Self-assessed neurological disturbances after surgical removal of impacted lower third molar: a pragmatic prospective study on 423 surgical extractions in 247 consecutive patients

Use of CBCT and panoramic radiography in the prediction of alterations in sensivity of the inferior alveolar nerve in third molars: A retrospective cross-sectional study

Objectives

We investigated which type of orthopantomography (OPG) was best able to predict neurological alterations of the inferior alveolar nerve (IAN) during extraction of a lower third molar (3 M).

Methods

We analysed cone beam computed tomographies (CBCTs) that were performed at a private dental clinic in Cartagena, Spain over five consecutive years. The CBCTs, together with their corresponding OPGs, had been prescribed for the surgical extraction of a lower 3 M.

Results

We analysed a total of 342 CBCTs and their corresponding OPGs. After explaining the risk of changes in the IAN sensitivity, 37 patients refused to undergo surgical extraction. The incidence of sensitivity alterations in the 332 dental extractions was 62 (19%): 44 were paraesthesias of the IAN, and 18 were associated with darkening of the root and interruption of the cortical line.

Conclusion

When an OPG revealed darkening of the root and interruption of the cortical line, the risk of contact between the lower 3 M and the IAN-that is, the probability of changes in IAN sensitivity-increased by over three-fold.

Association of the Inferior Alveolar Nerve Position and Nerve Injury: A Systematic Review and Meta-Analysis

Background: We aimed to compare the relationship between the buccal and lingual positions of the inferior alveolar nerve canal (IAC) relative to the lower third molar (LM3) and the rate of the inferior alveolar nerve (IAN) injury. Methods: A systematic search was performed in the following databases: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Journals@Ovid. No language or publication status restrictions were set. The publication year was set from 2009 to 2021. The process of meta-analysis was performed by Review Manager software (Cochrane Collaboration). Results: A total of 1063 articles were initially searched and full texts of 53 articles were read, and 11 satisfactory articles were found. There was a statistical difference between the rate of IAN injury and the lingual position and buccal position of the IAC relative to the LM3 roots (OR, 4.96; 95% CI, 2.11 to 11.62; p = 0.0002), with high heterogeneity (p = 0.001, I² = 65%). Conclusion: A statistical difference was found in the rate of IAN injury between cases where the IAC was positioned buccally and lingually of the LM3 roots. The IAC was at a relatively higher risk of damage in third molar extraction when it was located on the lingual position of the LM3 roots.

Prevalence of and risk factors for postoperative complications after lower third molar extraction: A multicenter prospective observational study in Japan

Lower third molar extraction is the most common surgical treatment among routine dental and oral surgical procedures. while the surgical procedures for lower third molar extraction are well established, the difficulty of tooth extraction and the frequency of postoperative complications differ depending on the patient's background. To establish a management protocol for the lower third molars, the prevalence of and risk factors for postoperative complications after lower third molar extraction were investigated in a large number of Japanese patients in a multicenter prospective study. During 6 consecutive months in 2020, 1826 lower third molar extractions were performed at the 20 participating institutions. The medical records of the patients were reviewed, and relevant data were extracted. The prevalence of and risk factors for postoperative complications were analyzed. The prevalence of postoperative complications after lower third molar extraction was 10.0%. Multivariate analysis indicated that age (≤32 vs >32, odds ratio [OR]: 1.428, 95% confidence interval [95% CI]: 1.040-1.962, P < .05), the radiographic anatomical relationship between the tooth roots and mandibular canal (overlapping of the roots and canal vs no close anatomical relationship between the roots and the superior border of the canal, OR: 2.078, 95% CI: 1.333-3.238, P < .01; overlapping of the roots and canal vs roots impinging on the superior border of the canal, OR: 1.599, 95% CI: 1.050-2.435, P < .05), and impaction depth according to the Pell and Gregory classification (position C vs position A, OR: 3.7622, 95% CI: 2.079-6.310, P < .001; position C vs position B, OR: 2.574, 95% CI: 1.574-4.210, P < .001) are significant independent risk factors for postoperative complications after lower third molar extraction. These results suggested that higher age and a deeply impacted tooth might be significant independent risk factors for postoperative complications after lower third molar extraction.

Effects of Low-Level Laser Therapy on Osseous Defects Distal to Mandibular Second Molar after Extraction of Impacted Third Molar

Objective

To evaluate the efficiency of low-level laser therapy on the distal osseous defects of the mandibular second molar (M2) after the adjacent impacted third molar (M3) extraction.

Methods

A total of 59 clinic cases were screened out, whose M3 were impacted and the distal alveolar bone of M2 had been destroyed horizontally. They were randomly divided into 2 groups based on whether they would have laser irradiation or not after M3 extraction. Then, postoperative complications of the 2 groups were compared. The alveolar bone level distal to M2 was established before and 3 to 6 months after M3 extraction by radiographic evaluation, which was compared between two groups.

Results

The incidence of severe pain and mouth-opening limitation was significantly lower in the LLLT group than that in the control group. The amount of bone formation in the LLLT group was higher than that in the control group 3 months after the operation, and the difference was statistically significant. But the difference was not statistically significant 6 months after surgery.

Conclusion

LLLT may alleviate postoperative complications and improve early osteogenesis. It is a viable option for use in the treatment of osseous defects distal to mandibular second molars following extraction of impacted third molars.

Automated Prediction of Extraction Difficulty and Inferior Alveolar Nerve Injury for Mandibular Third Molar Using a Deep Neural Network

Extraction of mandibular third molars is a common procedure in oral and maxillofacial surgery. There are studies that simultaneously predict the extraction difficulty of mandibular third molar and the complications that may occur. Thus, we propose a method of automatically detecting mandibular third molars in the panoramic radiographic images and predicting the extraction difficulty and likelihood of inferior alveolar nerve (IAN) injury. Our dataset consists of 4903 panoramic radiographic images acquired from various dental hospitals. Seven dentists annotated detection and classification labels. The detection model determines the mandibular third molar in the panoramic radiographic image. The region of interest (ROI) includes the detected mandibular third molar, adjacent teeth, and IAN, which is cropped in the panoramic radiographic image. The classification models use ROI as input to predict the extraction difficulty and likelihood of IAN injury. The achieved detection performance was 99.0% mAP over the intersection of union (IOU) 0.5. In addition, we achieved an 83.5% accuracy for the prediction of extraction difficulty and an 81.1% accuracy for the prediction of the likelihood of IAN injury. We demonstrated that a deep learning method can support the diagnosis for extracting the mandibular third molar.

CBCT Radiological Features as Predictors of Nerve Injuries in Third Molar Extractions: Multicenter Prospective Study on a Northeastern Italian Population

Background: Neurological alterations are one of the main complications occurring after the third molar extractions. The aim of this prospective multicenter cohort study was to find out Cone Beam Computed Tomography (CBCT) features and distribution of neurological complications in patients undergoing lower third molar surgery and to determine the radiological and patient-related factors that could be correlated to the occurrence of inferior alveolar and lingual nerves injury. Material and Methods: 378 patients who underwent lower third molar extraction from March 2018 to March 2019 were included. Clinical and radiological data were collected. CBCT features were recorded following Maglione et al. classification. Symptoms and characteristics of patients who experienced neurological alterations were evaluated. Results: 193 patients needed a second-level radiological exam (CBCT). In these patients, the most common feature was Maglione class 3: a higher frequency of apical or buccal mandibular canals in direct contact with the tooth was observed. 3.17% of the patients developed a neurological complication. Maglione class 4, increased age, and operative time were all positively correlated with neurological alterations. Conclusions: while the buccal or apical position of the mandibular canal was the more common findings, the lingual position was found to have a higher correlation with a negative outcome. Age and operative time were also found to be risk factors for developing nerve injury in the considered population.

Flapless Surgical Approach to Extract Impacted Inferior Third Molars: A Retrospective Clinical Study

This study aimed to compare a flapless surgical approach (FSA) with a traditional envelope flap (traditional approach (TA)). Every patient was treated with two approaches: TA and FSA. The primary outcome variables were both the discomfort during the post-operative convalescence and the correct final recovery of the impacted area. The secondary outcome variable was the average duration of the surgery. Post-operative pain and oedema were recorded. The measurements of soft tissue interface toward the distobuccal edge of the second molar were taken by periodontal probe before surgery (baseline) and 8 weeks after surgery. Statistical software was used to evaluate the data; a p-value < 0.05 was considered statistically significant. Twenty-four teeth of 12 patients (six Caucasian males and six Caucasian females, aged 23 ± 4 (17-30) years) with both lower impacted third molars (Ms3) were analysed. Considering an alpha error 0.05 that sample size allows power from 0.80 to 0.90, depending on the variable evaluated. Concerning attached gingiva, oedema and pain, the linear mixed model resulted in a statistically significant difference between the TA and FSA (p = 0.003; p < 0.01; and p = 0.018, respectively). Conversely, the model did not show a difference (p = 0.322) if pocket probing depth was considered. The FSA procedure was faster (p < 0.05) than the TA procedure (17 min and 8 s (±6 s) vs. 28 min and 6 s (±4 s), respectively). The results suggest that the FSA could be a suitable option for improving the surgical removal of lower Ms3. However, additional randomized controlled trial studies are necessary to confirm the reliability of our procedure and to verify its suitability in more complex Ms3 classifications.

The Evaluation of Further Complications after the Extraction of the Third Molar Germ: A Pilot Study in Paediatric Dentistry

Some authors suggest germectomy to prevent the impaction of mandibular third molars, which can cause anterior crowding. The aim of the study, conducted with 2 years of follow-up, was to clarify when the extraction of the germ of the third molar is optimal, together with possible post-operative complications. A new surgical approach was performed through the application of a combined suture, which can provide better wound healing. The study was performed on 25 patients with a mean age of 15.44 ± 2.06. Based on orthodontic and surgical indications, 46 germectomies were performed. Follow-ups were conducted after 1 week, 2 weeks, 4 weeks, 1 year and 2 years. All procedures were carried out by the same operator and were standardized. Data analysis was conducted using R-Software. Statistical evaluation used the chi-squared test and the Monte Carlo test. The level of significance was set as 0.05. Results showed that out of 46 germectomies, the prevalence of complications was 4.2% for two patients (8%). Both complications were observed in male patients. In the first case, the patient (at Nolla stage 7) showed delayed onset infections after four weeks; in the second case, the patient (at Nolla stage 6) showed bleeding immediately after surgery and suture. With reference to delayed onset infections, no statistically significant association was found among gender (χ² = 0.719; p = 0.396), germ development stage (χ² = 2.595; p = 0.658) or Winter's classifications (χ² = 0.046; p = 0.829); similarly, no significant associations were found among bleeding, gender (χ² = 0.719; p = 0.396), germ development stage (χ² = 2.595; p = 0.658) or Winter's classification (χ² = 0.046; p = 0.829). From our results, it is also possible to state that post-operative complications following germectomy of the mandibular third molar germ in adolescence occur in a significantly reduced percentage of patients, so this oral surgery treatment becomes a reliable surgical technique in adolescence.