Distribution of the intraosseous branch of the posterior superior alveolar artery relative to the posterior maxillary teeth.

Purpose: Preoperative identification of the intraosseous posterior superior alveolar artery (PSAA) is critical when planning sinus surgery. This study was conducted to determine the distance between the cementoenamel junction and the PSAA, as well as to identify factors influencing the detection of the PSAA on cone-beam computed tomography (CBCT). Materials and Methods: In total, 254 CBCT scans of maxillary sinuses, acquired with 2 different scanners, were examined to identify the PSAA. The distance from the cementoenamel junction (CEJ) to the PSAA was recorded at each maxillary posterior tooth position. Binomial logistic regression and multiple linear regression were employed to evaluate the effects of scanner type, CBCT parameters, sex, and age on PSAA detection and CEJ-PSAA distance, respectively. P-values less than 0.05 were considered to indicate statistical significance. Results: The mean CEJ-PSAA distances at the second molar, first molar, second premolar, and first premolar positions were 17.0±4.0 mm, 21.8±4.1 mm, 19.5±4.7 mm, and 19.9±4.9 mm for scanner 1, respectively, and 17.3±3.5 mm, 16.9±4.3 mm, 18.5±4.1 mm, and 18.4±4.3 mm for scanner 2. No independent variable significantly influenced PSAA detection. However, tooth position (b=-0.67, P<0.05) and scanner type (b=-1.3, P<0.05) were significant predictors of CEJ-PSAA distance. Conclusion: CBCT-based estimates of CEJ-PSAA distance were comparable to those obtained in previous studies involving cadavers, CT, and CBCT. The type of CBCT scanner may slightly influence this measurement. No independent variable significantly impacted PSAA detection.

The nasal spine suture: A novel approach for membrane stabilization.

BACKGROUND: Current evidence acknowledges guided bone regeneration (GBR) as a predictable therapeutic modality in the augmentation of a deficient alveolar ridge. Such deficiencies often reveal inadequate bone volume to support implant placement in a position amenable to prosthetic reconstruction. Additionally, an evolving body of literature demonstrates that membrane fixation may lead to improved clinical bone gain through positively influencing blood clot formation, stability, and the eventual osteogenic potential of the defect. Alternative benefits to membrane fixation, such as reduced graft displacement and reduction in wound micromotion, have also been cited as mechanisms for an increased regenerative response. METHODS AND RESULTS: The aim of this report was to present a case, including diagnosis, treatment, and follow-up for the reconstruction of a horizontal ridge deficiency. The patient's deficiency in ridge volume was found to be a developmental sequelae of lateral incisor agenesis, resulting in an underdeveloped midfacial region of the alveolar process subjacent to sites #7 and #10. The fixation protocol outlined in this report demonstrated adequate horizontal ridge augmentation to facilitate future prosthetic reconstruction with the use of implants. CONCLUSIONS: Numerous protocols have been established in an attempt to achieve effective barrier membrane stabilization for bone augmentation procedures. However, some techniques are poorly suited for the anatomically challenging region of the anterior maxilla. A case report describing the utilization of the anterior nasal spine for anchorage of a membrane-stabilizing suture may present a novel, safe, and effective technique for stabilizing the intended region of augmentation, as well as preventing graft migration beyond the membrane-maxilla interface. Key points Regarding guided bone regeneration (GBR) procedures, micromotion of the membrane or of the underlying particulate graft may negatively influence the volume of the augmented site. The ability to adequately stabilize the graft-membrane interface is recognized as a necessary prerequisite to predictably achieve optimal surgical outcomes. To the authors' knowledge, there is no clinical or scientific evidence regarding the use of the anterior nasal spine for membrane anchorage in maxillary GBR procedures, and thus a novel approach to membrane stabilization is introduced.

Factors influencing intraoperative and postoperative complication occurrence: A series of 1135 periodontal and implant-related surgeries.

OBJECTIVES: In periodontology, it is widely recognized that evidence characterizing the incidence and effect of treatment complications is lacking. The objective of this study was to assess the influence of operator-, procedure-, patient-, and site-associated factors on intraoperative and postoperative complication occurrence. MATERIAL AND METHODS: A single investigator reviewed records of patients treated by eight periodontics residents from July 2018 through June 2022. For each procedure, the investigator recorded each intraoperative and postoperative complication or indicated that no complication had occurred. These outcomes were analyzed against a panel of explanatory covariates. In addition, the severity of each postoperative complication was assessed using a standardized grading system. RESULTS: A total of 1135 procedures were included in the analysis. Intraoperative and postoperative complications were identified in 2.8% and 15.2% of procedures, respectively. The most common intraoperative complications were Schneiderian membrane perforation (1.3%) and gingival flap perforation/tear (1%), and the most common postoperative complications were dentin hypersensitivity (2.6%), excessive pain (2.5%), and infection (2.2%). Subepithelial connective tissue graft (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.6, 6.1; p < .001), guided bone regeneration (OR: 3.0, 95% CI: 1.4, 6.5; p = .004), and guided bone regeneration with implant placement (OR: 3.1, 95% CI: 1.3, 7.6; p = .011) were associated with higher odds of postoperative complication, whereas lateral sinus elevation (OR: 102.5, 95% CI: 12.3, 852.9; p < .001), transalveolar sinus elevation (OR: 22.4, 95% CI: 2.2, 224.5; p = .008), open flap debridement (OR: 36.4, 95% CI: 3.0, 440.7; p = .005), and surgically facilitated orthodontic therapy (OR: 20.5, 95% CI: 1.2, 358.4; p = .039) were associated with higher odds of intraoperative complication occurrence. CONCLUSIONS: Consistent with previous reports, procedure type appears to be the predominant factor driving complication occurrence. As analyses of treatment complications increase, individualized risk-benefit assessments will become progressively meaningful for patients.

Predictors of standardized in-service examination performance and residency outcomes in a graduate periodontics program.

PURPOSE/OBJECTIVES: The objectives of this study were to assess the influence of learner- and education-related factors on standardized in-service examination performance and determine whether in-service examination scores predict residency outcomes. METHODS: American Academy of Periodontology (AAP) In-service Examination (AIE) scores from 10 periodontics residency classes at a single center were recorded and compared against a panel of learner- and education-related variables using multiple linear regression models. Defined residency outcome measures were analyzed against AIE scores using binomial logistic regression. RESULTS: No evaluated learner- or education-related variable was a statistically significant predictor of AIE score in this study sample. Likewise, AIE score was not a statistically significant predictor of any assessed residency outcome. CONCLUSIONS: The AAP has performed a tremendous service to periodontics residents and programs by marshaling the leadership and expertise necessary to offer a professionally constructed assessment instrument. However, in the current study, no relationship could be identified between AIE score and any outcome, including first-attempt board certification. The AAP In-service Committee appears well situated to provide additional leadership focusing on exam implementation, which may enhance AIE value in competency decision making.

Protocol for ridge preservation at severely compromised extraction sockets: Consecutive case series.

BACKGROUND: The physiologic bone remodeling accompanying tooth extraction is a phenomenon well described in the dental literature. Extraction sockets severely compromised by local infection, trauma, iatrogenesis, or other factors may exhibit enhanced reduction in alveolar dimensions during healing. The purpose of this report is to present an alveolar ridge preservation (ARP) protocol specifically intended for use at severely compromised sites. METHODS: Seven patients presented to the Department of Periodontics, Army Postgraduate Dental School, Fort Gordon, Georgia, requiring extraction of teeth with partial or near-complete loss of the facial/buccal cortex. At each site, a cross-linked bovine collagen membrane was used to prevent collapse of the facial/buccal soft tissue and maintain space, a freeze-dried bone allograft was applied in the socket, and a dense polytetrafluoroethylene membrane covered the occlusal aspect. RESULTS: All sites healed uneventfully and resulted in favorable alveolar ridge dimensions for implant placement. CONCLUSION: Few authors have proposed specific ARP methods for managing severely deficient extraction sockets. The predominant recommendation has been staged reconstruction of the site applying hard and soft tissue augmentation. Observations reported herein suggest that staged reconstruction is avoidable at some extraction sockets exhibiting severe alveolar compromise. Controlled clinical investigation of this protocol appears warranted. KEY POINTS: Few authors have proposed alveolar ridge preservation (ARP) methods specifically intended for use at severely compromised extraction sockets. The prevailing recommendation at such sites is a staged protocol involving tooth extraction with delayed hard and soft tissue augmentation. The presented bilaminar ARP technique may eliminate the need for staged reconstruction at some severely compromised extraction sockets.

Clinical protocol selection for alveolar ridge augmentation at sites exhibiting slight, moderate, and severe horizontal ridge deficiencies.

FOCUSED CLINICAL QUESTION: What factors identify the optimal bone augmentation techniques for managing slight, moderate, and severe horizontal alveolar ridge deficiency (ARD) at dental implant sites? SUMMARY: Horizontal ARD is a concern at a high proportion of sites receiving dental implants, and clinicians have developed a variety of surgical procedures to address such defects. In a particular case, selection of the optimal treatment may depend predominantly on defect severity, location (anterior versus posterior), and configuration (contained versus noncontained). This report provides a framework for selecting an augmentation method when presented with a slight, moderate, or severe horizontal ARD at a site requiring dental implant placement. CONCLUSION: Multiple treatment options are available for planned implant sites exhibiting horizontal ARD; severe posterior and slight anterior defects intuitively call for different approaches. Although rigid guidelines for selecting the optimal augmentation method do not exist, some techniques are poorly suited for esthetically demanding sites. A framework considering defect severity, location, and configuration may help guide clinical decisions on this topic.

Double Spike-Standard Addition Technique and Its Application in Measuring Isotopes.

Double spike (DS) method has been extensively used in determining stable isotope ratios of many elements. However, challenges remain in obtaining high-precision isotope data for ultra-trace elements owing to the limitations of instrumental signal-to-noise ratios and the systematics of precision of DS-based measurements. Here, the DS-standard addition (SA) (DSSA) technique is proposed to improve measurements of isotope compositions of ultra-trace elements in natural samples. According to the U-shaped relationship between DS measurement uncertainty and the spike/sample ratio, theoretical equations and an error propagation model (EPM) were constructed comprehensively. In our method, a spiked secondary standard solution with a high, precisely known spike/sample ratio is mixed with samples such that the mixtures have spike/sample ratios within the optimal range. The abundances of the samples relative to the added standards (sample fraction; fspl) and the samples' isotope ratios can then be obtained exactly using a standard DS data reduction routine and the isotope binary mixing model. The accuracy and precision of the DSSA approach were verified by measurements of cadmium and molybdenum isotopes at as low as 5 ng levels. Compared with traditional DS measurements, the sample size for isotope analysis is reduced to 1/6-1/5 of the original with no loss of measurement precision. The optimal mixing range fspl = 0.15-0.5 is recommended. The DSSA method can be extended to isotope measurement of more than 33 elements where the DS method is applicable, especially for the ultra-trace elements such as platinum group and rare earth element isotopes.

Dental implants at sites of focal high and mixed density osseous lesions: Treatment strategies.

FOCUSED CLINICAL QUESTION: Under what circumstances may a clinician consider dental implant placement at a site exhibiting a focal high or mixed density (HMD) osseous lesion radiologically? SUMMARY: Some conditions and pathologic entities exhibiting high and mixed density radiological appearance pose low risk for dental implant failure or complications following implant surgery. However, other lesions represent contraindications to implant placement, and implant surgery at such sites can result in severe morbidity. CONCLUSION: Potential implant sites exhibiting focal HMD osseous lesions/conditions present varying levels of risk. In most cases, optimal management will include advanced imaging of the site, multidisciplinary consultations, and detailed informed consent to assure full understanding of procedural risks, benefits, and complications. Currently, clinical recommendations rely on case reports, opinion, and usual practice (level 3 evidence). The strength of each recommendation provided in this report is categorized as level C.

Influence of Lactobacillus reuteri, Bifidobacterium animalis subsp. lactis, and prebiotic inulin on dysbiotic dental biofilm composition ex vivo.

BACKGROUND: Probiotic bacterial supplementation has shown promising results in the treatment of periodontitis and the maintenance of periodontal health. The purpose of this investigation was to evaluate the influence of Lactobacillus reuteri or Bifidobacterium animalis subsp. lactis supplementation with and without prebiotic inulin on biofilm composition using an ex vivo biofilm model. METHODS: Subgingival plaque specimens from three periodontitis-affected human donors were used to grow biofilms on hydroxyapatite disks in media supplemented with varying combinations of prebiotic inulin, Lactobacillus reuteri, and Bifidobacterium animalis subsp. lactis. Relative abundances of bacterial genera present in mature biofilms were evaluated using 16S rRNA next-generation sequencing. Diversity metrics of microbial communities were evaluated using a next-generation microbiome bioinformatics platform. RESULTS: Inulin supplementation produced statistically significant dose-dependent increases in relative abundances of Lactobacillus and Bifidobacterium species (p < 0.001) with concomitant decreases in relative abundances of Streptococcus, Veillonella, Fusobacterium, Parvimonas, and Prevotella species (p < 0.001). Inoculation with L. reuteri or B. animalis subsp. lactis increased the relative abundance of only the supplemented probiotic genera (p < 0.05). Supplemental inulin led to a statistically significant decrease in biofilm alpha diversity (p < 0.001). CONCLUSIONS: The described ex vivo model appears suitable for investigating the effects of probiotic bacteria, prebiotic oligosaccharides, and combinations thereof on biofilm composition and complexity. Within the limitations imposed by this model, results from the present study underscore the potential for prebiotic inulin to modify biofilm composition favorably. Additional research further elucidating biologic rationale and controlled clinical research defining therapeutic benefits is warranted.

Guided protocol for indirect fabrication of a custom provisional restoration prior to immediate implant surgery in the esthetic zone.

BACKGROUND: Delivery of a high-quality provisional restoration at a maxillary anterior immediate implant site enhances patient-centered outcomes and promotes development of favorable hard and soft tissue architecture. The purpose of this report is to present a protocol relying upon compatible guided surgery and laboratory systems for fabrication of a custom provisional crown prior to immediate implant surgery in the esthetic zone. METHODS AND RESULTS: A female patient, aged 33 years, presented to the Army Postgraduate Dental School, Fort Gordon, Georgia, with an unfavorable prognosis for tooth #9. The patient elected extraction with immediate implant placement. Prior to the surgery, we utilized a cone-beam computed tomography volume, stone models, implant planning software, and an implant indexing system to fabricate a custom provisional crown. Following extraction of tooth #9 and immediate implant placement, the provisional crown exhibited excellent fit and finish, requiring virtually no chairside adjustment. We noted minimal change in baseline mucosal contours throughout the healing phase. CONCLUSION: The clinical/restorative protocol described in this report assured accurate three-dimensional implant positioning and permitted indirect fabrication of a high-quality custom provisional crown in advance of surgery. The laboratory workflow-which dental technicians/auxiliaries can master-has the potential to shorten surgery, enhance treatment outcomes, and increase patient satisfaction. KEY POINTS: Why is this case new information? This report provides a stepwise workflow guiding indirect fabrication of a custom provisional crown prior to immediate implant placement. What are the keys to successful management of this case? The described technique requires compatible laboratory and guided surgery systems to assure that the restoration accounts for the three-dimensional position and timing of the implant. What are the primary limitations to success in this case? Dental technicians/auxiliaries can master this protocol and independently produce high-quality provisional implant restorations under supervision, potentially enhancing practice efficiency. However, practitioners should provide adequate staff training to optimize reliability and quality.

Implant site development requirements in an advanced dental education program: A series of 290 implants.

PURPOSE: Our purpose was to assess the frequency and impact of various site development procedures provided before, during, and after implant placement in an advanced dental education program. METHODS: We evaluated all implant cases completed by two residents in each of three consecutive periodontics residency classes. Dependent variables included implant failure, complication occurrence, presence of radiographic bone loss, and need for tissue augmentation. We analyzed these outcomes against a panel of explanatory covariates. RESULTS: Our study sample involved 370 site development procedures at 290 implant sites in 160 patients. Three factors exhibited statistically significant associations with need for tissue augmentation: alveolar ridge preservation (ARP) (odds ratio [OR] 0.28; 95% confidence interval [CI] 0.13, 0.57), immediate implant placement (IIP) (OR 0.21; 95% CI 0.10, 0.47), and implant submergence (OR 8.3; 95% CI 4.5, 15.3). Four factors predicted treatment complications: ARP (OR 6.1; 95% CI 1.3, 29.1), IIP (OR 6.1; 95% CI 1.06, 35.3), implant submergence (OR 5.3; 95% CI 1.1, 24.9), and mandibular arch (OR 31.3; 95% CI 1.9, 500). Anterior sites (OR 2.7; 95% CI 1.3, 5.8) were more likely to receive IIP. CONCLUSIONS: In the evaluated sample, implant placement at a site exhibiting a favorable volume of native bone was rare. Seventy-eight percent of sites received hard tissue grafting during the treatment phase. The use of ARP or IIP at tooth extraction reduced subsequent tissue augmentation requirements. Education and training in ARP and other site development procedures may enhance the clinical practice and treatment outcomes of implant surgeons.

The Triangle Suture for Membrane Fixation in Guided Bone Regeneration Procedures: A Report of Two Cases.

INTRODUCTION: Existing evidence supports superior treatment outcomes in guided bone regeneration (GBR) procedures employing membrane fixation. The purpose of this report is to present a specific flap design and suturing method for stabilizing GBR barrier membranes. CASE PRESENTATION: Two generally healthy patients received GBR using native collagen membranes stabilized with absorbable sutures. In both cases, we fixed barrier membranes apically using "triangle" sutures. Sling sutures (Case 1) or triangle sutures (Case 2) secured the crestal and palatal aspects of the membranes. No postoperative complications occurred, and both sites exhibited favorable alveolar ridge volume for implant placement. CONCLUSIONS: The described triangle suture technique reliably stabilized GBR barrier membranes without the need for fixation hardware. Compared with suturing methods that limit graft volume and apply pressure over the grafted area, the triangle suture may offer clinical advantages.

Should Periodontists Prescribe Postoperative Oral Corticosteroids to Control Pain and Swelling? A Systematic Review.

FOCUSED CLINICAL QUESTION: In generally healthy patients receiving third molar, periodontal, or dental implant surgery, do postoperative oral corticosteroids effectively limit pain and swelling compared with placebo or alternative medications?

A critical review on the occurrence and distribution of the uranium- and thorium-decay nuclides and their effect on the quality of groundwater.

This critical review presents the key factors that control the occurrence of natural elements from the uranium- and thorium-decay series, also known as naturally occurring radioactive materials (NORM), including uranium, radium, radon, lead, polonium, and their isotopes in groundwater resources. Given their toxicity and radiation, elevated levels of these nuclides in drinking water pose human health risks, and therefore understanding the occurrence, sources, and factors that control the mobilization of these nuclides from aquifer rocks is critical for better groundwater management and human health protection. The concentrations of these nuclides in groundwater are a function of the groundwater residence time relative to the decay rates of the nuclides, as well as the net balance between nuclides mobilization (dissolution, desorption, recoil) and retention (adsorption, precipitation). This paper explores the factors that control this balance, including the relationships between the elemental chemistry (e.g., solubility and speciation), lithological and hydrogeological factors, groundwater geochemistry (e.g., redox state, pH, ionic strength, ion-pairs availability), and their combined effects and interactions. The various chemical properties of each of the nuclides results in different likelihoods for co-occurrence. For example, the primordial 238U, 222Rn, and, in cases of high colloid concentrations also 210Po, are all more likely to be found in oxic groundwater. In contrast, in reducing aquifers, Ra nuclides, 210Pb, and in absence of high colloid concentrations, 210Po, are more mobile and frequently occur in groundwater. In highly permeable sandstone aquifers that lack sufficient adsorption sites, Ra is often enriched, even in low salinity and oxic groundwater. This paper also highlights the isotope distributions, including those of relatively long-lived nuclides (238U/235U) with abundances that depend on geochemical conditions (e.g., fractionation induced from redox processes), as well as shorter-lived nuclides (234U/238U, 228Ra/226Ra, 224Ra/228Ra, 210Pb/222Rn, 210Po/210Pb) that are strongly influenced by physical (recoil), lithological, and geochemical factors. Special attention is paid in evaluating the ability to use these isotope variations to elucidate the sources of these nuclides in groundwater, mechanisms of their mobilization from the rock matrix (e.g., recoil, ion-exchange), and retention into secondary mineral phases and ion-exchange sites.

Neodymium-Doped Yttrium Aluminum Garnet Laser Photobiomodulation May Improve Neurosensory Function after Surgical Injury to Cranial Nerve V: A Report of Three Consecutive Cases.

OBJECTIVE: The purpose of this report was to document clinical responses to Nd:YAG laser energy in patients with surgical injury to terminal branches of the trigeminal nerve. BACKGROUND: Limited evidence from in vitro, animal, and human studies suggests infrared laser energy may positively influence recovery after peripheral or cranial nerve injury, although clinical effects of neodymiumdoped yttrium aluminum garnet (Nd:YAG) lasers remain unstudied in this context. METHODS: We applied Nd:YAG laser energy in the treatment of three consecutive patients presenting with altered neurosensory function following various oral and maxillofacial procedures. The time interval between surgical injury and laser photobiomodulation ranged from one week to two years. RESULTS: All patients exhibited reduction in the area of diminished sensation and partial recovery of normal neurosensory function. The two patients with long-standing neurosensory deficiency experienced near complete recovery of intraoral sensation, with residual zones of diminished sensation from the perioral skin. CONCLUSIONS: Although all patients in this case series demonstrated clinical improvements compared with baseline, controlled studies are needed to determine whether Nd:YAG laser energy accelerates or enhances recovery of neurosensory function after surgical nerve injury. Studies establishing the relative efficacies of Nd:YAG and diode lasers appear warranted.

Overlay Analysis of Cone-Beam Computed Tomography Volumes Acquired before and after Horizontal Alveolar Ridge Augmentation.

OBJECTIVE: The objective of this study was to illustrate the efficacy of a novel imaging analysis technology to capture horizontal and vertical dimensional changes following horizontal alveolar ridge augmentation (HRA). METHODS: Cone-beam computed tomography (CBCT) volumes from 65 HRA sites in 57 patients were available for evaluation, employing a three-dimensional analysis software to overlay preoperative and post-augmentation CBCT volumes. Horizontal and vertical alveolar ridge dimensional (HRD/VRD) changes were recorded considering a panel of patient-, site-, and procedure-related explanatory variables. RESULTS: VRD changes ranged from -2.9 to 3.0 mm, more than half anterior sites losing alveolar ridge height. Mean HRD increase at the 3- and 5-mm levels apical to the alveolar crest amounted to 2.3±1.6 and 2.4±1.3 mm, respectively, membrane fixation and non-resorbable membrane use associated with significantly greater gains. CONCLUSIONS: To date, studies reporting dimensional changes following HRA predominantly rely on serial in situ orofacial caliper recordings omitting vertical alterations. The protocol employed in this study allows simultaneous HRD and VRD evaluations and assures baseline and post-augmentation recordings are made at the same alveolar ridge position. Compared with in situ recording, CBCT overlay analysis may achieve a more complete characterization of dimensional changes following HRA.

Time- and Species-Dependent Bacterial Adhesion to Titanium over Short Exposure Periods: An In Vitro Study.

A considerable percentage of dental implant patients experience biofilm-mediated peri-implant disease following transmucosal abutment application. Bacterial adhesion is an early step in biofilm development. Our purpose was to assess adhesion of specific bacterial species to titanium over short exposure periods. Eight bacterial species were selected for this analysis: Streptococcus oralis, Streptococcus mitis, Gemella haemolysans, Streptococcus gordonii, Streptococcus sanguinis, Neisseria flavescens, Streptococcus salivarius, and Pseudomonas aeruginosa. We cultured each species with appropriate media and exposed titanium foil discs to the bacteria for 60, 15, 5, 1, or 0.25 minutes. Optical density at 600-nm wavelength (OD600) was assessed for the baseline inoculum and each species/exposure combination. The proportion of bacteria adherent to titanium was determined for each experimental condition. Striking titanium adhesion was noted for all evaluated species even when exposure time was limited to 15 seconds. Strategies to limit bacterial adhesion at dental implant surfaces may offer potential for improved treatment outcomes and preservation of peri-implant health.