Compressive force strengthened the pro-inflammatory effect of zoledronic acid on il-1ß stimulated human periodontal fibroblasts.

OBJECTIVES: The number of patients in dentistry taking bisphosphonates (BP) increases every year. There are only little data about the influence of biomechanical stress due to orthodontic treatment and periodontal inflammation in BP patients. This study focused on the effects of the induced inflammation by IL-1ß in compressed human periodontal ligament fibroblasts (HPdLF) exposed to the nitrogen-containing BP zoledronate in vitro. MATERIALS AND METHODS: HPdLF were incubated with 5 µmol/l zoledronate and 10 ng/ml IL-1ß for 48 h. In the last 3 h, cells were exposed to a compressive, centrifugal force of 34.9 g/cm2. Cell viability was analyzed directly after the compressive force by MTT assay. Gene expression of COX-2 and IL-6 was investigated using quantitative qRT-PCR. PGE-2 and IL-6 protein secretion were measured via ELISA. RESULTS: The cell viability of HPdLF was not affected. Without inflammatory pre-stimulation, COX-2 expression was increased by compression and zoledronate. IL-6 expression was increased under compression. On secretion level, the combination of compression and zoledronate induced a slightly increase of IL-6 secretion. In contrast, inflammatory pre-stimulation strengthened the compressive upregulation of COX-2, as well as induced a higher PGE-2 secretion. Further addition of zoledronate to pre-stimulated cells additionally strengthened the compression-induced upregulation of COX-2 and IL-6 expression as well as protein secretion compared to all other groups. CONCLUSIONS: Biomechanical stress might trigger a pro-inflammatory potential of BP further enhanced in the presence of an inflammatory pre-stimulation. CLINICAL RELEVANCE: To prevent excessive host inflammatory responses, occlusal overloading and mechanical stress due to orthodontic treatment should be avoided in BP patients with untreated periodontitis.

Incorrect measurements and misleading conclusions in the article "Comparison of the efficacy of tooth alignment among lingual and labial brackets: an in vitro study".

BACKGROUND/OBJECTIVE: To reproduce the methods and results of the study by Alobeid et al. (2018) in which the efficacy of tooth alignment using conventional labial and lingual orthodontic bracket systems was assessed. MATERIALS/METHODS: We used the identical experimental protocol and tested (i) regular twin bracket (GAC-Twin [Dentsply]) and lingual twin bracket systems (Incognito [3M]), (ii) together with NiTi 0.014" wires (RMO), and (iii) a simulated malocclusion with a displaced maxillary central incisor in the x-axis (2 mm gingivally) and in the z-axis (2 mm labially). RESULTS: The method described by Alobeid et al. (2018) is not reproducible, and cannot be used to assess the efficacy of tooth alignment in labial or lingual orthodontic treatment. Major flaws concern the anteroposterior return of the Thermaloy-NiTi wire ligated with stainless steel ligatures. The reproduced experimental setting showed that a deflected Thermaloy-NiTi wire DOES NOT move back at all to its initial stage (= 0 per cent correction) because of friction and binding (see supplemented video), neither with the tested labial nor with the lingual brackets. Furthermore, an overcorrection of up to 138 per cent, which the authors indicate for some labial bracket-wire combinations and which deserves the characterization "irreal", stresses the inappropriateness of the method of measurement.Further flaws include: a) incorrect interpretation of the measurement results, where a tooth tripping around (overcorrection) is interpreted as a better outcome than a perfect 100 per cent correction; b) using a statistical test in an inappropriate and misleading way; c) uncritical copying of text passages from older publications to describe the method, which do not correspond to this experimental protocol and lead to calculation errors; d) wrong citations; e)differences in table and bar graph values of the same variable; f) using a lingual mushroom shaped 0.013" Thermaloy-NiTi wire which does not exist; g) drawing uncritical conclusions of so called "clinical relevance" from a very limited in vitro testing. CONCLUSIONS: Clinical recommendations based on in vitro measurements using the Orthodontic Measurement and Simulation System (OMSS) should be read with caution.

Influence of clodronate and compressive force on IL-1ß-stimulated human periodontal ligament fibroblasts.

OBJECTIVES: The aim of this study was to investigate in vitro the effect of clodronate on interleukin-1ß (IL-1ß)-stimulated human periodontal ligament fibroblasts (HPdLFs) with the focus on inflammatory factors of orthodontic tooth movement with and without compressive force. MATERIALS AND METHODS: HPdLFs were incubated with 5 µM clodronate and 10 ng/mL IL-1ß. After 48 h, cells were exposed to 3 h of compressive force using a centrifuge. The gene expression of cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), matrix metalloproteinase 8 (MMP-8), and the tissue inhibitor of MMP (TIMP-1) was analyzed using RT-PCR. Prostaglandin E2 (PGE-2), IL-6, and TIMP-1 protein syntheses were quantified via ELISA. RESULTS: Compressive force and IL-1ß induced an overexpression of COX-2 gene expression (61.8-fold; p < 0.05 compared with control), diminished by clodronate (41.1-fold; p < 0.05 compared with control). Clodronate slowed down the compression and IL-1ß induced IL-6 gene expression (161-fold vs. 85.6-fold; p < 0.05 compared with control). TNF-α was only slightly affected without statistical significance. Clodronate reduced IL-1ß-stimulated MMP-8 expression with and without compressive force. TIMP-1 on gene and protein level was downregulated in all groups. Analyzing the MMP-8/TIMP-1 ratio, the highest ratio was detected in IL-1ß-stimulated HPdLFs with compressive force (21.2-fold; p < 0.05 compared with control). Clodronate diminished IL-1ß-induced upregulation of MMP-8/TIMP-1 ratio with (11.5-fold; p < 0.05 compared with control) and without (12.5-fold; p < 0.05 compared with control) compressive force. CONCLUSION: Our study demonstrates a slightly anti-inflammatory effect by clodronate under compressive force in vitro. Additionally, the periodontal remodeling presented by the MMP-8/TIMP-1 ratio seems to be diminished by clodronate. CLINICAL RELEVANCE: Reduction of pro-inflammatory factors and reduction of periodontal remodeling might explain reduced orthodontic tooth movement under clodronate intake.

Perception of esthetic orthodontic appliances: An eye tracking and cross-sectional study.

OBJECTIVE: To evaluate the perception of esthetic orthodontic appliances by means of eye-tracking measurements and survey investigation. MATERIALS AND METHODS: En face and close-up images with different orthodontic appliances (aligner appliance [a], aligner appliance and attachments [b], lingual appliance [c], ceramic brackets [d], no appliance [e; control]) were shown to 140 participants. Eye movement and gaze direction was recorded by eye-tracking system. For different anatomical areas and areas of the appliances, time to first fixation and total fixation time were recorded. The questions included in a visual analog scale regarding individual sentiency were answered by the participants. RESULTS: For all groups, the anatomical landmarks were inspected in the following order: (1) eyes, (2) mouth, (3) nose, (4) hair, and (5) ears. Only in group d, first fixation was on the mouth region (1.10 ± 1.05 seconds). All appliances except the lingual appliance (1.87 ± 1.31 seconds) resulted in a longer fixation on the mouth area (a, 2.97 ± 1.32 seconds; b, 3.35 ± 1.38 seconds; d, 3.29 ± 1.36 seconds). For close-up pictures, the fastest (0.58 seconds) and longest (3.14 seconds) fixation was found for group d, followed by group b (1.02 seconds/2.3 seconds), group a (2.57 seconds/0.83 seconds), and group c (3.28 seconds/0.05 seconds). Visual analog scale scoring of questions on visibility were consistent with eye-tracking measurements. With increasing visibility, the feeling of esthetic impairment was considered higher. CONCLUSIONS: Lingual orthodontic appliances do not change how the face is perceived. Other esthetic orthodontic appliances may change the pattern of facial inspection and are different in subjective perception.

Development of a novel histological and histomorphometric evaluation protocol for a standardized description of the mid-palatal suture - An ex vivo study.

The hard palate and mid-palatal suture are highly important for orthodontic treatment. In cases of transverse maxillary deficiency, palatal expansion is the treatment of choice. As nowadays a growing number of adult patients receive orthodontic treatment, an understanding of suture development throughout life is important to derive tailored orthodontic treatment techniques for each age group. Histological, histochemical and immunohistochemical stains (haematoxylin & eosin, Azan, Movat pentachrome, Masson-Goldner trichrome, Sirius Red, CD 31, osteopontin and TRAP) and histomorphometric analyses were re-established to detect the structural conditions of the mid-palatal suture in human cadavers of three different age groups (20-39, 40-59 and 60-80 years). The mid-palatal suture of the selected age groups (total of n = 12; n = 4 in every group m = f) exhibited marked differences in sutural morphology and metabolism. A wide, interdigitated and well-vascularized suture was observed in younger specimens compared with straighter and smaller sutures with fewer vessels and lower bone density in the 60-80 year group. The fibre composition within the sutural gap differed between the three age groups. Delicate fibres were found in the 20-39 year group, and a tightly interwoven 3D fibre-network was observed in the 40-59 year group. Atrophy primarily characterized the fibres in the 60-80 year group. This evidence demonstrates differences between the evaluated groups. These results suggest that the staining methods used are suitable for the description and evaluation of the morphology and metabolism of mid-palatal sutures. Further investigation is necessary to provide an in-depth description of sutural maturation over a lifetime.

Single tooth torque correction in the lower frontal area by a completely customized lingual appliance.

BACKGROUND: Aim of this study was to analyze the efficacy and precision of the completely customized lingual appliance (CCLA) regarding the single tooth torque correction. The study also examined external apical root resorptions as possible side effects of torque correction and the changings of the periodontal situation. METHODS: A case series of three patients were included. The patients showed a single tooth torque problem with a gingival recession and were treated with the CCLA. Plaster casts before and after treatment and plaster casts of the set up were scanned and superimposed. Deviations between the two plaster casts were analyzed at different points of interest. Changes of the gingival recession were compared before and after treatment. Relative root resorptions were measured by the orthopantomograms. Treatment times were assessed by the records of the patients. Results were presented descriptively. RESULTS: The mean change of the most apical part of the root reached by the orthodontic treatment was 1.8 ± 0.3 mm. The largest deviation between set up and final model was measured on the occlusal surface of the tooth 36 with 0.8 mm. Most measurement points showed a deviation of 0.5 mm or less. The depths of the gingival recession showed a significant reduction of 4.7 mm. The widths of the gingival recession were reduced by 1.1 mm. The average relative root resorption of the corrected teeth was 2.7 ± 1.5%. The average treatment time was 13.8 ± 4.5 months. CONCLUSIONS: This is the first study showing that the CCLA with its high precision is very effective in correcting single tooth torque problems. Orthodontic torque correction resulted in a significant reduction of gingival recessions and caused only negligible root resorptions.

Osteogenic differentiation of periodontal fibroblasts is dependent on the strength of mechanical strain.

OBJECTIVE: During orthodontic therapy the correct strength of mechanical strain plays a key role for bone remodelling during tooth movement. Aim of this study was to investigate the osteogenic differentiation of human periodontal ligament fibroblasts (HPdLF) depending on the applied strength of mechanical strain compared to osteoblasts (HOB). DESIGN: HPdLF and HOB were loaded with different strengths (1%, 5% and 10%) of static mechanical strain (SMS) for 12h in vitro. Viability was verified by MTT and apoptosis by TUNEL assay. Gene expression of cyclin D1, collagen type-1 (COL-I), alkaline phosphatase (ALP), osteocalcin, osteoprotegerin (OPG) and receptor activator of the NF-κB ligand (RANKL) were investigated using RT-PCR. OPG and RANKL synthesis was measured by ELISA and ALP activity by colorimetric assay. RESULTS: 10% of SMS led to a decrease in cell viability of both cells lines, but no increased rate of apoptosis. RT-PCR showed the highest increase of cyclin D1 expression for HPdLF and HOB when applied to 5% of SMS, and HOB showed a doubling of COL-I gene expression. HPdLF and HOB showed a strength-dependent synthesis of OPG and ALP activity, whereas HOB demonstrated a decrease in OPG synthesis and ALP activity when applied to 10% of SMS. CONCLUSION: Osteogenic differentiation of HPdLF correlates with increasing strength of SMS. HOB show decreased activity when applied to high SMS, demonstrating potential damage to the bone remodelling due to strain of high strength. SMS up to 5% provides the best conditions for bone formation at the tension site of tooth movement.

Influence of patient age and experience of the surgeon on early complications after surgical closure of the cleft palate--a retrospective cohort study.

Comparative studies on timing of palatoplasty are rare. The aim of this retrospective cohort study was to compare the influence of early (<14 months) and later (>14 months) one-step closure of the soft and hard palate on early complications. All non-syndromic patients from 1999 to 2009 were included; 6-14 months n = 41 and 15-24 months n = 53. Each palatoplasty was performed as a single-step procedure using bipedicled flaps by a team of two Maxillofacial Surgeons either supervising or operating. The surgeon was rated as "non-experienced" when having performed less than 10 palatoplasties under supervision. Main outcome variable is the occurrence of residual fistula. Fistula occurred in four (4.5%) of the patients. In the multivariate model with respect to the occurrence of fistula neither age, leucocyte count, duration of surgery, nor experience of the surgeon showed a significant influence on the occurrence of a fistula. Only reduced weight contributed to a significantly higher risk of post-operative fistula. In conclusion patient age, experience of surgeon, and duration of surgery had no influence on the early outcome. High leucocyte count had a tendency for and reduced weight had a significant influence on fistula occurrence. Long-term outcome on speech development and maxillary growth have to be collected.

Dental compensation for moderate Class III with vertical growth pattern by extraction of the lower second molars.

OBJECTIVES: Analysis of the effects and side effects of treatment of patients with moderate skeletal Class III and vertical growth pattern by means of extraction of the second molars in the lower jaw. PATIENTS AND METHODS: A total of 20 patients with a mean age of 12.9 years were examined retrospectively. Inclusion criteria consisted of a Wits value of 0 to -5, a posterior growth pattern of the mandible (Hasund analysis), an overjet of -2 to 1 mm, and an overbite of 0 to -3 mm. Treatment was performed using a straight-wire appliance. As part of the treatment, the lower second molars were extracted and Class III elastics attached. Cephalograms and orthopantomograms taken before and after treatment were used for evaluation. RESULTS: Treatment resulted in a significant change in the mean overjet from 0.5 mm to 2.1 mm and the attainment of a positive mean overbite of -1.0 mm to 0.9 mm. The occlusal plane rotated anteriorly from 18.8° to 13.7°. The skeletal parameters showed a change in the Wits value from -3.3 mm to -1.4 mm and an anterior mandibular rotation (ML-NSL 35.5° vs. 32.0°). The soft tissues revealed an increase in the distance between the lower lip and the "esthetic line" to the posterior (-2.0 mm vs. -3.9 mm). CONCLUSION: Dental compensation of moderate skeletal Class III with a tendency to an anterior open bite with vertical growth pattern by extracting the lower second molars, combined with Class III elastics, resulted in an anterior rotation of the occlusal plane and mandible. Eighteen of 20 patients achieved a physiological overjet and positive overbite. A prerequisite for this therapy is the presence of lower wisdom teeth; a potential side effect is elongation of the upper second molars.

Impacted upper canines: examination and treatment proposal based on 3D versus 2D diagnosis.

AIM: The purpose of this diagnostic cross-over study was to evaluate whether three-dimensional (3D) diagnostics (cone-beam computed tomography, CBCT) was superior to two-dimensional (2D) diagnostics (panoramic X-ray, OPG) in patients with impacted upper canines for assessing their position and the probability of their alignment. MATERIALS AND METHODS: Panoramic X-rays, CBCTs, and study casts of 21 patients with a total of 29 impacted maxillary canines were analyzed. Patients with syndromes or tooth aplasias were excluded. A total of 26 dentists of various specialist disciplines rated different parameters, such as canine position and their probability of alignment as well as their relation to and resorption of adjacent teeth. 2D X-rays and study casts were rated first; then 3D images and casts were evaluated at least 2 weeks later. The actual level of displacement was defined by two trained examiners and labeled as the master finding, according to modified criteria established by Ericson and Kurol (1988). RESULTS: In 64% of all patients, canine position was assessed concordantly in 2D and 3D images. 2D assessments were in slight agreement (κ = 0.374), while 3D ratings were in good agreement with the master findings (κ = 0.714). Two-thirds of the canines' apical regions were judged identifiable in 2D and 3D images; more than 1/4 of the canines' apices were not identifiable in 2D images, but were identifiable in 3D images. The diagnosis of lateral incisor root resorption in the CBCT agreed well with the master finding (κ = 0.634), but examiners overlooked slight resorption in 20% of the patients. In 82% of the patients teeth, treatment suggestions (orthodontic alignment or surgical removal) were the same for 2D and 3D images. Canine inclination visible in the panoramic X-rays was the most important factor influencing the treatment proposal. CONCLUSION: Small volume CBCT may be justified as a supplement to a routine panoramic X-ray in the following cases: when canine inclination in the panoramic X-ray exceeds 30°, when root resorption of adjacent teeth is suspected, and/or when the canine apex is not clearly discernible in the panoramic X-ray, implying dilaceration of the canine root. We intend to validate the results of this study in a clinical trial.

Plaque levels of patients with fixed orthodontic appliances measured by digital plaque image analysis.

INTRODUCTION: A digital plaque image analysis system was developed to objectively assess dental plaque formation and coverage in patients treated with fixed orthodontic appliances. METHODS: The technique was used to assess plaque levels of 52 patients undergoing treatment with fixed appliances in the Department of Orthodontics at Johannes Gutenberg University in Mainz, Germany. RESULTS: Plaque levels ranged from 5.1% to 85.3% of the analyzed tooth areas. About 37% of the patients had plaque levels over 50% of the dentition, but only 10% exhibited plaque levels below 15% of tooth coverage. The mean plaque coverage was 41.9% ± 18.8%. Plaque was mostly present along the gum line and around the orthodontic brackets and wires. CONCLUSIONS: The digital plaque image analysis system might provide a convenient quantitative technique to assess oral hygiene in orthodontic patients with multi-bracket appliances. Plaque coverage in orthodontic patients is extremely high and is 2 to 3 times higher than levels observed in high plaque-forming adults without appliances participating in clinical studies of the digital plaque image analysis system. Improved hygiene, chemotherapeutic regimens, and compliance are necessary in these patients.

Biocompatibility of orthodontic bands following exposure to dental plaque.

OBJECTIVE: The aim of this study was to assess the biocompatibility of orthodontic bands following exposure to the human oral environment. METHODS: Cell adherence and cell morphology of gingival fibroblasts grown on 32 orthodontic bands were tested. The bands were in place intraorally for 6 to 37 months. RESULTS: We observed cell adherence in 76% of the previously plaque-free surfaces. Cell morphology was 50% spherical and 50% elongated. The surfaces that had had plaque attached demonstrated cell adherence in 84% of the given areas; those cells were spherical in 42% and elongated in 58%. CONCLUSION: We conclude that individual oral hygiene habits during orthodontic treatment seem to have no effect on the biocompatibility of orthodontic bands, as we failed to discern a difference in either cell adherence or cell morphology in areas with and without prior plaque attachment.

Quantity and distribution of plaque in orthodontic patients treated with molar bands.

OBJECTIVE: The placement of orthodontic bands usually increases plaque accumulation due to numerous mechanical retention sites. The purpose of this investigation was to evaluate the amount and distribution pattern of biofilm in the oral (palatal and lingual) and interproximal regions surrounding orthodontic bands. MATERIALS AND METHODS: We evaluated the formation of biofilm on 32 orthodontic bands which had been placed intraorally for 6-37 months. Two parameters were measured: the percentage of surface covered by biofilm (quantity) and the biofilm distribution pattern of accumulation. We measured these two parameters in four regions of interest: the mesial and distal interproximal regions, as well as the mesial and distal regions of the oral attachment. RESULTS: The quantity of biofilm formation was similar in all four regions of interest, ranging from 13.3% to 16.8%. In contrast to biofilm quantity, distribution patterns differed in the four regions. In the mesial and distal interproximal regions it appeared as extensive insular areas in 87.5% and 71.9%, respectively, whereas it appeared more often supragingival and linear in nature in regions adjacent to the oral attachment, i.e. in 65.6% and 68.8%, respectively. CONCLUSION: Our results indicate that firstly, oral hygiene in the palatal and lingual regions of orthodontic bands seems as difficult as it is in the interproximal areas, thus requiring thorough hygiene in both areas. Secondly, orthodontic patients with a history of periodontal disease require special attention regarding the use of orthodontic bands.

Orthodontic space closure after first molar extraction without skeletal anchorage.

OBJECTIVE: The aim of the study was an analysis of effects and side-effects during mesialization of second molars after extraction of the first permanent molars using the anterior dentition/premolars (PM) as an anchorage unit. PATIENTS AND METHODS: A total of 35 patients were examined retrospectively who had undergone unilateral or bilateral first permanent molar extraction in the upper or lower arch due to carious lesions. Space closure was carried out in all cases through mesialization of the second molar using an elastic chain fixed to an edgewise stainless steel archwire and tying the anterior dentition/PM together with a continuous laceback ligature. Tooth movement was assessed from lateral cephalograms, orthopantomograms (OPGs) and images of the patient's study casts taken before and after the end of therapy. RESULTS: Space closure after first molar extractions by mesialization of the second molars without skeletal anchorage was largely achieved by bodily forward movement of the teeth, including a small tipping component or tooth-uprighting component when molars were already mesially inclined. Unilateral and bilateral mesialization of the second molars led to retrusion in the maxilla and mandible [(∆incl.=-3.6° (max., bil.), ∆incl.=-4.2° (mand., bil.)] and to translational retraction [(∆s=-2.3 mm (max., bil.), ∆s=-1.6 mm (mand., bil.)] of the incisors. Examination of the soft tissues revealed an increased posterior displacement of the upper and lower lips to the esthetic line [(∆s=-2.8 mm (max. bil.), ∆s=-2.2 mm (mand., bil.)]. In cases of unilateral mesialization less than 50% of the patients had a slight midline deviation in the mandible towards the extraction side. CONCLUSION: Side effects during mesialization of the second molars without skeletal anchorage in the anterior dentition/PM were observed primarily affecting the incisors integrated into the anterior anchorage unit. These side-effects resulted in posterior displacement of the soft tissues, including a change in profile. This must be taken into consideration when taking this therapeutic approach.

Long-term effects of traumatic injuries to incisors and periodontal tissues during childhood: a retrospective study.

AIM: The purpose of this study was to investigate the incidence of dentoalveolar growth disturbances, loss of teeth and esthetic impairment after the end of growth following traumatic injuries to incisors and periodontal tissues during childhood. MATERIALS AND METHODS: 41 patients having sustained dentoalveolar trauma before age 10 and who were now at least aged 16 years, and a total of 68 traumatized teeth were documented by clinical examination, dental casts and photographs. We determined the three-dimensional position of the traumatized teeth on the casts, as well as the traumatized teeth's pulp sensibility, percussive sound and sensitivity, shape and color. RESULTS: 82% of the traumatized teeth were in the upper dentition. 45% of the traumatized teeth experienced subluxation, nearly 30% luxation, 16% avulsion. At the time of the follow-up examination (mean 17.0 years post-trauma), 57% of the traumatized teeth were still in situ. Immediately after trauma 7.4% of the teeth were lost; up to 16 years post-trauma 35.6% of the teeth were lost because of failed root canal filling, root resorption or ankylosis. We observed no functional deviations. Dentoalveolar growth disturbances were rare. Three teeth were markedly discolored. CONCLUSION: Following dentoalveolar trauma during childhood, negative effects on growth, function and esthetics can be minimized by timely interdisciplinary treatment and by follow-up controls until the end of growth to achieve an outcome satisfying both the patient and clinician.

Spectrum of indications for palatal implants in treatment concepts involving immediate and conventional loading.

AIM: To analyze the spectrum of indications for second-generation palatal implants in relation to two different loading concepts in a prospective, multicenter, randomized controlled trial (RCT). PATIENTS AND METHODS: Forty-one patients were recruited to the study from 2006 to 2009. All implants (Orthosystem, Straumann, Basel, Switzerland; dimensions: 4.1 mm x 4.2 mm) were inserted in the median or paramedian region of the anterior palate, and each patient was randomized to one of two loading groups (immediate loading within the first week after insertion versus conventional loading after a 12-week healing phase). In this interim evaluation, we report preliminary results obtained six months after functional loading. RESULTS: All palatal implants were primarily stable at the time of insertion. One implant loss (12 weeks after surgical insertion) was documented in the cohort subjected to conventional loading, and one patient dropped out of the immediate-loading group. At the time of this investigation, 39 palatal implants are experiencing functional loads. Using both loading concepts, we had various orthodontic objectives, such as intrusion of anterior and/or posterior teeth, and the mesialization and distalization of posterior teeth. Both loading groups presented nearly identical indications, and the distribution of direct vs. indirect anchorage forms was also very similar during the active treatment. CONCLUSION: Comparison of the two treatment concepts revealed no clinical differences in implant stability. Patients undergoing immediate-loading therapy were subject to no limitations regarding indications at 6 months after functional loading compared with the patients who experienced conventional loading.

Clinical observations and success rates of palatal implants.

INTRODUCTION: Anchorage control is a challenge in orthodontics. Implants can be used to provide absolute anchorage.The aim of this study was to evaluate the success rates of palatal implants used for various anchorage purposes. METHODS: Thirty-four palatal implants were placed in 33 patients. In the adults (n = 9), the implants (n = 9) were placed in the median palatal suture. In the adolescents (n = 24), the implants (n = 25) were placed in the paramedian region. The implants were used to support a transpalatal arch, a modified distal jet appliance, or a modified hyrax screw. An implant was considered successful if it could be used as planned throughout the orthodontic treatment. The patients were asked to evaluate their pain perception after placement and explantation procedures. RESULTS: Three implants failed early (during the waiting period before orthodontic loading, within 3 months after placement). During the orthodontic loading period, no implants were lost. No statistically significant correlations were found between success rate and sex, age, primary stability, placement site (median or paramedian), implant size, or palatal depth. Pain perception after surgery was acceptable. The success rate of the palatal implants in this study was 91%. CONCLUSIONS: Palatal implants are a reliable method of providing absolute anchorage control in a variety of patients for different indications. They can be loaded both directly and indirectly.

Interdisciplinary approach for the treatment of periodontally compromised malpositioned anterior teeth: a case report.

Today many adult patients with periodontal disease demonstrate positioning of teeth that comprise their ability for proper mechanical tooth cleaning of approximal tooth surfaces. With adequate combined periodontal-orthodontic treatment it is possible to re-establish a healthy and well-functioning dentition. However, while orthodontic treatment can realign periodontally affected teeth, esthetic appearance may be compromised by gingival recession due to alveolar bone dehiscences or fenestrations in combination with a thin gingival biotype. This article reports an interdisciplinary (periodontic, orthodontic, restorative) approach for the treatment of a periodontally compromised patient with anterior dental malalignment. Periodontal therapy, including periodontal plastic surgery to obtain root coverage as well as orthodontic treatment by means of a miniscrew implant anchorage were used to achieve stable periodontal conditions and successful esthetic and functional final results.

Combined treatment of open bite - long-term evaluation and relapse factors.

BACKGROUND AND OBJECTIVE: Some patients with open bite who have been treated with combined fixed orthodontic appliances and bimaxillary osteotomy relapse in the vertical dimension after the end of treatment following initially successful correction of the vertical dimension. The aim of this study was to identify those parameters that raise the tendency to relapse. MATERIALS AND METHODS: Nineteen patients who underwent combined treatment using fixed orthodontic appliances and bimaxillary osteotomy due to open bite (overbite < 0 mm), were examined and documented at least 2 years after surgery. Pre- and post-orthodontic and pre- and post-operative study models and lateral head films were analyzed. Overbite reduction after the end of treatment was considered as relapse. RESULTS: In our study cohort, the appearance of relapse in the vertical correlated with the enlargement of Björk's sum angle (odds ratio 10.7) and Jarabak's ratio (odds ratio 7) by means of surgery, as well as with dysfunctional habits persisting after treatment such as mouth breathing (odds ratio 12.5) and a visceral swallowing pattern (odds ratio 8.3). The existence at baseline of isolated anteinclination of the anterior maxilla or isolated steep inclination of the mandible also made vertical relapse more probable (odds ratio 7.5). CONCLUSION: Particularly deserving of attention during the combined interdisciplinary treatment of patients with open bite are the achieved reduction in posterior facial height by surgical posterior impaction of the maxilla, as well as correction of dysfunctional parameters during swallowing and breathing.

Periodontal impact of surgically induced dental lesions in mandibular osteodistraction: an animal study.

AIM: The objective of the study was to evaluate the impact of dental lesions on the periodontium, in a canine model of mandibular osteodistraction. MATERIAL AND METHODS: In six adult male Beagle dogs, an osteotomy was made between the right second lateral incisor and canine, and a distraction device placed. The roots adjacent to the osteotomy were deliberately damaged by the reciprocating saw and chisel, with preservation of the attached gingiva. The osteodistraction protocol used was: latency of 7 days, rate of distraction 1mm per day, and rhythm once a day for 5 days. Vital staining was carried out with tetracycline, Xylenol Orange and Calcein Green. The dogs were sacrificed after 12 weeks of consolidation and the specimens were evaluated with light microscopy (native, polarized light, fluorescence, and after toluidin blue staining). RESULTS: The periodontal ligament (PDL) regeneration was observed in the 2500 slices examined. Cementum and dentine lesions were repaired by cellular cementum. Loose dentine and cementum-dentine fragments were embedded in regenerated PDL and their surface repaired by cementum. By means of light microscopic examination and within the limited observation time, no degenerative pulpal changes were found, when the pulp canal was not entered. Extensive pulp exposure and destruction resulted in ingrowth of the PDL and bone-like tissue. In that case, cellular cementum also lined the dentine surface of the pulp canal. CONCLUSION: Although there was an extensive reparative response to the para-pulpal lesions, none of the changes observed showed evidence of a loss of functional integrity of the periodontium at the distraction site. The fate of the tooth with exposed pulp canal remains uncertain.