Surgical experience and patient morbidity after third molar removal

Learning Curve in the Extraction of Impacted Lower Third Molars: A Prospective Cohort Study

INTRODUCTION

Third molar removal is one of the most common surgical procedures in dentistry. Therefore, it is important to evaluate the learning curve of dentists undergoing surgical training. Thus, the aims of this study were to assess the performance of oral surgery residents in third molar extractions based on operative time and the occurrence of incidents/complications, and to determine which variables are associated with surgical difficulty.

MATERIAL AND METHODS

A prospective cohort study was carried out in adults requiring an impacted lower third molar extraction. All procedures were performed by residents of a master's degree in Oral Surgery and Implantology. The outcome variables were operative time and surgeon-reported difficulty. A descriptive, bivariate and multivariate analysis was performed.

RESULTS

One hundred and 74 patients were operated on by six students. Similar performance was observed among the surgeons. Although a significant improvement in operative time was seen after 10 cases, a non-significant decreasing trend of incidents was also found. The multivariate analysis revealed an association between difficulty with crown/root sectioning and impaction against the second molar.

CONCLUSIONS

At least 10 lower impacted third molar extractions performed by postgraduate students with experience in tooth extractions are required to improve the operative time. Incidents seem to decrease slightly with the number of procedures performed. Surgical difficulty seems to be related to the need for crown/tooth sectioning and greater impaction against the second molar. Further studies are required to confirm these findings.

Evaluation of the usefulness of platelet-rich fibrin (PRF) in mandibular third molar surgery with 3D facial swelling analysis: a split-mouth randomized clinical trial

BACKGROUND

Third molar surgery is associated with various postoperative complications (PC). Different strategies, including the application of platelet-rich fibrin (PRF), have been implemented to reduce PC. Digital technologies have proven useful in objectively assessing postoperative facial swelling. This study aimed to evaluate the effect of PRF on reducing facial swelling after lower third molar surgery using a 3D face scanner.

METHODS

A randomized split-mouth clinical trial was set up and 32 patients (18 to 32 years), requiring extraction of both mandibular third molars, were recruited at the Oral Surgery Clinic of the Magna Graecia University of Catanzaro. The primary predictive variable was the application or not of PRF plugs and membranes in the post-extraction socket. Primary outcome variable was facial swelling recorded with a face scanner preoperatively (T0), after three (T1) and seven (T2) days. Qualitative and quantitative data analysis were conducted following an automated and standardized imaging analysis workflow using the 3D Slicer software. Secondary outcome variables were trismus, recorded by measuring the maximum buccal opening with a caliper, pain, recorded using a visual analogue scale (VAS), and duration of the surgery. Descriptive and bivariate analysis were performed by setting the significance level [Formula: see text] = 0.05.

RESULTS

All patients exhibited a significant increase in facial swelling at T1, followed by a subsequent reduction from day 3 to day 7, with a slight persistence of edema observed on the seventh day. No significant data emerged from the statistical analysis conducted. Linear differences in PRF group reported improved values of postoperative swelling only in the T1-T2 and T0-T2 phases of analysis. Volumetric differences favored PRF group compared with control group in all phases. VAS was lower in PRF group only at T2, compared with control group.

CONCLUSIONS

Application of PRF in post-extraction sockets showed effectiveness in reducing facial swelling. Its advantages, including accessibility, cost-effectiveness, and absence of adverse reactions, make it an optimal treatment choice in reducing post-surgical sequelae.

Permanent lingual nerve injury after dental procedures: a retrospective study of 228 patients

Lingual nerve injury (LNI) is a rare, serious complication and previous studies include limited numbers of cases. The aim of this retrospective study was to report the neurosensory outcomes for a large patient cohort with permanent LNI and correlate the mechanism of injury (surgical vs non-surgical) to neurosensory characteristics. Demographics, procedural parameters, mandibular third molar (M3) position, surgeon type, neurosensory test results, and symptoms were recorded for 228 patients and analysed. The majority were female (67.1%). Overall, 59.6% of LNIs were caused by M3 removal and 36.4% by local anaesthesia. Complete loss occurred more frequently in surgical LNIs (P = 0.013). The presence of pain did not differ significantly, however the burning type of pain was significantly more frequent in non-surgical LNIs (P = 0.008) along with altered gustation (P = 0.025). The most common M3 position related to LNI was distoangular (40.4%), class III (63.2%), level A (58.1%) (Winter/Pell and Gregory classifications). The majority of patients undergoing M3 removal were >24 years. A total of 71.7% showed no sign of recovery and 5.5% reported further impairment in their condition. Overall, nine patients underwent microsurgical repair. This study presents neurosensory characteristics potentially decisive for timely referral of operable LNIs.

Assessment of Changes in the Outcome of Autogenous Tooth Grafts Over Time: A Clinical Study Evaluating Periodontal Healing in Bone Defects After Lower Third Molar Removal

BACKGROUND

The removal of impacted lower third molars (ILTMs) is associated with bone defects in the distal area of second molars. Different methods have been described to minimize these defects.

PURPOSE

The primary objective was to assess changes in probing depth (PD) over time (up to 36 months) between test (grafted) and control (ungrafted) groups; the graft was obtained from the extracted ILTM.

STUDY DESIGN, SETTING, SAMPLE

This split-mouth randomized clinical trial was conducted at the Postgraduate Course in Oral Surgery of the Faculty of Dentistry of the Complutense University of Madrid. Adult patients requiring bilateral ILTM extraction with adjacent second molars were recruited, excluding pregnant/lactating women, patients in treatment with nonsteroidal anti-inflammatory drugs and patients with periodontal diseases.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

The predictor variable was the graft technique. The bone defect after ILTM removal was treated with autogenous tooth graft (ATG) in the test group, leaving the control group ungrafted.

MAIN OUTCOME VARIABLE

PD on the distobuccal, distomedial, and distolingual surfaces was recorded in both groups and averaged at baseline (T0), 3 (T1), 6 (T2), and 36 months (T3) postoperatively.

COVARIATES

Sex, age, surgical time, ILTM situation and position between groups were assessed.

ANALYSES

ANOVA repeated measures for comparisons between groups and the Friedman test for comparisons within the groups over time were applied. Statistical significance was established with a confidence interval of 95% (P < .05).

RESULTS

The sample comprised 22 patients (6 males, 16 females) with a mean age of 21.68 ± 2.19 years; 44 ILTM extractions were performed. Statistically significant differences in PD average were found between groups (P < .001, 95% confidence interval) at 3 (1.63 ± 0.29), 6 (1.76 ± 0.3), and 36 months (1.74 ± 0.36). Reductions from T0 to T3 of 2.74 ± 0.28 (P < .001) and 0.54 ± 0.3 (P = .43) were observed in test and control groups, respectively.

CONCLUSION AND RELEVANCE

ATG placed on the distal surface of lower second molars and almost completely filling the extraction socket improved PD 3, 6 and 36 months after ILTM. Furthermore, no significant changes in PD were observed over time; no major complications occurred. ATG appears to be a viable alternative graft material for this procedure.

Is the third molar the most frequently extracted tooth? A population-based study utilizing dental panoramic radiographs in adults

OBJECTIVES

The study aimed to examine the authenticity of the often-mentioned statement that the third molar is the most frequently extracted tooth. This finding has not been shown previously in a large population-based sample.

MATERIALS AND METHODS

Data comprised a nationally representative sample of 6082 panoramic radiographs taken from adults in the cross-sectional Health 2000 Survey. From the radiographs, all missing teeth were recorded. Information on congenital agenesis of individual teeth was retrieved from two published meta-analyses. Primary outcome was the frequency of missing teeth by tooth type. Explanatory variables were age, sex, and the jaw (maxilla/mandible). Statistical analyses included χ2 test and binomial logistic regression.

RESULTS

Mean age of participants (46% men, 54% women) was 53 years (SD 14.6; range 30‒97 years). Missing teeth occurred more often in women than in men (P < 0.001). The third molar was most frequently missing and the canine least frequently. In the maxilla and mandible, the third molar was missing more often than each of the other tooth types up to the age of 80 years (P < 0.01).

CONCLUSIONS

When considering the rates of congenital agenesis of individual teeth, it is concluded that the third molar remained the most common tooth extracted up till the age of 80 years.

CLINICAL RELEVANCE

The third molar is the most common target for extraction, but also the most common tooth associated with malpractice claims, and therefore, calls for skills, adequate equipment, and other resources for a successful extraction.

Development of a risk prediction model for surgical site infection after lower third molar surgery

BACKGROUND

There is little evidence regarding risk prediction for surgical site infection (SSI) after lower third molar (L3M) surgery.

METHODS

We conducted a nested case-control study to develop a multivariable logistic model for predicting the risk of SSI after L3M surgery. Data were obtained from Hokkaido University Hospital from April 2013 to March 2020. Multiple imputation was applied for the missing values. We conducted decision tree (DT) analysis to evaluate the combinations of factors affecting SSI risk.

RESULTS

We identified 648 patients. The final model retained the available distal space (Pell & Gregory II [p = 0.05], Pell & Gregory III [p < 0.01]), depth (Pell & Gregory B [p < 0.01], Pell & Gregory C [p < 0.01]), surgeon's experience (3-10 years [p = 0.25], <3 years [p < 0.01]), and simultaneous extraction of both L3M [p < 0.01]; the concordance-statistic was 0.72. The DT analysis demonstrated that patients with Pell and Gregory B or C and simultaneous extraction of both L3M had the highest risk of SSI.

CONCLUSIONS

We developed a model for predicting SSI after L3M surgery with adequate predictive metrics in a single center. This model will make the SSI risk prediction more accessible.

Effect of Third Molar Surgery on Sleep Health Parameters of Young Adults: An Observational Study

Background and Objectives: The role of surgical extraction of the third molar in patients' sleep quality remains unclear, although it is one of the most common oral surgical procedures. The aim of this study is to assess the changes in patient-reported sleep health outcomes after third molar surgery and to investigate any associations between sleep parameters and post-extraction pain. Materials and Methods: Young adults without known comorbidities who were in need of mandibular third molar surgical extraction were included. All participants completed a sleep diary, the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI) and Athens Insomnia Scale (AIS) questionnaires, which were used to assess sleep habits, daytime sleepiness, sleep quality and insomnia severity one week before and after extraction. In addition, a visual analog scale was completed postoperatively to assess the perception of pain. Results: Out of 75 patients who completed the study protocol, 32 (42.7%) were males and 43 (57.3%) were females, with a mean age of 24.01 (±3.43) years. Postoperatively, statistically significant higher scores were observed for PSQI [4.85 (±2.32) before vs. 5.39 (±2.75) after, p = 0.041], AIS [5.56 (±3.23) before vs. 6.91 (±4.06) after, p < 0.001] and average weekly number of nocturnal awakenings [2.01 (±3.72) before vs. 4.19 (±5.20) after, p < 0.001] but not for ESS, average weekly sleep duration and average weekly sleep onset latency. Pain perception was increased in patients who slept worse on almost all seven postoperative days, although this did not reach statistical significance. Conclusions: Third molar surgery impacts sleep quality and insomnia severity in the first week after extraction, while there is no effect on daytime sleepiness. The worsening of subjective sleep symptoms after extraction may be associated with an increased perception of pain.

Risk assessment of inferior alveolar nerve injury after wisdom tooth removal using 3D AI-driven models: A within-patient study

OBJECTIVE

To compare a three-dimensional (3D) artificial intelligence (AI)- driven model with panoramic radiography (PANO) and cone-beam computed tomography (CBCT) in assessing the risk of inferior alveolar nerve (IAN) injury after mandibular wisdom tooth (M3M) removal through a within-patient controlled trial.

METHODS

From a database of 6,010 patients undergoing M3M surgery, 25 patients met the inclusion criteria of bilateral M3M removal with postoperative unilateral IAN injury. In this within-patient controlled trial, preoperative PANO and CBCT images were available, while 3D-AI models of the mandibular canal and teeth were generated from the CBCT images using the Virtual Patient Creator AI platform (Relu BV, Leuven, Belgium). Five examiners, who were blinded to surgical outcomes, assessed the imaging modalities and assigned scores indicating the risk level of IAN injury (high, medium, or low risk). Sensitivity, specificity, and area under receiver operating curve (AUC) for IAN risk assessment were calculated for each imaging modality.

RESULTS

For IAN injury risk assessment after M3M removal, sensitivity was 0.87 for 3D-AI, 0.89 for CBCT versus 0.73 for PANO. Furthermore, the AUC and specificity values were 0.63 and 0.39 for 3D-AI, 0.58 and 0.28 for CBCT, and 0.57 and 0.41 for PANO, respectively. There was no statistically significant difference (p>0.05) among the imaging modalities for any diagnostic parameters.

CONCLUSION

This within-patient controlled trial study revealed that risk assessment for IAN injury after M3M removal was rather similar for 3D-AI, PANO, and CBCT, with a sensitivity for injury prediction reaching up to 0.87 for 3D-AI and 0.89 for CBCT.

CLINICAL SIGNIFICANCE

This within-patient trial is pioneering in exploring the application of 3D AI-driven models for assessing IAN injury risk after M3M removal. The present results indicate that AI-powered 3D models based on CBCT might facilitate IAN risk assessment of M3M removal.

Factors affecting number of third molars extracted in a single visit

OBJECTIVE

This cross-sectional study evaluated the number and characteristics of third molars extracted in a single visit in primary care and their associations with patient's age and sex and operator's experience.

MATERIALS AND METHODS

The data included all appointments where routine and surgical extractions of third molars were performed in 2016 in primary care of the City of Helsinki. Statistics included χ2 and Mann-Whitney U tests, and binomial logistic regression.

RESULTS

In total of 10,894 appointments, the number of extracted third molars was 12,728, yielding an average of 1.2 third molars per visit. Mean age of patients (55% women, 45% men) at extraction was 32.2 years (range 12 - 97 years). Most appointments (83.7%, n = 9,118) comprised extraction of one, 15.8% two, 0.4% three, and 0.1% four third molars. Number of teeth extracted at a time did not differ by sex. Increasing age was associated with a reduction in the likelihood of several third molar extractions in a visit (OR 0.96; 95% confidence interval (CI) 0.96-0.97). Multiple third molars were extracted significantly more likely if the operator was experienced (OR 2.32; 95%CI 1.90-2.84). Multiple extractions were also associated with the mandible, operative extractions, unerupted teeth and caries.

CONCLUSIONS

Third molars were typically extracted one at a time. In health care units, it is appropriate to consider extraction of several third molars in a single visit, if need for extraction of other third molars exist. Concentrating the extractions of younger patients on experienced operators would reduce the number of patients' visits.

Do anatomical variations of the mandibular canal pose an increased risk of inferior alveolar nerve injury after third molar removal?

OBJECTIVES

The present study aimed to assess whether anatomical variations of the mandibular canal are associated with neurosensory disturbances of the inferior alveolar nerve (IAN) following mandibular third molar removal.

METHODS

Two observers compared the detection of third molar root-nerve relations and bifurcations of the mandibular canal on panoramic radiographs and CBCT images of 201 patients undergoing removal of 357 mandibular third molars. Potential neurosensory disturbances of the IAN were surveyed ten days after surgery. Fisher's Exact was performed to correlate presence of canal variations to postoperative neurosensory disturbances. Positive and negative predictive values (PPV, NPV) and likelihood ratios (LR + , LR-) were calculated.

RESULTS

Thirteen patients reported postoperative altered sensation of the lower lip, with 2 of them having mandibular canal bifurcations on the ipsilateral side of the injury. Fisher's Exact showed that the studied mandibular canal variations were not related to postoperative neurosensory disturbances. CBCT was superior in visualization of anatomical variations of the mandibular canal. Prevalence of bifurcations was 14% on CBCT and 7% on panoramic radiographs. In both imaging modalities and for all parameters, PPVs were low (0.04 - 0.06) and NPVs were high (0.92 - 0.98), with LR ranging around 1.

CONCLUSION

In the present study, the assessed mandibular canal variations had limited predictive value for IAN neurosensory disturbances following third molar removal.

CLINICAL RELEVANCE

While a close relation between the third molar and the mandibular canal remains a high risk factor, mandibular canal variations did not pose an increased risk of postoperative IAN injury after third molar removal.