Premolar Area Research Articles

Evaluation of the accuracy of full-arch impressions between three different intraoral scanners and conventional impressions: A prospective in vivo study.

This in-vivo study evaluated the accuracy of full-arch digital impressions obtained through different intraoral scanning technologies regarding trueness and efficiency against the standard alginate impressions. Alginate impressions were taken from 50 subjects, and the resulting stone casts were scanned using the Trios 3Shape desktop scanner. In-vivo scans were conducted on each participant using three intraoral scanners: Medit, CEREC Primescan, and 3Shape Trios. The scanned files were superimposed onto two software platforms: the 3Shape Orthoanalyser and Geomagic software. This superimposition was performed against the reference model to calculate 3D and 2D deviations, enabling efficiency comparisons between digital and traditional workflows based on work time in minutes. Measurements and comparisons were made in three planes: transverse, sagittal, and vertical dimensions for all the models and stone casts. Statistical analysis employed SPSS 23, with the significance level set at P<0.05. Significant deviations were observed between the three intraoral scanners and the alginate impression, with molar and premolar areas showing greater imprecision across dental arches. Compared to the alginate technique, Medit i500 tended to reduce the transverse dimension in the areas mentioned above, while CEREC exhibited higher precision. Molar and premolar areas emerged as the regions with the greatest discrepancies, both in excess and deficiency, compared to the alginate impression. This difference in dimensions was, however, statistically insignificant overall. 3Shape Trios exhibited the shortest scan times, indicating higher efficiency. Among the intraoral scanners, Medit recorded the longest scanning duration. Accepting the null hypothesis, the scans obtained using all three scanners were comparable with statistically insignificant differences in the measurements. The three scanners differed in the total scan time taken, with the Medit scanner requiring the longest scan time and the 3Shape TRIOS 3 scanner demonstrating the shortest scan duration.

Immediately versus early placed bone-level-tapered implants supporting all-ceramic crowns on titanium base abutments: 1-year radiographic and pink esthetic outcomes of a multicenter pilot RCT.

Aim of this study was to assess survival rates, radiographic, and pink esthetic outcomes of a bone-level-tapered (BLT) implant following immediate or early implant placement. Patients in need of tooth extraction and one implant in the anterior or premolar area were recruited in five centers. Patients were randomly assigned to the immediate or early placement protocol. Implants were restored with all-ceramic crowns cemented to titanium-base-abutments. Radiographic bone levels, implant stability quotient (ISQ), and pink esthetic outcomes were assessed. Data were analyzed descriptively. Level of significance was set at 0.05. Differences between groups were tested using Wilcoxon-signed-rank and Mann-Whitney-U test as nonparametric tests. A total of 60 patients received 60 BLT implants (Institut Straumann). At 12-months, 59 implants (98.3%) were osseointegrated. The mean distance from implant shoulder to first bone-to-implant contact was 0.15 ± 0.59 mm without significant differences between the groups. Median ISQ values increased from 75.5 to 78.5. A mean buccal recession of 0.1 ± 0.70 mm occurred with no difference between groups. The mean papilla height gain in both groups was 0.5 ± 1.47 mm mesially and 0.4 ± 1.36 mm distally. After 1 year, immediately and early placed BLT implants exhibit similar bone level changes, ISQ values, and pink esthetic outcomes. The present research contributes to the knowledge on clinical outcomes of immediately and early placed BLT implants restored with buccally microveneered ceramic single crowns out of two different ceramic materials. The research shows that similar esthetic and radiographic outcomes can be reached by means of immediate implant placement compared to the conventional early placement protocol. The improvement of esthetic soft-tissue parameters over time was shown for both implant placement protocols.

Maksillada İki Farklı Ogmentasyon Tekniğinin Karşılaştırılması: Olgu Sunumu

Aim: &#x0D; Dental implant applications are most common treatment methods for rehabilitation of edentulous jaws. The severe bone deficiency could not be allowed implant therapies. Various augmentation methods could be used for reconsruction. In this case report tent-pole and onlay grafting techniques were performed in case at edentulous maxilla with radiological evaluation at 6 months follow-up.&#x0D; Materials and Methods:&#x0D; CBCT (Cone beam computed tomography) were obtained from patient. Extraction of all teeth and explantation of 2 implants were planned because of periodontal problems. The ramus onlay grafting was decided to apply for both anterior side of the maxilla and tent pole technique for right premolar area of maxilla.&#x0D; Results:&#x0D; It was observed 3.5 mm horizontal bone gain at the right maxillary anterior side, 4.8 mm horizontal bone gain at the left maxillary anterior side and 3.4 mm horizontal and 6.8 mm vertical bone gain at right premolar side after 6 months.&#x0D; Conclusion:&#x0D; Tent pole and onlay grafting methods are successful treatment options for alveolar ridge augmentation. Nevertheless, autografts could not be enough in every case. In this situation, xenografts and allografts applications with tent pole technique could be preferred as an effective method for alveolar ridge augmentation both horizontally and vertically.

Immediate implant placement in the premolar maxillary area: a cone-beam computed tomography study.

This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA). The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA. A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

Impact of type and position of abutment connection on microstrain distribution: an in vitro study.

The aim of this study was to investigate microstrains around two non-parallel implant-supported prostheses and different abutment connections and positions under vertical static load using strain gauges. 4 models simulating the mandibular unilateral free-end were fabricated. 8 implants (4.0 × 10 mm and 5.0 × 10 mm) were inserted in the second premolar, perpendicular to the occlusal plane, and the second molar, tilted at 15°. Four groups were analyzed: engaging and angled abutments (control group), both non-engaging abutments, both screw-and cement-retained prosthesis (SCRP) abutments, and engaging and non-engaging abutments. Strain gauges were placed buccally, lingually, mesially, and distally adjacent to each implant. The restoration was cement-retained in the control group and screw and cement-retained in the rest. Zirconia bridges were fixed on the abutment with NX3, and a 300 N vertical static load was applied. Microstrains were recorded and analyzed. Both non-engaging abutments showed the highest compressive microstrains (-52.975), followed by engaging, angled abutment (-25.239). SCRP-SCRP abutments had the lowest compressive microstrains (-14.505), while the engaging, non-engaging abutments showed tensile microstrains (0.418). Microstrains in SCRP-SCRP and engaging, non-engaging groups were significantly lower than in the control group (α = .05). Premolar areas showed compressive microstrains (-47.06), while molar sites had tensile microstrains (+0.91), with microstrains in premolars being significantly higher than in molar area (α = .05). The types of abutment connections and positions may have a potential effect on microstrains at the implant-bone interface. SCRP-SCRP abutments could be an alternative to use in non-parallel implant-supported prostheses when two implants make an angle of no more than 20 degrees.

Odontogenic Keratocyst Imitating Lateral Periodontal Cyst: A Case Report

Collateral Odontogenic Keratocyst (OKC), a rare variant of OKC, is usually present in the mandibular premolar area and is often confused with lateral periodontal cysts due to common features. A 58-year-old male patient presented with a painless swelling in the mandibular left premolar area. The clinical and radiographical features were suggestive of a lateral periodontal cyst. Surgical enucleation followed by peripheral ostectomy was performed and the sample was sent for histopathological examination. The histopathological study demonstrated typical features of OKC. Owing to the high recurrence rate, the patient is kept on regular follow-up. During follow-ups, there were no clinical and radiographical signs of recurrences.

Relation between maxillary sinus pneumatization and the thickness of the mandibular inferior border in panoramic radiographs

BackgroundMaxillary sinus pneumatization is a physiological process that can adversely affect bone availability for further dental rehabilitation. If a relation between the thickness of the mandibular cortex and maxillary sinus pneumatization is proven, future bone availability can be deducted. Material and methodsIn this cross-sectional study, 85 panoramic radiographs were evaluated. All patients were between 19 and 70, had at least lost a second premolar, first molar, or second molar on one side of the maxilla, and had these teeth on the other side. Four lines were digitally drawn on the radiographs to determine the superior and inferior borders of the sinus on both sides. The amount of inferior sinus border progression was deducted using the digitally-measured lines' ratios. The following tests were done using IBM SPSS ver. 24: Pearson's correlation coefficient test, Tukey's dual comparison posthoc test, One-way ANOVA test, and the independent T-test (p = 0.05). ResultsThere was a negative correlation between the inferior mandibular cortex's thickness and the maxillary sinus's pneumatization (p < 0.001). Also, there was a significant difference between maxilla sinus pneumatization in the second premolar, first, and second molar areas based on the inferior mandibular cortex’s thickness (p = 0.009). ConclusionsBased on the present study, there is a significant relationship between the thickness of the inferior mandibular cortex and maxillary sinus pneumatization, especially for women and patients above 40 years old.

Interproximal contact loss between implant restorations and adjacent natural teeth: A systematic review and meta-analysis.

This systematic review was conducted to evaluate the prevalence of interproximal contact loss (ICL) between implant restorations and adjacent teeth in relation to age, gender, follow-up time, and arch location. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Open Science Framework (OSF). The formulated population, intervention, comparison, outcome (PICO) question was "What is the prevalence of the ICL between implant restoration and adjacent teeth?" The search strategy used four main electronic databases and an additional manual search was performed until February 2023. Clinical studies that evaluated the prevalence of interproximal open contact between implant restorations and adjacent teeth were included. A qualitative analysis for clinical studies was used to assess the risk of bias. In addition, a single-arm meta-analysis of proportion was performed to evaluate the percentage of mesial versus distal open contact and total ICL between implant restoration and adjacent teeth. Fifteen studies published between 2014 and 2023 met the eligibility criteria. Seven studies presented ICL rates higher than 20%. All studies evaluated ICL in posterior regions (molar, premolar area). Five studies had an ICL rate lower than 50% and three studies had an ICL rate higher than 50%. One study assessed the interproximal contact at three months post-restoration insertion, four studies assessed the interproximal contact at 1-year follow-up and nine studies evaluated the interproximal contact over 2 years of follow-up. Mesial and distal ICL rates were 44.2% (95% CI: 30.6% to 58.6%) and 27.5% (95% CI: 10.5% to 55.0%), respectively. The heterogeneity between studies was high (I2 (95% CI) = 87.8% (75.9% to 93.8%). Based on the results of the included studies, the prevalence of ICL was high, occurring more frequently at the mesial contact. There were no significant differences in relation to age, gender, and arch location.

A retrospective study of dynamic navigation system-assisted implant placement

BackgroundTo evaluate the accuracy of implant placement assisted by a dynamic navigation system, as well as its influencing factors and learning curve.MethodsAt Macao We Care Dental Center, 55 cases of implant placement using dynamic navigation were retrospectively evaluated. To evaluate their accuracy, the apex, tip, and angle deviations of preoperatively planned and postoperatively placed implants were measured. The effects of the upper and lower jaws, different sites or lateral locations of dental implants, and the length and diameter of the implants on accuracy were analyzed, as well as the variation in accuracy with the increase in the number of surgical procedures performed by dentists.ResultsThe implant had an apex deviation of 1.60 ± 0.94 mm, a tip deviation of 1.83 ± 1.03 mm, and an angle deviation of 3.80 ± 2.09 mm. Statistical differences were observed in the tip deviation of implants at different positions based on three factors: jaw position, lateral location, and tooth position (P < 0.05). The tip deviation of the anterior teeth area was significantly greater than those of the premolar and molar areas. There were no statistically significant differences in apex deviation, tip deviation, or angle deviation between the implants of different diameters and lengths (P > 0.05). There were significant differences in the angle deviation between the final 27 implants and the first 28 implants. Learning curve analysis revealed that angle deviation was negatively correlated with the number of surgical procedures, whereas the regression of apex deviation and tip deviation did not differ statistically.ConclusionsThe accuracy of dynamic navigation-assisted dental implants meets the clinical needs and is higher than that of traditional implants. Different jaw positions, lateral locations, and implant diameters and lengths had no effect on the accuracy of the dental implants guided by the dynamic navigation system. The anterior teeth area had a larger tip deviation than the posterior teeth area did. As the number of dynamic implantation procedures performed by the same implant doctor increased, the angle deviation gradually decreased.

Influence of retainer design and number of inlay boxes on the biomechanical behavior of zirconia cantilever resin bonded fixed dental prosthesis.

The development of dental adhesives with enhanced bond strength has assisted minimally invasive dentistry. The aim of this study was to evaluate the fracture load and stress distribution pattern of two retainer designs for posterior cantilever resin bonded fixed dental protheses (RBFDPs). Forty human mandibular molars were divided into two groups according to the retainer design; lingual coverage (LC) and occlusal coverage (OC) retainers. Each main group was then divided according to the number of inlay boxes (n = 10); one inlay and two inlay boxes. High translucency (3Y) zirconia was used to manufacture all restorations, and a dual-polymerizing adhesive resin cement was used for bonding. All specimens underwent 10,000 cycles of thermocycling (5-55°C), 240,000 cycles of dynamic loading (50 N, descending speed v = 30 mm/second, frequency = 1.6 Hz), and failure load test. Both one-way and two-way ANOVA tests were used to analyze the data. The four models included in the in-vitro study are part of the finite element analysis (FEA). When the restorations failed, maximal principal stress values on restorations, enamel, dentin, and luting resin were investigated. A statistically significant (p = 0.018) higher failure load was recorded for OC1 (627.00 ± 153.4 N) than the other groups; (548.0 ± 75.6 N, 521.20 ± 11.3 N, and 509.20 ± 14.9 N for LC1, LC2, and OC2, respectively). With regard to failure mode, one inlay box designs showed more favorable failure pattern than those of two inlay boxes. FEA showed higher stress magnitude transmitted to the tooth structure in models LC2 and OC2. Lingual coverage and occlusal coverage retainers are promising designs capable to withstand the normal occlusal force for cantilever RBFDP in premolar area. The use of two inlay boxes decreased the fracture load of the two retainer designs and increased the stress transmitted to the tooth and resulted in high incidence of catastrophic failure. Monolithic high translucent zirconia RBFDP could be considered as a viable treatment option to substitute missing posterior tooth, with improved esthetics and biocompatibility.

Reduced bone dimension in patients affected by oligodontia: A retrospective study on maxillary and mandibular CBCT.

Oligodontia (OD) is a rare developmental condition characterized by the absence of six or more teeth. Dental implant placement may be challenging due to anatomical factors. This study aims to evaluate the alveolar bone dimensions in OD patients compared with controls. On maxillary and mandibular cone-beam computed tomography (CBCT), bone height and width were measured at every tooth and edentulous site. The distance to the inferior alveolar nerve was also measured. Fifty-three OD patients (40 maxillary and 32 mandibular CBCT) and 82 controls (51 maxillary and 31 mandibular CBCT) were compared using mixed models. Compared with those in OD patients, maxillary permanent teeth and edentulous sites showed significantly higher mean height in control patients (incisive-canine site height: +2.12 mm; edentulous incisive-canine site height: +4.46 mm [p > .001]). For the mandibular permanent teeth, mean height was higher in controls than in OD patients at the incisive-canine (+3.82 mm [p > .001]) and premolar areas (+2.06 mm [p > .001]). Only edentulous incisive-canine sites were significantly different between controls and OD patients (mean: +0.52 mm [p > .001]). Changes in alveolar nerve position were observed in case of molar agenesis. Maxillary and mandibular bone dimensions are reduced in OD patients compared with controls both in sites with permanent teeth and in edentulous areas.

Electron Microscopy (EM) Analysis of Collagen Fibers in the Peri-Implant Soft Tissues around Two Different Abutments.

The design of the implant prosthesis-abutment complex appears crucial for shaping healthy and stable peri-implant soft tissues. The aim of the present animal study was to compare two implants with different healing abutment geometries: a concave design (TEST) and a straight one (CTRL). Transmission electron microscopy (TEM) was used to quantify the three-dimensional topography and morphological properties of collagen at nanoscale resolution. 2 swine were included in the experiment and 6 implants per animal were randomly placed in the left or right hemimandible in either the physiologically mature bone present between the lower canine and first premolar or in the mandibular premolar area, within tooth extraction sites. Each CTRL implant was positioned across from its respective TEST implant on the other side of the jaw. After 12 weeks of healing, 8 specimens (4 CTRL and 4 TEST) were retrieved and prepared for histological and TEM analysis. The results showed a significantly higher percentage of area covered by collagen bundles and average bundle size in TEST implants, as well as a significant decrease in the number of longitudinally oriented bundles with respect to CTRL implants, which is potentially due to the larger size of TEST bundles. These data suggest that a concave transmucosal abutment design serves as a scaffold, favoring the deposition and growth of a well-organized peri-implant collagen structure over the implant platform in the early healing phase, also promoting the convergence of collagen fibers toward the abutment collar.

Clinical outcomes of arch expansion with Invisalign: a systematic review

ObjectiveThis study aims to assess the scientific evidence regarding the clinical outcomes of Invisalign therapy in controlling orthodontic tooth movement.Materials and methodsAn electronic search was conducted on PubMed, Cochrane Library, Web of Science, Embase, and Scopus from November 2015 to November 2022 to identify relevant articles. Methodological shortcomings were highlighted, and an evaluation of the quality of the included studies was completed using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool.ResultsFifteen non-randomized controlled trials were included in the analysis. Most non-randomized controlled trials (n=11; 73%) were rated with a moderate risk of bias according to the ROBINS-I tool. There were statistically significant differences between the pretreatment and posttreatment arches. The average expansion was significantly different from that predicted for each type of tooth in both the maxilla and mandible. Furthermore, the efficiency decreased from the anterior area to the posterior area in the upper arch.ConclusionDespite the fact that arch expansion with Invisalign® is not entirely predictable, clear aligner treatment is a viable option for addressing dentition crowding. The efficacy of expansion is greatest in the premolar area. More research focusing on treatment outcomes with different materials of aligners should be conducted in the future. Overcorrection should be considered when planning arch expansion with Invisalign. In the maxilla, the expansion rate decreases from the anterior to the posterior, and presetting sufficient buccal root torque of posterior teeth may result in improved efficiency of expansion.

Research Paper: Accuracy of Panoramic Radiography in Determining the Distance to Anatomical Landmarks Compared to Cone-Beam Computed Tomography

Introduction. The aim of this study was to determine the accuracy of digital panoramic radiography in estimating the height of bone between alveolar crest and anatomical landmarks of both jaws( maxillary sinus and inferior alveolar nerve canal) in molar and premolar areas in comparison with CBCT. Methods and Materials. A total of 217 samples from patients who had both digital panoramic radiographs and CBCT before implant insertion were selected. Shortest distance between alveolar crest and IANC (of mandible), and between the alveolar crest and maxillary sinus (of maxilla) in molar and premolar area has been measured. The differences of these measurements have been analyzed using paired t-test, the Bland-Altman plot and ICC. Results. Measurements of panoramic radiography were significantly greater than CBCT in mandibular premolar and molar area plus maxillary premolar area (p&lt;0.001, p&lt;0.001, p=0.008 respectively), but the results were insignificant in maxillary molar area (p=0.147). By using ICC, the measurements were closely and positively correlated in all areas, with correlation coefficient ranging from 0.916 to 0.947. The Bland-Altman plots showed significant difference between two modalities except maxillary molar area (p&lt;0.05). Conclusion. Panoramic radiographs contain valuable information of both jaws, however they could not be reliable for meticulous measuring such as distance to anatomical regions- except posterior maxillary one - in surgeries. So that, it is essential to use precise 3D systems such as CBCT for implant measurements.

Evaluating cone cut in rectangular collimation in intraoral radiography: application of ALADA and radiation stewardship

ObjectiveRectangular collimation is a popular method used in intraoral radiography to reduce patient exposure to ionizing radiation. One of the perceived drawbacks of rectangular collimation is the possibility of an increase in cone cut errors ultimately impacting the diagnostic value of the radiographs. Thus, the aim of this study was to explore the frequency of cone cut errors in radiographs taken using a rectangular collimator.Materials and methodsRadiographs taken using PSP plates at Academic Center for Dentistry Amsterdam in the Netherlands by staff and students from January to December 2015 were assessed for cone cut errors. The radiographs were grouped as bitewings, front teeth, inferior premolars and molars, and superior premolars and molars and categorized as no cone cut, cone cut but diagnostically usable, and cone cut but diagnostically not usable. The results were entered into Microsoft Excel and analyzed thereafter.ResultsA total of 53,684 radiographs were assessed, 79% had no cone cut errors and consequently 21% had some degree of cone cut. However, the diagnostic value was unaffected in 18% of the radiographs with cone cut. Only 3% of the radiographs were deemed diagnostically unusable due to cone cut. The most common area of cone cut was in the premolar and molar areas while cone cut in the front teeth was least likely to be diagnostically unusable.ConclusionCone cut from the use of a rectangular collimator does not seem to result in an increase of diagnostically unusable radiographs. Thus, rectangular collimation should be preferred as it decreases the amount of radiation exposure to the patient while producing diagnostically usable radiographs and thus allowing the dental professional to adhere to the ALADA principle and practice radiation stewardship.Clinical relevanceScientific rationale for the study: rectangular collimation is a method used to reduce patient exposure to ionizing radiation; however, this benefit is negligible if radiographs must be retaken due to cone cut errors that make the radiograph diagnostically unusable. Therefore, the aim of this study was to explore the frequency of cone cut in radiographs taken using a rectangular collimator. Principal findings: cone cut was observed in 21% of the radiographs; however, only 3% of the radiographs were considered diagnostically unusable. Practical implications: rectangular collimation does not result in a high number of diagnostically unusable radiographs and should be used to reduce patient exposure to ionizing radiation.

Assessment of the alveolar bone loss in fresh socket implant procedures with immediate implant loading via temporary preformed anatomical healing caps: Comparison of two different lengths of the implant collar

PurposesThe aim of the present clinical and radiologic retrospective study was to evaluate alveolar bone remodeling, in terms of alveolar width and peri‑implant bone level, two years after immediate implant positioning (with two different collar lengths, 0.8 mm and 2.0 mm) and loading of preformed healing cap. The Null hypothesis, H0 is: there was no difference between the two groups of implants. MethodsPatients suffering from single-tooth edentulous areas in premolar, cuspid, and incisive areas were treated with fresh-socket implants and immediate preformed anatomical healing caps. Each final crown restoration was fabricated 3 months later. Primary outcomes (related to loss of the alveolar width and peri‑implant bone level) and secondary outcomes (testing adverse events, and measuring implant/prosthesis survival) were acquired and analyzed. ResultsA two-year retrospective analysis was conducted on 31 patients (19 female and 12 male), who underwent dental implant placement with implants having two different lengths of the collar: group A, 0.8 mm, and group B, 2.0 mm. As for the width of the alveolar crest, there was a negligible loss (less than half a millimeter) reported for both the groups, anyway reaching a statistical significance. Preoperative alveolar widths (9.50±0.67 mm and 9.45±0.90 mm, respectively for groups A and B) were different from the two-year alveolar widths (9.20±0.74 mm and 8.93±0.99 mm, respectively for groups A and B) with p-values ≤ 0.0049. When the marginal bone loss was assessed, significant differences were registered between the two procedure groups (-1.42±0.34 mm for group A and -0.11±0.15 mm for group B with a p-value < 0.0001). ConclusionsThe proper design of a healing abutment was very important to preserve the emergence profile immediately after extraction and implant placement. The length of the implant collar used with an immediate healing abutment appeared to affect the preservation of the alveolar crest with predictable final results.

THE USE OF MEDICINES BASED ON HYALURONIC ACID IN THE COMPLEX TREATMENT OF DISORDERS OF THE ARCHTECTONICS OF THE VESTIBULE OF THE MOUTH

Improving the effectiveness of diagnosis, comlex treatment of patients with maxillomandibular anomalies on the background of architectonics disorders of the vestibule of the mouth. The frenulum of the lips, buccal frenulums, ankyloglossia are the etiological factors in the development of maxillofacial anomalies. They are the reason for the change in the position of a separate group of teeth after the end of active treatment. Often architectonics disorders of the vestibule of the mouth course of gum. 30 people with maxillomandibular anomalies 12-15 years old on the background of architectonics disorders of the vestibule of the mouth were examined and treated, where plastic interventions on the vestibule of the mouth were important. All patients had plastic surgery of the vestibule of the mouth by the classical method. There was secondary tension of wound. Patients of the I group were prescribed chlorhexidine-denta in the postoperative period. Patients of the II group were prescribed chlorhexedine-denta and gengigel.&#x0D; The peculiarity of the clinical course of maxillomandibular anomalies on the background of disorders of the architectonics of the vestibule of the mouth was a pronounced change in the architecture of the vestibule of the mouth (less than 5 mm, 96.7% (29/30) of all patients have buccal frenulum). Indicators of cytomorphometric and rheographic researches indicated a deficiency of blood supply in these areas. The results of clinical and laboratory examination showed a significant difference between surgical interventions, where the wound healed by primary and secondary tension. Long-term results after the proposed method of correction of disorders of the architectonics of the vestibule of the mouth and the use wound-healing drug based on hyaluronic acid in the postoperative period indicate the formation of a normorphic scar, no recurrence and recession of the gums in the projection of buccal frenulum, normalization of clinical and laboratory indicators. The obtained data differ significantly from those in other groups of patients (p &lt;0.05).&#x0D; Surgical correction of architectonics disorders of the vestibule of the mouth is an important step in the complex treatment of patients with maxillomandibular anomalies on the background of architectonics disorders of the vestibule of the mouth. The peculiarity of the clinical course of maxillomandibular anomalies on the background of architectonics disorders of the vestibule of the mouth was a pronounced change in frenulum fixation less than 5 mm, 85.0% (51/60) of patients have connective tissue strands in the area of canines and premolars, in 78.3% of patients - catarrhal hygnivitis). The results of the clinical research were confirmed by cytomorphometric and rheographic researches and indicated a lack of blood supply in these areas. Long-term results after the proposed method of correction of architectonics disorders of the vestibule of the mouth and the use of chlorhexidine dent and gingigel in the postoperative period indicate the formation of normorthophic scar, no recurrence and recession of the gums in the projection of canines and premolars, normalization of clinical and laboratory results. The obtained data differ significantly from those in other groups of patients (p &lt;0.05).

Determination of Palatal Soft Tissue Thickness and Safe Zone for Palatal Soft Tissue Harvest Using CBCT: A Retrospective Study.

Our decision to conduct this study was motivated by the dearth of knowledge on geographical variations in the thickness of the palatal masticatory mucosa. The aim of the present study is to comprehensively analyze the palatal mucosal thickness and indicate the safety zone for palatal soft tissue harvesting using cone beam computed tomography (CBCT). Material and Methods. As this was a retrospective analysis of cases previously reported to the hospital, written consent was not acquired. The analysis was carried out on 30 CBCT images. Two examiners evaluated the images separately to avoid bias. Measurements were done from the midportion of the cementoenamel junction (CEJ) to the midpalatal suture in a horizontal line. Measurements were recorded from the maxillary canine, first premolar, second premolar, first molar, and second molar and were marked in axial and coronal sections at distances of 3, 6, and 9 mm from the CEJ. The relationship between palate soft tissue thickness in relation to each tooth, palatal vault angle, teeth, and the greater palatine grove was evaluated. Differences in the palatal mucosal thickness according to age, gender, and tooth site were evaluated. Categorical data were presented as frequencies and percentages. Numerical data are presented as mean and standard deviation values. They are explored for normality using Shapiro-Wilk's test. Data are normally distributed and are analyzed using one-way ANOVA followed by Tukey's post hoc test for independent variables and paired t-test for repeated measures. The significance level is set at p ≤ 0.05 for all tests. Statistical analysis is performed with R statistical analysis software version 4.1.3 for Windows. For sex and nationality, there was no significant association (p > 0.05), while for age, cases 35 years and older had significantly higher mucosal thickness than cases younger than 35 years old (p < 0.001). For all teeth, the association was statistically significant (p < 0.001). For the canine and first premolar, cases with deep angles had significantly higher mean values than those with moderate angles (p < 0.001). For other teeth, cases with deep angles had significantly higher mean values than other angles (p < 0.001). Palatal mucosal thickness varied significantly from the canine to the second molar; the most appropriate site for graft harvesting is the canine to second premolar area which is 9-12 mm from the midpalatal suture aspect and is considered a safe zone for harvesting palatal graft.

Influence of buccal and palatal bone thickness on post-surgical marginal bone changes around implants placed in posterior maxilla: a multi-centre prospective study

BackgroundNumerous clinical variables may influence early marginal bone loss (EMBL), including surgical, prosthetic and host-related factors. Among them, bone crest width plays a crucial role: an adequate peri-implant bone envelope has a protective effect against the influence of the aforementioned factors on marginal bone stability. The aim of the present study was to investigate the influence of buccal and palatal bone thickness at the time of implant placement on EMBL during the submerged healing period.MethodsPatients presenting a single edentulism in the upper premolar area and requiring implant-supported rehabilitation were enrolled following inclusion and exclusion criteria. Internal connection implants (Twinfit, Dentaurum, Ispringen, Germany) were inserted after piezoelectric implant site preparation. Mid-facial and mid-palatal thickness and height of the peri-implant bone were measured immediately after implant placement (T0) with a periodontal probe and recorded to the nearest 0.5 mm. After 3 months of submerged healing (T1), implants were uncovered and measurements were repeated with the same protocol. Kruskal-Wallis test for independent samples was used to compare bone changes from T0 to T1. Multivariate linear regression models were built to assess the influence of different variables on buccal and palatal EMBL.ResultsNinety patients (50 females, 40 males, mean age 42.9 ± 15.1 years), treated with the insertion of 90 implants in maxillary premolar area, were included in the final analysis. Mean buccal and palatal bone thickness at T0 were 2.42 ± 0.64 mm and 1.31 ± 0.38 mm, respectively. Mean buccal and palatal bone thickness at T1 were 1.92 ± 0.71 mm and 0.87 ± 0.49 mm, respectively. Changes in both buccal and palatal thickness from T0 to T1 resulted statistically significant (p = 0.000). Changes in vertical bone levels from T0 to T1 resulted not significant both on buccal (mean vertical resorption 0.04 ± 0.14 mm; p = 0.479) and palatal side (mean vertical resorption 0.03 ± 0.11 mm; p = 0.737). Multivariate linear regression analysis showed a significant negative correlation between vertical bone resorption and bone thickness at T0 on both buccal and palatal side.ConclusionThe present findings suggest that a bone envelope > 2 mm on the buccal side and > 1 mm on the palatal side may effectively prevent peri-implant vertical bone resorption following surgical trauma.Trial RegistrationThe present study was retrospectively recorded in a public register of clinical trials (www.clinicaltrials.gov - NCT05632172) on 30/11/2022.

Effect of maxillary constriction orthodontic correction using a fixed appliance with a screw in teenagers during a growth spurt

Relevance. The research is relevant because of a high prevalence of anterior and posterior crowding in children with mixed and permanent dentition (from 42 to 86 %), for whom the correction of the dentition form and the size is recommended by fixed expanding appliances with a screw. After the teenage growth spurt, the growth and development of jaws end, steady pathological signs form, there are psychological problems in a face and smile selfperception, and the question of the orthodontic treatment duration arises.Purpose. To study the effectiveness of treatment of patients with maxillary premolar area constriction during growth spurt using two modifications of fixed Hyrax expander.Material and methods. We examined 22 male patients aged 10.6 to 13 y.o. (average age 11.2 ± 1.6 years old) with permanent dentition, constriction of the posterior teeth and crowding of incisors, treated with a fixed expander (Hyrax appliance) in the upper jaw during the growth spurt. The patients formed two groups. Group 1 (n = 11) had the Hyrax screw at the level of the upper first premolars, and Group 2 (n = 11) had the Hyrax lock located at the first permanent molars. The patients activated the expander independently by ¼ turn every other day for six months. Then the appliance remained in the mouth for three months. We studied the maxillary expansion results on plaster models before and after six months of the expander fixation using the Tonn, Pont, Korkhaus, Bolton method.Results. The study has established that orthodontic correction of transversal abnormalities with a fixed Hyrax expander affects the maxillary posterior teeth expansion, changes their parameters and improves their movement. At the same time, in Group 1, the width between the first premolars and the first molars reached the norm calculated from the sum of the mesiodistal dimensions of the upper incisors, and in Group 2, the width between the first permanent molars exceeded the normal, and inter-first-premolar distance did not reach the normal values for three months of activation.Conclusion. Fixed Hyrax expander showed the best results if the screw was at the level of first premolars during the teenage growth spurt.