Assessment of traumatic mandibular nerve using MR neurography sequence: a preliminary study.

BACKGROUND: Iatrogenic mandibular nerve damage resulting from oral surgeries and dental procedures is painful and a formidable challenge for patients and oral surgeons alike, mainly because the absence of objective and quantitative methods for diagnosing nerve damage renders treatment and compensation ambiguous while often leading to medico-legal disputes. The aim of this study was to examine discriminating factors of traumatic mandibular nerve within a specific magnetic resonance imaging (MRI) protocol and to suggest tangible diagnostic criteria for peripheral trigeminal nerve injury. METHODS: Twenty-six patients with ipsilateral mandibular nerve trauma underwent T2 Flex water, 3D short tau inversion recovery (STIR), and diffusion-weighted imaging (DWI) acquired by periodically rotating overlapping parallel lines with enhanced reconstruction (PROPELLER) pulse sequences; 26 injured nerves were thus compared with contra-lateral healthy nerves at anatomically corresponding sites. T2 Flex apparent signal to noise ratio (FSNR), T2 Flex apparent nerve-muscle contrast to noise ratio (FNMCNR) 3D STIR apparent signal to noise ratio (SSNR), 3D STIR apparent nerve-muscle contrast to noise ratio (SNMCNR), apparent diffusion coefficient (ADC) and area of cross-sectional nerve (Area) were evaluated. RESULTS: Mixed model analysis revealed FSNR and FNMCNR to be the dual discriminators for traumatized mandibular nerve (p < 0.05). Diagnostic performance of both parameters was also determined with area under the receiver operating characteristic curve (AUC for FSNR = 0.712; 95% confidence interval [CI]: 0.5660, 0.8571 / AUC for FNMCNR = 0.7056; 95% confidence interval [CI]: 1.011, 1.112). CONCLUSIONS: An increase in FSNR and FNMCNR within our MRI sequence seems to be accurate indicators of the presence of traumatic nerve. This prospective study may serve as a foundation for sophisticated model diagnosing trigeminal nerve trauma within large patient cohorts.

Variations in the Position of Mandibular Foramen in Temporomandibular Ankylosis Patients.

Aim: To evaluate the variation in the position of the mandibular foramen and mandibular canal in patients with and without temporomandibular joint ankylosis. Materials and Methods: 100 temporomandibular joints were evaluated of which 50 joints were ankylosed joints (Group A) and the rest 50 were normal joints (Group B) without ankylosis. These groups were further divided into those with growing potential (less than 18 years) and those without growing potential (above 18 years). The position of the mandibular foramen was measured from its center to the glenoid fossa, sigmoid notch, coronoid notch, gonion and posterior border on CBCT scans. The position of the mandibular canal was measured from the outer aspect of the canal to the lower border of the mandible, buccal and lingual cortical plates and the alveolus in the region of the 1st, 2nd and 3rd molars. Results: The mean distance of the foramen from the base of the skull in Group A was 19.01 mm while the same for Group B was 31.26 mm. The mandibular foramen was found to be closer to the occlusal plane (5.43 mm) in Group A as compared to the mean distance of 6.21 mm reported in Group B. There was no significant difference in the position of the foramen from the posterior border, gonion and sigmoid notch between the groups. The mental foramen was seen more commonly posterior to the 2nd premolar and closer to the first molar region in Group A while in Group B it was seen anterior or near the 2nd premolar. In Group A, the mean distance of the canal to the buccal cortical plate in the 1st and 2nd molar regions was 3.65 mm and 5.76 mm, respectively, while in Group B it was 6.09 mm and 6.59 mm. The canal was further away from the lower border in ankylosis cases (8.79 mm) than the control group (7.41 mm). On comparing the unaffected side in unilateral cases with the normal mandible, the canal and the foramen location were similar to that of a normal mandible with the values in the lower range that is usually seen in normal mandibles. Conclusion: Ankylosis of the mandible is a debilitating condition especially when it develops in an individual prior completion of growth as it can affect the mandibular anatomy. Understanding the variations that accompany a deranged mandible can assist the surgeon in planning of surgical procedures in a manner that limits the possible complications resulting from surgery.

Dental Pulp-Derived Mesenchymal Stem Cells Increase Axon Numbers in Mental Nerve Repair.

Aim: The mental nerve, the extended part of the inferior alveolar nerve, is often injured during dentoalveolar, orthognathic, or tumor surgery. Numerous therapeutic interventions, including surgery and pharmacotherapy, have been used to enhance the recovery of nerve injuries. Dental pulp stem cells (DPSCs) represent an easily accessible source of adult stem cells that can be isolated from the pulp of extracted teeth. This study evaluated the effect of DPSCs on the regeneration of the mental nerve injury model of rabbits. Methods: In this presented study, DPSCs were cultured and cell characterizations were performed by using flow cytometry and immunostainings. Bilateral mental nerve injury models of rabbits were created. In the control group (n = 10), saline was applied, and in the study group (n = 10), 2 × 106 DPSCs were applied to the repaired nerve areas. After 3 weeks, animals were killed and histological examination was obtained by using Masson's trichrome staining. An unpaired Student's t test was used when comparing the groups. Differences were considered to be statistically significant at P values of less than 0.05. Results: The DPSCs demonstrated a homogeneous population of mesenchymal stromal cells which expressed cluster of differentiation CD44, CD73, CD90, and CD105 and lack of CD34, CD45, and HLA-DR. Our finding clearly demonstrated that a lower number of cross-sectioned axons were founded in the control group (60.18 ± 2.52) compared to the study group (72.96 ± 2.43) (p = 0.00). Conclusions: DPSCs promote mental nerve axonal regeneration. These results suggest that DPSCs provide an important accessible source of adult stem cells for mental nerve regeneration.

Concordance Analysis of Lower Third Molar Surgery Classifications: A Comparative Study.

The high frequency and complexity of mandibular third molar (M3M) surgery have led several authors to the development of classification systems for better evaluation and management in oral surgery. This study compared the classifications of Juodzabalys and Daugela et al. (JD), Sammartino et al., Chang et al., Jhamb et al., Maglione et al., and Nemsi et al. to understand the concordance between the scores of M3M surgery. Two types of analysis were conducted: the relationship between the M3M and the inferior alveolar nerve (IAN), and the overall difficulty score based on the tooth's angulation and its spatial position with the adjacent structure. The analysis of the classifications on the relationship between M3M and IAN resulted in a concordance of 26.1%. In the pairwise comparisons, the classifications of Nemsi et al. and Jhamb et al. showed the highest concordance of 59.5%. Analyzing the total scores difficulty, the JD et al., Chang et al., and Sammartino et al. classifications demonstrated a concordance level of 25.5%. A pairwise assessment revealed a higher concordance degree between the classifications of Sammartino et al. and Chang et al. (57.4%). The results highlight the limits in establishing a comprehensive and objective classification for the surgical difficulty of M3M, possibly attributed to variations in the methodology for computing total scores. An objective, automated, and non-operator-dependent classification method for assessing the surgical difficulty of M3M is still needed.

The anterior loop of the inferior alveolar nerve within the mentonian foramen: a scoping review.

PURPOSE: The aim of this study is to delineate the safety zone concerning the anteriorization of the AL and correlate it with the behavior of the AL, analyzing its feasibility. METHODS: Adhering to the Joanna Briggs Institute (JBI) manual guidelines, both the protocol and this review were conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) checklist. MeSH terms, combined with free terms, were utilized to search for articles in the following databases: Embase, LILACS, LIVIVO, PubMed/MEDLINE, Scopus, Web of Science, and grey literature. RESULTS: Fifteen articles were select following the eligibility criteria. An average safe zone of 4.75 mm in humans was observed, with a prevalence 60.8% and average anterior length of the AL of 2.09 mm in humans. CONCLUSION: The AL has varied patterns across different populations, then, it could not be asserted a 100% safe zone. Preoperative analysis of the AL with CBCT is always necessary. While it could be stated that a safe zone should be employed as an inviolable region, stipulated measures of a safe zone should be regarded as an area of greater attention in preoperative planning.

Comparative effectiveness of preemptive administration of ibuprofen and ibuprofen-arginine on the anesthetic success of inferior alveolar nerve block in teeth with symptomatic irreversible pulpitis - A double-blind randomized clinical trial.

OBJECTIVES: This study examined the impact of premedication with ibuprofen and ibuprofen-arginine and the influence of preoperative pain and anxiety on inferior alveolar nerve block (IANB) efficacy in cases of symptomatic irreversible pulpitis. MATERIALS AND METHODS: The study involved 150 SIP patients who were randomly assigned to receive ibuprofen (600 mg), ibuprofen-arginine (1,155 mg), or a placebo 30 min before IANB. Preoperative anxiety and pain levels were assessed using the Modified Dental Anxiety Scale and the Heft-Parker visual scale. IANB efficacy was determined by the absence of or mild pain during the procedure. Statistical analysis included chi-square, z-tests, Analysis of Variance, and Student's t tests. RESULTS: The ibuprofen and ibuprofen-arginine groups exhibited significantly higher IANB success rates (62% and 78%, respectively) compared to the placebo group (34%). However, no significant difference was observed between the ibuprofen and ibuprofen-arginine groups. Patients with successful IANB in the ibuprofen and ibuprofen-arginine groups displayed lower median anxiety scores (8) than those with failed blocks (15) and lower mean preoperative pain scores (118.3). CONCLUSION: In cases of symptomatic irreversible pulpitis the preemptive medication with ibuprofen-arginine effectively increased the efficacy of the inferior alveolar nerve block The inferior alveolar nerve block efficacy was influenced by preoperative anxiety levels and the intensity of pain. CLINICAL RELEVANCE: This research underscores the potential benefits of oral premedication with ibuprofen and ibuprofen-arginine in improving anesthesia outcomes in cases of symptomatic irreversible pulpitis.

Measurement of the mandibular canal and mandibular incisive canal using cone beam tomography in adults from South Brazil.

PURPOSE: To identify and measure the distance from the dental apices to the mandibular (MC) and mandibular incisive (MIC) canals, the diameter of the MC and the distances of the mental foramen (MF). METHODS: In this retrospective study, cone-beam computed tomography scans of 144 adult patients (males and females) from a dental school in South Brazil were evaluated. Cross-sections were selected on the MC and the MIC paths, perpendicular to the mandibular base, and measurements were taken from the dental apices to the mandibular cortices. The measurement and location of the mandibular and mental foramen on both sides were compared. Paired t-tests compared sides, while Student's t-tests compared sexes (P < 0.05). RESULTS: The distance from the dental apices to the upper wall of the MC was closest in the third molar and farthest in the central incisor region. In both sexes and sides, the path of the MC is in most cases lingually in the molar regions and moves to the buccal region from the second premolar. The MF emerges in the regions between the premolars or near the second premolar. CONCLUSION: The results of this study highlight the importance of evaluating specific individual characteristics of a given population.

Altered sensation following extrusion of an endodontic file treated by intentional replantation: case report and treatment recommendations.

OBJECTIVE: An altered sensation during endodontic treatment can occur due to the extrusion of endodontic materials. This study aims to discuss intentional replantation to address paresthesia resulting from an endodontic file penetrating the inferior alveolar nerve canal (IANC) and provide a protocol for managing nerve injuries in such incidents. CASE PRESENTATION: A 12-year-old girl developed paresthesia when an endodontic file separated and was inadvertently pushed through the apical foramen into IANC during root canal treatment of the mandibular left first molar. A CBCT scan revealed the file penetrating the canal towards the inferior border of the mandible. After considering the treatment options, intentional replantation was deemed suitable. The tooth was a-traumatically extracted and preserved in sterile saline. The surgeon then carefully cleaned and irrigated the socket. The radiographic assessment confirmed successful file removal from the socket. The Root ends were resected, and retrograde preparation and obturation were conducted using ultrasonic tips and MTA. The tooth was then replanted into the socket. Successful replantation was confirmed by tooth stability and an audible click. The patient was prescribed antibiotics and steroids. Subsequently, after completing the endodontic treatment. a stainless-steel crown was cemented. The successful intentional replantation procedure resulted in rapid improvement in the patient's condition. The normal sensation had been restored, indicating nerve recovery. At the 15-month follow-up, Periapical bone healing and the eruption of the adjacent second molar were observed, affirming the treatment protocol's overall success. CONCLUSION: Prompt intervention and immediate intentional replantation facilitated direct inspection of the separated file within the socket. Collaboration between an oral maxillofacial surgeon and an endodontist ensures expedited and targeted treatment, leading to favorable outcomes.

Inferior alveolar nerve injury resulting from different implant rotary instruments: An ex vivo comparative study in human cadaveric mandibles.

The present study aimed to evaluate the degree of nerve injury on inferior alveolar nerve (IAN) by different implant drills resulting from direct canal intrusion into inferior alveolar canal (IAC). A cadaveric study involving 7 human mandibles was performed to evaluate mechanical injury of canal enclosed IAN resulting from different drills. In group 1, osteotomies were created using different drills with 1 mm of intracanal intrusion, simulating accidental drill intrusion into canal. In group 2, drilling was stopped when the tip has breached into IAC, limited by tactile feedback of operator. The depth and width of nerve defects were assessed using optical coherence tomography. A significant difference in defect depth was found (p < 0.001) in group 1. A sinus lift reamer inflicted the least damage (0.068 ± 0.022 mm). It was also found that the mean defect depth was significantly different when a twist drill was used (p = 0.016). Sinus lift reamer can be used safely for osteotomy preparation in mandible when bone height is limited or when radiographic visualization of canal is poor. Bone corticalization around IAC does not provide adequate protection for IAN in the event of accidental intracanal intrusion.

Cone Beam CT Assessment of Mandibular Foramen and Mental Foramen Positions as Essential Anatomical Landmarks: A Retrospective Study in Vietnam.

INTRODUCTION: The mandibular foramen (MnF) and the mental foramen (MF) are essential anatomical landmarks that should be considered before any surgical procedures in the mandible. This study aimed to investigate the characteristics of the MnF and MF in relation to adjacent anatomical structures, as well as age and gender differences, using cone beam computed tomography (CBCT) projections. METHODS: The study was conducted from August 2023 to January 2024 at the Can Tho University of Medicine and Pharmacy Hospital, Vietnam. In this retrospective study, 50 CBCT images of Vietnamese patients were randomly taken for various clinical purposes. Furthermore, relevant data, such as gender and age groups, were selected to evaluate the correlations, along with specific inclusion criteria. Patients within the age range of 18-69 with a symmetrical mandible were included. RESULTS: The distance of the MnF-MN was 29.6±5.0 mm (right) and 30.1±4.6 mm (left) in males and 25.0±4.2 mm (right) and 26.3±5.0 mm (left) in females. The distance of the MnF-posterior border of the ramus (P) was 16.2±3.6 mm (right) and 15.0±2.3 mm (left) in males. For females, it was 17.1±2.9 mm (right) and 13.8±1.7 mm (left). The distance of the MF-body mandible (MB) was 15.4±2.4 mm (right) and 15.6±2.0 mm (left) in males and 14.0±2.1 mm (right) and 14.3±1.6 mm (left) in females. The distance of the MF-mandibular midline (MM) was 27.0±2.6 mm (right) and 27.0±2.9 mm (left) in males and 25.3±2.0 mm (right) and 25.1±2.2 mm (left) in females. These distances showed statistically significant differences depending on gender (P<0.05). CONCLUSION: It can be said that CBCT provides comprehensive information about the MnF and the MF for dentists in research and clinical practice.

Effect of Back-Pressure Anesthesia on Postoperative Pain after the Endodontic Treatment in Patients with Symptomatic Irreversible Pulpitis: Randomized Double-Blind Clinical Trial.

INTRODUCTION: The present study evaluated the effect of 2 different back pressure-based supplemental anesthesia on postoperative pain in patients receiving endodontic treatment for a mandibular molar with symptomatic irreversible pulpitis. METHODS: One-hundred-thirty-five adult patients with symptomatic irreversible pulpits in a mandibular first or second molar, received an initial inferior alveolar nerve block (IANB) injection with 2% lidocaine with 1:80,000 epinephrine. Ten minutes following the injection, access to cavity preparation began. Lip numbness was a must for all patients. The Heft-Parker visual analogue scale (HP-VAS) was used to measure pain during endodontic therapy. Success of primary injections was defined as no or mild pain (less than 55 mm on HP-VAS) during access preparation. The patients with initial successful anesthesia served as control and received endodontic treatment. Ninety-five patients with unsuccessful primary anesthesia randomly received either intraligamentary injections of 2% lidocaine with 1:80,000 epinephrine or intrapulpal injections with similar anesthetic solution. Endodontic treatment was re-initiated and canals were instrumented till working length under copious irrigation. Intracanal medicament of calcium hydroxide was placed and teeth received a temporary restoration. Postoperative pain was measured at 2 hours, 4 hours, 6 hours, 24 hours, and 3 days. Data were analyzed using the Pearson chi-square test, one-way analysis of variance, and one-way repeated measures analysis of variance. RESULTS: The initial initial inferior alveolar nerve block was successful in 40 cases (out of 135). The intraligamentary injections were successful in 33 out of 47 cases (70%), and intrapulpal injections were successful in all cases (45/45). The patients receiving intraligamentary injections reported significantly higher pain scores at all intervals till 24 hours. After 3 days, the pain significantly reduced in all the groups with no significant difference between them. CONCLUSIONS: Patients receiving supplementary intraligamentary injections can experience increased postoperative pain till 24 hours after the endodontic treatment. The pain scores reduced to the level of the control group after 3 days.

Clinical Assessment of Preemptive Analgesia on Success of Pulpal Anesthesia and Postendodontic Pain in Children with Irreversible Pulpitis: A Randomized Comparative Study.

Introduction: Optimal pain management of symptomatic pulpitis in formative years goes a long way in developing a positive dental attitude. Efforts should be made to increase the success of anesthesia, thus diminishing negative dental experiences. The aim of the study was to assess the efficacy of preemptive analgesia on the success of pulpal anesthesia following inferior alveolar nerve block (IANB) in children with symptomatic irreversible pulpitis and on reducing postendodontic pain. Materials and methods: The research design was an in vivo, three-group, parallel, quadruple-blind study. A total of 75 patients were randomly allocated to one of the three groups-group I: ibuprofen, group II: combination of ibuprofen and paracetamol, and group III: multivitamin (placebo). Premedication was given 45 minutes before treatment, and patients received IANB in a standardized manner. Pain during pulpectomy was recorded using the face, legs, activity, cry, consolability (FLACC) scale and postoperatively using Wong-Baker's pain rating scale (WBPRS) at 4, 12, and 24 hours. Success was measured if the pain felt was of no or mild intensity. Results: Success of IANB was 64% for ibuprofen, 72% for the combination group, and 40% for the placebo group, with no statistically significant difference between all groups (p = 0.06) on the FLACC scale. At 4 hours postoperatively, a significant difference (p = 0.02) was found among groups with more children experiencing no or mild pain in groups I and II and the highest number of rescue medications taken by the placebo group. Conclusion: Ibuprofen and a combination of ibuprofen and acetaminophen as preemptive analgesics had no significant effect on the success rate of IANB, although it was effective in reducing pain at 4 hours postoperatively. How to cite this article: Gori NA, Patel MC, Bhatt RK, et al. Clinical Assessment of Preemptive Analgesia on Success of Pulpal Anesthesia and Postendodontic Pain in Children with Irreversible Pulpitis: A Randomized Comparative Study. Int J Clin Pediatr Dent 2024;17(1):72-78.

Flipped classroom teaching model with video instruction improves skills in local anesthesia training.

Background/purpose: Local anesthesia (LA) training is an essential clinical skill in dental education. However, the traditional teaching method of student-to-student injection has ethical concerns. This study investigated whether a flipped classroom (FC) teaching model with instructional videos improves students' skills in administering LA. Materials and methods: Fourth-year dental students in 2017 (traditional teaching, n = 70) and 2018 (FC model, n = 79) were assessed for their ability to perform an inferior alveolar nerve block and lingual nerve block. The FC group watched pre-recorded videos prior to a hands-on training session. Skills were evaluated using a 24-item checklist converted to letter grades. Perceptions of the FC approach were also surveyed. Results: The FC group showed statistically significantly higher final grades than the traditional teaching group (P < 0.05). Most FC students agreed that the videos improved clarity and learning objectives. Conclusion: The FC teaching model with procedural video instruction improved skills and confidence in administering LA over traditional teaching methods. Videos can be a beneficial supplement in pre-clinical dental training.

The Management of a Geriatric Patient Using Dabigatran Therapy on Dentigerous Cyst with Oral Bleeding.

Jaw cysts represent a great matter of interest in oral and maxillofacial surgery. Jaw cyst surgery is a common intervention in oral surgery but, in the case of a multidisciplinary patient, the oral surgeon needs to meet with other specialists. A cyst is an epithelium-lined sac containing fluid and/or semisolid material due to epithelial cell proliferation, degeneration, and liquefaction; the hypertonic solution withdraws liquids from the surrounding tissues, while internal pressure exerts an equal strength on the cyst walls. Dentigerous cysts are the second most common odontogenic cysts after radicular cysts, and commonly few or no symptoms are reported. However, the most common diagnosis for dentigerous cyst is represented by eruption of the affected tooth or accidental diagnosis. Commonly, dentigerous cysts may be related to impacted third molars; in the case of impacted third molars and a dentigerous cyst, the tooth should be removed along with the cyst in the same intervention. Mandibular dentigerous cysts are common in children and adults, while dentigerous cysts are a rare neoformation in elderly patients. Treatment usually involves removal of the entire cyst and the associated unerupted tooth. This intervention may be more difficult if the cyst is large, the third molar is in contact with the mandibular nerve, and/or the patient has a medical history that may represent a relative or absolute contraindication. We present the case of a rare symptomatic manifestation of dentigerous cyst in an elderly patient in treatment with dabigatran therapy; for the treatment of dentigerous cysts in the elderly, we suggest a multidisciplinary approach with the use of the histological examination and a careful follow-up.

Endoscopically-assisted extraction of broken roots or fragments within the mandibular canal: a retrospective case series study.

PURPOSE: To assess the impact of endoscope-assisted fractured roots or fragments extraction within the mandibular canal, along with quantitative sensory testing (QST) alterations in the inferior alveolar nerve (IAN). METHODS: Six patients with lower lip numbness following mandibular third molar extraction were selected. All patients had broken roots or fragments within the mandibular canal that were extracted under real-time endoscopic assistance. Follow-up assessments were conducted on postoperative days 1, 7, and 35, including a standardized QST of the lower lip skin. RESULTS: The average surgical duration was 32.5 min, with the IAN exposed in all cases. Two of the patient exhibited complete recovery of lower lip numbness, three experienced symptom improvement, and one patient remained unaffected 35 days after the surgery. Preoperative QST results showed that the mechanical detection and pain thresholds on the affected side were significantly higher than those on the healthy side, but improved significantly by postoperative day 7 in five patients, and returned to baseline in two patients on day 35. There were no significant differences in the remaining QST parameters. CONCLUSIONS: All endoscopic surgical procedures were successfully completed without any additional postoperative complications. There were no cases of deterioration of IAN injury, and lower lip numbness recovered in the majority of cases. Endoscopy allowed direct visualization and examination of the affected nerve, facilitating a comprehensive analysis of the IAN.

The alveolar canals and foramina in the first edition of Terminologia Oroanatomica: a preview.

Anatomy was initially developed out of necessity to decrease surgery complications. Over time, anatomists and surgeons have sometimes used different terms for the same anatomical structures, thus resulting in numerous discrepancies in terminology between anatomy and surgery. To avoid any confusion or misunderstanding and to better elucidate the oral anatomy terms, the Federative International Programme for Anatomical Terminology (FIPAT) organized a group of specialists on oral anatomy, Terminologia Oroanatomica (ToA) working group, composed of dentists, anatomy researchers, anatomy educators, oral and maxillofacial surgeons, and oral and maxillofacial radiologists. Within the ToA working group, major anatomical structures in the mandible, such as the mandibular canal, were focused and discussed to determine the most appropriate term, i.e., inferior alveolar canal. Although yet to be approved by the International Federation of Associations of Anatomists (IFAA), this article will preview some changes suggested by the ToA.

Inferior Alveolar Nerve Canal Segmentation on CBCT Using U-Net with Frequency Attentions.

Accurate inferior alveolar nerve (IAN) canal segmentation has been considered a crucial task in dentistry. Failing to accurately identify the position of the IAN canal may lead to nerve injury during dental procedures. While IAN canals can be detected from dental cone beam computed tomography, they are usually difficult for dentists to precisely identify as the canals are thin, small, and span across many slices. This paper focuses on improving accuracy in segmenting the IAN canals. By integrating our proposed frequency-domain attention mechanism in UNet, the proposed frequency attention UNet (FAUNet) is able to achieve 75.55% and 81.35% in the Dice and surface Dice coefficients, respectively, which are much higher than other competitive methods, by adding only 224 parameters to the classical UNet. Compared to the classical UNet, our proposed FAUNet achieves a 2.39% and 2.82% gain in the Dice coefficient and the surface Dice coefficient, respectively. The potential advantage of developing attention in the frequency domain is also discussed, which revealed that the frequency-domain attention mechanisms can achieve better performance than their spatial-domain counterparts.

Use of Adult Dry Human Mandibles to Study of Mandibular Foramen from Various Bony Landmarks.

Background: Precise knowledge of the mandibular foramen's location is essential for clinical and surgical procedures, especially the inferior alveolar nerve block. Variability in its position concerning different bony landmarks can significantly impact clinical outcomes. Materials and Methods: This study examined 30 Adult dry human mandibles to determine the mandibular foramen's positions in relation to specific bony landmarks: the occlusal plane, posterior border of the ramus, and lingula. Measurements were obtained using a calibrated digital caliper, and statistical analysis was performed. Results: The study revealed significant variations in the position of the mandibular foramen. In relation to the occlusal plane, the mandibular foramen was found at an average height of approximately 15.2 mm (±2.1 mm). Regarding the posterior border of the ramus, it was situated at an average distance of about 18.5 mm (±3.4 mm). In relation to the lingula, the average distance was approximately 21.8 mm (±4.0 mm). These results underscore the considerable individual differences and anatomical variations in the mandibular foramen's location among the studied specimens. Conclusion: The observed variations in the position of the mandibular foramen emphasize the need for clinicians and surgeons to be cognizant of these differences when performing procedures involving the inferior alveolar nerve block. Understanding these anatomical variations is crucial for enhancing clinical precision, reducing complications, and ensuring optimal outcomes.

Two-stage extraction by partial grinding of impacted mandibular third molar in close proximity to the inferior alveolar nerve.

BACKGROUND: Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve (IAN). AIM: To proposes a method for the partial grinding of an impacted mandibular third molar (IMM3) near the IAN to prevent IAN injury during IMM3 extraction. METHODS: Between January 1996 and March 2022, 25 patients with IMM3 roots near the IAN were enrolled. The first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and IMM3. After 6 months, when the root tips were observed to be away from the IAN on X-ray examination, the remaining part of the IMM3 was completely removed. RESULTS: All IMM3s were extracted easily without symptoms of IAN injury after extraction. CONCLUSION: Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.

Is 3T MR nerve-bone fusion imaging a viable alternative to MRI-CBCT to identify the relationship between the inferior alveolar nerve and mandibular third molar.

OBJECTIVES: To investigate the feasibility of MRI nerve-bone fusion imaging in assessing the relationship between inferior alveolar nerve (IAN) / mandibular canal (MC) and mandibular third molar (MTM) compared with MRI-CBCT fusion. MATERIALS AND METHODS: The MRI nerve-bone fusion and MRI-CBCT fusion imaging were performed in 20 subjects with 37 MTMs. The Hausdorff distance (HD) value and dice similarity coefficient (DSC) was calculated. The relationship between IAN/MC and MTM roots, inflammatory, and fusion patterns were compared between these two fused images. The reliability was assessed using a weighted κ statistic. RESULTS: The mean HD and DSC ranged from 0.62 ~ 1.35 and 0.83 ~ 0.88 for MRI nerve-bone fusion, 0.98 ~ 1.50 and 0.76 ~ 0.83 for MRI-CBCT fusion. MR nerve-bone fusion had considerable reproducibility compared to MRI-CBCT fusion in relation classification (MR nerve-bone fusion κ = 0.694, MRI-CBCT fusion κ = 0.644), direct contact (MR nerve-bone fusion κ = 0.729, MRI-CBCT fusion κ = 0.720), and moderate to good agreement for inflammation detection (MR nerve-bone fusion κ = 0.603, MRI-CBCT fusion κ = 0.532, average). The MR nerve-bone fusion imaging showed a lower ratio of larger pattern compared to MR-CBCT fusion (16.2% VS 27.3% in the molar region, and 2.7% VS 5.4% in the retromolar region). And the average time spent on MR nerve-bone fusion and MRI-CBCT fusion was 1 min and 3 min, respectively. CONCLUSIONS: Both MR nerve-bone fusion and MRI-CBCT fusion exhibited good consistency in evaluating the spatial relationship between IAN/MC and MTM, fusion effect, and inflammation detection. CLINICAL RELEVANCE: MR nerve-bone fusion imaging can be a preoperative one-stop radiation-free examination for patients at high risk for MTM surgery.