A systematic review of the complications of high-risk third molar removal and coronectomy: development of a decision tree model and preliminary health economic analysis to assist in treatment planning

Establishing universal sectioning depth and angle for surgical coronectomy of impacted mandibular third molars: an imaging-based study

Introduction

Coronectomy is a safer option than extraction for third molars with an increased risk of injury to the inferior alveolar nerve. However, it can still cause complications due to a lack of standardized and effective tooth sectioning techniques. We proposed a standardized protocol for third molar coronectomy involving standardized tooth sectioning parameters to minimize potential complications, surgical failure, and the need for further procedures.

Methods

The study was conducted on 69 eligible archived CBCTs. The coronal sections of the mandibular at the anterior-most level of the lower third molar were used to determine various axes and reference points. This was done to establish the target angle and depth for the coronectomy sectioning. The data on the depth and angle of the sectioning was presented in means and standard deviation. A multivariate analysis of variance was used to determine the impact of study variables on drill depth and angle. Linear regression and correlation between study variables were also used to predict the drill depth and angle.

Results

The samples included 46 males and 23 females aged from 21 to 47 years. The mean drill angle was determined as 25.01 ± 3.28. The mean drill depth was 9.60 ± 9.90 mm. The bucco-lingual tilt had a significant effect on the drill depth, F(1, 62) = 5.15, p < 0.05, but no significant impact on the drill angle, F(1, 62) = 29.62, p > 0.05. The study results suggest that a standardized sectioning protocol can be effective during surgical coronectomy procedures.

Discussion

Drilling at a 25-degree angle to a depth of 9.5 mm is advisable to obtain the desired results. This approach will ensure no remaining enamel is left, minimize the chances of root extrusion and future eruption, and improve the outcome.

Residual enamel removal to improve outcomes of mandibular third molar coronectomy: A single-center retrospective cohort study

This study aimed to analyze post-coronectomy complications, chronological root survival rate (success rate) using Kaplan-Meier analysis, and postoperative radiographic signs for root extraction. A total of 555 mandibular third molar coronectomies were clinically and radiologically evaluated (mean follow-up period, 27.2 months; range, 1 month to 10.5 years). Complications were observed in 22 (4.0%) cases. Temporary inferior alveolar nerve damage was observed in one (0.2%) case, and 21 (3.8%) retained roots required extraction between 1 and 64 months after coronectomy due to dry socket (two cases, 0.4%), primary non-wound closure (10 cases, 1.8%), secondary root exposure (seven cases, 1.3%), and submucosal root eruption (two cases, 0.4%). Residual enamel after coronectomy was more significantly found on 13 (61.9%) of 21 extracted roots than on 30 (5.6%) of 534 surviving roots. Kaplan-Meier analysis revealed an overall survival rate of 93.8% at 5 years and 92.2% at 10 years. The 5-year survival rates differed significantly (p < 0.001) between the enamel-free (97.0%) and residual enamel-attached (58.3%) roots. The Cox proportional hazards model showed a hazard ratio of 20.87 (95% confidence interval, 8.58-50.72). The long-term outcomes of coronectomy were satisfactory, and a higher success rate is expected when the enamel is completely removed during coronectomy.

The success rates and outcomes of mandibular third molar coronectomy: 167 cases

PURPOSE

The purpose of this study was to assess success rates and to report complications of coronectomy of mandibular third molars (M3M), including intra-operative failure, pain, infection, dry socket, inferior dental alveolar (IAN) and lingual nerve (LN) injuries and re-operation rates.

METHODS

Retrospective analysis of 167 coronectomies completed between January 2017 to December 2022 was undertaken.

RESULTS

The success of coronectomy was 93%. Intra-operative failure was reported to be 3.6% (n = 8). Complications accounted for pain (15%, n = 24), infection (9%, n = 15) and dry socket (3.6%, n = 6). Three patients required removal of M3M root at 3 months (n = 2) and 24 months (n = 1), accounting for 1.8% re-operation rate. A total of number of patients who suffered a nerve injury was 12; three of these were permanent (LN - 1.2%, n = 2; IAN - 0.6%, n = 1), nine were temporary (IAN - 1.2%; n = 2, LN - 2.4%; n = 4; site not specified - 1.8%, n = 3). No patients with intra-operative failure and re-operation suffered IAN or LN injury post-operatively.

CONCLUSION

Coronectomy offers a successful strategy for management of high risk M3M. The treatment outcomes can be improved with careful case selection and adjusting surgical technique, including assessment of root morphology, incomplete crown sectioning technique and avoidance of lingual retraction. Reporting of coronectomy success as a factor of surgical outcome, presence or absence of permanent IAN injury, persistent symptoms or any other long-standing complications (such as LN injury), and the need for re-operation accounting for root migration status may be a useful tool to measure coronectomy 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.

Benefits of Coronectomy in Lower Third Molar Surgery: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this study was to measure and compare coronectomy versus extraction in patients at increased risk for inferior alveolar nerve (IAN) injuries associated with third molar removal in terms of IAN injury and other complications.

METHODS

The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist. We conducted a comprehensive literature search across six databases and the gray literature from July 15 to August 01, 2022. We employed Rayyan software to identify and remove duplicate articles to ensure data integrity. Our research followed the strategy patient (P), intervention (I), comparison (C), outcome (O), and study (S): (P) patients needing lower third molar surgery at higher risk of IAN injury; (I) surgery options, coronectomy or complete extraction; (C) comparisons included reduced risks of nerve injuries, postoperative complications (pain, infection, alveolitis), and increased risks of reoperation, root migration, and extraction; (O) desired outcomes were preventing nerve injuries and reducing other surgical complications; and (S) observational study designs (cohort, case-control). Excluded from consideration were studies involving teeth other than lower third molars, as well as reviews, letters, conference summaries, and personal opinions. To gauge the certainty of evidence, we employed the Grading of Recommendation, Assessment, Development, and Evaluation instrument, selecting the most current papers with the highest levels of evidence for inclusion. The primary outcome variable of our study centered on evaluating the incidence of IAN injury, and secondly, the lingual nerve (LN) injury, the postoperative pain, infection, localized alveolitis, the necessity for surgical reintervention, root migration, and extraction. These assessments were carried out with respect to their chosen operative technique for managing third molars, either coronectomy or extraction, as predictor variables. We also considered covariates such as age, gender, and the presence of systemic diseases in our analysis to account for potential confounding factors. The pooled data underwent rigorous analysis utilizing an inverse variance method with both random and fixed effect models by the "metabin" function in the R program's meta-package. Additionally, we assessed the risk of bias in the selected studies by utilizing the Joanna Briggs Institute's Critical Appraisal Checklist for Studies Reporting Prevalence Data and the Critical Appraisal Checklist for Case Reports.

RESULTS

Of the 1,017 articles found, after applying the inclusion and exclusion criteria, 42 were included in this study (29 cohort and 13 case-control studies), including 3,095 patients from 18 countries. The meta-analysis showed that coronectomy reduced the risk of IAN injury [OR (Odds Ratio): 0.14; 95% CI (confidence intervals): 0.06-0.30; I2 (inconsistency index) = 0%; P = .0001], postoperative pain (OR: 0.97; 95% CI: 0.33-2.86; I2 = 81%; P = .01), and alveolitis (OR: 0.38; 95% CI: 0.13-1.09; I2 = 32.2%; P = .01) when compared to complete tooth extraction. However, it also highlighted a greater risk of reintervention (OR: 5.38; 95% CI: 1.14-25.28; I2 = 0.0%; P = .01).

CONCLUSIONS

This study has demonstrated that coronectomy is associated with a decreased risk for IAN injury and decreased pain and localized alveolitis when compared to complete tooth extraction. However, it is essential to acknowledge the higher likelihood of requiring reintervention with coronectomy. Therefore, clinicians should carefully consider the advantages and potential drawbacks of both techniques and tailor their choices to the unique clinical circumstances of each patient.

The effect of individual drilling sleeves on the precision of coronectomy tooth sections. An in vitro 3D-printed jaw model experiment

OBJECTIVES

The aim of this in vitro study was to evaluate the effect of a 3D-printed drill sleeve (DS) on the precision and duration of coronectomy sections.

MATERIALS AND METHODS

Thirty-six trainees and oral surgeons performed 72 coronectomy cuts in a 3D-printed, entirely symmetric mandible model. Coronectomy was performed freehand (FH) on one side and with a DS on the other side. The occurrence of "too superficial" (≥ 4 mm unprepared lingual tooth tissue) and "too deep" (drilling ≥ 1 mm deeper as tooth contour) cuts and sectioning times were registered.

RESULTS

In 7 cases, the sections were "too deep" with FH, while none with DS (OR: 18.56; 95%CI: 1.02-338.5; p = 0.048). The deviation between virtually planned and real cut depths was significantly greater in the FH group (1.91 ± 1.62 mm) than in DS group (1.21 ± 0.72 mm) (p < 0.001). A total of 18 "too superficial" buccolingual sections occurred with FH, while 8 cases with DS (OR: 3.50; 95%CI: 1.26-9.72; p = 0.016). Suboptimal sections did not correlate with experience (p = 0.983; p = 0.697). Shortest, suboptimal drillings were most frequently seen distolingually (OR: 6.76; 95% CI: 1.57-29.07; p = 0.01). In the inexperienced group, sectioning time was significantly longer with FH (158.95 ± 125.61 s vs. 106.92 ± 100.79 s; p = 0.038).

CONCLUSIONS

The DS effectively reduced tooth sectioning times by less experienced colleagues. Independently from the level of experience, the use of DS obviated the need for any preparation outside the lingual tooth contour and significantly decreased the occurrence of "too superficial" cuts, leaving thinner unprepared residual tooth tissue lingually.

CLINICAL RELEVANCE

Coronectomy sections may result in lingual hard and soft tissue injury with the possibility of damaging the lingual nerve. The precision of the buccolingual depth-control can be improved, while surgical time can be reduced when applying a drilling sleeve.

A New Approach for Explaining and Treating Dry Sockets: A Pilot Retrospective Study

Objective Dry socket, a common complication following a tooth extraction, is characterized by severe and radiating pain that typically begins one to four days after the extraction. Despite several risk factors, the exact cause and underlying mechanisms of dry sockets remain unclear. This study aims to propose a novel pathogenesis and management approach for dry sockets based on an infectious process. Methods The study was conducted by reviewing medical records, at a private dental clinic, of patients who fit the inclusion criteria; these patients appeared to have come between April 2022 and April 2023. The study included all patients with age ≥17 years diagnosed with dry socket that was resistant to conventional topical treatment, and who received treatment with ciprofloxacin 500 mg three times per day during the study period. Results Out of 15 patients who received treatment with ciprofloxacin 500 mg three times per day during the study period, 11 patients (73.3%) were completely relieved of symptoms within 24 hours, with no need for additional painkillers or nonsteroidal anti-inflammatory drugs (NSAIDs). In addition, two patients (13.3%) had a partial response after 48 hours, where their pain was ameliorated from severe to moderate with the use of conventional painkillers (including paracetamol and NSAIDs) and steroidal anti-inflammatory drugs such as dexamethasone (8 mg IM daily) to have total relief. On the other hand, the other two patients (13.3%) had a negative response to the treatment and were out of reach for follow-up. Conclusion These clinical outcomes, coupled with previous laboratory data, could explain all clinical aspects of dry sockets and provide substantial support for the hypothesis that an infectious mechanism plays the principal role in the pathophysiology of dry sockets.

Neurosensory Deficits of Inferior Alveolar Nerve Following Impacted Mandibular Third Molar Extraction: Comparison of One-Stage Complete Extraction with Two-Stage Partial Coronectomy Surgical Technique

Objectives

Inferior alveolar nerve neurosensory deficit is a worrisome complication of surgical extraction of impacted mandibular third molars. A novel approach using two-stage partial coronectomy has been proposed as an alternative surgical procedure to reduce this complication. This study compared neurosensory deficits of inferior alveolar nerve following impacted mandibular third molar extraction using one-stage complete extraction with the two-stage partial coronectomy technique.

Material and Methods

Subjects with mesioangular or horizontal impacted mandibular third molar with an intimate relationship with inferior dental canal who met the inclusion criteria were recruited for the study. Subjects were divided into one-stage and two-stage partial coronectomy techniques. The subjects were evaluated for the presence of inferior alveolar neurosensory deficit, and the relationships of neurosensory nerve deficit with sex, age and type of impaction.

Results

Neurosensory deficit was observed in 5 subjects (7.8%), with all cases seen in the one-stage group. This difference was statistically significant (p = 0.03). The relationship between the incidence of neurosensory deficit and age, sex, type of impaction, surgical difficulty, operating time and root morphology was not statistically significant (p > 0.05).

Conclusion

Findings from this study suggest partial coronectomy compared to one-stage complete extraction reduces the incidence of Inferior alveolar nerve neurosensory deficit.

The radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars

OBJECTIVES

The indication for removal of asymptomatic fully impacted third molars is still controversial. In this study, radiological and histological investigation of the dental follicle of asymptomatic impacted mandibular third molars was performed, aiming to provide a reference for clinical prophylactic extraction of these teeth.

METHODS

Patients with impacted mandibular third molars were included and the maximum width of the dental follicle around the crown was measured in horizontal, sagittal and coronal sections by cone beam computed tomography. The dental follicles were stained with haematoxylin-eosin, analysed by a pathologist and classified as normal, inflammatory or cystic. A Chi-squared test was used to analyse the association of the incidence of inflammation and cysts with the clinical variables of the impacted mandibular third molars.

RESULTS

Thirty-seven samples were normal dental follicles; 52 samples showed inflammatory infiltration with an incidence of 57.14%; 2 samples with a maximum dental follicle width of 2-3 mm were diagnosed as odontogenic cysts, and the incidence was 2.20%. There was no significant difference in the incidence of inflammatory and cystic dental follicles between males and females, or between different age groups (P > 0.05). With an increase of the maximum width of the dental follicle, there was a rise in the incidence and degree of infiltration of chronic nonspecific inflammation.

CONCLUSION

Asymptomatic impacted mandibular third molars tend to be extracted, especially for teeth with a 2-3 mm maximum width of the dental follicle on radiological examination.

Does the addition of cone-beam CT to panoral imaging reduce inferior dental nerve injuries resulting from third molar surgery? A systematic review

Objective

This systematic review aims to examine whether cone-beam CT (CBCT) assessment influences the incidence of nerve injury following high-risk mandibular third molar (MTM) surgery.

Study Design

Randomised controlled trials comparing two and three-dimensional imaging for assessing high-risk MTMs were included. MEDLINE, EMBASE, CENTRAL and the Dentistry and Oral Science Source (DOSS) were systematically searched along with extensive grey literature searches, hand searching of web sites, and detailed citation searching up to 3 September 2022. Risk of bias was assessed against the Cochrane Risk of Bias Tool (RoB 2.0). Certainty of the evidence was assessed using GRADE.

Results

Two authors independently screened 402 abstracts prior to full text screening of 27 articles, which culminated in seven RCTs for inclusion. Two studies were assessed as high risk of bias overall. The other five raised some concerns largely due to unblinded patients and lack of prior trial registration. Just one study reported significantly less nerve injuries following CBCT. The remaining six articles found no significant difference.

Conclusion

The seven RCTs included in this systematic review offered moderate quality evidence that CBCT does not routinely translate to reduced incidence of nerve injury in MTM removal. A single study provided low quality evidence for a consequent change in the surgical approach. Low quality evidence from 3 studies suggested CBCT does not influence the duration of third molar surgery.

Virtual consultations for oral surgery patients

BACKGROUND

Following Covid-19, many departments have incorporated teledentistry into practice. As new consultation methods are introduced, it's imperative that patients have as similar an experience with virtual consultations to ensure informed decision-making. This project evaluated patients' perceptions of video consultations and determined if patients seen virtually received the same standard of information by auditing compliance with sending patient information leaflets (PILs) following video consultation.

METHOD

The department's PILs were used to create an inclusion list for patients requiring a PIL. A retrospective audit assessed the notes of 100 video consultations for records of if PILs were sent and by what method. The department's PILs were digitalised and a clinical mailbox introduced enabling clinicians to email patients a PIL hyperlink. The audit was repeated for 88 video consultations. Patient and staff feedback was gathered via online surveys.

RESULTS

Initially, 51% of cases met the criteria requiring a PIL and 16% of patients were sent PILs. Following mailbox introduction, 53% of cases met the criteria and 94% were sent PILs, 100% via email. Patient and staff feedback was positive regarding video consultations and digital PILS. Technical difficulties were reported in 44% of cases.

CONCLUSIONS

Patients perceive virtual consultations to be a positive change and the introduction of a mailbox enhances video consultations in an efficient and cost-effective manner. Patient information can be standardised, via digital PILs, regardless of consultation type. As departments implement post-pandemic changes, utilisation of a mailbox can provide multiple improvements to care.

To prophylactically extract or not to extract partially erupted mesio-angularly impacted lower third molars?

Introduction Prophylactic removal of mesio-angularly impacted mandibular third molars (MAIM3Ms) has been discouraged by the National Institute for Health and Care Excellence in 2000. Consequently, partially erupted MAIM3Ms are retained for longer and only extracted if complications arise. The debate whether to extract prophylactically or to monitor these teeth is ongoing.Pathologies associated with retained partially erupted MAIM3Ms Retaining third molars long into adulthood has been associated with an increased risk of distal cervical caries and external root resorption of the second molar, periodontal disease and pericoronitis, among other pathologies. Although watchful monitoring can help to identify these pathologies, their nature often leads not only to a poor prognosis for the third molar, but also for the second molar, which then requires costly and time-consuming restorative or even prosthodontic work.Considering prophylactic extractions While an individual risk assessment is paramount, prophylactic removal of partially erupted MAIM3Ms has been shown to have positive effects on oral health-related quality of life, to relieve the pressure on secondary care services and to be economically feasible for the NHS.Conclusion While long-term prospective cohort studies are necessary to put an end to the ongoing controversy, patients' needs and wishes should be at the forefront of the provision of care.

Current thinking in lower third molar surgery

The removal of lower third molar teeth is one of the most common surgical procedures performed worldwide, but many concepts in this surgery have been unclear and have engendered different opinions. This paper aims to review current thinking in certain pertinent aspects of this surgery to update the reader on the most current research and synthesise it to make clinical recommendations. Topics covered include preoperative imaging, timing of removal, flap design, lingual retraction, coronectomy, lingual split, closure techniques, and use of antibiotics, steroids, and drains.

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.