Adjacent Root Research Articles

Cone-beam computed tomography evaluation of impacted and transmigrated mandibular canines: a retrospective study.

The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental patients applied between December 2015 and December 2017 were evaluated retrospectively.2591 CBCT images, including mandible in their field of view, were determined and evaluated regarding the presence of mandibular canine impaction. 66 impacted mandibular canines of 58 patients were analyzed in detail regarding their location, morphology, associated pathologies, and their relationship with the neighboring anatomic structures, the role of these factors on transmigration, as well as treatments applied. The Pearson Chi square test was used between the groups. Transmigration was observed in 53% of impacted mandibular canines. Teeth with transmigration were localized horizontally, below the apex of adjacent teeth frequently, and had no contact with mandibular cortical bone mostly. 62% of mandibular canines were in contact/proximity with the incisive mandibular canal. The most applied treatment for transmigrated teeth was surgical removal, followed by radiographic monitoring, but orthodontic traction was not preferred in any case. For non-transmigrated teeth, the most applied treatment options were surgical removal, orthodontic traction, and radiographic monitoring, respectively. Autotransplantation was not preferred in any case of impacted teeth. Vertical position of the crown tip (p < 0.05) and the presence of deciduous mandibular canines and their resorption showed significant relation to transmigration (p < 0.05). Transmigration is common among impacted mandibular canines. Resorption of adjacent teeth roots was one of the possible complications of impaction and likely contact/proximity of incisive mandibular canal with impacted mandibular canines, which may pose difficulties in surgical treatment, can be better detected by CBCT.

Cebuano cultural identities: prospects for a culturally responsive pedagogy

This study described the Cebuano cultural identities and prospects in search of a culture-based instruction model. This sought to find out the linguistic varieties of the Cebuano speakers; contrast the differences and similarities in the inasal making process; and identify the variations in the celebrations of festivals in Cebu. This study utilized a case study design with 15 research participants from the three selected cluster locations. These Cebuano cultural identities vary according to geographic location and other socio-historical factors. Clipping and borrowing of words and expressions, from adjacent islands and roots of the colonial past, are indicative of these factors of language variations. The practices of inasal making are based on inherited traditions of the place such as variations on the use of logistics and needed ingredients to embellish the entire corpus of a sanitized butchered pig before its roasting. Towns and cities celebrate festivals in thanksgiving of their patron saint – a symbolism of their religious and cultural traditions. These varied cultural orientations support the argument to establish a cultural grounding on instructional initiatives in the Asian context. The findings juxtapose the exploration of Inasal Teaching Model (ITM) as a localized and a contextualized teaching model that serves as a nexus in various phases of instruction, for quality teaching in the field of culture-based education.

Augmented reality for dental implant surgery: enhanced ICP

Augmented reality surgery has not been successfully implemented in dental implant surgery due to the negative impact of an incorrect implant placement. This research aimed to improve the convergence between computed tomography derived teeth model and real-time stereo view of patient’s teeth to provide high registration accuracy. Enhanced iterative closest point algorithm is proposed to reduce the error caused due to matching wrong points. Weighting mechanism and median value are used to reduce alignment error caused due to matching wrong points. In addition, random sample consensus (RANSAC) algorithm is used to detect and remove the outlier. Furthermore, the current solution for dental implants did not provide the position and orientation of the surgical tool, and without this information, there is a risk of damaging adjacent structure, dental nerves, and root canals. Optical tracking device is used in the proposed solution to address this information and ensure that nerve does not get damaged during the dental implant placement surgery. While the state-of-the-art solution provided 0.44 mm registration accuracy, the proposed solution was improving it by providing 0.33 mm registration accuracy. Additionally, the proposed system can produce good results despite not having a good initialization. The processing time improved to 14 fps in comparison to the 9-fps given by state-of-the-art solution. The proposed system improved the accuracy of convergence and the processing time compared to the globally optimal-ICP algorithm. We also employed RANSAC algorithm to detect and remove the outlier on the estimation and reduce the influence of extreme points.

ERRATUM.

ERRATUM.

SauFRa Technique for the Fixation of Resorbable Membranes in Horizontal Guided Bone Regeneration: A Technical Report.

Membrane fixation in guided bone regeneration (GBR) has been traditionally achieved using resorbable pins, titanium tacks or miniscrews. However,these techniques are marredwith a number of clinical challenges. This article presents the "SauFRa" technique, a novel technique for stabilization of resorbable membranes in both, single as well as multiple implant sites while avoiding the shortcomings of other suturing techniques described in literature. Furthermore, the technique also eliminates the possibility of complications observed when using resorbable pins, titanium tacks or miniscrews, such as damage to adjacent roots during insertion. The authors' employed this technique in89 patients (51 male and 35 female)and found no complications like tissue dehiscence, infectionor graft migration.

What Is the Role of Endodontic Predisposing Factors in Early Implant Failure?

We aimed to investigate a possible relationship between early implant failure (EIF) and an adjacent root canal-treated tooth and/or tooth with a periapical lesion (PL), considering the duration between implantation and root canal treatment (RCT). The importance of prior RCT and/or presence of a PL before implantation was also investigated. A total of 810 implants from 342 patients were included and scored according to the implant failure before abutment connection, adjacent root canal treated teeth, adjacent teeth without RCT, no adjacent teeth, adjacent teeth with PL, extraction of teeth with PL, and/or RCT before implantation. The durations between the extraction and implantation and between RCT and implantation adjacent to the root canal-treated teeth were recorded. The time from the RCT of adjacent teeth to implant placement was categorized into 5 groups: less than 4 weeks before implantation, 4-12 weeks before implantation, at least 12 weeks before implantation, within 4 weeks after implantation, and at least 4 weeks after implantation. Among the endodontic predictors, a prior PL on the tooth extracted was associated with an increased risk of EIF (P < .05, odds ratio: 4.37; 95% confidence interval: 1.604-11.891). Furthermore, EIF was more likely to occur when the RCT of an adjacent tooth was performed within 4 weeks of implantation (P < .05). Additional investigations with larger sample sizes are necessary to validate our findings.

Cocktail Treatment with a Gelatin Sponge Impregnated with Ropivacaine, Dexamethasone, and Vitamin B12 Promotes Early Postoperative Recovery after Percutaneous Endoscopic Lumbar Discectomy: A Retrospective, Case-Controlled Study

Percutaneous endoscopic lumbar discectomy (PELD) can only relieve mechanical compression but cannot directly reduce the inflammatory reaction of the adjacent nerve root, which contributes to persistent pain and physical disabilities postoperatively. Numerous studies have explored the application of epidural steroids after an open lumbar discectomy in relieving pain by reducing local inflammatory reactions and further peridural scar formation. To explore that whether "cocktail treatment" in which a gelatin sponge was impregnated with ropivacaine, dexamethasone, and vitamin B12 promoted early postoperative recovery after PELD. Retrospective, case-controlled study. All data were from Hong-Hui Hospital in Xi'an. Between January 2016 and January 2017, 100 patients of single-level lumbar disc herniation were treated with PELD in our hospitals. The cocktail treatment was applied in the first 50 patients (group cocktail), and an equal size gelatin sponge without drugs was used in the other 50 patients as control (group noncocktail). The clinical outcome evaluation included the Visual Analog Scale (VAS) score for back and leg pain and Oswestry Disability Index (ODI) score. There was a significant difference in the mean periods of return to work (4.25 ± 1.88 weeks in the cocktail group and 5.18 ± 2.19 weeks in the noncocktail group) (P < 0.01). Compared with the preoperative data, a significant improvement in VAS scores of back pain and sciatica and ODI were observed in each follow-up interval (P < 0.05, respectively). In the noncocktail group, there were visible fluctuations in the 3 indicators within the first week after surgery. This phenomenon was not observed in the cocktail group, a difference that was statistically significant (P < 0.05, respectively). In further follow-up, no significant differences were observed between the 2 groups (P > 0.05, respectively). The nonrandomized, single-center, retrospective design is a major limitation of this study. The "cocktail treatment" with a gelatin sponge impregnated with ropivacaine, dexamethasone, and vitamin B12 promotes early and satisfactory back and leg pain relief and fast functional recovery after PELD. Endoscopic lumbar discectomy, lumbar disc herniation, steroids, nerve root block, gelatin sponge.

C5 Palsy After Cervical Spine Decompression: Topographic Correlation With C6 Chassaignac Tubercle?: A Fresh-Cadaveric Study of the Cervical Spine and Rediscussion of Etiological Hypotheses.

Cadaveric study on fresh unprocessed, nonpreserved, undyed specimens, which has not previously been reported. Our aim was to explore the possible topographic correlation of the C5 nerve root with regards to its course and regional relation to C6 Chassaignac tubercle. C5 palsy is reported amongst the most frequent postoperative complications of cervical spinal procedures. We hypothesized that etiologic mechanisms proposed thus far in the current literature, although with some plausible explanation, still cannot explain why the C5 nerve root and not any other level suffer a postoperative palsy. Six fresh cadavers had extensive layer by layer dissection performed by two surgeons (one of whom has experience as an anatomy demonstrator and dissector). Roots of brachial plexus were exposed in relation to cervical transverse processes. Photographs were taken at each stage of the exposure. We observed a close relation of the path of the C5 nerve root with the C6 tubercle bilaterally. Moreover, we noted a steeper descent of C5 in comparison with the other adjacent roots. Steeper angle of the C5 nerve root and close proximity to C6 Chassaignac tubercle may play a role in predisposing it to neuropraxia. Detailed anatomical photographs on fresh unprocessed cadaveric specimens are novel. Peculiar anatomical features and recent experimental evidence discussed do highlight a postganglionic extraforaminal etiology corresponding well to the demographic meta-analysis data on clinical features of postoperative C5 palsy. Exploring an alternative unified "neurophysiologic stress and critical tipping point" etiological model that encompasses current theories and correlates known metanalyses observations, we believe further studies would be prudent to ascertain/refute these findings. 3.

THE ROLE OF EKG IN RAISING EARLY SUSPICION OF AN ENDOCARDITIS COMPLICATION

When AV node conduction abnormalities manifest on EKG in patients with suspected infective endocarditis, abscess of the adjacent aortic root should always be suspected as a complication of endocarditis. A 50-year-old gentleman with a history of coronary artery disease status post CABG and aortic

Modulation of Arabidopsis Flavonol Biosynthesis Genes by Cyst and Root-Knot Nematodes.

Although it is well established that flavonoid synthesis is induced in diverse plant species during nematode parasitism, little is known about the regulation of genes controlling flavonol biosynthesis during the plant–nematode interaction. In this study, expression of the Arabidopsis thaliana flavonol-specific transcription factor, AtMYB12, the flavonol synthase genes, AtFLS1, 2, 3, 4, and 5, and the gene encoding the central flavonoid enzyme, chalcone synthase (AtCHS), were examined in plant roots during infection by Heterodera schachtii (sugar beet cyst) and Meloidogyne incognita (root-knot) nematodes. These experiments showed that AtMYB12 was transiently upregulated at 9 dpi in syncytia associated with sugar beet cyst nematode infection and that an Atmyb12-deficient line was less susceptible to the parasite. This suggests that, rather than contributing to plant defense, this gene is essential for productive infection. However, the AtCHS and AtFLS1 genes, which are controlled by AtMYB12, did not exhibit a similar transient increase, but rather were expressly downregulated in syncytia relative to adjacent uninfected root tissue. Genetic analyses further indicated that AtFLS1 contributes to plant defense against Cyst nematode infection, while other AtFLS gene family members do not, consistent with prior reports that these other genes encode little or no enzyme activity. Together, these findings indicate a role of AtMyb12 in promoting the early stages of Cyst nematode infection, while flavonols produced through the action of AtFLS1 are essential for plant defense. On the other hand, a transient induction of AtMYB12 was not observed in galls produced during root-knot nematode infection, but this gene was instead substantially downregulated, starting at the 9 dpi sampling point, as were AtCHS and AtFLS1. In addition, both the AtMYB12- and AtFLS1-deficient lines were more susceptible to infection by this parasite. There was again little evidence for contributions from the other AtFLS gene family members, although an AtFLS5-deficient line appeared to be somewhat more susceptible to infection. Taken together, this study shows that sugar-beet cyst and root-knot nematodes modulate differently the genes involved in flavonol biosynthesis in order to successfully infect host roots and that AtFLS1 may be involved in the plant basal defense response against nematode infection.

Biomimetic properties of engineered periodontal ligament/cementum in dental implants

The conventional concept of osseointegrated dental implants based on direct connection to alveolar bone lacks a structured periodontal ligament (PDL) as in natural tooth. This limits the physiologic and functional efficiency of the implant in cushioning occlusal overload, orthodontic tooth movement, and proprioception. Development of bio-mimetic implants that can satisfy the bio-functional requirements of the natural tooth will be an innovative approach and preliminary researches in this area has been reported. This review includes in vivo studies which reported structural features and functional efficiency of an artificial PDL or cementum developed around dental implants. The electronic search identified 12 animal studies and one human trial which utilized retained or adjacent natural tooth roots, exogenous scaffold materials, dental progenitor cells derived from PDL of extracted tooth root as PDL substitutes. The result of the review is dominated by bio-hybrid implants that used dental follicles separated on the particular embryonic day and cell sheets from immortalized human cells. A summary of the currently available research on artificial PDL/cementum around dental implants highlights the potential need of autologous cell-derived tissues to bioengineer a fully functional implant design

Results of cone-beam computed tomography of the affected maxillary canines

With the development of three-dimensional (3D) imaging, conventional x-ray examinations of the maxillary canines begin to be performed using computed tomography (CT). Recently, cone-beam computed tomography (CBCT) has become an alternative to traditional CT in the diagnosis and treatment planning of affected teeth. Objectives: to determine the main features of the affected canines of the upper jaw and their effect on the adjacent teeth using CBCT. Materials and methods. 68 patients (79 affected maxillary canines) were examined (30.9% men and 69.1% women) at average age 32.7±2.44 years. Unilateral canine lesions were observed in 57 (83.8%) patients, bilateral — in 11 (16.2%) patients. The affected canines on the left — 57.0%, on the right — 43.0%. In 38 (55.9%) cases, canines were affected as a result of trauma, in 30 (44.1%) cases — due to caries. Results. Palatal localization prevailed. Out of 51 canines with resorption, soft resorption was determined in 29 cases, moderate — in 22 cases. In 64.6% of cases, resorption of adjacent teeth took place — with 33 lateral incisors, 17 central incisors and with the first premolar. With the buccal position, resorption was observed in 10 (19.6%) cases, with the palatal and central position in 39 (76.5%) and 2 (3.9%) cases, respectively. In the palatal position, root resorption exceeded that in the buccal and central position by 3.9 times (p<0.01) and 19.6 times (p<0.001). Root rupture was visualized in 44.3% of cases. Conclusion. CBCT made it possible to assess the degree of resorption of the lateral roots of the incisors adjacent to the affected maxillary canines. The method contributes to a more accurate representation of adjacent root resorptions, slopes and depth of the affected canines.

Incisor root resorption associated with palatally displaced maxillary canines: Analysis and prediction using discriminant function analysis

Incisor root resorption associated with palatally displaced canine (PDC-IRR) is an important phenomenon that might alter the orthodontic treatment plan. The aims of this study were to investigate the prevalence and characteristics of PDC-IRRs, to compare PDC-IRR and PDC-No-IRR groups, to identify predictors for PDC-IRR, and to produce a valid PDC-IRR prediction model using discriminant function analysis. Cone-beam computed tomography images for 107 palatally displaced canines (PDCs) and 51 fully erupted nondisplaced canines (NDC) were analyzed for the presence of incisor root resorption (IRR). The PDCs were divided into 2 groups: PDC-IRR (52 canines) and PDC-No-IRR (55 canines). The 3 groups were compared, and the following variables were measured: canine follicle size, contact with adjacent incisors, associated dental abnormalities, sector analysis, canine vertical relation to adjacent root, lateral incisor angulation and inclination, canine angulation and distance to reference planes (dental midline, midpalatal suture, occlusal plane, pterygoid vertical plane, and lateral incisor), and space available for canine in the dental arch. Discriminant functional analysis was used to produce a discriminant function equation to predict PDC-IRR. Root resorption affected 74% of lateral incisors adjacent to PDCs and 25.5% of lateral incisors adjacent to NDCs. IRR was located lingually in 41% of PDCs and in the mid and apical thirds in 89%. In the PDC-IRR group, 94.2% of canines were in contact with adjacent roots compared with 23.6% in the PDC-No-IRR group (P<0.001). Canine follicle size was>2mm in 42% of PDC subjects. Overall mean value of follicle width in PDC canines was 1.79±1.06mm. Peg-shaped lateral incisors were recorded in 19% of PDC subjects compared with 4% in NDCs (P=0.012). The stepwise analysis using cone-beam computed tomography records produced a discriminant function based on 3 variables. The analysis correctly predicted the outcome in 83% of subjects. The variables contributing to the prediction equation were canine contact with adjacent incisors, size of canine dental follicle, and the presence of peg-shaped lateral incisor. Canines in contact with adjacent incisor roots was the only risk factor detected for PDC-IRR. Very good predictive discrimination (83%) emerged for PDC-IRR subjects. Predictors of PDC-IRR were canine contact with adjacent incisor, size of canine dental follicle, and presence of peg-shaped lateral incisor.

A combination of pathologies - facet joint synovial cyst, epidural lipomatosis and conjoined nerve root anomaly in the lumbar spine of a 45-year-old patient. A case report

Facet joint synovial cysts are abnormal fluid-filled cystic formations that develop from a degenerative process of the facet joints. Spinal epidural lipomatosis is a process of excessive accumulation of fat in the epidural space. Conjoined nerve root (CNR) anomaly refers to an anatomical variation in which two adjacent nerve roots share a common dural sleeve. The aforementioned three rare pathologies cause the same pathological process of stenosis, therefore compressing the nervous structures. A 45-year-old female patient was admitted to the Department of Neurosurgery with severe low back and radicular pain, and numbness along her left leg. Antalgic posture, painful paravertebral muscle tenderness, L4 radiculopathy, and L5 and S1 dermatome hypoesthesia on the left as well as positive straight leg raising sign (Laseque) were present upon examination. CT and MRI scanning showed stenosis on L4-L5 level caused by bilateral synovial cyst formation. Microsurgical decompression by foraminotomy at L4-L5 level on the left with dissection of the synovial cyst and epidural lipomatosis was performed. In the course of the operation CNR anomaly was discovered. The complete decompression alleviated the symptoms and after 3 uneventful postoperative days the patient was discharged. Spinal stenosis causing compression upon nervous structures is a process that could be caused by a number of conditions. The incidence of rare pathologies and anomalies or even the more rarely occurring combination of them must be considered on daily basis in the clinical practice in order to make the correct diagnosis and plan the best possible treatment for the patient.

Do hybrid arch bar screws pose a risk to the dentition?

Objective Hybrid arch bars have become popular alternatives to traditional Erich arch bars for use in craniomaxillofacial surgery. They offer the benefit of decreased time for application, reduced risk of sharps exposure to healthcare personnel, and decreased risk of compromised periodontal health. However, it has not been established if they pose a significant risk to the dentition. Damage to the teeth, such as violation of the pulpal canal or root fracture, can lead to clinically significant sequelae. The purpose of the study was to examine if the screws contact or violate the tooth structure during placement. Study Design A retrospective radiographic review of 50 patients treated with Stryker SMARTLock Hybrid Maxillomandibular fixation system at University Medical Center Hospital in New Orleans, from January 2018 to August 2018, was conducted. Postoperative axial slices of computed tomography (CT) scans were examined for screw position relative to the adjacent tooth roots. Patients were excluded if they were fully edentulous, were incarcerated, or did not have arch bars applied to both arches. Variables examined were screw violation of the periodontal ligament, gross disruption of tooth root dentin, pulpal violation, and root fracture. The location of the tooth injured with regard to the maxilla versus the mandible and the anterior, premolar, or molar dentition was also examined. Statistical analysis was performed with unpaired t test and 1-wayanalysis of variance with Tukey's post hoc test. Results Fifty patients were analyzed, for a total of 507 screws in 100 arches with 1340 teeth present. Overall, 31.49% of teeth had contact or injury with the screws, with screw violation of the periodontal ligament (7.39%), dentin (19.78%), and pulp (3.81%) and root fracture (0.45%). There was a significantly higher incidence of root fracture in the mandible (N = 5) versus maxilla (N = 1) (P Conclusions Hybrid arch bars offer many benefits to the surgeon, but there is no risk of the screw contacting or violating the tooth structure. There is an increased risk to the anterior dentition and the maxillary dentition. The mandibular teeth are also more likely to experience root fracture compared with the maxillary teeth. The hybrid arch bars should be applied with consideration to patient anatomy and tooth position to prevent injury to the tooth roots.

Glorious pairs of roots and Abelian ideals of a Borel subalgebra

Let $${{\mathfrak {g}}}$$ be a simple Lie algebra with a Borel subalgebra $${{\mathfrak {b}}}$$ . Let $$\Delta ^+$$ be the corresponding (po)set of positive roots and $$\theta $$ the highest root. A pair $$\{\eta ,\eta '\}\subset \Delta ^+$$ is said to be glorious, if $$\eta ,\eta '$$ are incomparable and $$\eta +\eta '=\theta $$ . Using the theory of abelian ideals of $${{\mathfrak {b}}}$$ , we (1) establish a relationship of $$\eta ,\eta '$$ to certain abelian ideals associated with long simple roots, (2) provide a natural bijection between the glorious pairs and the pairs of adjacent long simple roots (i.e., some edges of the Dynkin diagram), and (3) point out a simple transform connecting two glorious pairs corresponding to the incident edges in the Dynkin diagram. In types $${{\mathbf {\mathsf{{{DE}}}}}}_{}$$ , we prove that if $$\{\eta ,\eta '\}$$ corresponds to the edge through the branching node of the Dynkin diagram, then the meet $$\eta \wedge \eta '$$ is the unique maximal non-commutative root. There is also an analogue of this property for all other types except type $${{\mathbf {\mathsf{{{A}}}}}}_{}$$ . As an application, we describe the minimal non-abelian ideals of $${{\mathfrak {b}}}$$ .

An effective mesiodens extraction method involving an intraoral approach through the nasal floor bone

AbstractA mesiodens is a supernumerary tooth located in the maxillary central region, frequently found in an inverted, impacted position, which can cause delayed or ectopic eruption of the permanent incisors. Unerupted supernumerary teeth are typically removed by the traditional palatal or labial approach. However, the traditional approach may induce injury to the adjacent root or damage the surrounding soft tissue because a deeply impacted mesiodens requires excessive bone removal in the anterior maxilla. The aim of the present study was to introduce an effective tooth extraction method involving an intraoral approach through the floor bone of the nasal cavity.

The relationship between algebraic equations and $(n,m)$-forms, their degrees and recurrent fractions

Algebraic and recursion equations are widely used in different areas of mathematics, so various objects and methods of research that are associated with them are very important. In this article we investigate the relationship between $(n,m)$-forms with generalized Diophantine Pell's equation, algebraic equations of $n$ degree and recurrent fractions. The properties of the $(n,m^n+1)$-forms and their characteristic equation are considered. The author applied parafunctions of triangular matrices to the study of algebraic equations and corresponding recurrence equations. The form of adjacent roots of the annihilating polynomial of arbitrary $(n,m)$-forms over the field of rational numbers are explored.&#x0D; The following question is very important for some applied problems: Is a given form the largest by module among its adjacent roots? If it is so, then there is a periodic recurrence fraction of $n$-order that is equal to this $(n,m)$-form, and its $m$th rational shortening will be its rational approximation. The author has identified the class $(n,m)$-forms with the largest module among their adjacent roots and showed how to find periodic recurrence fractions of $n$-order and rational approximations for them.

Maxillary Sinus and Surrounding Bone Anatomy With Cone Beam Computed Tomography After Multiple Teeth Loss

The aim of this multicenter study was to examine the residual alveolar bone anatomy and sinus mucosa pattern at maxillary sinus regions in multiple teeth loss. This study was conducted with cone beam computed tomography images of 518 patients (267 females and 251 males) with multiple posterior maxillary teeth loss. Variables associated with sinus membrane (SM), sinus dimensions, ostium, septa, sinus neighborhood, alveolar bone height and ridge width, posterior superior alveolar artery, and adjacent roots were evaluated. No (58.2%) or flat (19.3%) thickening morphology was detected at most of the SMs. Membrane thickening and mucosal-like morphology was more prevalent for male patients (P = 0.005). The mean sinus width was relatively low (3.64 ± 3.33 mm) at the 5-mm level and showed an expected increase toward upper levels. Most of the sinus spaces were dimensionally average (39.5%) or wide (44.7%), and no effect of gender was observed in terms of sinus dimensions (P > 0.05). Multiple teeth loss plays a role in creating an imaginary sinus anatomy constituted of a relatively narrow space compared with single-tooth loss cases, from 3.6-mm mean coronal width to 11.3 mm in the apical portion.

Adjacent intact nociceptive neurons drive the acute outburst of pain following peripheral axotomy

Injury of peripheral nerves may quickly induce severe pain, but the mechanism remains obscure. We observed a rapid onset of spontaneous pain and evoked pain hypersensitivity after acute transection of the L5 spinal nerve (SNT) in awake rats. The outburst of pain was associated with a rapid development of spontaneous activities and hyperexcitability of nociceptive neurons in the adjacent uninjured L4 dorsal root ganglion (DRG), as revealed by both in vivo electrophysiological recording and high-throughput calcium imaging in vivo. Transection of the L4 dorsal root or intrathecal infusion of aminobutyrate aminotransferase inhibitor attenuated the spontaneous activity, suggesting that retrograde signals from the spinal cord may contribute to the sensitization of L4 DRG neurons after L5 SNT. Electrical stimulation of low-threshold afferents proximal to the axotomized L5 spinal nerve attenuated the spontaneous activities in L4 DRG and pain behavior. These findings suggest that peripheral axotomy may quickly induce hyperexcitability of uninjured nociceptors in the adjacent DRG that drives an outburst of pain.