BACKGROUND: The analgesia after lower third molar alveolectomy is based on the use of non-steroidal anti-inflammatory drugs (NSAIDs) that have significant risks, and are contraindicated in the third trimester of pregnancy. Aiming to reduce NSAIDs use after this surgery, we quantified analgesic effects of ultrasound (US)-guided extraoral mandibular nerve block.
METHODS: Thirty-six patients were equally allocated to the experimental or control group, based on their willingness to receive experimental US-guided extraoral mandibular nerve block for postoperative analgesia. The experimental block applied prior to lower third molar alveolectomy, was followed by standard intraoral inferior alveolar nerve block. In the control group, patients received only intraoral block of inferior alveolar nerve. All patients reported pain level (visual analogue scale, VAS) right after the application of blocks. The next day, patients reported duration of pain-free time and the use of analgesic.
RESULTS: The US-guided extraoral mandibular nerve block prolonged the pain-free time to 8 h (vs. 4 in control group, P < 0.001) and reduced NSAIDs use (12 patients needed analgesic in experimental vs. 17 patients in control group, P = 0.038). The application of experimental block was less painful (VAS = 2) than the application of intraoral inferior alveolar nerve block (VAS = 4, P = 0.011). In 8/18 patients in the experimental group US-guided extraoral mandibular nerve block solely achieved adequate surgical anesthesia.
CONCLUSIONS: US-guided extraoral mandibular nerve block prolonged pain-free period and reduced the use of NSAIDs after lower third molar alveolectomy, thus proving to be successful analgesia method for this dental surgery.
BACKGROUND: https://classic.
RESULTS: gov/ct2/show/NCT06009302 , identification number: NCT06009302, date of registration: 18/08/2023.

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.

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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: DPSCs promote mental nerve axonal regeneration. These results suggest that DPSCs provide an important accessible source of adult stem cells for mental nerve regeneration.

BACKGROUND: 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).
CONCLUSIONS: It can be said that CBCT provides comprehensive information about the MnF and the MF for dentists in research and clinical practice.

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.

BACKGROUND: Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve (IAN).
OBJECTIVE: 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.
CONCLUSIONS: Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.

OBJECTIVE: 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.

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.

BACKGROUND: The most severe complication that can occur after mandibular third molar (MM3) surgery is inferior alveolar nerve (IAN) damage. It is crucial to have a comprehensive radiographic evaluation to reduce the possibility of nerve damage. The objective of this study is to assess the diagnostic accuracy of panoramic radiographs (PR) and posteroanterior (PA) radiographs in identifying the association between impacted MM3 roots and IAN.
METHODS: This study included individuals who had PR, PA radiographs, and cone beam computed tomography (CBCT) and who had at least one impacted MM3. A total of 141 impacted MM3s were evaluated on CBCT images, and the findings were considered gold standard. The relationship between impacted MM3 roots and IAN was also evaluated on PR and PA radiographies. The data was analyzed using the McNemar and Chi-squared tests. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of PR and PA radiographies were determined.
RESULTS: Considering CBCT the gold standard, the relationship between MM3 roots and IAN was found to be statistically significant between PR and CBCT (p = 0.00). However, there was no statistically significant relationship between PA radiography and CBCT (0.227). The study revealed that the most prevalent limitation of the PR in assessing the relationship between MM3 roots and IAN was the identification of false-positive relationship.
CONCLUSIONS: PA radiography may be a good alternative in developing countries to find out if there is a contact between MM3 roots and IAN because it is easier to get to, cheaper, and uses less radiation.