Pederson scale fails to predict how difficult it will be to extract lower third molars

Distribution and impaction patterns of third molars in a sample of German population: Retrospective analysis in a high turnover maxillofacial department

BACKGROUND

The surgical removal of impacted third molars is considered a routine procedure for oral and maxillofacial surgeons. However, the distribution of impacted molars varies among different populations. A study into impaction patterns in the German population is currently not described. The aim of this retrospective study is to determine patterns of impacted third molars in a sample of German population, to identify gender and age specific differences as well as further risk factors for impacted molar extraction and to compare these results with other studies.

MATERIALS AND METHODS

The clinical findings and digital panoramic radiographs of 84 patients with a total of 243 impacted third molars that had been subjected for tooth extraction, from January to September 2023, were collected and analyzed. All third molars were analyzed according to Winter´s angulation, Pell and Gregory Score of depth and relationship to ramus. Furthermore, inferior alveolar nerve and maxillary sinus proximity were identified through a newly developed risk score and an analysis of patient´s gender and age regarding impaction patterns was performed.

RESULTS

No significant gender specific differences were found regarding the impaction patterns. Third molar angulations significantly differed regarding patient´s age (cut-off 26 years). In comparison, third molar depth, bone coverage, nerve approximity and angulation patterns differed from the results of other populations.

CONCLUSION

The results of this study can serve as a baseline for further studies of third molar impactions in the German population to minimize perioperative complications in impacted third molar surgery.

Variability in Positions and Factors Contributing to Surgical Difficulty of Impacted Third Molars

OBJECTIVES

 This study aimed to provide valuable insights into the variability of third molar positions and factors influencing their surgical time and technique.

MATERIALS AND METHODS

 This cross-sectional study included a total of 48 eligible participants, aged 18 to 45 years, diagnosed with impacted teeth, and who had undergone surgery. Exclusion criteria comprised the absence of the second molar, the presence of systemic diseases, a history of radiation therapy, and pregnancy or lactation. Participants completed a questionnaire covering demographic data, physical metrics, and information on systemic conditions and disorders. Preoperative assessments included vital sign measurements. Panoramic imaging was employed to evaluate the third molar distance to the occlusal plane, degrees of angulation, eruption space, and distance to the alveolar inferior canal. Surgical difficulty in this study was measured by two outcomes: surgical time and technique.

STATISTICAL ANALYSIS

 To assess differences in impacted third molar positions among groups, Independent samples t-test and One-way analysis of variance were used for normally distributed data without outliers; otherwise, the Mann-Whitney U test and Kruskal-Wallis H test were utilized. The Spearman's rank correlation was utilized to explore relationships between vital signs, impacted third molar positions, surgical time, and surgical technique.

RESULTS

 There were no significant differences in third molar positions between age and body mass index groups. Significant differences in distance to the occlusal plane were observed between third molars in quadrants 2 and 3 (p = 0.002) and quadrants 2 and 4 (p = 0.005). A significant difference in eruption space was found between sexes (p = 0.016). A significant negative correlation was discovered between surgical time and respiration rate per minute (p = 0.028).

CONCLUSION

 This study found that males have greater third molar eruption space than females, and maxillary third molars have a greater distance to the occlusal plane compared with mandibular third molars. The importance of vital signs as contributing factors to surgical difficulty is highlighted, emphasizing their relevance in clinical practice.

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.

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.

Effect of submucosal administration of dexamethasone on postoperative discomfort after third molar surgery

Aim

To compare the impact of submucosal dexamethasone (4 mg) administered after the onset of local anesthesia on postoperative discomfort after third molar surgery and compare the parameters with a control group that did not receive the drug.

Methods

A total of 60 patients indicated for surgical removal of impacted mandibular third molars (mesioangular, Class II or III, and position B or C) were randomly divided into two groups of 30 patients each. After the onset of local anesthesia, the first group (Group A) received a submucosal injection of 4 mg dexamethasone adjacent to the surgical site, and the control group (Group B) received no drug. Pain, swelling, and trismus were recorded at follow-up visits on the 1st, 2nd, and 7th postoperative days. Assessment of postoperative discomfort was performed by evaluating responses through a modified postoperative symptom severity scale questionnaire, which was administered to the patients on the 7th postoperative day.

Results

The difference in subjective pain values and the mean number of analgesics consumed was not significant between the groups. The difference in postoperative swelling was statistically significant on the 1st, 2nd (P < 0.0001), and 7th postoperative days (P = 0.0152). The difference in postoperative trismus was highly significant on 1st and 2nd postoperative days (P < 0.0001). The difference in the mean total quality of life (QOL) score, Eating, Appearance, Daily activity subscale (P < 0.0001), and Social Isolation subscale (P = 0.0002) was statistically significant between both groups.

Conclusion

It was found that the administration of submucosal dexamethasone resulted in significantly lesser postoperative swelling and trismus and better QOL outcomes.

Surgical difficulty and postoperative course of the third molar extraction under general anesthesia: An intervention trial

BACKGROUND

Third molar extractions are one of the most common surgical procedures in the area of ​​stomatology. However, we know that even if they are minor surgeries, they can cause a postoperative period with local and systemic repercussions. Thus, the aim of this intervention trial is to determine the relationship between clinical parameters (pain, inflammation and trismus) and serum parameters (C-reactive protein (CRP), IL-6 and fibrinogen) that are modified in the first postoperative week, and the appearance of complications after extraction with general anesthesia, using the Pederson scale.

METHODS

The research question was: Can postoperative discomfort after third molar extraction under general anesthesia be predicted using Pederson scale? An interventional trial was carried out of third molar extractions under general anesthesia in Dr. Peset University Hospital. Patient selection was performed randomized using MS Excel. Then were divided into two groups (n = 126): group A (2 complex extractions) and group B (4 extractions: 2 simple and 2 complex). All parameters were collected at the surgery and 7 days after surgery.

RESULTS

The clinical postoperative parameters showed significant differences in relation to surgical difficulty. In summary, the degree of surgical difficulty can be predicted with the Pederson scale before extracting mandibular third molars. CRP and fibrinogen levels increase significantly with the degree of surgical difficulty.

CONCLUSION

Significant differences (p < 0.001) were observed in all the intraoperative parameters according to surgical difficulty as assessed by the Pederson scale. Therefore, this scale was a good indicator to estimate the patient's postoperative period.

Can Topical Agents (Arnica and Mucopolysaccharide Polysulfate) Reduce Postoperative Pain, Edema and Trismus Following Mandibular Third Molar Surgery?

BACKGROUND

Postoperative supplemental maintenance following mandibular third molar surgery remains an area of interest.

PURPOSE

Topical agents can modulate inflammatory processes. The aim of the present study was to determine if topical application of arnica or mucopolysaccharide polysulfate (MPSP) reduces pain, trismus, and edema following the removal of impacted mandibular third molars.

MATERIALS AND METHODS

A single center randomized controlled clinical trial was conducted. The patients were randomized into three groups: the control group (standard therapy [ST]: antibiotic + nonsteroidal anti-inflammatory drugs twice a day), the arnica group (arnica + ST), and the MPSP group (MPSP + ST). The patients' pain, trismus, and edema values were measured preoperatively and on postoperative days 1, 3, 5, and 10. Sex, age, and operation time were also included. Analyses included descriptive statistics, analysis of variance, post hoc tests, and determinations of intraclass correlation coefficients. Statistical significance was set at P < .05.

RESULTS

Sixty patients with a mean age of 26.98 ± 10.88 years were included in the study; 55% were females and 45% were males. The mean operation time was 23.8 ± 3.27 minutes. According to the visual analogue scale scores (in centimeter units), the arnica and MPSP groups felt less pain than the control group until day 5 (0.6 ± 0.88, 3.75 ± 1.16, 4.75 ± 1.29, and 1.05 ± 1.10, respectively, for the arnica group; 0.35 ± 0.59, 3.25 ± 1.62, 5.0 ± 1.65, and 1.50 ± 1.32 for the MPSP group; and 1.30 ± 1.17, 5.75 ± 1.37, 7.05 ± 1.10, and 3.15 ± 1.53 for the control group; P < .05). The trismus was lower on days 1, 3, and 5 in the arnica group (-8.05 ± 2.82, -12.15 ± 3.1, and -2.15 ± 1.81, respectively) than in the control group (-12 ± 3.82, -15.65 ± 4.81, and -4±2.81, respectively) (P < .05). The edema was lower on days 1 and 3 in the MPSP group (0.95 ± 2.2 and 1.75 ± 3.7, respectively) than in the control group (2.45 ± 0.9 and 3.6 ± 0.8, respectively) (P < .05). Arnica and MPSP had similar pain-relieving action, but arnica was more effective at reducing trismus, while MPSP was more effective at reducing edema.

CONCLUSIONS

Topical application of arnica or MPSP may have a beneficial effect on relieving pain 5 days after surgery, but arnica was also effective at reducing trismus, while MPSP was also effective at reducing edema. Both arnica and MPSP reduced postoperative sequelae.

Mandibular third molar extraction: perceived surgical difficulty in relation to professional training

BACKGROUND

Establishing the level of surgical difficulty pre-operatively is an essential step in ensuring correct treatment planning. This study set out to determine whether the knowledge and experience acquired by dentists who had received different levels of training influenced, firstly, the perceived levels of difficulty of a variety of cases of mandibular third molar (MTM) extraction and, secondly, the perceived difficulty deriving from a series of factors (patient-related factors, anatomical and radiographic factors, operative factors).

METHODS

This cross-sectional, descriptive, observational study took the form of a survey. Using a visual analog scale (VAS), participants evaluated both the perceived difficulty of 30 cases of MTM extraction described by means of digital panoramic radiographs and the perceived difficulty deriving from a series of factors conditioning MTM extraction. The results underwent statistical analysis with SPSS Statistics 28.0 software. Non-parametric tests (Mann Whitney test for independent samples and the Kruskal-Wallis test) were applied.

RESULTS

A total of 389 surveys were available for analysis. Dental practioners with no surgical training saw the intervention as presenting greater difficulty. Professionals with postgraduate training in oral surgery considered patient-related factors more important than operative factors, in contrast to dentists who had not received oral surgery training.

CONCLUSIONS

Dental training has a signficant influence on the perceived difficulty of MTM extraction and also affects opinions about which factors have greater or lesser influence on surgical difficulty.

Assessment of Difficulty in Mandibular Third Molar Surgery by Lambade-Dawane-Mali's Index

PURPOSE

The evaluation of mandibular third molar (M3) difficulty is extremely important. This study aims to measure the association between preoperative Lambade-Dawane-Mali's (LDM) M3 difficulty index and postoperative assessment of difficulty score.

MATERIAL AND METHODS

This prospective cohort study included patients with impacted M3 reported to the Department of OMFS, RRK Dental College, Akola, from 2017 to 2022. The preoperative surgical difficulty was estimated using the predictor, LDM index with scores, easy (15-25), moderate (25-30), and difficult (>30). The postoperative surgical difficulty was analyzed with the primary outcome variable, total time intervention measured from the beginning of incision to the final suturing, wherein extraction was classified as easy if time (<15 minutes), moderate (15-30 minutes), and difficult (>30 minutes). The secondary outcome variable, Modified Parant's Scale (MPS), defines four levels of difficulty required for extraction of M3: Easy I (forceps extraction), Easy II (requiring osteotomy), Difficult III (coronal sectioning), and Difficult IV (complex extraction). Data were analyzed using agreement between LDM difficulty with three established criteria (time, MPS, Pederson index) and were assessed with Cohen's Kappa statistics. McNemar's test for paired data was used to assess concordance between two criteria of evaluation with a P-value <.05 was considered statistically significant.

RESULTS

The study sample included 1000 patients with a mean age of 26.7 ± 7.6 years and 456 (45.6%) females. Preoperative LDM difficulty assessed postoperatively by MPS indicated 99% were correctly identified by LDM preoperatively to have difficult and 99% easy outcomes. Inter-criteria agreement and Kappa statistics suggested a positive Kappa value (κ) and statistically significant agreement between the LDM index with perioperative time (κ = 0.8930), MPS (κ = 0.6488), and Pederson index (κ = 0.4920) at P-value 0.0001. Pair-wise comparisons of LDM criteria with perioperative time, MPS, and Pederson scale were assessed by McNemar's test, which evaluated concordance between the two criteria.

CONCLUSION

Postoperative evaluation of surgical difficulty in M3 extraction was strongly correlated with preoperative variables in the LDM difficulty-scoring index. Preoperative evaluation helps in envisaging the difficulty, planning surgical management, and helps in better time scheduling.

Post-Operative Complications and Risk Predictors Related to the Avulsion of Lower Impacted Third Molars

Background and Objectives: This prospective cohort study aimed to evaluate the onset and severity of pain and other complications following lower impacted third molar extraction and to identify potential risk predictors. Materials and Methods: Twenty-five patients were treated with at least one lower impacted third molar extraction. The primary outcome was the onset of post-operative pain, evaluated at 6 h, 12 h, 24 h, 48 h, 72 h, and 7 days. The secondary outcomes (trismus, edema, alveolitis, dehiscence, neuralgic injury, and suppuration) were recorded at 3, 7 and 21 days after oral surgery. A correlation analysis was performed to identify potential associations between patient- and tooth-related factors and VAS (Visual Analogue Scale) scale. When a statistically significant correlation was identified, a regression analysis was performed. Results: Most of the patients were female (84%) with a mean age of 25 ± 3 years; the reason for oral surgery was dysodontiasis in 60% of cases, while the most frequent Pell and Gregory class was BII (36%). The VAS scale showed the onset of mild pain at 6 h (44%), 12 h (48%), 24 h (68%) and 48 (68%) after surgery. Trismus, edema, and alveolitis were observed at 3-day (20%, 64% and 12%, respectively) and at 7-day (16%, 12% and 4%, respectively) follow-up. Neuralgic injury was reported in one case (4%). The linear regression analysis showed a statistically significant association (p < 0.05) between the duration of oral surgery and VAS scores at 6 and 12 h. Finally, the binary logistic regression identified systemic disease, Pell and Gregory classification, duration of oral surgery, VAS at 6 and 12 h, trismus, and edema at 3 and 7 days as predictive factors of post-operative complications. Conclusions: Within their limits, the results of this study suggest that the onset of post-operative complications increases in proportion to the duration of the surgical procedure.

Reliability of two difficulty indexes in predicting the surgical extraction difficulty of impacted mandibular third molars

Introduction: The aim of this study was to compare the reliability and the agreement of the Pederson and Pernambuco difficulty indexes in predicting the surgical extraction difficulty of the impacted mandibular third molars. Materials and methods: A prospective observational cohort study was conducted on 83 patients who had undergone surgical removal of impacted mandibular third molar. The difficulty of extraction was determined preoperatively according to the total scores obtained from the Pederson and Pernambuco difficulty indexes, the operative difficulty was determined by the surgical technique and the duration of extraction. The accuracy of prediction of the surgical difficulty and the degree of agreement of the two indexes were calculated. Results: The accuracy of Pederson and Pernambuco indexes in predicting the operative difficulty measured by duration of surgery was 36.1% and 55.4% respectively, and with operative difficulty measured by the technique was 21.7% and 37.3% respectively with statistically significant differences. The agreement between the 2 indexes was poor. Conclusion: Both indexes were limited in predicting the surgical difficulty of impacted mandibular third molars although the Pernambuco index was better than the Pederson index and the agreement between the two indexes was poor.

Evaluation of Third Molar Impaction Distribution and Patterns in a Sample of Lebanese Population

BACKGROUND

Classifications of impaction based on panoramic radiographs such as the ones of Pell and Gregory and Winter are essential to allow a better understanding of third molar position regarding depth and bone coverage of the impacted tooth and to evaluate the difficulties of the surgical procedures. The aim of the study was to classify upper and lower third molars teeth in a sample of a Lebanese population and compare the data to results from other studies.

MATERIALS AND METHODS

Digital panoramic radiographs of 71 patients with a total of 181 wisdom teeth from patients that had been subjected for third molars extraction, from November 2016 to November 2018, were collected and analyzed. The mean age was 26.25 years. All third molars were categorized according to Pell and Gregory by using A, B, C scores for depth in upper and lower third molars, and angulations were classified according to Winter's classification. Nonparametric normality tests evaluating age group and gender distribution were conducted by utilizing the Chi-square test for age distribution and the binomial and Kruskal-Wallis tests for gender.

RESULTS

In the Pell and Gregory classification, the lower third molars showed type B impaction as the most frequent with 66.1% for the right side and 60.3% for the left side; the maxillary third molars both showed the type C impaction as the most frequent with 63.3% for the right side and 59.2% for the left side. According to the Winter classification, lower third molars showed mesio-angulation as the most frequent angle of impaction with 41.1% for right mandibular side and 46.5% for mandibular left side; As for the maxillary third molars, the disto-angulation was the most frequent angulation seen in both maxillary right and left side teeth 53.3% and 43.2%.

CONCLUSIONS

Comparison of our results with other populations has shown similarities in certain criteria like angulation and relation to ramus, but most results varied. Thus, the current study can be taken as a baseline for further studies.

Evaluation of Infection and Effective Factors in Impacted Mandibular Third Molar Surgeries: A Cross-Sectional Study

Background and Aim. Some complications, including infection, may occur following the surgeries of impacted teeth. In order to reduce the risk of infection, it is necessary to evaluate the risk factors of infection after third molar surgeries. Although research has been published in this area, the risk factors and causes of infection are still unclear. This study aimed to investigate infection incidence and effective factors in hard tissue impacted mandibular third molar surgeries in the Iranian population. Materials and Methods. This cross-sectional study was performed on 148 patients. The incidence of infection was recorded one week, two weeks, and one month after surgery. Independent variables included age, gender, the presence of periapical radiolucent lesions measuring ≥3 mm, the caries of the adjacent second molar, education level of the surgeon, difficulty index, suture type, and flap type. The outcome variable was the incidence of infection. Results. Among the study subjects, 37.2% were male and 62.8% were female. The mean age was 25.24 ± 4.31 years at the time of surgery. Although early onset infection occurred in 3.4% of patients, none of them developed a delayed-onset infection during the four weeks after surgery. Pederson difficulty index (OR = 3.81, $P=0.03$ ) and the education level of the surgeon (OR = 0.14, $P=0.021$ ) were associated with postop infection. Conclusions. Based on the results of the current study, postop infection was rare. Furthermore, both the Pederson difficulty index and the education level of the surgeon could predict the risk of infection after impacted mandibular third molar surgeries.

[Constructions of the scale of difficulty in the extraction of impacted mandibular third molars by using Delphi method]

OBJECTIVE

To evaluate the relevant indicators affecting difficulty in the extraction of impacted mandibular third molars and score difficulty of different operation and risk indicators, so as to build an intuitive and accurate scale to help operators make more accurate analysis and prediction of difficulty before the operation.

METHODS

Based on literature and the clinical review, the difficulty indicators of tooth extraction were summarized. Firstly, 10 doctors from Peking University School and Hospital of Stomatology who had been engaged in alveolar surgery for a long time established an expert nominal group, and then rated whether the summarized indicators needed to be retained in the form of face-to-face questionnaires. A level 1 and 2 item frame for evaluating difficulty in the tooth extraction was formed after discussion; Then Delphi method was used to send a questionnaire to 30 experts by e-mail. After two rounds of scoring and modification, the scale of difficulty in the extraction of impacted mandibular third molars was formed.

RESULTS

The recycling rate of two rounds of questionnaires was 100.0%, which showed that the experts were very enthusiastic about the study; The authority coefficients (Cr) of the two rounds of Delphi expert consultation were both 0.92, which showed that the results were representative and authoritative. After two rounds of grading and revision, the variable coefficient (CV) decreased and the Kendall's concordance coefficient (W) increased, which were statistically significant: In the first round, the CV was 0.24 and W was 0.56 (P < 0.001), and in the second, the CV was 0.19 and W was 0.72 (P < 0.001), which indicated that there was a good convergence among the expert opinions. Finally, a scale of difficulty in the tooth extraction containing 12 items at level A and 37 items at level B was formed, including operation difficulty indicators, risk difficulty indicators and common difficulty indicators.

CONCLUSION

Based on comprehensive literature retrieval, the study has put forward the concept that difficulty in the extraction of impacted mandibular third molars is composed of operation difficulty and risk difficulty. Using Delphi method, the long-term clinical experience and professional knowledge of experts are transformed into quantitative indicators as a scoring scale. The scale has certain representativeness and authority.

Correlation of Variables for WHARFE Assessment and Pederson Difficulty Index for Impacted Mandibular Third Molar Surgery-A Prospective Clinical Study

Objectives

To assess the correlation of factors of WHARFE assessment and Pederson difficulty index for impacted mandibular third molar surgery.

Study Design

A comparative study of difficult factors utilizing Pederson WHARFE and WAR lines was performed involving patients undergoing surgical removal of mandibular third molars for 100 such teeth.

Results

The Spearman's rho correlation run to determine the relationship between Pederson difficulty index and WHARFE assessment values showed a strong, positive monotonic correlation at the 0.05 level (2-tailed; rs = 0.242, n = 100, p = 0.015 < 0.05).

Conclusion

The study has revealed WHARFE assessment to be a more reliable and consistent measure for the radiological evaluation of surgical difficulty over the contemporary Pederson difficulty index.

Piezo-surgery technique and intramuscular dexamethasone injection to reduce postoperative pain after impacted mandibular third molar surgery: a randomized clinical trial

Background

Surgical extraction of the impacted mandibular third molar is commonly associated with postoperative pain, swelling, and trismus. Usually, rotatory instruments like burs have been used for osteotomy, while Piezosurgery is an innovative technique introduced to overcome the weaknesses related to the conventional technique. In addition, Dexamethasone administration before the extraction of impacted third molars is an efficient way to reduce postoperative pain due to robust anti-inflammatory activity. The purpose of the study is to evaluate the effect of piezo-surgery and dexamethasone injection on postoperative sequelae after the surgical extraction of impacted mandibular third molars, and ultimately to compare their effect on reducing postoperative pain.

Methods

A randomized controlled clinical trial was conducted with a sample of 80 patients. Participants were divided into four groups: Group 1 (Conventional rotatory), Group 2 (Conventional rotatory with 8 mg dose of dexamethasone 30 min before surgery), Group 3 (Piezo-surgery), and Group 4 (Piezo-surgery with 8 mg dose of dexamethasone 30 min before surgery). The outcome variables were surgical working time calculated in minutes, maximal mouth opening measured in millimeters using Vernier Caliper at baseline and day 3 and postoperative pain assessed using a Visual Analog Scale (VAS) on days 1, 3, and 7.

Results

The surgical working time was longer in piezo-surgery groups compared with the conventional rotatory instruments groups (15.82 ± 3.47 vs 23.33 ± 2.54; p value < 0.0001). The lowest reduction in mouth opening between baseline and 3rd-day post-op was found in the Piezo-surgery with Dexamethasone group (mean difference = 5.0, SD = 3.9, p value < 0.0001) followed by the Piezosurgery without Dexamethasone group (mean difference = 5.8, SD = 4.5, p value < 0.0001) and the highest average was reported by the Conventional rotatory without Dexamethasone (mean difference = 9.7, SD = 4.5, p value < 0.0001. In the four groups, the mean pain score was highest on the 1st day and gradually decreased over the following days. Comparison of the 1st and 3rd postoperative pain between groups revealed a lowest mean pain score in the Piezo-surgery with Dexamethasone group, followed by Conventional rotatory with Dexamethasone group and a highest mean score in the Conventional rotatory without Dexamethasone group (p value < 0.0001).

Conclusion

The association of Piezosurgery osteotomy and Dexamethasone intramuscular injection could be an effective combination to reduce postoperative pain and trismus after impacted third molar surgery.

Trial registration: NCT04889781 (https://clinicaltrials.gov/), Date of Registration: 17/05/2021 (retrospectively registered), https://clinicaltrials.gov/ct2/show/NCT04889781?term=NCT04889781&draw=2&rank=1

The influence of flap design on patients' experiencing pain, swelling, and trismus after mandibular third molar surgery: a scoping systematic review

Third molar removal surgery usually comes accompanied by postoperative discomfort, which could be influenced by the surgical approach chosen. This scoping systematic review aimed at compiling the available evidence focused on the influence of flap design, including envelope flap (EF), triangular flap (TF), and modified triangular flap (MTF), on postoperative pain, swelling, and trismus, as primary outcome measures, and any result mentioning healing promotion or delay, as secondary outcome measure, after mandibular third molar extraction surgery. An electronic search, complemented by a manual search, of articles published from 1999 to 2020 was conducted in the Medline (PubMed), EMBASE and Web of Science databases including human randomized controlled trials, prospective, and retrospective studies with at least 15 patients. The risk of bias of the included studies was assessed either with the Cochrane’s Risk of Bias tool or with the Newcastle-Ottawa scale. Every step of the review was performed independently and in duplicate. The initial electronic search recovered 2102 articles. After applying the inclusion criteria, 12 articles were included. For patient’s perceived postoperative pain, TF and MTF frequently reported better results than EF. For swelling, the literature is divided, despite a trend favoring EF. For trismus, data showed that its occurrence is mostly associated with the duration of the surgery rather than with the chosen flap. For healing, the limited data is inconclusive. Finally, randomized studies showed a high risk of bias, whereas nonrandomized studies were mostly of good quality and low risk of bias. Although there was no clear consensus regarding the influence of different flap designs for third mandibular molar extraction on postoperative clinical morbidities; the surgeon’s experience, estimated surgical difficulty, molar position and orientation, and surg ery duration should be considered when choosing among the different flap designs.

The Pattern of Mandibular Third Molar Impaction and Assessment of Surgery Difficulty: A Retrospective Study of Radiographs in East Baltic Population

Classifications of impacted teeth allow defining the type and degree of retention, as well as assessing the degree of difficulty of the procedure. The aim of this study was to conduct retrospective analysis of the degree of retention and difficulty in the surgical removal of impacted mandibular third molars in the clinical material of the Department of Oral Surgery in 2013–2018. This study included 1585 dental panoramic radiographs of patients of the Department of Oral Surgery, who reported in 2013–2018, in order to perform surgical removal of the impacted mandibular third molar. Based on dental panoramic radiographs, the degree of retention was determined based on classifications according to Winter, according to Pell and Gregory, according to Tetsch and Wagner, and according to Asanami and Kasazaki. The difficulty of the procedure was also assessed based on the Pederson index. The most common types of lower wisdom tooth impaction are as follows: in Winter’s classification, mesial-angular impaction; in Tetsch and Wagner’s classification, oblique medial-angular impaction; in Pell and Gregory’s classification, impaction grade 2A; and in Asanami and Kasazaki’s classification, 3A and anterior inclination. In most cases of surgical removal of an impacted tooth, the anticipated difficulty of the procedure was rated as very difficult.

Review of Difficulty Indices for Removal of Impacted Third Molars and a New Classification of Difficulty Indices

BACKGROUND

A number of efforts have been made to establish a reliable assessment model for the surgical removal of impacted third molars. Although many such models have been proposed, none is considered universally applicable, and controversy remains. The earlier attempts were based exclusively on radiographic variables, whereas recent evidence is associated with nonradiographic and demographic variables.

PURPOSE

This article aimed to prepare review of the relevant literature to summarize the important indices given till date, tabulating only new indices as old indices are mentioned in almost all text books, their merits and demerits and their specificity and sensitivity (if assessed in the literature). In addition to it, authors also aimed to introduce a new descriptive classification of all indices based on pre- and postoperative assessment and further classify based on clinical, radiographic and demographic factors, surgical technique and time. This article will be of academic and practical help for residents and clinicians.

METHOD

A literature search was conducted in Medline, PubMed, Google Scholar, Science Direct and Cochrane electronic database with keywords-impacted mandibular third molar, difficulty indices, validity of, sensitivity, specificity. No publication year limit was used. The abstracts of the articles were retrieved, reviewed and sorted based on the following inclusion and exclusion criteria. Articles which include a new index, validate difficulty index, compare two or more difficulty indices, specificity and sensitivity of particular index are included. Duplicate articles, articles on complication, flap design, drug study, radiographic relation of inferior alveolar nerve, suturing, classification, only assessing factor affecting difficulty of third molar surgery are not included.

RESULTS

Total 39 (36 articles + 3 books) are included. A total of 20 individual indices were found in the literature; each has been described in brief in this review. These indices are also listed in chronological order with their specificity and sensitivity if accessed in the literature.

CONCLUSION

There is a definite need to derive and validate an user-friendly index that could be used for preoperative prediction of difficulty. To the best of our knowledge, this review including all indices till date and classification proposed is the first on this subject.

Single-channel electroencephalography and its associations with anxiety and pain during oral surgery: a preliminary report

Background

This study aimed to assess the course of anxiety and pain during lower third molar (LTMo) surgery and explore the role of mobile and single-channel electroencephalography under clinical and surgical conditions.

Methods

The State-Trait Anxiety Inventory (STAI), Corah's Dental Anxiety Scale (DAS), and Interval Scale of Anxiety Response (ISAR) were used. The patient self-rated anxiety (PSA), the pain felt during and after surgery, EEG, heart rate (HR), and blood pressure (BP) were assessed.

Results

The Attention (ATT) and Meditation (MED) algorithms and indicators evaluated in this study showed several associations. ATT showed interactions and an association with STAI-S, pain during surgery, PSA level, HR, and surgical duration. MED showed an interaction and association with DAS, STAI-S, and pain due to anesthesia. Preclinical anxiety parameters may influence clinical perceptions and biological parameters during LTMo surgeries. High STAI-Trait and PSA scores were associated with postoperative pain, whereas high STAI-State scores were associated with more pain during anesthesia and surgery, as well as DAS, which was also associated with patient interference during surgery due to anxiety.

Conclusions

The findings suggest that single-channel EEG is promising for evaluating brain responses associated with systemic reactions related to anxiety, surgical stress, and pain during oral surgery.

What Are the Effects of Methylprednisolone Injection Into the Masseter and Gluteal Muscle on Pain, Edema and Trismus After Impacted Lower Third Molar Surgery? A Randomized Clinical Trial

PURPOSE

Methylprednisolone is widely administered after impacted third molar surgery. This study compared the effect of methylprednisolone injection into the masseter and gluteal muscle on pain, edema, and trismus after impacted lower third molar surgery.

METHODS

This was a single-blind placebo-controlled randomized clinical trial. Sixty patients with an impacted lower third molar were included and randomly assigned into 3 groups. Each group received 1 of the following medications half an hour before surgery: Group I: 40 mg methylprednisolone injected into masseter muscle; Group II: 40 mg methylprednisolone injected into gluteal muscle; Group III: considered as control group with no intervention. The level of pain was recorded 1, 5, and 7 days after surgery using visual analog scale, and the amount of edema was measured 5 and 7 days after surgery using ultrasound imaging. The amount of trismus was measured 5 and 7 days after surgery based on the distance between incisor edge of upper and lower centrals. Friedman test was used to compare the level of pain, trismus and edema in each group at different times. Kruskal-Wallis test was used to compare the level of pain, trismus and edema among different groups at each time. Significance level was set at P < .05.

RESULTS

There was no significant difference among the 3 groups (a total of 60 patients (31 females and 29 males), aged 19 to 35 years) considering edema (P = .250, CI = 0.22 ± 0.42), trismus (P = .337, CI = -5.93 ± 2.22) and pain (P = .285, CI = -2.91 ± 0.40) relief.

CONCLUSIONS

Postsurgical pain, edema, and trismus were not reduced by intramuscular injection of methylprednisolone before third molar surgery.

Postoperative effects of intra-alveolar application of 0.2% chlorhexidine or 1% hyaluronic acid bioadhesive gels after mandibular third molar extraction: a double-blind randomized controlled clinical trial

OBJECTIVE

The aim of this study was to analyze the postoperative effects of intra-alveolar applications of 0.2% chlorhexidine (CHL) or 1% hyaluronic (HA) acid bioadhesive gels following the extraction of mandibular impacted third molars (MITMs).

MATERIALS AND METHODS

In this double-blind randomized controlled clinical trial, 90 patients with one asymptomatic MITM were randomized into three group (n = 30 per group): group 1 (0.2% CHL), group 2 (1% HA), and group 3 (control). Visual analogue scales (VAS) were used to assess postoperative pain 24, 48, and 72 h and 7 days after surgery. Postsurgical complications were recorded: trismus, alveolitis osteitis, infection, or hematoma.

RESULTS

In order from least to greatest, postoperative pain at all evaluation times was 0.2% CHL < 1% HA < control. At 24 h, statistically significant differences were found between both study groups and the control groups (0.2% CHL/control: P = 0.001; 1% HA/control: P = 0.010). At 48 and 72 h, significant differences were only found between 0.2% CHL and the control group (P = 0.229 and P = 0.046, respectively). At 7 days, no significant differences were found between any groups. Comparing the incidence of postoperative trismus, alveolitis osteitis, infection, or hematoma, although complications were more frequent in the control group, no statistical differences between groups were found (P > 0.050).

CONCLUSIONS

Both 0.2% CHL and 1% HA bioadhesive gels applied intra-alveolarly minimize the postoperative complications after MITM extraction. Further research is necessary to confirm the present results.

CLINICAL RELEVANCE

This study might help to reduce the postsurgical complications in patients after MITM extraction.

Bucco alveolar bone thickness of mandibular impacted third molars with different inclinations: a CBCT study

PURPOSE

To compare the buccal alveolar bone thickness of mesioangulated mandibular impacted third molars (MITM) with buccal versus lingual inclination using cone-beam computed tomography (CBCT).

METHODS

This retrospective cross-sectional study evaluated 69 individuals (39 women and 30 men) who presented a total of 101 mesioangulated MITM according to the Winter classification and in B position according to the Pell and Gregory classification. The average age was 22.99 ± 3.94 years. The superior, medial and inferior alveolar thickness regarding buccal (n = 44) or lingual (n = 57) mandibular third molar inclination were measured. T test or Mann-Whitney U test and finally, a multiple linear regression were applied (p < 0.05).

RESULTS

The buccal alveolar bone thickness of mesioangulated mandibular impacted third molars was significantly greater in the group with lingual inclination compared to the group with buccal inclination, in the superior region (6.21 ± 3.27 vs. 4.85 ± 3.06; p = 0.036). The lingual inclination significantly influenced the buccal alveolar bone thickness in the middle region (p = 0.011).

CONCLUSIONS

The mesioangulated MITM in B position with lingual inclination have a greater thickness of the superior and medial buccal alveolar bone than the MITM with buccal inclination. These results should be considered during MITM diagnosis and surgical planning.

Effects of pain catastrophizing and anxiety on analgesic use after surgical removal of impacted mandibular third molars

Background

In dentistry, pain is a factor that negatively affects treatments and drug use. The aim of this study was to evaluate the correlations of the postoperative analgesic use with pain catastrophizing and anxiety in patients who underwent removal of an impacted mandibular third molar.

Methods

We recruited 92 patients who underwent the extraction of impacted mandibular third molar. In this study, the Pederson index was used to preoperatively determine the difficulty of surgical extraction. Patients were asked to note the number of analgesics used for 7 postoperative days. Patients were divided into two groups based on the Pain Catastrophizing Scale: low and high score groups. State-Trait Anxiety Inventory-trait and State-Trait Anxiety Inventory-state questionnaires were used to determine the anxiety levels of the patients. The obtained data were examined to evaluate the correlations of pain catastrophizing and anxiety with the postoperative analgesic use.

Results

In this study, 92 patients, including 60 women and 32 men, were recruited. The analgesic use was higher in women than in men but with no significant difference (P > 0.05). Pain Catastrophizing Scale scores were higher in women than in men but with no significant difference (P > 0.05). The analgesic use was higher in patients with high pain catastrophizing than in those with low pain catastrophizing but with no significant difference (P > 0.05). State-Trait Anxiety Inventory-trait scores were higher in women than in men but with no significant difference. However, state-Trait Anxiety Inventory-state scores were significantly higher in women than in men (P < 0.05).

Conclusion

The postoperative analgesic use may be higher in patients who catastrophize pain than in others. Knowing the patient's catastrophic characteristics preoperatively would contribute to successful pain management and appropriate drug selection.

Patient, radiological, and operative factors associated with surgical difficulty in the extraction of third molars: a systematic review

The aim of this systematic review was to determine the patient, radiological, and operative variables associated with surgical difficulty in the extraction of third molars, according to a visual analogue scale completed by the surgeon, operative time, or surgical technique. Searches of the PubMed (MEDLINE), Scopus, and Cochrane Library databases were conducted by two independent reviewers. Randomized and non-randomized clinical trials and prospective cohort studies evaluating surgical difficulty in the extraction of impacted mandibular or maxillary third molars according to patient, radiological, and operative variables were included. The full texts of 21 of the 859 articles initially retrieved were analysed, and 15 articles were included in the final systematic review. All 15 reported prospective cohort studies. The following variables were found to be on the spectrum of highly difficult or complex cases: older patient age and being overweight (patient variables), surgeons with little experience and the use of complex surgical techniques requiring tooth sectioning linked to hard tissue impaction (operative variables), and adverse radiological factors such as deep impaction, unfavourable angulation and root morphology, and a close relationship with the second molar, maxillary sinus, or the inferior alveolar nerve canal (radiological variables).

Does Mandibular Gonial Angle Predict Difficulty of Mandibular Third Molar Removal?

PURPOSE

Predicting the difficulty of impacted mandibular third molar (IM3M) removal remains a controversial issue because many variables have been associated with increased operation time. Thus, the main objective of this study was to assess the influence of the gonial angle on the surgical difficulty of IM3M extraction.

PATIENTS AND METHODS

A prospective cohort study of patients requiring IM3M removal was conducted. The gonial angle measured with a goniometer was considered the primary predictor variable. The primary outcome variable was operation time. Difficulty also was recorded by surgeons using a 100-mm visual analog scale (VAS). Postoperative complications (pain, swelling, and trismus at 48 hours and 7 days) were registered as secondary outcome variables. A descriptive bivariate statistical analysis, Pearson correlations and scatter plots, and an explanatory multiple linear regression model were performed. Significance was set at P < .05.

RESULTS

The sample comprised 60 participants (17 men and 43 women) with a mean age of 25.2 years (standard deviation, 7.1 years). No significant correlations were found between the gonial angle and operation time, VAS difficulty score, and postoperative complications. Regression analysis confirmed this lack of effect of the gonial angle. The operation time was significantly affected by surgical experience (P = .016) and patient age (P = .009), whereas the 100-mm VAS difficulty score was only related to surgical experience (P = .001).

CONCLUSIONS

The gonial angle is not related to the surgical difficulty of IM3M removal. Moreover, this variable is not associated with the occurrence of postoperative complications. According to the findings in this cohort, surgical experience and patient age are the only variables significantly related to increased operation time.

Development of a New Index to Assess the Difficulty Level of Surgical Removal of Impacted Mandibular Third Molars in an Asian Population

PURPOSE

This study aimed to develop a straightforward and accurate index of impacted third molar removal difficulty through analyzing various factors to assess the difficulty level of impacted mandibular third molar (IMTM) extraction.

MATERIALS AND METHODS

This prospective cohort study included 203 patients who required IMTM extraction. All patients were selected using the preset selection criteria. The present study assessed operation difficulty with operating time. A mathematical model and regression analysis were performed to explore 6 main factors (age, number of roots, degree of bone impaction, shape of roots, and impaction angle and its relation). Appropriate correction coefficients were obtained to formulate a new IMTM removal difficulty predictive index. Consistency of the κ value was checked to evaluate performance.

RESULTS

Degree of bone impaction had the highest correlation coefficient (0.576), followed by shape of roots (0.359), and the lowest correlation coefficient was for number of roots. The Pederson index for these 203 patients showed that 75, 76, and 52 patients had low, moderate, and high difficulty levels, respectively, whereas the new index categorized 78, 85, and 40 patients as having low, moderate, and high difficulty. Comparison of the Pederson index and new index with operating time showed κ agreements of 65.30 and 77.9% (P < .01), suggesting that the prediction results of the new index are more objective and accurate.

CONCLUSION

The newly proposed index is straightforward and efficient and exhibited promising results in κ agreement. Because of its straightforward nature, it is better suited for Chinese public hospitals with a large volume of patients who require alveolar surgery. The detection of predictor variables could be useful for graduate students, professionals, and general dental practitioners contemplating IMTM removal to assess the difficulty level of IMTM extraction.

Relationship Between Surgical Difficulty of Third Molar Extraction Under Local Anesthesia and the Postoperative Evolution of Clinical and Blood Parameters

PURPOSE

To determine whether the Pederson scale is a good predictor of the surgical difficulty of third molar extraction and establish whether such surgical difficulty is directly related to the postoperative course as assessed from clinical (pain, inflammation, and trismus) and blood (C-reactive protein, interleukin-6 [IL-6], and fibrinogen) parameters.

MATERIALS AND METHODS

A prospective observational study was conducted of 2 groups of patients who underwent simple or surgical third molar extraction under local anesthesia. Clinical and blood parameters and possible complications were recorded for 1 week after extraction.

RESULTS

A total of 118 patients were studied. Surgical difficulty as predicted by the Pederson scale showed significant differences (P < .001) for osteotomy, sectioning of the crown, root sectioning, duration of intervention, type of closure, and number of sutures. Under conditions of equal surgical difficulty, the evolution of the groups was similar for pain and inflammation, although trismus was greater for patients subjected to surgical extraction. After the operation, marked increments were recorded in serum C-reactive protein, IL-6, and fibrinogen, although without differences among different levels of surgical difficulty. The probability of complications was similar in the routine and surgical extraction groups. The appearance of complications was the principal cause of alterations in clinical and blood parameters.

CONCLUSIONS

The Pederson scale is a good predictor of the surgical difficulty of third molar removal as assessed from different clinical and blood parameters. C-reactive protein, IL-6, and fibrinogen concentrations varied considerably after the operation but were not influenced by the degree of surgical difficulty. The presence of postoperative complications was associated with a poorer evolution of clinical and blood parameters.

Effect of One-Suture and Sutureless Techniques on Postoperative Healing After Third Molar Surgery

PURPOSE

The wound closure technique for lower third molar surgery (LTMS) is an operative factor that influences wound healing and the occurrence of early postoperative complications. The present study investigated 2 closure techniques (partial closure using 1 suture and the suture-less technique) after use of a modified buccal envelope flap for LTMS.

MATERIALS AND METHODS

We performed a prospective, randomized, double-blind, split-mouth, controlled trial. Partial closure using 1 suture was compared with closure using the sutureless technique. The surgical sites were divided into 2 groups, group A (1 suture) and group B (sutureless). Each patient received both treatments at the same surgery. During the first postoperative week, all patients were asked to daily assess pain, facial swelling, and bleeding using self-assessment scales. All patients attended the follow-up appointment at 1 week to objectively assess facial swelling and wound healing and at 1 month to assess wound healing. An analysis of data was performed using the statistical package SPSS Statistics, version 24 (IBM Corp, Armonk, NY). A P value ≤ .05 was accepted as statistically significant.

RESULTS

A total of 37 patients with bilateral impacted third molars of similar surgical difficulty were recruited. Of the 37 patients, 34 successfully completed the study. The results showed a statistically significant difference between the 2 techniques in postoperative pain at days 5 (P = .046) and 6 (P = .034); socket healing at 1 week (P = .002) and 1 month (P = .014), and soft tissue healing at 1 week (P = .016).

CONCLUSION

We found the 1-suture technique for LTMS to be superior to the sutureless technique in the reduction of postoperative pain and improving wound healing during the early postoperative period. We found no difference between the 2 techniques in the reduction of postoperative swelling.

The potential of heart rate variability for exploring dental anxiety in mandibular third molar surgery

An objective method to recognize patient psychology using heart rate variability (HRV) has recently been developed and is increasingly being used in medical practice. This study compared the potential of this new method with the use of conventional surveys measuring anxiety levels in patients undergoing impacted third molar (ITM) surgery. Patient anxiety was examined before treatment in 64 adults who required ITM surgery, using two methods: measurement of HRV and conventional questionnaire surveys (state section of the State-Trait Anxiety Inventory (STAI-S) and Dental Fear Survey (DFS)). Both methods were assessed for their respective abilities to determine the impact of personal background, the amount of information provided, and the surgical procedure on patient psychology. Questionnaires and HRV yielded the same finding: dental experience was the single background factor that correlated with patient anxiety; the other factors remain unclear. The STAI-S showed a significant relationship between the information provided to the patient and their anxiety level, while the DFS and HRV did not. In addition, HRV demonstrated its ability to assess the effects of the surgical procedure on patient psychology. HRV demonstrated great potential as an objective method for evaluating patient stress, especially for providing real-time information on the patient's status.

Evaluation of Kharma scale as a predictor of lower third molar extraction difficulty

Background

The Evaluation of the degree of lower third molar (L3M) extraction difficulty is extremely important for both clinicians and patients. This study aimed to evaluate the validity of a new index (Kharma scale) as a preoperative predictor index of the difficulty of surgical removal of impacted L3M.

Material and Methods

Extraction difficulty of a series of 49-impacted L3M was predicted preoperatively by Kharma scale, and postoperative difficulty was assessed with a modified Parant scale.

Results

The sensitivity of Kharma scale, as a predictor of difficulty, was 18.2% and the specificity was 68.4%. Likelihood ratios for the Kharma categories also indicated that the scale is of little value for predicting a difficult extraction. There was no significant association between the Kharma score and duration of operation, but high-modified Parant scores were significantly associated with longer operations.

Conclusions

The proposed Kharma scale was unreliable as preoperative predictor of the L3M extraction difficulty, and both radiological and clinical information must be taken into account.

Key words:Kharma scale, prediction scale, lower third molar, extraction difficulty.

Extraction of mandibular third molars: proposal of a new scale of difficulty

We evaluated the accuracy of a new scale of surgical difficulty for the extraction of impacted mandibular third molars, which includes consideration of previously underestimated variables. Two hundred patients with impacted third molars were enrolled, and a preoperative clinical and radiographic assessment of difficulty was made by an oral surgeon using the new index. Five oral surgeons with similar degrees of experience then evaluated the surgical difficulty during operation. The kappa test and weighted kappa were used to evaluate the level of agreement between the preoperative and postoperative evaluations. This was 0.73, which indicated a substantial concordance between the preoperative and postoperative assessments of difficulty indicated by the new scale. The linear weight of kappa was 0.8 and the quadratic weight 0.87. We recommend this new scale of surgical difficulty for the extraction of impacted third molars for use in clinical practice.

Pernambuco index: predictability of the complexity of surgery for impacted lower third molars

This study aimed to develop and validate an index of surgical difficulty for the removal of impacted lower third molars. The study was performed in two steps. The first was a cross-sectional analysis of clinical, demographic, and radiographic variables collected from patients undergoing the removal of an impacted lower third molar between 2008 and 2012. The second step was a prospective cohort study involving the same surgical procedures to validate the index; this was performed between 2013 and 2016. Univariate regression analysis was applied, followed by multiple linear regression analysis. A total of 753 surgical procedures were analyzed in the first stage, which led to the identification of the most important variables and their levels of significance. The index was then applied to 280 surgical procedures. The preoperative difficulty was in concordance with the index results in all cases. Among cases with a low level of difficulty, 93.1% had been indexed as low difficulty; likewise, among cases with a high level of difficulty, there was 87.9% concordance with the index. With the use of reference statistics in the development and quality assurance processes, this validated index has proven to be a reliable and easily applicable instrument, with high sensitivity, specificity, and accuracy.

Predictive factors of difficulty in lower third molar extraction: A prospective cohort study

Background

Several publications have measured the difficulty of third molar removal, trying to establish the main risk factors, however several important preoperative and intraoperative variables are overlooked.

Material and Methods

A prospective cohort study comprising a total of 130 consecutive lower third molar extractions was performed. The outcome variables used to measure the difficulty of the extraction were operation time and a 100mm visual analogue scale filled by the surgeon at the end of the surgical procedure. The predictors were divided into 4 different groups (demographic, anatomic, radiographic and operative variables). A descriptive, bivariate and multivariate analysis of the data was performed.

Results

Patients’ weight, the presence of bulbous roots, the need to perform crown and root sectioning of the lower third molar and Pell and Gregory 123 classification significantly influenced both outcome variables (p< 0.05).

Conclusions

Certain anatomical, radiological and operative variables appear to be important factors in the assessment of surgical difficulty in the extraction of lower third molars.

Key words:Third molar, surgical extraction, surgical difficulty.

Which factors are associated with difficult surgical extraction of impacted lower third molars?

Objectives

The aim of this retrospective study was to investigate factors associated with increased difficulty in the surgical extraction of impacted lower third molars and to improve identification of difficult cases.

Materials and Methods

A total of 680 patients who required 762 surgical extractions of impacted lower third molars from 2009 to 2014 were enrolled in the study. Demographic factors, clinical factors, radiographic factors, surgical extraction difficulty, and presumed causes of difficulty were collected. Data were statistically analyzed using IBM SPSS Statistics version 23.

Results

Age, sex, depth of impaction, and blurred radiographic image influenced difficulty in surgical extraction. The position of the impacted tooth influenced surgical difficulty, especially when it was accompanied by other factors.

Conclusion

It is challenging to design a reliable and practical instrument to predict difficulty in surgical extraction of impacted lower third molars. To identify very difficult cases, root investigation using computed tomography is advised when impacted tooth position suggests difficult extraction.

Variations in the buccal-lingual alveolar bone thickness of impacted mandibular third molar: our classification and treatment perspectives

Selecting either buccal or lingual approach for the mandibular third molar surgical extraction has been an intense debate for years. The aim of this observational retrospective study was to classify the molar based on the proximity to the external cortical bone, and analyze the position of inferior alveolar canal (IAC) of each type. Cone-beam CT (CBCT) data of 110 deeply impacted mandibular third molars from 91 consecutive patients were analyzed. A new classification based on the mean deduction value (MD) of buccal-lingual alveolar bone thickness was proposed: MD≥1 mm was classified as buccal position, 1 mm>MD>−1 mm was classified as central position, MD≤−1 mm was classified as lingual position. The study samples were distributed as: buccal position (1.8%) in 2 subjects, central position (10.9%) in 12 and lingual position (87.3%) in 96. Ninety-six molars (87.3%) contacted the IAC. The buccal and inferior IAC course were the most common types in impacted third molar, especially in lingually positioned ones. Our study suggested that amongst deeply impacted mandibular third molars, lingual position occupies the largest proportion, followed by the central, and then the buccal type.

A simple score for evaluation of the complexity of third-molar extractions

OBJECTIVES

This article proposes a simple preoperative score to evaluate the complexity of tooth extractions of the third mandibular molar and to estimate the time involved.

STUDY DESIGN

We consider 11 factors (demographic, anatomic, and radiologic) that favor the surgery and that can be identified through standard clinical and radiologic examinations. The number of favorable factors (NFF) relative to each patient constitutes his/her score. The analysis of 1500 extractions performed by various surgeons with experience from 2 to 25 years evidences a quadratic inverse correlation between NFF and the time required for the surgery.

RESULTS

The shape of the time distribution suggests the existence of 3 major classes of patients characterized by time of 4 to 10 minutes, 11 to 20 minutes, and 21 to 40 minutes. The corresponding NFF brackets, as identified by their frequency distributions and validated by the receiver operating characteristic curve method, are 5 to 11 (mean [SD], 6.8 [1.6]), 2 to 4 (3.3 [1.3]), and 0 to 1 (0.8 [1.0]), respectively.

CONCLUSIONS

Our results show the good performance of this score as a predictor of the surgical time and its applicability in daily practice regardless of operator experience, background, and level of surgical ability.

Four osteotomy methods with piezosurgery to remove complicated mandibular third molars: a retrospective study

PURPOSE

Piezosurgery has been used widely in oral and maxillofacial surgery, but there has been no report systematically describing an osteotomy method with piezosurgery for complicated mandibular third molar removal. The aim of this study was to introduce 4 osteotomy methods using piezosurgery and evaluate their effects.

MATERIALS AND METHODS

A retrospective study was conducted of patients with a complicated impacted mandibular third molar requiring extraction. The predictor variable was the extraction technique. Four osteotomy methods using piezosurgery were tested according to different impaction types: method 1 involved complete bone removal; method 2 involved segmental bone removal; method 3 involved bone removal combined with tooth splitting; and method 4 involved block bone removal. Outcome variables were success rate, operative time, major complications (including nerve injury, mandible fracture, severe hematoma, or severe edema), and serious pyogenic infection. Data were analyzed using descriptive statistics.

RESULTS

The study was composed of 55 patients with 74 complicated impacted mandibular third molars. All impacted mandibular third molars were removed successfully. The average surgical time was 15 minutes (range, 8 to 26 minutes). Thirty-eight molars (51.4%) were extracted by method 1, 18 molars (24.3%) by method 2, 12 molars (16.2%) by method 3, and 6 molars (8.1%) by method 4. Two cases (2.7%) developed postoperative infections and recovered within 1 week using drainage and antibiotic administration.

CONCLUSION

The 4 osteotomy methods with piezosurgery provide effective ways of removing complicated impacted mandibular third molars.

Patient anxiety and surgical difficulty in impacted lower third molar extractions: a prospective cohort study

Encountering patients who are fearful and anxious is common in dental practice and these factors can increase the complexity of dental procedures. A prospective cohort study was performed to assess whether patient anxiety influences the difficulty of impacted lower third molar extraction and to identify other predictive factors of surgical difficulty; 102 extractions done under local anaesthesia were assessed. Several preoperative variables were recorded (demographic, anatomical, and surgical) and patient anxiety was assessed through the use of various questionnaires. Extraction difficulty was measured using the operation time (OT) and a 100-mm visual analogue scale (difficulty VAS) completed by the surgeon. Patients with deep impacted third molars that required bone removal and tooth sectioning showed higher levels of preoperative anxiety. Significant correlations were found between questionnaire scores and the surgical difficulty (OT and difficulty VAS). OT was also related to age, depth of impaction, third molar angulations, proximity of the third molar roots to the mandibular canal, hard and soft tissue coverage, and the need to perform an ostectomy and tooth sectioning. Impacted lower third molar extraction is significantly more difficult in anxious patients. Other demographic, radiological, and surgical factors were also found to be significantly related to the surgical difficulty.

Effect of age, sex and level of surgical difficulty on inflammatory complications after third molar surgery

BACKGROUND

Patients' factors such as age and sex and surgical variables such as level of difficulty have been linked with surgical outcome in third molar surgery. The aim of this study was to determine the effect of these variables on inflammatory complications in patients undergoing third molar surgery.

METHODS

Patients referred to our institution for surgical extraction of their impacted lower third molar between January 2007 and December 2008 were the subjects of the study. Patients' demographics as well as types of impaction, indication and level of difficulty based on Pederson criteria were obtained. Post operative pain, swelling and mouth opening limitation were evaluated at day 1, day 2, day 3, day 5 and 1 week after the surgery and analyzed. A p value of less than 0.05 was considered significant.

RESULTS

A total of 150 patients aged 16-38 years (25.9 ± 4.47) met the inclusion criteria. Male accounted for 66 (44.0 %) while females were 84 (56.0 %), giving male to female ratio of 1:1.3. Age, sex and difficulty index had no effect on pain and trismus throughout the periods of postoperative evaluation (p > 0.05). Postoperative swelling was not affected by gender but patients above 25 years who had high scores of difficulty index had more facial swelling.

CONCLUSION

The results of this study shows that age, gender and the level of surgical difficulty have no effect on pain and mouth opening limitation after third molar surgery.

Assessment of factors associated with surgical difficulty during removal of impacted maxillary third molars

PURPOSE

Estimating the difficulty of removing third molars is a common dilemma. However, the estimation of the difficulty associated with maxillary third molar surgery has not yet been defined. The aim of the present study was to determine the degree of difficulty and identify predictor variables associated with the occurrence of difficulty in the removal of impacted maxillary third molars.

MATERIALS AND METHODS

A prospective cohort study was carried out involving patients who underwent at least 1 surgical removal of an impacted maxillary third molar at the Oral and Maxillofacial Surgery Unit, University of Pernambuco (Pernambuco, Brazil). Predictor variables indicative of surgical difficulty were classified by their demographic, clinical, and radiographic aspects. Degree of surgical difficulty was categorized as low, moderate, or high based on the surgical technique used. Descriptive and bivariate statistics were computed.

RESULTS

In total, 106 patients fulfilled the eligibility criteria and 204 surgeries were performed. Patients' mean age was 22.8 ± 2.2 years and the proportion of women to men was 3:1. Approximately 20% of patients were overweight. Surgical difficulty was generally low and 5 variables were significantly associated with the occurrence of a high degree of surgical difficulty.

CONCLUSION

Surgical difficulty during the removal of impacted maxillary third molars is generally low. However, for cases with a high degree of difficulty, identification of predictor variables may be useful for students and inexperienced clinicians to consider the decision not to execute the procedure, thus avoiding complications that often require complex management.

Is Pederson Index a True Predictive Difficulty Index for Impacted Mandibular Third Molar Surgery? A Meta-analysis

The aim of this meta-analysis was to find out the clinical reliability of Pederson index in assessing the difficulty of surgery for impacted mandibular 3rd molar. The relevant articles were selected by Hand search and electronic media (Medline, Pubmed, Embase Cochrane library, ISI web of science) from Jan 2000 to Dec 2010. All the relevant articles were properly screened and findings were extracted from the articles. Pederson index had shown low sensitivity and specificity in predicting the difficulty of surgery for impacted mandibular 3rd molar. Positive and negative likelihood ratio had also shown the unreliability of Pederson index. The meta-analysis of the current literature concluded that Pederson index is not a reliable test to predict the surgical difficulty of impacted mandibular 3rd molar.

Evaluation of the agreement by examiners according to classifications of third molars

OBJECTIVES

This study recorded and evaluated the intra- and inter-group agreement degree by different examiners for the classification of lower third molars according to both the Winter's and Pell & Gregory's systems.

STUDY DESIGN

An observational and cross-sectional study was realized with forty lower third molars analyzed from twenty digital panoramic radiographs. Four examiner groups (undergraduates, maxillofacial surgeons, oral radiologists and clinical dentists) from Aracaju, Sergipe, Brazil, classified them in relation to angulation, class and position. The variance test (ANOVA) was applied in the examiner findings with significance level of p<0.05 and confidence intervals of 95%.

RESULTS

Intra- and inter-group agreement was observed in Winter's classification system among all examiners. Pell & Gregory's classification system showed an average intra-group agreement and a statistical significant difference to position variable in inter-group analysis with greater disagreement to the clinical dentists group (p<0.05).

CONCLUSIONS

High reproducibility was associated to Winter's classification, whereas the system proposed by Pell & Gregory did not demonstrate appropriate levels of reliability.