing to palatal alteration. Thus, early orthodontic and logopedic control of formerly orally intubated preterm infants is recommended, as opposed to non-intubated infants. From the orthodontic point of view, nasal intubation should be favored. The role that palatal protection plates and pressure-dispersing pads for the head have in palatal development remains unclear.

Palatal development of preterm and low birthweight infants compared to term infants -- What do we know? Part 3: discussion and conclusion.

BACKGROUND: It has been hypothesized that prematurity and adjunctive neonatal care is 'a priori' a risk for disturbances of palatal and orofacial development which increases the need for later orthodontic or orthognathic treatment. As results on late consequences of prematurity are consistently contradictory, the necessity exists for a fundamental analysis of existing methodologies, confounding factors, and outcomes of studies on palatal development in preterm and low birthweight infants. METHOD: A search of the literature was conducted based on Cochrane search strategies including sources in English, German, and French. Original data were recalculated from studies which primarily dealt with both preterm and term infants. The extracted data, especially those from non-English paper sources, were provided unfiltered in tables for comparison (Parts 1 and 2). RESULTS: Morphology assessment of the infant palate is subject to non-standardized visual and metrical measurements. Most methodologies are inadequate for measuring a three-dimensional shape. Several confounding factors were identified as causes contributing to disturbances of palatal and orofacial development. CONCLUSION: Taking into account the abovementioned shortcomings, the following conclusions may be drawn for practitioners and prospective investigators of clinical studies. 1) The lack of uniformity in the anatomical nomenclature of the infant's palate underlines the need for a uniform definition. 2) Metrically, non-intubated preterm infants do not exhibit different palatal width or height compared to matched term infants up to the corrected age of three months. Beyond that age, no data on the subject are currently available. 3) Oral intubation does not invariably alter palatal morphology of preterm and low birthweight infants. 4) The findings on palatal grooving, height, and asymmetry as a consequence of orotracheal intubation up to the age of 11 years are inconsistent. 5) Metrically, the palates of orally intubated infants remain narrower posteriorly, beginning at the second deciduous molar, until the age of 11 years. Beyond that age, no data on the subject are currently available. 6) There is a definite need for further, especially metrical, longitudinal and controlled trials on palatal morphology of preterm and low birthweight infants with reliable measuring techniques. 7) None of the raised confounding factors for developmental disturbances may be excluded until evident results are presented. Thus, early orthodontic and logopedic control of formerly premature infants is recommended up to the late mixed dentition stage.

A subjective comparison of two lingual bracket systems.

The purpose of this prospective, longitudinal study was to compare the influence of two lingual bracket systems on subjective oral comfort, speech, mastication and oral hygiene. Forty-two native speakers of standard German (32 females, 10 males; mean age 27.1 years, standard deviation 12.2) were enrolled and completed a standardized questionnaire directly before insertion of lingual brackets (T0), within 24 hours of bond-up (T1) and 3 months (+/- 1 week) later (T2). Eighteen of the patients were treated with prefabricated brackets (Ormco, seventh generation) (PB group) and 24 with customized brackets (Incognito) (CB group). While no significant intergroup differences were recorded at any of the times with respect to tongue position, conversation pattern, swallowing or oral hygiene, the CB group experienced significantly fewer tongue space restrictions, speech disturbances and impairments in chewing and biting than the PB group at T1 and T2. At T2, pressure sores, reddening or lesions to the tongue were recorded significantly less often in the CB group than in the PB group. This enhanced patient comfort in the CB group was attributed to the smaller dimensions of the customized brackets. This aspect could play a role in attracting more patients to lingual orthodontics in the future. Information given to the patient on the duration and extent of the restrictions associated with lingual orthodontics must be differentiated according to the bracket system used.

Comparison of the effect on oral discomfort of two positioning techniques with lingual brackets.

Using a standardized questionnaire, 41 patients (12 men, 29 women; mean age 31.5 +/- 12.1 years) were interviewed prospectively on their subjective oral comfort, various oral functions, and professional qualification before indirect application of lingual brackets (T0), within 24 h of application (T1), and three months later (+/- 1 week) (T2). In 22 of the 41 patients, the brackets were positioned with the Bonding with Equalized Specific Thickness (BEST) technique (BEST group) and in 19 patients by the Transfer Optimized Positioning (TOP) method (TOP group). Despite positive adaptation, the patients in both groups still reported a significant deficiency in tongue space at T2 as well as significantly more frequent lesions to the tongue. The BEST group was affected significantly more often by these problems than the TOP group. At T2, the tongue position was also rated as changed significantly more often in the BEST group than in the TOP group. Although the BEST positioning technique leads to greater impairments in oral comfort than the TOP technique, it offers the orthodontist the advantage of less bending input. In both techniques, there is a need for detailed briefing of patients about the extent and duration of impairments induced by lingual brackets.

Comparison of 3 bonded lingual appliances by auditive analysis and subjective assessment.

The aim of this prospective study was to compare for the first time the influences of lingual appliances of different dimensions on sound performance and oral comfort. The study group comprised 12 subjects (10 women, 2 men; mean age, 33.96 years). Their sound production was recorded by means of a digital audio tape recorder before, 10 minutes after, and 24 hours after placement of the different appliances for semiobjective assessment by 3 blinded speech professionals. This was followed by supplementary subjective ratings of sound performance and oral comfort by the patients. All lingual appliances induced significant impairment in sound performance and oral comfort. However, they varied significantly with respect to the degree of impairment. The smaller the appliance, the less pronounced the impairments it induced. The smallest changes were induced by a bonded canine-to-canine retainer, followed by customized lingual brackets and prefabricated lingual brackets. By using lower-profile customized brackets, the orthodontist can significantly enhance patient comfort and significantly reduce impairments of sound performance in comparison with prefabricated brackets with larger dimensions. Before placing a lingual appliance, however, patients should be briefed on possible effects such as impaired sound production and decreased oral comfort.

Interdisciplinary study of orthopedic and orthodontic findings in pre-school infants.

BACKGROUND AND AIM: The assessment of correlations between orthopedic and orthodontic data based on interdisciplinary studies is of scientific and practical interest in the differentiation of preventive diagnostic and therapeutic fields between orthodontics and orthopedics. In the published literature there are various studies analyzing the correlations between specific Angle classes and orthopedic parameters. Results of these studies indicate a potential correlation between scoliosis and Class II malocclusion as well as between weak body posture and Class II malocclusion. The aim of the present interdisciplinary study was to examine correlations between orthodontic and orthopedic findings in pre-school infants and to evaluate them with respect to preventive recommendations. PATIENTS AND METHOD: 59 pre-school infants (29 boys, 30 girls) aged 3.5-6.8 years (mean: 5.0 years) were enrolled in this study. A standardized orthodontic and orthopedic examination protocol was used. RESULTS: The orthodontic examination showed Angle class distributions comparable with those in non-selected groups (Class I: 63%, Class II: 32%, Class III: 5%). The orthopedic examination revealed pathologic findings in 52% of the subjects, with statistically significant correlations between scoliosis and Class II malocclusion (p = 0.033) and between weak body posture and Class II malocclusion (p = 0.028). CONCLUSION: It can be concluded from the results that the orthodontic finding of Angle Class II in pre-school infants should induce prophylactic screening. The orthodontist could then not only initiate early orthodontic treatment to prevent incisor trauma in patients with extreme overjet, but could also take account of potential orthopedic malformations on a preventive interdisciplinary basis in pre-school infants with Class II malocclusions.

Oral comfort, function and hygiene in patients with lingual brackets. A prospective longitudinal study.

BACKGROUND: Oral comfort, speech, mastication and swallowing, as well as oral hygiene were to be evaluated in a prospective longitudinal study before and after insertion of lingual brackets. PATIENTS AND METHOD: 22 patients (five male, 17 female, mean age 34.7 years, SD 10.4) were enrolled in the study and filled in a standardized questionnaire directly before placement of lingual brackets (T0), within 24 hours thereafter (T1), and 3 months (+/- 1 week) later (T2). At both T1 and T2, treatment was confined to the upper arch. RESULTS: In comparison with T0, significantly poorer results were recorded at T2 for the parameters "restriction of the tongue space", "lesions to the tongue", "tongue position", "subjective and semiobjective rating of articulation", "chewing", "biting" and "oral hygiene", although significant improvements, i.e. adaptations, had been recorded from T1 to T2 with the exception of the parameters "tongue space", "tongue position", "chewing", "biting" and "oral hygiene". At none of the registration timepoints was fluid intake impaired by the lingual brackets. CONCLUSION: The results of the present study suggest that detailed briefing on the extent and duration of potential impairments in oral comfort, functions and hygiene is advisable prior to the insertion of lingual brackets.

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

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 25.9 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.

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

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 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.

Speech performance in lingual orthodontic patients measured by sonagraphy and auditive analysis.

Esthetically appealing, externally invisible, lingually applied orthodontic brackets are in increasing demand. Because the brackets are placed lingually, however, they appear to cause some problems with respect to speech. This study is the first to present a prospective evaluation of the articulation of 23 patients with lingual brackets by means of an innovative combination of test methods. An acoustic, objective evaluation of articulation measured by digital sonagraphy was related to a semiobjective auditive evaluation by 10 speech professionals, to a semiobjective auditive evaluation by close contacts of the patients, and to a subjective auditive evaluation by the patients themselves, the latter 2 using standardized questionnaires. The tests were performed before (T1), within 24 hours after (T2), and 3 months (+/- 1 week) after (T3) the start of therapy. In comparison with the initial findings, a significant deterioration in articulation was recorded with all test methods at T2 and T3. Using a new combination of methods, our investigations show the need for detailed briefing of patients about the extent and duration of changes in speech resulting from lingual brackets.

Optimizing presurgical orthodontic planning by means of the transverse coordinate simulation system (TCSS).

INTRODUCTION: When planning bilateral sagittal split osteotomies according to Obwegeser and Dal Pont, inaccuracies in the presurgical prediction of the transverse osteotomy gaps may occur. This is due to limitations of plaster models when simulating surgery on an articulator. AIM: This paper demonstrates the transverse coordinate simulation system which allows presurgical prediction of the transverse discrepancy between the tooth bearing and the proximal segment after displacement, thus minimizing uncertainty for the surgeon. METHOD: Diagnostic landmarks (taken from lateral and frontal cephalograms) and clinical data describing mandibular dimensions are transferred to a two-dimensional coordinate diagram. A mandibular model is then constructed using the anterior arch form, the temporomandibular joint distance and the prospective incision pattern. RESULT: Movements in the horizontal plane and displacement of the three segments (two condylar and one mandibular arch segment) can be simulated and measured. CONCLUSION: Transverse coordinate simulation system effectively increases the accuracy of presurgical planning without additional CT data or three-dimensional jaw models. This technique may decrease the number of additional surgical manoeuvres resulting from unexpectedly wide transverse discrepancies at the osteotomy site, which often increase surgery time, necessitate additional bone grafting, and entail the risk of healing disturbances and of malrotation or dislocation of the condyle.