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.

Three-Dimensional Evaluation of Autogenous Ramus Block Graft Donor Site and Its Relation to Mandibular Canal.

Sufficient bone volume is necessary for placing a dental implant in an ideal position. To restore severely insufficient bone volume, autogenous block graft procedures with various intraoral donor sites are presented in the literature. The aims of this retrospective study are to present the dimensions and volume of the potential ramus block graft site, and to evaluate possible effect of mandibular canal diameter and its position in relation to mandibular ramus block graft volume. Two-hundred cone-beam computed tomography (CBCT) images were evaluated. The maximum length, width, height, and volume of the potential ramus block graft site, mandibular canal diameter, mandibular canal-mandibular basis distance, and mandibular canal-crest distance were measured. Mandibular canal diameter, mandibular canal-crest distance, and mandibular canal-mandibular basis distance were 3.139 ± 0.446 mm, 15.376 ± 2.562, and 7.834 ± 1.285 mm, respectively. In addition, the dimensions of the potential ramus block graft sites were measured 11.156 ± 2.297 mm × 10.390 ± 3.420 mm × 8.816 ± 1.720 mm (height × length × width). Moreover, the potential ramus bone block volume was calculated as 1.076 ± 0.398 cm3. While a positive correlation was detected between mandibular canal-crest distance and the potential ramus block graft volume (r = .160, P = .025), a negative correlation was found between mandibular canal-mandibular basis distance and the potential ramus block graft volume (r = -.020, P = .001). Mandibular ramus is one of the predictable intraoral donor sites for bone augmentation procedures. However, ramus has some volumetric limitations related to its neighboring anatomic structures. It seems to be important to evaluate lower jaw in a 3-dimensional manner to prevent surgical complications.

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.

Dental caries and associated salivary biomarkers in patients with cystic fibrosis.

PURPOSE: To evaluate the caries status of the Cystic fibrosis (CF) children and adolescents with the comparation of some biochemical markers, secretory-immunoglobulin-A (sIgA), and antimicrobial peptides in the saliva. METHODS: In this cross-sectional descriptive study, the approval Ethics Board was obtained. Unstimulated saliva samples were collected from CF and healthy control children (non-CF) patients. Both groups underwent the same dental and periodontal evaluation scheme of the assessment. Human beta defensin (HBD1), human alpha defensin (HNP-1), cathelicidin (LL-37), sIgA in saliva were evaluated by enzyme-linked immunoassay method. A general biochemical analysis was performed. Statistical analysis was performed by using Statistical Package for the Social Sciences Version 20.0 (SPSS Inc.). RESULTS: A total of 21 (9 male, 12 female) CF and 23 (11 male, 12 female) control patients were participated with the mean age of 10.17 ± 3.38 and 9.52 ± 2.15 years, respectively. In control children, DMFT/S (decayed-missing-filled-tooth/surface-in-permanent-dentition), dmft/s (decayed-missing-filled-tooth/surface-in-primary-dentition) values were higher; DT (decayed-tooth in permanent dentition), ft (filled-tooth in primary dentition) and plaque index values were statistically significantly higher (p = 0.042, p = 0.005, p = 0.038, respectively) than CF patients. Bicarbonate was higher in control group; sodium, chloride, and total protein were higher in CF group; magnesium, calcium and phosphate levels were similar in each group (p > 0.05). Alpha and beta defensin-1 levels in control group was statistically significantly higher (p = 0.037 and p = 0.020, respectively), while LL37 and sIgA were not statistically significantly higher (p > 0.05) than CF group. CONCLUSIONS: Children with CF had lower caries in permanent teeth, filling in primary teeth, and an altered salivary biomarker profile, especially in HNB1, HNP1. Therefore, it is important to conduct periodic oral-dental controls among CF patients during their childhood.

Association between ridge morphology and complexity of implant placement planning in the posterior mandible.

STATEMENT OF PROBLEM: Uncertainties regarding the 3D ridge morphology of the posterior mandible can greatly increase the risk of surgical complications during dental implant placement. By using cone beam computed tomography (CBCT) imaging and a computer-guided implant treatment software program before any invasive procedure, it is possible to assess ridge morphology and understand the surgical complexity and risk level. PURPOSE: The purpose of this radiological clinical study was to evaluate a large series of CBCT images to evaluate ridge shape variations along posterior mandibular edentulous regions and to clarify their associations with the level of implant planning complexity. MATERIAL AND METHODS: One hundred and twenty CBCT files were analyzed retrospectively for a total 240 hemimandibular sites. Images of each edentulous region of the mandibular first and second premolar and first and second molar sites were evaluated in the sagittal plane. Ridge morphology and implant planning complexity per site were assessed. Categorical variables were presented as number of events and percentages. The chi-square test was used to compare the categorical variables (P=.05). RESULTS: Of 491 partially edentulous mandibular sites, 235 were on the right, and 256 were on the left. Forty-two sites had a distal adjacent tooth, while 266 sites had no distal adjacent tooth. The sagittal bone sections demonstrated oblique (40.53%), straight (31.77%), S-shape (24.24%), hourglass (2.44%), and basal bone (1.02%) ridge morphologies. Implant complexity was deemed straightforward in 66.19% of sites, while 31.6% were identified as advanced and 2.54% as complex. When ridge morphology was evaluated from straight to basal-round bone shape, the implant complexity followed the same trend of change from a straightforward to complex procedure (P=.001) for edentulous second and first molar regions. No significant differences were noted at edentulous second premolar sites (P=.063). The missing second molar sites with oblique morphology were predicted to have 60.9% straightforward complexity, and first molar sites with oblique morphology had 55.8% straightforward implant complexity. Second premolars with straight ridge morphology had 71.7% straightforward complexity, whereas first premolars with the same shape had 92.5% straightforward implant complexity. CONCLUSIONS: Careful evaluation of sagittal CBCT images can provide significant clinical information regarding ridge shape and anticipated surgical complexity before and at the time of implant placement. Surgical complexity is greatest at the most posterior mandibular edentulous sites, and extra attention and caution should be exercised during the surgical planning phases of implant surgery.

Epigenetic adaptations of the masticatory mucosa to periodontal inflammation.

BACKGROUND: In mucosal barrier interfaces, flexible responses of gene expression to long-term environmental changes allow adaptation and fine-tuning for the balance of host defense and uncontrolled not-resolving inflammation. Epigenetic modifications of the chromatin confer plasticity to the genetic information and give insight into how tissues use the genetic information to adapt to environmental factors. The oral mucosa is particularly exposed to environmental stressors such as a variable microbiota. Likewise, persistent oral inflammation is the most important intrinsic risk factor for the oral inflammatory disease periodontitis and has strong potential to alter DNA-methylation patterns. The aim of the current study was to identify epigenetic changes of the oral masticatory mucosa in response to long-term inflammation that resulted in periodontitis. METHODS AND RESULTS: Genome-wide CpG methylation of both inflamed and clinically uninflamed solid gingival tissue biopsies of 60 periodontitis cases was analyzed using the Infinium MethylationEPIC BeadChip. We validated and performed cell-type deconvolution for infiltrated immune cells using the EpiDish algorithm. Effect sizes of DMPs in gingival epithelial and fibroblast cells were estimated and adjusted for confounding factors using our recently developed "intercept-method". In the current EWAS, we identified various genes that showed significantly different methylation between periodontitis-inflamed and uninflamed oral mucosa in periodontitis patients. The strongest differences were observed for genes with roles in wound healing (ROBO2, PTP4A3), cell adhesion (LPXN) and innate immune response (CCL26, DNAJC1, BPI). Enrichment analyses implied a role of epigenetic changes for vesicle trafficking gene sets. CONCLUSIONS: Our results imply specific adaptations of the oral mucosa to a persistent inflammatory environment that involve wound repair, barrier integrity, and innate immune defense.

Treatment of Excessive Gingival Display by Using Botulinum Toxin-A Targeting Yonsei Points and Zygomatic Major Muscles.

ABSTRACT: The aim of this clinical report is to present satisfying and unsatisfying treatment results of a patient with excessive gingival display (EGD) treated via botulinum toxin injections in different time points. A 22-year-old male patient referred to the Department of Periodontology with a complaint of EGD. The patient opted the treatment with botulinum toxin-A injections. During the first treatment, injections at Yonsei points were performed. After the first EGD treatment, the patient did not satisfy with his smile. The closure of gingival display was not sufficient, especially in posteriors. However, he did not demand for reinjection. Six months after the first treatment, he was advised to have 2 injection points per side including zygomatic major muscles as well as Yonsei points. Two weeks after the second treatment, the patient totally satisfied with his new smile. Yonsei point is a safe and repeatable injection point for the practitioners. However, the authors suggested injections targeting zygomatic major muscles as well as Yonsei point injections to treat the patients with mixed EGD.

Quantity and Quality of Intraoral Autogenous Block Graft Donor Sites with Cone Beam Computed Tomography.

PURPOSE: The autogenous bone block graft is regarded as the gold standard material due to reported osteoconductive, osteoinductive, and osteogenic properties. Various intraoral donor sites for autogenous block grafts are presented in the literature. The aim of this study was to radiographically evaluate the maximum dimensions, volume, and bone quality values of these sites. MATERIALS AND METHODS: According to the inclusion criteria, 50 cone beam computed tomography (CBCT) images from 50 subjects were evaluated. The maximum length, width, height, and volume of autogenous regions where block grafts could be harvested were measured. Radiographic bone quality was calculated by using Hounsfield units derived from CBCT (CBCT-HU). RESULTS: The mean age of 50 subjects (19 men and 31 women) was 55.84 ± 15.9 years. In this study, the symphysis was the largest potential donor site (3.14 ± 1.05 cm3), while maxillary tuberosity was the smallest (0.53 ± 0.34 cm3). These results correlated with bone density values, where the symphysis retained the highest values (937.31 ± 160.59 CBCT-HU) and the maxillary tuberosity had the lowest values (360.87 ± 141.48 CBCT-HU). CONCLUSION: Intraoral bone blocks have restrictions due to surrounding vital anatomical structures. The surgeons should consider these vital structures using accurate CBCT evaluation. The volume and density of the maximal bone harvest from the symphysis was statistically higher in comparison with ramus, palatal, and maxillary tuberosity bone blocks.

In-depth morphological evaluation of tooth anatomic lengths with root canal configurations using cone beam computed tomography in North American population.

OBJECTIVE: This study aimed to assess the association between tooth size and root canal morphology by using CBCT analysis. METHODOLOGY: In this retrospective study, tooth anatomic lengths (crown and root lengths, buccolingual and mesiodistal dimensions) of 384 patients were assessed and correlated with Vertucci's root canal morphology classification. Data was analyzed for gender-related differences using the independent sample t-test, ANOVA, and the Pearson's correlation for a possible relation between anatomic lengths and canal morphology. RESULTS: The maxillary first and second premolars showed a greater predilection for Type IV and II variants, respectively, while the mandibular first premolar showed a greater predilection for Type II canal system. The root canal system of the mandibular second premolar showed maximal diversity (47% Type I, 30% Type II, and 20% Type III). The dimensions were greater in men regardless of tooth type. The most significant relation (p<0.05) between the anatomic size and canal morphology was observed in the maxillary first premolars, followed by the mandibular canines (buccolingual dimension) and the lower second premolars (crown length). Negative correlations existed between the crown length and the patient's age for the anterior teeth and mandibular second premolar (r=-0.2, p<0.01). CONCLUSIONS: The most common canal formation for anterior teeth was the Type I. The anatomic lengths had the strongest influence on the canal configuration of the maxillary first premolar, with Type IV being the most common root canal system. The mandibular second premolars showed maximal diversity in the canal classification terms and had a significant correlation with their crown lengths. CLINICAL RELEVANCE: The complex relationship between the canal morphology and anatomic tooth sizes need meticulous awareness and recognition during endodontic procedures, in conjunction with the demographic variabilities.

Levels of pro- and anti-inflammatory cytokines in cystic fibrosis patients with or without gingivitis.

BACKGROUND: Inflammatory periodontal diseases are caused by interaction between gram negative, anaerobic bacteria and host response. Persistent infection of Pseudomonas aeruginosa in cystic fibrosis (CF) patients also cause increased pro-inflammatory response and the imbalance of pro- and anti-inflammatory response in brochoalveolar lavage fluid which leads to destruction of lungs. The aim of this study is to evaluate periodontal status of CF patients, to measure level of cytokines and biochemical molecules in gingival crevicular fluid (GCF), and to detect presence of P. aeruginosa in dental plaque samples. MATERIALS AND METHODS: GCF samples were collected from 41 CF patients and 39 healthy (non-CF) subjects. Interleukin (IL)-1ß, IL-17, IL-10, human neutrophil elastase (HNE), cystic fibrosis transmembrane regulator (CFTR) protein, and human ß-defensin-1 (HBD1) in GCF were evaluated by ELISA method. Dental plaque samples were collected from 18 CF patients with history of P. aeruginosa colonization and 15 non-CF subjects. Presence of P. aeruginosa was evaluated by using conventional culture methods and molecular methods. RESULTS: Levels of IL-1ß, HNE, and HBD1 in CF patients were significantly higher than non-CF subjects. However, IL-10 level was significantly lower in CF patients. Increased pro-inflammatory (IL-1ß) and decreased anti-inflammatory (IL-10) cytokine levels were observed in GCF samples from CF patients, irrespective of their periodontal status. P. aeruginosa were detected in four samples of 18 CF patients, and all were negative in non-CF group. CONCLUSIONS: As a result of this study, CF coexists increasing pro-inflammatory and decreasing anti-inflammatory response locally. Due to increasing pro-inflammation, CF patients should be followed-up more often than non-CF children.

Treatment of Various Types of Gummy Smile With Botulinum Toxin-A.

The objective of this article is to present 3 various types of gummy smile treated with botulinum toxin-A injection per site at Yonsei points. The patients, who visited the department to demand a more aesthetic smile, were classified according to gummy smile type: asymmetric, anterior, and mixed. Botulinum toxin-A injection at Yonsei point was considered. Preinjection and postinjection pictures were taken, and the severity of excessive gingival display was measured for each tooth between second premolars. Two weeks after botulinum toxin injections, no complication was noted. The amount of excessive gingival display for each tooth between second premolars was measured less than 3 mm, and the percentage of improvement for each case was calculated 100%. The botulinum toxin injection at Yonsei point may be a predictable and noninvasive treatment option for various types of gummy smile.

Radio-Morphometric Evaluation of Greater Palatine Canal and Pterygopalatine Fossa Component: Maxillary Anesthetic Implications.

This is a retrospective analytical cross-sectional study involving 131 cone-beam computed tomography (CBCT) scans of adult (18-99 years) that assessed greater palatine canal (GPC) attributes (length, curvature angle, diameter of curvature) and the type of the trajectory of GPC-pterygopalatine fossa (PPF) component. The GPC is an important landmark that connects the oral cavity and PPF. It contains greater and lesser palatine nerves, along-with descending palatine artery and vein by extending from the inferior part of the PPF to the hard palate. The GPC acts as a pathway for infiltration of local anesthesia. The inferior orbital fissure (IOF) is in close proximity to these vital anatomic structures and hence accurate identification of its location during regional block anesthesia is crucial. This is one of the very few studies investigating these important structures on CBCT scans highlighting the importance of preoperative scans for the anatomic determination. The images were analyzed for the lengths and anatomic paths of the right and left GPC-PPF in sagittal plane. The diameters of the upper (higher bony aspect of PPF) and lower openings (GPC opening) displayed statistically significant differences in the comparison between males and females (P < 0.05). Overestimation or underestimation of the GPC length can cause a lack of anesthesia and undesirable diffusion of the anesthetic solution into the orbit thorough the IOF causing diplopia, or into the cranial cavity. A thorough understanding of GPC length and pathway types is obligatory for proper anesthetic administration and performing any maxillofacial procedures.