Orthodontic treatment need in a representative adult cohort.

BACKGROUND AND OBJECTIVE: There is currently no representative information for central Germany on the prevalence of dental malalignments and jaw discrepancies in permanent dentition. The aim of this study was to describe the extent of tooth and jaw malformations in a representative adult population according to conventional orthodontic indices. SUBJECTS AND METHODS: Three dimensionally (3D)-oriented study casts were measured from a representative sample of adults from the Halle and Leipzig urban areas consisting of 102 men and 143 women aged between 18 and 39 years, yielding a total of 245 volunteers. The index values we determined were the Index of Orthodontic Treatment Need (IOTN), the German Orthodontic Indication Groups (OIG) and the Occlusal Index (OI). The descriptive evaluation of the data and group comparisons (U test, chi(2) test) were performed with SPSS® 13.0. RESULTS: More than half of the adults we examined were assessed as needing treatment according to the IOTN (61.6%), the German OIG (59.6%) and the OI (58.4%; intermediate severity = 5.92). We observed no significant differences in age or gender. CONCLUSION: This is the first time that the prevalence of orthodontic findings has been documented for the central German area in a cohort representative of the population. Our results reveal a great need for therapy. As the classifications describe different patient groups, the individual need for treatment is inadequately documented.

Assessment of quality of life in patients undergoing orthognathic surgery.

CLINICAL QUESTION: Analysis to date on the impact of a pronounced skeletal dentofacial deformity on quality of life remains inadequate. OBJECTIVE: The objective of this study was to introduce a validated and internationally comparable questionnaire for the assessment of quality of life, and to use this questionnaire in a consecutively-selected patient cohort. MATERIAL AND METHODS: The Orthognathic Quality of Life Questionnaire (OQLQ) used internationally was translated into German and adapted in accordance with EU guidelines (OQLQ-G). A total of 50 patients (f = 25, m = 25) indicated for combined orthodontic and surgical treatment were included in the study. In addition to the assessment of individual questions, the patients were classified according to the following categories: (1) perception of the malocclusion, (2) masticatory function, (3) esthetics, and (4) social aspects. The statistics were assessed with software SPSS((R)) 15.0 (chi-squared test; p = 0.05). RESULTS: Patients with a pronounced dentofacial malocclusion demonstrated a considerably high awareness of the degree of the deformity. Responses frequently included severe and very severe functional restrictions (50.4%) and/or esthetic impairment (43.0%). With regard to social aspects, the responders also reported a reduction in quality of life. CONCLUSION: An internationally-comparable assessment of quality of life in patients with a pronounced jaw discrepancy was carried out for German-speaking countries. This pilot study demonstrates that their quality of life is significantly impaired.

Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material.

The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG) and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005). Data were analyzed by ANOVA (p=0.05) and Bonferroni post hoc test (p=0.05). In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N). Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test) were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N). Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test). In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material

The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG) and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005). Data were analyzed by ANOVA (p=0.05) and Bonferroni post hoc test (p=0.05). In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N). Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test) were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N). Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test). In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

Influence of different brazing and welding methods on tensile strength and microhardness of orthodontic stainless steel wire.

The aim of this study was to compare the mechanical strength and microhardness of joints made by conventional brazing and tungsten inert gas (TIG) and laser welding. A standardized end-to-end joint configuration of the orthodontic wire material in spring hard quality was used. The joints were made using five different methods: brazing (soldering > 450 degrees C) with universal silver solder, two TIG, and two laser welders. Laser parameters and welding conditions were used according to the manufacturers' guidance. The tensile strengths were measured with a universal testing machine (Zwick 005). The microhardness measurements were carried out with a hardness tester (Zwick 3202). Data were analysed using one-way analysis of variance and Bonferroni's post hoc correction (P < 0.05). In all cases, brazing joints ruptured at low levels of tensile strength (198 +/- 146 MPa). Significant differences (P < 0.001) between brazing and TIG or laser welding were found. The highest means were observed for TIG welding (699-754 MPa). Laser welding showed a significantly lower mean tensile strength (369-520 MPa) compared with TIG welding. Significant differences (P < 0.001) were found between the original orthodontic wire and the mean microhardness at the centre of the welded area. The mean microhardness differed significantly between brazing (1.99 GPa), TIG (2.22-2.39 GPa) and laser welding (2.21-2.68 GPa). For orthodontic purposes, laser and TIG welding are solder-free alternatives to joining metal. TIG welding with a lower investment cost is comparable with laser welding. However, while expensive, the laser technique is a sophisticated and simple method.

The influence of different disinfectants on primary impression materials.

OBJECTIVE: To investigate the dimensional changes and the surface quality of dental impression materials after disinfection with 3 chemically different agents. METHOD AND MATERIALS: Four alginate impression materials and 1 addition silicone material were selected. The impressions were made from a brass model simulating a 3-unit fixed partial denture. The chemical disinfection was performed with 3 different disinfectants for 10 minutes. Three samples of each impression material and disinfectant agent were investigated. As a control, 3 impressions of each material were made without any disinfection. The casts were made with a type IV dental stone. For each cast, 6 diameters and 3 distances were measured. To evaluate the dimensional stability, measurements were taken at a magnification of 34X with a light microscope. The surface quality was recorded using a profilometer. RESULTS: The dimensional change and surface quality differed minimally; however, statistically significant differences were found between alginate and addition silicone impression materials (ANOVA, P < .05). Casts from the silicone impressions were more accurate than the casts from alginate impressions. CONCLUSION: Different impression disinfection methods have only a marginal influence on dimensional stability and surface quality of dental casts. To achieve a higher precision, the use of an addition silicone can be recommended.

Reliability of the Beighton Hypermobility Index to determinate the general joint laxity performed by dentists.

UNLABELLED: The findings in the literature concerning an association between general joint laxity (GJL) and temporomandibular disorders (TMDs) are inconsistent. Both differences in study designs and the lack of information about the precision of GJL measurements may be contributing to this inconsistency. AIM: The aim of this study was thus to investigate the reliability (the inter-rater and intra-rater test-retest reliability and internal consistency) of GJL measurements taken by dentists in a general dental practice setting. MATERIAL AND METHODS: A cohort of 50 patients ranging from 20 to 60 years in age (56% female) from a general dental practice was examined twice by two dentists addressing the GJL according to the Beighton Index. The second exam took place after 4 weeks. The inter-rater and intra-rater reliability of measurements was calculated using the intraclass correlation coefficient (ICC). Cronbach's alpha was used to assess the measurements' internal consistency. RESULTS: Inter- and intra-rater reliability was found to be very good to excellent (ICC: 0.84-0.94). Cronbach's alpha (mean 0.75, range 0.66-79) yielded acceptable internal consistency measurements. CONCLUSION: The Beighton Index is a reliable instrument for dentists when assessing general joint laxity.

The importance of temporomandibular function for patient satisfaction following orthognathic surgery.

AIM: From the patient's point of view, the main reasons for undertaking orthognathic surgical treatment are esthetic improvements in dentofacial appearance. The aim of this study was to analyze various factors that influence patient satisfaction regarding treatment results. PATIENTS AND METHODS: A total of 102 (f = 67, m = 35) patients were examined after an average follow-up of 47 months. The average age at surgical intervention was 24.3 years. We evaluated the answers to a patient-satisfaction questionnaire, the Helkimo Index findings, nerve function parameters, and the frequency of intra- and post-operative complications. RESULTS: 91% of the patients were satisfied or very satisfied with the result. Answers to the questionnaire revealed that 80 (79%) patients would undergo treatment again, and 22 (21%) patients would not. There were no significant differences between the two groups concerning age, gender, type of surgical intervention, diagnosis, nerve function and complications. Statistically-significant differences were found in the Helkimo Index D 0 - D III, and pain reported in joints and movements (chi(2)-test, p < 0.05). CONCLUSIONS: We demonstrate that treatment results were influenced by the craniomandibular functional status. More pronounced symptoms of craniomandibular dysfunction correlated with lower patient satisfaction.

Evaluation of vertical parameters in cephalometry.

AIM: The aim of this study was to determine the validity of different vertical parameters in cephalometry. MATERIALS AND METHODS: The cephalograms of 94 patients were used in this study. The inclusion criteria were as follows: skeletal Class I, completion of maximum skeletal growth, and no history of orthodontic therapy. The control group consisted of 34 subjects with very good occlusion (overbite 2-4 mm). The patients were classified with the help of dental casts: Group 1 (n = 31) patients with cover-bite (overbite > 5.5 mm) and Group 2 (n = 29) patients with anterior open bite (overbite < -0.5 mm). In addition to the 24 standard cephalometric measurements (Bergen-Analysis), we included individualized norm values (Segner & Hasund), the Overbite Depth Indicator (ODI) described by Kim, the Denture Frame Analysis (DFA) described by Sato, and facial-type evaluations according to Schopf. RESULTS: We observed significant differences among the three study groups in all the vertical parameters tested. We demonstrated statistically-significant classification results for the Segner & Hasund harmony box's individualized norm values (83.8%), and those of the ODI (77.7%) and ML-AB angle (76.6%). CONCLUSIONS: Based on the vertical cephalometric parameters, we succeeded in statistically differentiating among the groups with open bite, cover-bite and the control group. Various measurements must be taken to ensure that the cephalometric vertical relationships are reliably evaluated.

Classification of anterior open bite using individualized cephalometry.

OBJECTIVE: The objective of this study was to describe the cephalometric characteristics of the open bite, and to classify the open bite according to individualized norms. MATERIAL AND METHOD: The lateral cephalograms of 134 patients with an anterior open bite (min -0.5 mm) were analyzed. Patients were classified according to the inclination of the jaws, applying the principles of individualized cephalometry. The harmony box described by Hasund was used to define individualized norms for the inclination of the upper and lower jaws in each patient. The open bite was classified into four sub-types: (1) dental, (2) skeletal with enlarged ML-NSL angle, (3) skeletal with reduced ML-NSL angle, and (4) skeletal with deviations in upper and lower jaws. A skeletal open bite was found in 89 patients (66.4%). A dental open bite was found in 45 patients (33.6%). RESULTS: A number of significant differences were found between these four groups using single-factor variance analysis and the Bonferroni a posteriori test, (p < or = 0.05, p < or = 0.01, p < or = 0.001). The most prominent variables were index value of anterior facial hight, total facial height ratio, gonial angle, and Y-axis. No significant differences were found for overbite, however. CONCLUSION: It was possible to use individualized norms to classify the open bite into four sub-types. The demarcation between the four groups was supported statistically. The extent of the anterior open bite does not allow any conclusions as to the craniofacial pattern.

Possibilities and limitations of comprehensive treatment of mentally retarded patients with cleft lip, alveolus and palate.

The comprehensive, successful treatment of patients with cleft lip, alveolus and palate requires numerous surgical interventions and very close cooperation between various medical and dental specialists. The willingness and ability of the patient to undergo treatment are undoubtedly important factors in achieving optimal treatment outcomes. The presented case report shows that limited compliance makes it much more difficult for speech pathologists and orthodontists to treat mentally retarded patients. Only with combined orthodontic therapy and orthognathic surgery could the dental and skeletal abnormalities be corrected in adulthood.