Mandibular Molar Region Research Articles

Survival Rate of Single Implant When Replacing the Mandibular Second Molars: Importance of Implant Length

Purpose: Restoration of the mandibular second molar with single implants has many limitations. This includes poor bone quality, reduced alveolar bone, large occlusal force, and difficulty in surgical approach. The purpose of this study was to analyze the survival rate of single implants in second molar restoration and evaluate the effect of associated factors regarding implant length, diameter, and guided bone regeneration (GBR). Materials and Methods: Altogether, 137 patients (77 males and 60 females; age range: 19 to 81 years; mean age 53.6 years) were treated with 147 single implants in the mandibular second molar region by an experienced surgeon between 2006 and 2019. The cumulative survival rate (CSR) was analyzed using a life-table analysis and the effect of associated factors on the survival was compared using Log Rank Test. Results: Four of the 147 implants failed. Thus, the five-year cumulative survival rate was 97.1%. In three out of four cases, implant failed after the 4th, 6th, and 8th year of implantation. In one of the four cases, the implant failed within four months of implantation. A significant change was observed in CSR with respect to the implant length. However, no difference was observed in CSR with respect to the implant diameter and GBR.Conclusion: This study reveals that replacing the mandibular second molar with a single implant is an effective and reliable treatment. However, the implant length over 10mm is recommended for successful result if there is sufficient residual alveolar bone.

Dentinogenic ghost cell tumor: A case report with review of literature

Dentinogenic ghost cell tumor is a rare odontogenic neoplasm first described by Praetorious et al in 1981. It is a solid variant of calcifying odontogenic cyst. This tumor shows no gender predilection and is seen more in mandibular anterior and molar region. Clinically, this tumor presents as two forms, Intraosseous & Extraosseous. Ghost cells are pathognomonic in diagnosing this tumor. Very few cases of this rare dentinogenic ghost cell tumor have been reported in the literature till date.

<strong>Alveolar bones density assessment of dental implant sites using cone-beam computed tomography </strong>

ABSTRACTIntroduction: a preoperative assessment of bone density plays a vital role in the success of dental implant treatment. the maxilla and mandibular alveolar bone had a variety of bone densities. Therefore, dental imaging is an important step before placing a dental implant. Recently, Cone beam computed tomography (CBCT) is widely used in dental medicine and also recommended by AAOMR for preoperative implant placement. The aims of this study is to analyzed the alveolar bone density of the dental implant sites for dental implant planning using CBCT. Methods: ninety-three CBCT data were retrieved from the database of the department of oral and maxillofacial radiology at Dental Hospital Faculty of Dentistry Universitas Trisakti and examined. The recipient sites for dental implant placement were determined based on CBCT data using implant planning software (i-Dixel). The alveolar bones value is recorded in grayscale value (GV). Results: a great variety of alveolar bone density was observed ranging from 134-891 GV. One-way ANOVA was conducted, and statistically significant was only shown at the anterior mandibular region and molar mandibular region. However, no statistical differences were observed when comparing the male and female groups using the T-test. Conclusion: Critical evaluation through dental CBCT can be made before dental implant placement in the alveolar bones. the lowest alveolar bone density was observed in maxillary molar dental implant sites with mean 322 GV and highest alveolar bone density was shown in mandibular anterior dental implant sites with mean 558.8 GV. Determining the bone density at the dental implant site before dental implant placement is crucial. Primary stability and secondary stability is determined by bone density. Therefore, higher value of alveolar bone density is needed for dental implant placement. Keywords: alveolar bone density assessment; dental implant; cone-beam computed tomography.

Effect of Low-Level Diode Laser Bio-Stimulation on Implant Stability Before, During and After Immediate Implants in Mandibular Molars. (A Randomized Clinical Study)

Aim: Tooth loss can affect the person’s life dramatically. Tooth loss is accompanied by bone loss in all dimensions, so preservation of the bone is mandatory for placement of dental implant. Immediate implant can preserve alveolar bone. Due to difference in shape between the implants and extracted roots a gap appears between the immediately placed implant and the extraction socket resulting in jumping distance, Bone grafts are commonly used to fill this gap, recent studies suggest that jumping gaps shouldn’t always be grafted. Low level bio stimulation has stimulatory effect on bone cells so it can be used in immediate implants to increase bone formation around the implants. Materials and methods: this study was carried in the hospital of future university. A total of twelve patients with non-restorable mandibular molar participated in this study. A total of twenty implants were placed immediately in mandibular molar region without bone grafting, thew were divided equally into two groups. Surgical technique was similar for both groups. After immediate implant placement with primary stability of 35 N, both groups received custom made healing collar using flowable composite to seal the jumping distance.The study group (intervention) received a total of 60J/cm2 .10J/cm2 3 days before extraction, another 10J/cm2 at the fresh socket, another 10 J/cm2 after osteotomy, another 10J/cm2 after implant placement, another 20J/cm2 at the follow up visit with 3 days interval. After six weeks secondary implant stability was measured for both groups using Resonance Frequency Analysis device (RFA). Prosthetic phases started for implants that showed sufficient secondary stability. Results: All implants enrolled in this study showed sufficient secondary stability except for one totally avulsed implant from the control group. Study group showed more stability upon measuring using RFA device after six weeks of implant placement. The study group has shown a higher secondary stability compared to control group, the mean ISQ value of study (71.89±2.67) was significantly higher than control (62.43±8.62). Conclusion: Based on the results of our study we concluded that low level diode laser 980nm has a stimulatory effect on bone formation when applied before, during and after immediate implant placement, According to this study 60J/cm2 is recommended dose and it also gave better soft tissue healing results

Variance of radiographical alveolar bone mineral density by the anatomical morphology of mandibular bone

PurposeEvaluating the bone mineral density (BMD) of alveolar bone is useful for dental treatments. The DentalSCOPE is an image analysis system developed to evaluate the BMD of alveolar bone. The aim of this study was to evaluate the relationship between cross-sectional anatomical size and BMD value. Materials and methodsThirty-four subjects (adult dental patients and volunteers) participated in this study. Intraoral radiographs of the mandibular molar region were acquired. Using DentalSCOPE software, three to four line-shaped regions of interest (ROIs) were obtained in the alveolar septum region. Cross-sectional CT images of mandible at the same position to above mentioned line-shaped ROI was reconstructed from subject's dental CBCT images. The measurements were performed using cross-sectional CT images and compared with BMD value. Results and discussionFor stepwise multiple linear regression analysis, the buccal-lingual width of the mandibular body (mandible width) and the CT value of the cancellous bone were adopted as explanatory variables that affected the BMD of the mandible. The BMD value increased by 20 mg/mm2 when the mandible width increased by 1 mm, and the BMD value increased by 5 mg/mm2 when the CT value of the cancellous bone increased by 1%. ConclusionIn the clinical application of alveolar bone BMD, the effect of the anatomical morphology of alveolar bone should be taken into consideration.

The Radiological Evaluation of Mandibular Canal Related Variables in Mandibular Third Molar Region: a Retrospective Multicenter Study.

The aim of this retrospective study was to investigate anatomical structure of mandibular canal and the factors those increase the possibility of inferior alveolar nerve damage in mandibular third molar region of Turkish population. Overall 320 participants with 436 mandibular third molars were included from four different study centers. Following variables were measured: type and depth of third molar impaction, position of mandibular canal in relation to third molars, morphology of mandibular canal, cortication status of mandibular canal, possible contact between the third molars and mandibular canal, thickness and density of superior, buccal, and lingual mandibular canal wall, bucco-lingual and apico-coronal mandibular canal diameters on cone-beam computed tomography scans. Lingual mandibular canal wall density and thickness were decreased significantly as the impaction depth of mandibular third molar was increased (P = 0.045, P = 0.001 respectively). Highest buccal mandibular canal wall density and thickness were observed in lingual position of mandibular canal in relation to mandibular third molar (P = 0.021, P = 0.034 respectively). Mandibular canal with oval/round morphology had higher apico-coronal diameter in comparison to tear drop and dumbbell morphologies (P = 0.018). Additionally, mandibular canals with observed cortication border and no contact with mandibular third molar had denser and thicker lingual mandibular canal wall (P = 0.003, P = 0.001 respectively). Buccal and lingual mandibular canal wall density, thickness and mandibular canal diameter may be related with high-risk indicators of inferior alveolar nerve injury.

The evaluation of stress on bone level and tissue level short implants: A Finite Element Analysis (FEA) study

PurposeThis study aimed to evaluate the difference between the stress level and distribution around the BL and TL short implants, and their surrounding structures, using finite element analysis. MethodsTwo different study models were constructed: BL model and TL model. Two dental implant systems (ITI (Straumann, Waldenburg, Switzerland) and NTA Short) with a diameter of 4.1 mm and 4 mm and with a length of 6 mm were used in this study. In each model, implants were placed in the mandibular 1st molar region. The von Mises stress and maximum principal (tensile) and minimum principal (compressive) stresses were evaluated. ResultsThe highest stress values recorded in the BL implants (von Mises: 342.77 MPa), in the peri‑implant bone around the BL implants (maximum principal stress: 114.1 MPa), as a result of oblique loading, and overall stress values were found to be higher in the BL model. However, these measured values appeared to be low to cause a fracture, when considering the yield strengths of the materials and bone. ConclusionsThe stress values were higher in the BL model, but not high enough to cause failure. Short implants could be an effective method of treatment for patients unsuitable for advanced surgical techniques.

Comparative evaluation of short or standard implants with different prosthetic designs in the posterior mandibular region: a three-dimensional finite element analysis study

The purpose of this study is to evaluate the stress distribution of splinted or nonsplinted restorations supported by 2 short or 2 standard dental implants in the mandibular molar region using three-dimensional finite element analysis. Two standard implants (4.8 × 10mm) were placed in the mandibular molar area. Two short implants (4.8 × 6 mm) were located in the mandibular molar atrophied area. Implant-supported prostheses were simulated with splinted or nonsplinted crowns design. Vertical load of 200 N and oblique load of 100 N were applied on the central fossa and the buccal cusps. Evaluation of stress distribution in implants and peri-implant cortical bone using the finite element analysis software (Ansys, Version 2020, R2), a multipurpose computer design program. The maximum principal stress of cortical bone around the implants was higher in nonsplinted crowns when compared to splinted crowns. The stress concentration of cortical bone surrounding implants increased as the implant length decreased either splinted crowns or nonsplinted crowns. The short implants with nonsplinted crowns showed lower stresses when compared to standard implants with nonsplinted crowns. The results suggest that the nonsplinted prostheses supported by short dental implants might be considered in the molar area of the atrophic mandible.

Single-Unit Short Implants in the Molar Region: A Retrospective Study with a Minimum 3-Year Follow-up.

The high biomechanical loads in molar region wounds challenge the indication for short implants to be used as a single-unit implant. This study reports on the outcomes of single-unit short implants (≤ 8.0 mm) in the maxillary and mandibular molar regions. Forty-nine short implants were placed in 48 patients to replace a missing molar tooth. Two-piece restorations with screw retention were fabricated. During the follow-up, implant survival and marginal bone loss (MBL) were assessed. The known implant length was used as a reference to calibrate the linear measurements on digital periapical radiographs, and descriptive statistical analysis was performed. The implants were followed over a period of 47 ± 12 months. No implant failure was recorded, and no prosthesis failure was observed. The average MBL was 0.15 ± 0.5 mm. The mean crown height space was 13 ± 3 mm. The overall crown-to-implant ratio was 1.7 ± 0.4. Two technical complications occurred due to the loosening of the unit abutment. After screw re-tightening, no more screw loosening was observed. This study supports the use of short implants as a single-unit implant in the maxillary and mandibular molar regions.

Anatomic considerations for immediate implant placement in the mandibular molar region: a cross-sectional study using cone-beam computed tomography

There is concern regarding immediate implantation in the molar region because of discrepancy between socket size and inserted implant diameter. The purpose of this study was to assess the local anatomy of the posterior mandibular region in relation to immediate implant placement using cone-beam computed tomography (CBCT). Using CBCT imaging data, 204 mandibular first molars and 201 mandibular second molars were assessed for the interradicular and alveolar bone dimensions, tooth sizes and proximity to vital structures. The cross-sectional mandibular shape and root configuration of these molars were determined. Distances to the inferior alveolar canal (IAC) from the root apices of the first molar were significantly greater than the second molar. Up to 14.5% of second molars had less than 10 mm of vertical bone height between the IAC and furcation bone crest. Interradicular bone width of < 3 mm was found in 57% of second molars. All first molars in this study had two to three roots while 16% of second molars presented with a single root. The prevalent mandible shape at the first and second molars was the parallel and undercut ridges, respectively. The mandibular second molars from samples of a Southeast Asian population presented with greater anatomical difficulties for immediate implant placement which include absent or inadequate interradicular bone thickness, higher incidence of unfavourable mandible shape and increased proximity to vital structures.

MULTIPLE DENTIGEROUS CYSTS IN A PEDIATRIC PATIENT: CASE REPORT

Although dentigerous cysts are the most common developmental odontogenic cysts, multiple synchronous lesions in nonsyndromic patients are a rare event. A 10-year-old patient was admitted to the intensive care unit presenting painful progressive bilateral facial swelling. Medical history was unremarkable. Intraoral examination revealed an increase of volume in the region of the bilateral mandibular and left maxillary molars. Magnetic resonance imaging showed expansive and well-defined lesions in those regions, associated with the crown of the impacted second molars. Under general anesthesia, aspiration was performed, and a yellowish fluid content was observed. Enucleation of the cystic lesions was performed along with extraction of the involved second molars. Histopathologic analysis revealed fragments of cystic lesions lined by a thin, nonkeratinized odontogenic epithelium, leading to the diagnosis of multiple dentigerous cysts. The postoperative period was uneventful and the patient does not show clinical or radiographic signs of recurrence after 2 years of follow-up. Although dentigerous cysts are the most common developmental odontogenic cysts, multiple synchronous lesions in nonsyndromic patients are a rare event. A 10-year-old patient was admitted to the intensive care unit presenting painful progressive bilateral facial swelling. Medical history was unremarkable. Intraoral examination revealed an increase of volume in the region of the bilateral mandibular and left maxillary molars. Magnetic resonance imaging showed expansive and well-defined lesions in those regions, associated with the crown of the impacted second molars. Under general anesthesia, aspiration was performed, and a yellowish fluid content was observed. Enucleation of the cystic lesions was performed along with extraction of the involved second molars. Histopathologic analysis revealed fragments of cystic lesions lined by a thin, nonkeratinized odontogenic epithelium, leading to the diagnosis of multiple dentigerous cysts. The postoperative period was uneventful and the patient does not show clinical or radiographic signs of recurrence after 2 years of follow-up.

Mylohyoid Ridge as a Predictor of Available Bone for Implant Placement: A Cone-Beam Computed Tomography (CBCT) Retrospective Observational Study.

Introduction: The posterior mandibular region, due to the presence of vital structures, poses a high risk during implant placement because of its susceptibility to neurovascular injury and perforation of the lingual cortex. A breach in implant length and available bone height may lead to serious intraoperative and postoperative complications. Prediction of the exact location of the inferior alveolar nerve and submandibular fossa anatomy is a prerequisite for ideal implant placement, which is always not possible with conventional radiographic and clinical techniques.Materials and methods: One hundred ten cone-beam computed tomographies (CBCTs) of patients were acquired from the radiological archives of a radiological center in Chennai. DICOM files from CBCT were exported to Bly Sky Plan software. Cross-sections of the second molar and first molar were extracted following the inclusion criteria. The linear dimension between the mandibular canal and mylohyoid ridge and anatomic variables of the submandibular fossa were measured digitally on the left and right sides using software measuring tools. Descriptive statistics were done. The unilateral and bilateral site and gender differences were evaluated. Bone height superior to the mandibular canal was correlated with the submandibular fossa parameters; depth of undercut in the vertical and horizontal directions; and angle of the undercut.Results: The mandibular canal was on average 5.5 mm and 4 mm inferior to the Mylohyoid ridge in the second molar region and first molar region, respectively, with the right and left sides showing no statistically significant difference. The depth of fossa undercut in vertical and horizontal dimensions was higher in the second molar region compared to the first molar region. The height of the deepest point of the undercut in the vertical dimensions showed a positive correlation with the bone available between the mandibular canal and the mylohyoid ridge.Conclusion: Keeping 2 mm of safety factor in consideration, implants can be safely placed up to the mylohyoid ridge in 100% of cases and 2 mm below the mylohyoid ridge in 78.9% of cases in the mandibular second molar region. In keeping with a safety factor of 2 mm, implants can be safely placed up to the mylohyoid ridge in 82.6% of cases and 2 mm below the mylohyoid ridge in 43.1% of cases in the first molar region. A more pronounced undercut was seen in the second molar region than in the first molar region. Deeper fossa undercuts in vertical dimension are associated with more inferior positioning of the mandibular canal.

A Prospective Clinical Study Evaluating the Efficacy of Intra-Ligamentary Anesthetic Solutions in Mandibular Molars Diagnosed as Symptomatic Irreversible Pulpitis with Symptomatic Apical Periodontitis.

Accomplishing painless endodontic treatment, especially in the mandibular molar region, is challenging. Hence, the aim of the study was to compare the efficacy of 2% lidocaine and 4% articaine when used as supplemental intra-ligamentary (IL) anesthesia in mandibular molars having symptomatic irreversible pulpitis with symptomatic apical periodontitis after failed Inferior Alveolar Nerve Block (IANB) injection. In this prospective study, one-hundred and forty-seven adult patients diagnosed with irreversible pulpitis in a mandibular tooth were included who received IANB with 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. Patients who experienced pain were recorded using the Heft–Parker visual analog scale (HP-VAS score ≥ 55 mm) and received supplement intra-ligament injection with either4% articaine or 2% lidocaine with 1:100,000 epinephrine. Supplementary intra-ligament injections resulted in 82.6% and 91.3% of profound anesthesia in the first molar region for 2% lidocaine and 4% articaine, respectively. Similarly, an additional IL injection of articaine success percent (78.9%) in the second molar region was higher than lidocaine (63.1%). The overall success ratio revealed no significant difference in achieving profound anesthesia of either solution. In this study population, there was no difference in the success ratio of anesthesia between 2% lidocaine and 4% articaine when used as supplemental IL injection.

Efficacy and Safety of Concentrated Growth Factors and Platelet- Rich Fibrin on Stability and Bone Regeneration in Patients with Immediate Dental Implants: A Randomized Controlled Trial.

Immediate dental implants revolutionized the field of implant dentistry with significant advantages over conventional implants. The lack of adequate bone in the extraction socket raises the question of the appropriate timing of implant loading. Platelet concentrates have been used widely to accelerate bone regeneration in the maxillofacial region. This study evaluates the effect of platelet concentrates on bone healing and implant stability in the maxillary and mandibular molar regions. Bone regeneration is regulated by several growth factors, particularly vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1); therefore, quantification of these factors in platelet concentrates and its correlation with bone healing has been assessed in this study. The primary aim of this randomized clinical trial was to compare the stability of immediate dental implants in the maxillary and mandibular molar regions treated with platelet-rich fibrin (PRF) versus concentrated growth factors (CGF) using resonance frequency analysis (RFA). The secondary objectives were to evaluate the bone regenerate around implants with the use of PRF and CGF and to quantify growth factors VEGF and TGF-β1 in the prepared CGF and PRF and their correlation with bone healing, if any. A total of 36 patients were randomized into three groups (12 each): control, PRF, and CGF. In all patients, immediate implants were placed either with or without platelet concentrate (PRF or CGF). Implant stability was measured using RFA immediately postoperatively and at 4, 8, and 12 or 16 weeks (12 weeks for mandible and 16 weeks for maxilla) postoperatively. Radiodensity and the bone gap (horizontal/vertical) were measured on intraoral periapical radiographs immediately postoperatively and at 8 weeks and 12 or 16 weeks postoperatively. On comparing the implant stability quotient (ISQ), radiodensity/grayscale (GS), and horizontal and vertical bone gap (HG and VG), there was no significant difference noted between the three groups at any point in time. On ISQ analysis at 8 weeks, the control group showed a significant improvement (P = .04), whereas at 12 or 16 weeks, significant improvement was seen in PRF (P = .03) and CGF groups (P = .02). In GS assessment, only the control group showed significant improvement at 12 or 16 weeks (P = .009). In horizontal and vertical bone gap analysis all three groups showed significant improvement at 8 weeks (control [P < .001], PRF [P = .001], CGF [P = .01]) as well as 12 or 16 weeks (control [P < .001], PRF [P < .001], CGF [P = .006]). The enzyme-linked immunosorbent assay (ELISA) quantification of VEGF and TGF-β1 showed significant concentration of VEGF in PRF as compared to the plasma, while concentration of TGF-β1 was found to be comparable in both groups. The application of platelet concentrates seems to enhance stability of implants, but intergroup results were nonsignificant at all time points. There was no statistically significant difference between the three groups when comparing quality (radiodensity/grayscale) and quantity (horizontal and vertical gap reduction) of bone regenerate. Studies with larger sample sizes are required to make conclusive assertions regarding efficacy of platelet concentrates in dental implants.

Evaluation of the Accuracy of Measurements Made at Probable Implant Site Using Cone-Beam Computed Tomography

Introduction: Computed Tomography (CT) was the most used 3D radiographic diagnostic technique for years, but cone-beam computed tomography (CBCT) was created to reduce radiation exposure, costs, and accessibility issues . Aim: To evaluate the accuracy of CBCT measurements made at probable implant sites. Materials and Methodology: This was a retrospective study that compared panoramic reconstructed CBCT with RVG measurements at 77 probable implant sites, especially mandibular posterior tooth-bounded edentulous areas. Measurements made were the mesiodistal width of the edentulous area at the crest and at the highest point of the adjacent tooth's contour and the length of the natural teeth in the mandibular first molar region from the highest cusp to the apex next to the edentulous area. Statistical analysis was done with the Statistical Package for the Social Sciences (SPSS) and the independent t-test. Results: The mean difference between CBCT and radiovisiography (RVG) readings for mesiodistal width at the crest and highest contour of the edentulous bounded two neighboring teeth was −0.21039 and 0.02961, respectively, which was not statistically significant. The mean difference between CBCT and RVG readings along the tooth was 0.80481, which was statistically significant (P = 0.018). RVG outperformed CBCT (SD = 1.7) in estimating tooth length. Conclusion: Conventional RVG radiographic measurements were similar to real tooth length, whereas CBCT panoramic reconstructions underestimated the lengths by 15% but were clinically acceptable. Clinical CBCT application requires operator abilities and knowledge with software. It is critical to pay close attention to the calibration of data obtained from clinical examination and CBCT.

Role of NOD2 and hepcidin in inflammatory periapical periodontitis

The immunological response occurring during periapical inflammation includes expression of nucleotide binding oligomerization domain containing 2 and hepcidin. Nucleotide binding oligomerization domain containing 2 deficiency increases infiltration of inflammatory cells close to alveolar bone. Hepcidin has an important role in iron metabolism affecting bone metabolism.We investigated the role of nucleotide binding oligomerization domain containing 2 and hepcidin in inflammatory periapical periodontitis. Periapical periodontitis was induced in rats and confirmed by micro-computed tomography. Nucleotide binding oligomerization domain 2 and hepcidin were evaluated through immunohistochemistry. Bioinformatics analysis was undertaken usingthe Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases. Micro-computer tomography revealed alveolar bone resorption in the periapical region and furcation area of mandibular molars in rats of the periapical periodontitis group. Immunohistochemistry showed increased expressionof nucleotide binding oligomerization domain containing 2 and hepcidin around root apices in rats of the periapical periodontitis group. Bioinformatics analysis of differentially expressed genes in inflamed and non-inflamed tissues revealed enrichment in the NOD-like receptor signaling pathway. Our data suggest that nucleotide binding oligomization domain contain2 and hepcidin have important roles in periapical periodontitis severity because they can reduce alveolar bone loss.They could elicit new perspectives for development of novel strategies for periapical periodontitis treatment.

Effects of conventional complete dentures and implant-supported overdentures on alveolar ridge height and mandibular bone structure: 2-year and 6-year follow-up study.

The aim of this study was to compare the changes in mandibular bone structure in edentulous patients who were rehabilitated with conventional complete dentures (CCD) and implant supported overdentures (ISO), by evaluating alveolar bone loss (ABL), panoramic mandibular index (PMI), mandibular cortical width (MCW), gonion index (GI), antegonial index (AI), and articular eminence inclination (AEI). Panoramic radiographs of 63 edentulous patients using CCD, 63 edentulous patients using ISO, and 126 patients without tooth loss were evaluated. Edentulous patients had a 2-year and 6-year follow-up panoramic radiograph image. ABL (anterior, premolar, and molar regions), MCW, PMI, AI, GI, and AEI were measured in each patient. Variation between measurements was analyzed using repeated measures ANOVA test and post hoc Tukey test. Both edentulous groups showed significantly lower mean than without tooth lost group in all measures (p < 0.000). ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.000), right premolar (p = 0.005), left premolar (p = 0.005), right molar (p < 0.000), and left premolar (p < 0.000) regions in short term. ISO group showed significantly lower mean ABL than CCD group in anterior (p = 0.021), right molar (p < 0.000), and left premolar (p < 0.000) regions in long-term. There is no statistically significant difference between the CCD and ISO groups in right premolar (p = 0.200) and left premolar (p = 0.134) regions in long term. Both edentulous groups showed significantly lower mean MCW (p < 0.000), PMI (p < 0.000), AI (p < 0.000), GI (p < 0.012), and AEI (p < 0.002) than the without tooth loss group. There is no statistically significant difference between the CCD and ISO groups in terms of changes in the mean MCW, PMI, AI, GI, and AEI measurement in short and long term (p > 0.000). In the short and long term, edentulism reduced alveolar crest height, MCW, and AEI in individuals, but had no effect on PMI, AI, or GI. The use of prosthesis did not prevent the decrease of alveolar crest height, MCW, or AEI (CCP or ISO). In the short and long term, however, ISO created less ABL in the mandibular anterior and molar regions than CCD. ABL cannot be halted in edentulous people, but by using ISO instead of CCD for rehabilitation, resorption can be reduced.

Structural features of the roots and root canals of mandibular premolars and molars based on data of modern radiological methods of investigation used in dentistry

Objective. To determine the structural features of the root canals of mandibular premolars and molars, to assess the quality of endodontic treatment on the basis of cone-beam computed tomography (CBCT).Materials and methods. The structure of 50 teeth (premolars and molars of the mandible) after performed endodontic treatment was studied retrospectively on the basis of CBCT in 50 patients. The number of roots, as well as root canals and their angle of inclination, the presence of additional canals were taken into account. The obtained data were processed statistically.Results. No significant differences in the angle of inclination of the root canals and the number of roots were found. The ratio of unsatisfactory episodes of endodontic treatment was 82 %. Destructive processes in the periapical region were revealed in all the examined teeth.Conclusion. The results of the study prove the neсessity to develop the differentiated use of surgical methods for the treatment of foci of chronic odontogenic infections in the periapical region of mandibular molars and premolars.

Evaluation of change in trabecular bone structure surrounding dental implants by fractal dimension analysis and comparison with radiomorphometric indicators: a retrospective study.

BackgroundThe trabecular bone surrounding dental implant show some structural changes during healing period. The purpose of this study is to observe the change in trabecular bone with fractal dimensional analysis from baseline to 3rd month of implant placement. It was also aimed to determine the correlation of fractal dimension (FD) change with morphometric indices, mandibular cortical index (MCI) and mandibular cortical width (MCW).MethodsDigital panoramic radiographs taken from 14 patients were evaluated in this study. A total of 30 implants which were placed on mandibular premolar or molar region were included. MCI and MCW assessments were made on baseline radiograph and FD were analyzed on baseline and 3rd month radiograph. FD change by time was recorded separately for every ROI. A paired sample t-test was used to evaluate the change between FD-baseline and FD-3rdmonth values. One-way ANOVA was used to determine the relationship between FD change and MCI. FD change and MCW measurements correlation was calculated by Pearson correlation analysisResultsFD value increased in 75 of 90 implant-adjacent regions evaluated in the 3rd month and it was observed that the FD values were statistically significantly increased in the mesial, distal and apical regions at the 3rd month measurements. There was no statistically significant relationship between mean FD change and MCI, and there was no correlation between mean FD change and MCW value.DiscussionThere are many studies evaluating the resorptive changes in bone. However, there are few studies investigating whether there is a correlation between pre- and post-operative trabecular pattern with MCI and MCW. The results of this study indicate that the implants have an improving effect on bone trabeculation in the region where they are placed.

LINGUAL NERVE IN RELATION TO MANDIBULAR THIRD MOLAR REGION: A CADAVERIC STUDY

Background: The lingual nerve is the terminal branch of the mandibular division of trigeminal nerve. The spatial relationship of lingual nerve to the mandibular alveolar crest varies widely. This variation can be among the gender, age, dental status and between the right and left side of the same sample. This study was aimed to determine the relationship of lingual nerve to mandibular third molar region. Methods: An observational study was carried out from January 2021 to December 2021.The study sample was 15 cadavers including both right and left sides. The lingual nerve was exposed by dissecting the infra temporal region following the standard procedures of Cunninghams Manual of Dissection. The diameter of the lingual nerve, vertical and horizontal distance were measured. The results of all these measurements were tabulated and mean standard deviation were calculated using SPSS version 16. Results: Out of 30 lingual nerves examined, the mean horizontal distance was 3.99 ± 0.96 mm, the mean vertical distance was 12.67 ± 1.76 mm while the diameter of the lingual nerve was 2.46 ± 0.54 mm. Conclusions: The lingual nerve always lies in close proximity of alveolar bone and surgeons operating in this region need to be aware during any surgical interventions or any procedures in this region. A thorough apprehension of the spatial location of the lingual nerve enable to lessen the lingual nerve injury.