Evaluation of Cortical Thicknesses and Bone Density Values of Mandibular Canal Borders and Coronal Site of Alveolar Crest.

Objectives: The objectives of this retrospective study are to measure the amount of the alveolar crest cortication and cortication around the mandibular canal, and to evaluate bone density values of alveolar crest, cortication around mandibular canal, and possible implant placement area for edentulous sites. Material and Methods: Six hundred forty-two cone-beam computed tomography scans from 642 subjects were evaluated in four centers. Cortical thicknesses of alveolar crest and mandibular canal cortical borders (buccal, lingual, apical, and coronal) in each mandibular posterior teeth region were measured. Bone density of alveolar crest and mandibular canal cortical borders (buccal, lingual, apical, and coronal) in each mandibular posterior teeth region were recorded. The correlations between numeric variables were investigated using Pearson's correlation test. Results: The largest cortical border of the canal was measured 1.1 (SD 0.71) mm at the left second molar area and in coronal side of the mandibular canal (MC). Left and right first premolar regions showed higher bone density values compared to the other sites in all bone density values evaluations. The buccal side of the canal at the right first premolar region showed the highest bone density values (832.32 [SD 350.01]) while the coronal side of the canal at the left second molar region showed the lowest (508.75 [SD 225.47]). The bone density of possible implant placement area at the both left (692.25 [SD 238.25]) and right (604.43 [SD 240.92]) edentulous first premolar showed the highest values. Positive correlations between the bone density values of alveolar crest and the coronal side of MC were found in molar and left second premolar regions (P < 0.05). Conclusions: Results may provide information about the amount of cortication and bone densities tooth by tooth for posterior mandible to surgeons for planning the treatment precisely.

Effects of Crest Morphology on Lingual Concavity in Mandibular Molar Region: an Observational Study.

Objectives: The aim of this radiological study is to evaluate the lingual concavity dimensions and possible implant length in each posterior tooth region according to posterior crest type classification by using cone-beam computed tomography. Material and Methods: According to inclusion criteria, 836 molar teeth regions from 209 cone-beam computed tomography images were evaluated. Posterior crest type (concave, parallel, or convex), possible implant length, lingual concavity angle, width, and depth were recorded. Results: In each posterior tooth region, concave (U-type) crest was detected most frequently while convex (C-type) was the lowest. Possible implant length values were higher in second molar regions than first molars. Lingual concavity width and depth were decreasing from second molars to first molars for both sides. Additionally, lingual concavity angle showed higher values in second molar sites than first molars. In all molar teeth regions, lingual concavity width values were the highest in concave (U-type) crest type while they were the lowest in convex (C-type) crest type (P < 0.05). Lingual concavity angle values were recorded as the highest in concave (U-type) and the lowest in convex (C-type) crest type at the left first molar and right molars (P < 0.05). Conclusions: The lingual concavity dimensions and possible implant length may vary according to crest type and edentulous tooth region. Due to this effect, the surgeons should examine crest type clinically and radiologically. All parameters in the present study are decreasing while moving from anterior to posterior as well as from concave (U-type) to convex (C-type) morphologies.

Assessment of Radiodensity at Mandibular Periapical Bone Sites using Three-Dimensional Cone-Beam Computed Tomography.

Objectives: The aims of this retrospective study were to objectively assess bone density values obtained by cone-beam computed tomography and to map the periapical and inter-radicular regions of the mandibular bone. Material and Methods: In total, periapical bone regions of 6898 roots scanned by cone-beam computed tomography were evaluated retrospectively, and the results were recorded using Hounsfield units (HU). Results: The correlation between periapical HU values of adjacent mandibular teeth were strongly positive (P ˂ 0.01). The anterior region of the mandible yielded highest mean HU value (633.55). The mean periapical HU value of the premolar region (470.58) was higher than that was measured for molar region (374.58). The difference between furcation HU values of the first and second molars was unnoticeable. Conclusions: The results of this study have tried to evaluate the periapical regions of all mandibular teeth, which could ease to predict the bone radiodensity before implant surgery. Even though the Hounsfield units provide the average radio-bone density, a site-specific bone tissue evaluation of each case is essential for appropriate cone-beam computed tomography preoperative planning.

Possible Association between the Quantity of Peri-implant Crevicular Fluid, Clinical Indices, and the Dimensions of Endosseous Implants.

Objectives: The objectives of this clinical observational study are to measure peri-implant crevicular fluid volume based on dental implant diameter and length, and to evaluate the possible relationship between peri-implant crevicular fluid/gingival crevicular fluid volumes and clinical periodontal indices. Material and Methods: The information about length and diameter of dental implants was noted. Clinical indices (probing depth, plaque index, gingival bleeding time index, and gingival index) were recorded. Peri-implant crevicular fluid (PICF)/gingival crevicular fluid (GCF) volumes were measured from 4 sites (mesial, buccal, distal, and lingual/palatal) of each dental implant including its one or more equivalent natural tooth/teeth. Results: One-hundred-sixty-one loaded dental implants and 221 natural teeth of 101 patients were evaluated. The length of dental implant had no effect on PICF volume (P > 0.05). However, PICF volumes of narrow (< 3.5 mm) and wide (> 4.5 mm) diameter implants were higher than standard diameter implants (≥ 3.5 mm, and ≤ 4.5 mm) (P < 0.05). PICF and GCF volumes of areas with peri-implant/periodontal diseases were significantly higher than healthy areas (P < 0.05). PICF and GCF volumes showed positive correlations with clinical indices (P < 0.05). Conclusions: In accordance with the results of the present study, the implant diameter, not the implant length, affects peri-implant crevicular fluid volume.

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

Objectives: 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. Material and Methods: 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. Results: 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). Conclusions: Buccal and lingual mandibular canal wall density, thickness and mandibular canal diameter may be related with high-risk indicators of inferior alveolar nerve injury.

Inferior alveolar nerve topography and its bifurcation features: a cone beam computed tomography evaluation.

BACKGROUND: Mandibular canal (MC) is the most important vital structure in mandible to prevent from complications such as bleeding and paresthesia. The aims of the present study were to inform the features (diameter, distances to the mandibular borders, and distance to tooth apex) of the MC for each posterior tooth region, and to present the bifurcation features of the MC. METHODS: Four-hundreds-eighteen MC images of 209 patients were evaluated. The parameters were recorded from right and left hemi-mandibles for each posterior teeth region: 1) MC diameter; 2) MC and mandibular basis distance; 3) MC and crest distance; 4) MC and tooth apex distance; 5) MC and buccal plate distance; 6) MC and lingual plate distance; and 7) possible implant length (the distance between 2 mm coronal of the MC and 1 mm apical of the crest). Additionally, MC bifurcation type and bifid mandibular canal length were noted for right and left sides. RESULTS: While higher MC diameter values were recorded at molars, MC diameter in first premolars bilaterally were the lowest. In premolars, MC and mandibular basis distance showed higher values than molars. There was a trend of decrease in MC and crest distance from molars to premolars. The highest MC and tooth apex distance was measured in second molar; however, the lowest was in the first premolar. Additionally, MC and buccal plate distances were higher in molars, while MC and lingual plate distances were higher in premolars. Possible implant length in first premolar was the lowest, when it was the highest in second molars. CONCLUSIONS: For simulating overall MC topography, it extended bucco-coronally from molars to premolars. Due to this topography, possible implant length increased from premolars to molars.

Elevated Interleukin-17A expression in amlodipine-induced gingival overgrowth.

BACKGROUND AND OBJECTIVES: Amlodipine, a calcium channel blocker derivative, is frequently used by patients with high blood pressure. Studies reported that it can induce gingival overgrowth. However, the underlying mechanism is not fully described yet. Interleukin-17A (IL-17A) is known as a proinflammatory cytokine, but current studies indicate that it has a role in fibrotic disorders and epithelial-mesenchymal transition (EMT). The aim of this study was to figure out the possible role of IL-17A in amlodipine-induced gingival overgrowth. MATERIALS AND METHODS: Twenty-nine (29) individuals participated in the study, and they were assigned into 3 groups based on medical status and clinical periodontal examination; 9 patients with amlodipine-induced gingival overgrowth, 11 patients with inflammatory gingival overgrowth, and 9 healthy individuals as a control group. Clinical periodontal parameters including plaque index (PI), gingival index (GI), and gingival overgrowth index (GOI) were recorded. Blood and gingival crevicular fluid (GCF) samples were obtained. Gingival tissues were taken by appropriate periodontal surgery following initial periodontal therapy. To detect IL-17A on tissue samples, immunohistochemistry (IHC) was performed. Quantitative analysis was done, and the expression level of IL-17A was given as the percent positively stained cells. Enzyme-linked immunosorbent assay (ELISA) kits were used to analyze IL-17A in serum and GCF samples. RESULTS: All recorded clinical parameters were significantly higher in gingival overgrowth groups compared with control. Evaluation of inflammation on tissue sections did not show any significant change within the groups. Immunohistochemistry findings showed that IL-17A expression was increased in amlodipine samples (81.90%) compared with control samples (42.35%) (P < .001). There was an increase in the inflammatory group (66.08%) which is significantly less than the amlodipine group (P < .05). IL-17A levels in serum and GCF samples were not different within the study groups. CONCLUSION: In this study, elevated IL-17A expression regardless of inflammation shows that amlodipine might cause an increase of IL-17A in gingival tissues. This increase might induce fibrotic changes and EMT in gingival overgrowth tissues. The association of IL-17A with fibrosis and EMT in gingival tissues requires further investigation.

An alternative treatment for hopeless implants: Coronal resection.

Dental implant surgery is a highly reliable therapy with widespread use all over the world. However, various accidental symptoms and complications such as peri-implantitis have been reported, and occasionally necessitate implant removal. This alternative technique was performed to minimize the harmful effect of conventional resective explantation procedures. The present case concerns a 55-year-old woman who had two dental implants in the mandibular incisor regions who apparently developed severe marginal peri-implantitis. Presence of lesion was confirmed by two and three-dimensional radiographic images. Explantation was indicated because of the excessive ongoing bone loss around implants. Due to avoid serious complications such as jaw fracture, coronal resection technique (partial explantation) was suggested. After the full thickness flap was elevated, affected part of both implants were resected, and osseointegrated healthy apical parts were left in the basal bone. Wound healing was uneventful at one week follow-up. Proper locater abutments were tightened after 5 months of the partial explantation procedure, and final denture was applied in the oral cavity. The radiologic and clinical examinations showed successful outcome at 12-months follow-up. Minimally resective peri-implantitis therapy may be achieved using this non-traumatic coronal implant resection approach.

Mandibular cortical indices and their relation to gender and age in the cone-beam computed tomography.

OBJECTIVES: The purpose of this study is to evaluate normal ranges of cortical bone Hounsfield units indices through cone beam CT images, and to investigate their relationships with age and sex. METHODS: 700 adult human cone beam CT images were evaluated retrospectively, and divided into 4 age groups. Six different cortical bone Hounsfield unit measurements were applied bilaterally, where gender and age were recorded. Collected data were subjected to statistical analysis and ANOVA tests were used for various comparisons. RESULTS: The cortical bone measurements between female and male patients were significantly different (p<0.05). Cortical bone thickness indices showed greater values in male patients compare to female patients (p<0.05). Quantitative mandibular indices were significantly lower in first age group (18-30 years) than other three older age groups (p<0.01). CONCLUSION: The results of this study seems to propose a persistent alteration in the mandibular cortical bone with age and that this influced by sex. Further studies with larger patient groups are needed to clarify and understand these mandibular indices.

Morphological Classification of Extraction Sockets and Clinical Decision Tree for Socket Preservation/Augmentation after Tooth Extraction: a Systematic Review.

OBJECTIVES: The aim of present study was to review current literature concerning extraction socket classification immediately following tooth extraction and the rationales for socket preservation/augmentation procedures and with reference to it suggest novel clinical decision tree for extraction socket preservation/augmentation in aesthetic and non-aesthetic area. MATERIAL AND METHODS: The search protocol used the electronic MEDLINE (PubMed) and EMBASE databases for articles published between January 1 2009 and May 1 2019. The search included only human studies published in English. Outcomes were the indications and reasons for socket preservation/augmentation and classification of extraction sockets. RESULTS: Ten studies fulfilled the inclusion criteria and were selected for the study. Although there are various types of extraction socket classifications none of them could completely evaluate all morphological parameters of alveolar ridge. Furthermore, present study revealed that indications for extraction socket preservation/augmentation have wider spectrum than socket morphology and are related to surrounding tissue anatomy or dental implantation operation indications and timing. Based on currently proposed extraction socket classifications and rationales, a novel decision tree for extraction socket preservation/augmentation immediately after tooth extraction in aesthetic and non-aesthetic area was suggested. CONCLUSIONS: The need of extraction socket preservation/augmentation immediately after tooth extraction should be determined by the aesthetic, functional and risk-related viewpoint. A novel clinical decision tree for extraction socket preservation/augmentation immediately after tooth extraction in aesthetic and non-aesthetic zones can be useful tool in socket preservation/augmentation procedures.

The 2nd Baltic Osseointegration Academy and Lithuanian University of Health Sciences Consensus Conference 2019. Summary and Consensus Statements: Group I - Biological Aspects of Tooth Extraction, Socket Healing and Indications for Socket Preservation.

INTRODUCTION: The task of Group I was to review and update the existing data concerning the physiologic process of socket healing, in the absence or presence of grafting materials or platelet concentrates, addressing the associated molecular and cellular events that culminate in the restoration of the lost tissue architecture and functionality. The second task was to review current literature concerning extraction socket classification immediately following tooth extraction and the rationales for socket preservation/augmentation procedures and with reference to it suggest novel clinical decision tree for extraction socket preservation/augmentation in aesthetic and non-aesthetic area. MATERIAL AND METHODS: The main areas indicated by this group were as follows: socket healing process, including haemostasis and coagulation, inflammatory phase, proliferative phase, bone tissue modelling and remodelling; socket healing with graft materials and autologous platelet concentrates; extraction socket classifications; indications and reasons for extraction socket preservation/augmentation. The systematic reviews and/or meta-analyses were registered in PROSPERO, an international prospective register of systematic reviews: http://www.crd.york.ac.uk/PROSPERO/. The literature in the corresponding areas of interest was screened and reported following the PRISMA (Preferred Reporting Item for Systematic Review and Meta-Analysis) Statement: http://www.prisma-statement.org/. Method of preparation of the systematic reviews, based on comprehensive search strategies, was discussed and standardized. The summary of the materials and methods employed by the authors in preparing the systematic reviews and/or meta-analyses is presented in Preface chapter. RESULTS: The results and conclusions of the review process are presented in the respective papers. One theoretical review-analysis and one systematic review were performed. The group's general commentaries, consensus statements, clinical recommendations and implications for research are presented in this article.

Assessment of morphological and anatomical characteristics of mental foramen using cone beam computed tomography.

PURPOSE: To determine the shape, position, vertical height, surrounding bone characteristics, and opening angle of mental foramen (MF) using dental cone beam computed tomography (CBCT). METHODS: A retrospective study was performed on 663 patients. CBCT records analyzed for the shape, position, and surrounding bone measurements of the MF using Simplant 3D software (Hasselt, Belgium). Opening angle of MF was also assessed. Kruskal-Wallis and Mann-Whitney U tests were employed to test significant differences between parameters, genders and ages. RESULTS: All mental foramina were visualized. Regarding location, 49.2% of the MFs were located between first and second premolars, 7.7 distal and 39.7% coincident to the apex of the mandibular second premolar. The mean MF opening angle was 45.4° on the right side, and 45.9° on the left. There were no statistically differences between gender groups with regard to the opening angle degrees. CONCLUSIONS: This study may provide useful information about variations in the position, shape and size, angle of mental foramen, which may help the practitioners to perform safer mental nerve blocks and surgical procedures.

Transplantation of Autogenous Bone Block With an Osseointegrated Implant: Seedling Technique With Twelve-Month Follow-Up.

OBJECTIVE: Loss of teeth frequently results in compound horizontal and vertical alveolar bone defects. An appropriate bone structure is the key for implant placement and bony support of soft tissues. Advanced bone augmentation techniques are required for the reconstruction of these defects. This report will present a new bone block grafting technique with 12-month follow-up. METHOD: The seedling technique was used to augment the alveolar bone 3-dimensionally with autologous bone block and an osseointegrated implant in a 2-stage procedure. Horizontal and vertical bone loss is revealed after cone beam radiographic examination in the right maxillary lateral incisor area. Initially, the implant was placed at the right maxillary tuber area, where the bone was abundant. After 2-months healing phase, the osseointegrated implant was harvested with the surrounding bone and transplanted to the anterior region of maxilla to augment the horizontal and the vertical components of the recipient site. Transplanted implant inserted into autogenous bone block was fixed with mini plate to the adjacent native bone. Prosthetic restoration was applied 4 months after the transplantation. RESULTS: Seven months after the first surgery, treatment of anterior bone deficiency was accomplished. The patient was fully satisfied with the function and the esthetics of the restoration. The radiological and clinical examinations at 1-year follow-up evaluation showed successful outcome of transplanted autogenous bone block without any resorption. CONCLUSION: This clinical report demonstrated that anterior maxillary single-tooth replacement, according to seedling concept of autogenous bone block with osseointegrated implant, is a successful and predictable treatment modality.

Accessory Mental/Buccal Foramina: Case Report and Review of Literature.

The presence of the additional mental foramen of the mandible is considered to be a rare anatomical occurrence. Only a few cases have been reported. In these cases, only 1 foramen is called the mental foramen and the others are termed either accessory mental foramen or accessory buccal foramen. The purpose of this article was to present a case with computed tomography images and suggest that preoperative cone beam computed tomography should be performed to detect any anatomical variation. In addition, we present all reasonable terminology to ease the communication through unique terminology among surgeons.