Comparison of morbidity following the removal of mandibular third molar by lingual split, surgical bur and simplified split bone technique

Incidence of lingual nerve damage following surgical extraction of mandibular third molars with lingual flap retraction: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to examine more recent data to determine the extent of lingual nerve injury (LNI) following the surgical extraction of mandibular third molars (M3M). A systematic search of three databases [PubMed, Web of Science and OVID] was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The inclusion criteria encompassed studies on patients who underwent surgical M3M extraction using the buccal approach without lingual flap retraction (BA-), buccal approach with lingual flap retraction (BA+), and lingual split technique (LS). The outcome measures expressed in LNI count were converted to risk ratios (RR). Twenty-seven studies were included in the systematic review, nine were eligible for meta-analysis. Combined RR for LNI (BA+ versus BA-) was 4.80 [95% Confidence Interval:3.28-7.02; P<0.00001]. The prevalence of permanent LNI following BA-, BA+ and LS (mean%±SD%) was 0.18±0.38, 0.07±0.21, and 0.28±0.48 respectively. This study concluded that there was an increased risk of temporary LNI following M3M surgical extractions using BA+ and LS. There was insufficient evidence to determine whether there is a significant advantage of BA+ or LS in reducing permanent LNI risk. Operators should use lingual retraction with caution due to the increased temporary LNI risk.

Surgical techniques for the removal of mandibular wisdom teeth

BACKGROUND

Pathology relating to mandibular wisdom teeth is a frequent presentation to oral and maxillofacial surgeons, and surgical removal of mandibular wisdom teeth is a common operation. The indications for surgical removal of these teeth are alleviation of local pain, swelling and trismus, and also the prevention of spread of infection that may occasionally threaten life. Surgery is commonly associated with short-term postoperative pain, swelling and trismus. Less frequently, infection, dry socket (alveolar osteitis) and trigeminal nerve injuries may occur. This review focuses on the optimal methods in order to improve patient experience and minimise postoperative morbidity.

OBJECTIVES

To compare the relative benefits and risks of different techniques for surgical removal of mandibular wisdom teeth.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health Trials Register (to 8 July 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library; 2019, Issue 6), MEDLINE Ovid (1946 to 8 July 2019), and Embase Ovid (1980 to 8 July 2019). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication.

SELECTION CRITERIA

Randomised controlled trials comparing different surgical techniques for the removal of mandibular wisdom teeth.

DATA COLLECTION AND ANALYSIS

Three review authors were involved in assessing the relevance of identified studies, evaluated the risk of bias in included studies and extracted data. We used risk ratios (RRs) for dichotomous data in parallel-group trials (or Peto odds ratios if the event rate was low), odds ratios (ORs) for dichotomous data in cross-over or split-mouth studies, and mean differences (MDs) for continuous data. We took into account the pairing of the split-mouth studies in our analyses, and combined parallel-group and split-mouth studies using the generic inverse-variance method. We used the fixed-effect model for three studies or fewer, and random-effects model for more than three studies.

MAIN RESULTS

We included 62 trials with 4643 participants. Several of the trials excluded individuals who were not in excellent health. We assessed 33 of the studies (53%) as being at high risk of bias and 29 as unclear. We report results for our primary outcomes below. Comparisons of different suturing techniques and of drain versus no drain did not report any of our primary outcomes. No studies provided useable data for any of our primary outcomes in relation to coronectomy. There is insufficient evidence to determine whether envelope or triangular flap designs led to more alveolar osteitis (OR 0.33, 95% confidence interval (CI) 0.09 to 1.23; 5 studies; low-certainty evidence), wound infection (OR 0.29, 95% CI 0.04 to 2.06; 2 studies; low-certainty evidence), or permanent altered tongue sensation (Peto OR 4.48, 95% CI 0.07 to 286.49; 1 study; very low-certainty evidence). In terms of other adverse effects, two studies reported wound dehiscence at up to 30 days after surgery, but found no difference in risk between interventions. There is insufficient evidence to determine whether the use of a lingual retractor affected the risk of permanent altered sensation compared to not using one (Peto OR 0.14, 95% CI 0.00 to 6.82; 1 study; very low-certainty evidence). None of our other primary outcomes were reported by studies included in this comparison. There is insufficient evidence to determine whether lingual split with chisel is better than a surgical hand-piece for bone removal in terms of wound infection (OR 1.00, 95% CI 0.31 to 3.21; 1 study; very low-certainty evidence). Alveolar osteitis, permanent altered sensation, and other adverse effects were not reported. There is insufficient evidence to determine whether there is any difference in alveolar osteitis according to irrigation method (mechanical versus manual: RR 0.33, 95% CI 0.01 to 8.09; 1 study) or irrigation volume (high versus low; RR 0.52, 95% CI 0.27 to 1.02; 1 study), or whether there is any difference in postoperative infection according to irrigation method (mechanical versus manual: RR 0.50, 95% CI 0.05 to 5.43; 1 study) or irrigation volume (low versus high; RR 0.17, 95% CI 0.02 to 1.37; 1 study) (all very low-certainty evidence). These studies did not report permanent altered sensation and adverse effects. There is insufficient evidence to determine whether primary or secondary wound closure led to more alveolar osteitis (RR 0.99, 95% CI 0.41 to 2.40; 3 studies; low-certainty evidence), wound infection (RR 4.77, 95% CI 0.24 to 96.34; 1 study; very low-certainty evidence), or adverse effects (bleeding) (RR 0.41, 95% CI 0.11 to 1.47; 1 study; very low-certainty evidence). These studies did not report permanent sensation changes. Placing platelet rich plasma (PRP) or platelet rich fibrin (PRF) in sockets may reduce the incidence of alveolar osteitis (OR 0.39, 95% CI 0.22 to 0.67; 2 studies), but the evidence is of low certainty. Our other primary outcomes were not reported.

AUTHORS' CONCLUSIONS

In this 2020 update, we added 27 new studies to the original 35 in the 2014 review. Unfortunately, even with the addition of these studies, we have been unable to draw many meaningful conclusions. The small number of trials evaluating each comparison and reporting our primary outcomes, along with methodological biases in the included trials, means that the body of evidence for each of the nine comparisons evaluated is of low or very low certainty. Participant populations in the trials may not be representative of the general population, or even the population undergoing third molar surgery. Many trials excluded individuals who were not in good health, and several excluded those with active infection or who had deep impactions of their third molars. Consequently, we are unable to make firm recommendations to surgeons to inform their techniques for removal of mandibular third molars. The evidence is uncertain, though we note that there is some limited evidence that placing PRP or PRF in sockets may reduce the incidence of dry socket. The evidence provided in this review may be used as a guide for surgeons when selecting and refining their surgical techniques. Ongoing studies may allow us to provide more definitive conclusions in the future.

"Piezosurgery vs bur in impacted mandibular third molar surgery: Evaluation of postoperative sequelae"

Purpose

Piezosurgery is a relatively novel, precise and safe technique of ostectomy in the domain of oral and maxillofacial surgery. Our aim was to compare the inflammatory outcomes of osteotomy using piezosurgery and conventional bur in impacted mandibular third molar (IM3M) surgery.

Subjects and method

The study implemented a randomized, double-blind, crossover design. 120 sides in 60 patients were randomly allocated to the two interventions used, viz; conventional bur and piezosurgery. The primary outcome variables evaluated were facial swelling, trismus, pain, and paresthesia. Additionally, the duration of surgery and the frequency of soft tissue injuries with the use of two techniques were also evaluated.

Results

Pain, swelling, trismus, and soft tissue injuries emerged to be significantly higher with the use of bur as compared to the piezo. The duration of surgery was significantly extended in the piezo group and no significant difference was observed in the occurrence of paresthesia between the two groups.

Conclusion

The result suggests that piezosurgical osteotomy technique is superior to conventional bur in terms of the postoperative inflammatory outcomes in IM3M surgery.

Hard Tissue Preservation in Minimally Invasive Mandibular Third Molar Surgery Using In Situ Hardening TCP Bone Filler

Background

Maintenance of hard tissue in the case of impacted third molars (M3M) with close relationship to the mandibular canal is still a surgical challenge which may be overcome using the inward fragmentation technique.

Methods

A consecutive case series of 12 patients required the extraction of 13 impacted M3M with a close relationship to the inferior alveolar nerve (IAN). Via occlusal miniflaps, M3M were exposed occlusal under endoscopic vision and removed by inward fragmentation. All patients received socket preservation with resorbable in situ hardening TCP particles to reduce the risk of pocket formation at the second molar.

Results

All 13 sites healed uneventfully. Bone height was assessed using CBCT cross-sectional reformats pre- and 3 months postoperatively. The bone height was reduced by 1.54 mm lingual (SD 0.88), 2.91 mm central (SD 0.93), and 2.08 mm buccal (SD 1.09). Differences were significant at a 0.05% level. No tissue invagination at the extraction sites was observed.

Conclusions

Major bone defects can be avoided safely using inward fragmentation surgery. The self-hardening bone filler appears to enhance the mineralization of the intrabony defect.

Adjacent tooth trauma in complicated mandibular third molar surgery: Risk degree classification and digital surgical simulation

Analysis of adjacent tooth resistance is essential in wisdom teeth extraction to prevent adjacent tooth trauma, however it lacks adequate attention nowadays. This study aims at suggesting special extraction methods based on adjacent tooth resistance analysis for prevention of adjacent tooth damage. In this study, 136 complicated mandibular third molars extracted using piezosurgery were reviewed and classified based on the adjacent teeth resistances shown in orthopantomogram (OPG) during their mesio-distal rotations: degree I refers to teeth with no adjacent teeth resistance; degree II refers to teeth with resistance released after mesial-half crown sectioning; degree III refers to teeth which still had resistance after mesial-half crown sectioning. With the use of surgical simulations using cone beam computerized tomography (CBCT) reconstruction, all teeth in degree I were designed to rotate mesio-distally; 86.36%(38/44) teeth in degree II were designed to rotate mesio-distally after mesio-half crown sectioning; 69.09%(36/55) teeth in degree III were designed to rotate bucco-lingually. All teeth were extracted successfully, and only one adjacent tooth was subluxated due to the incomplete bone removal. Our study suggested that in order to prevent adjacent teeth trauma, complete bone removal is of importance, and impacted teeth with higher adjacent teeth trauma risks should consider bucco-lingual rotations.

Postsurgical consequences in lower third molar surgical extraction using micromotor and piezosurgery

Background:

One of the most critical and crucial steps in surgical extraction is cutting the bone or osteotomy, for which many techniques are used, e.g., chisels and mallet, rotary instruments, and ultrasound bone-cutting instruments. If they are not used judiciously, they can be hazardous.

Objectives:

To assess the efficiency of piezosurgery unit over micromotor while performing surgical extraction of lower third molars by assessing the time taken for the surgery and measuring postoperative parameters such as pain, trismus, and swelling.

Materials and Methods:

Thirty patients having bilateral impacted third molars with the same difficulty index were selected for the study. One side surgical removal was done using micromotor and other side by piezosurgery with an interval of 15 days. After each surgery, time taken to finish was measured and patients were followed up on postoperative days 1, 3, 5, 7, and 15 for assessing pain, trismus, and swelling. Data obtained were statistically analyzed.

Results:

The mean time taken for the micromotor group is 37.90 min whereas by the piezosurgery group is 54.63 min, showing a statistically significant difference (P < 0.001). Furthermore, there is statistically significant difference (P < 0.001) in the level of pain, trismus, and swelling on postoperative days 1, 3, 5, and 7. Even the intragroup comparison of piezosurgical group for trismus and swelling showed no statistically significant difference on postoperative day 7, indicating faster recovery of trismus and swelling. On postoperative day 15, there was no difference in any parameter in both groups indicating complete symptom-free recovery in both groups.

Conclusion:

It takes more time to perform surgical extraction of third molars when piezosurgical unit is used. Despite that, it causes less pain postoperatively with faster improvement in trismus and quicker reduction in swelling.

Surgical techniques for the removal of mandibular wisdom teeth

BACKGROUND

The surgical removal of mandibular wisdom teeth is one of the most common operations undertaken in oral and maxillofacial surgery. The most common indication for surgery is infection about a partially erupted tooth that is impacted against bone or soft tissues. Other indications include unrestorable caries, pulpal and periapical pathology, fracture of the tooth and cyst development, amongst others. Most commonly the benefits of surgical removal of a wisdom tooth include alleviation of the symptoms and signs of pericoronitis and its potential consequences. However, surgery is frequently associated with postoperative pain, swelling and trismus. Less commonly complications include infection, including dry socket, trigeminal nerve injuries and rarely fracture of the mandible.

OBJECTIVES

To compare the relative benefits and risks of different techniques for undertaking various aspects or stages of the surgical extraction of mandibular wisdom teeth.

SEARCH METHODS

We searched the Cochrane Oral Health Group's Trials Register (to 21 March 2014), CENTRAL (The Cochrane Library 2014, Issue 1), MEDLINE (OVID) (1946 to 21 March 2014) and EMBASE (OVID) (1980 to 21 March 2014). We searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. There were no restrictions regarding language or date of publication in the electronic searches.

SELECTION CRITERIA

RCTs comparing surgical techniques for removal of mandibular wisdom teeth.

DATA COLLECTION AND ANALYSIS

Two review authors conducted assessment of relevance, risk of bias and data extraction. Study authors were contacted for additional information. RRs were used for dichotomous data and MDs for continuous data, unless the event rate was very low and Peto ORs were used. The pairing of the split-mouth studies was taken into account in the analysis for both dichotomous and continuous outcomes, and parallel group and split-mouth studies were combined using the generic inverse variance method. Random-effects models were used provided there were more than three studies (fixed-effect models otherwise).

MAIN RESULTS

A total of 35 trials (2569 patients) were included. The interventions under consideration fell into seven broad categories, with many comparisons including only a small number of trials. Twenty-one of the trials were assessed at high risk of bias, the remaining 14 as unclear. The results are described in the summary of findings tables.Triangular flaps were associated with a 71% reduction in alveolar osteitis at one week (RR 0.29, 95% CI 0.11 to 0.78; three trials, moderate quality) and reduction in pain at 24 hours (MD -0.21, 95% CI -0.32 to -0.10; two trials, moderate quality) compared with envelope flaps. There was no evidence of a difference in overall infection rates, in maximum mouth opening or in permanent sensation. However, there was some evidence that residual swelling after one week was slightly increased in the triangular flap groups compared to envelope flap types (MD 0.66 mm, 95% CI 0.26 to 1.07; two trials, low quality). We found no data on temporary sensation, or adverse events.There was low quality evidence from two studies, looking at the use of a retractor during third molar surgery, to indicate more cases of temporary altered sensation (up to one month) when a retractor was used (Peto OR 5.19, 95% CI 1.38 to 19.49; two trials, low quality). One study reported that this did not persist for more than six months in either group. We found no data for use of a retractor on other primary outcomes or adverse effects (including fracture of the mandible).Due to the small number of studies, the different comparisons evaluated, the variable outcomes reported and the paucity of useful data for all primary outcomes we were not able to draw any conclusions concerning bone removal in third molar surgery.There was insufficient evidence from single studies of very low quality on irrigation method (manual versus mechanical) or irrigation volume (low or high) to determine whether there were differences or not for the outcomes of alveolar osteitis or postoperative infection. We found no data for any of the other primary outcomes.There was insufficient evidence (low to very low quality) that any wound closure technique (primary versus secondary) was superior to another for the outcomes of alveolar osteitis, postoperative infection or maximum mouth opening achieved after seven days, or reactionary bleeding. There was evidence that secondary wound closure was associated with reduced pain at 24 hours (MD 0.79, 95% CI 0.35 to 1.24; four trials, moderate quality) and slightly reduced swelling after one week (MD 0.33, 95% CI 0.09 to 0.57; seven trials, moderate quality).We found no data on other primary outcomes.There was some evidence that the use of a surgical drain was associated with less postoperative swelling (MD -0.90, 95% CI -1.62 to -0.19; five trials, moderate quality) and greater maximum mouth opening one week after surgery (MD 3.72 mm, 95% CI 2.84 to 4.59; two trials, moderate quality). There was insufficient evidence from a single study (low quality) to determine whether the presence of a drain made any difference to pain at 24 hours postoperation. There were no data for the other primary outcomes.Although two RCTs compared coronectomy with complete extraction, flaws in the design and the unit of analysis of these studies meant that there were no reliable data available for inclusion.

AUTHORS' CONCLUSIONS

The thirty-five included trials looked at a range of different surgical techniques. The comparisons related to seven broad aspects of the surgical procedures for impacted mandibular third molars: type of surgical flap raised, use of retractors, techniques for bone removal, wound irrigation, wound closure, wound drainage, and complete/incomplete tooth removal. The quality of the body of evidence for each of these comparisons was very low to moderate due to the small number of trials and patients, and the majority of the trials being at high risk of bias (65%) with the remainder at unclear risk of bias.The evidence for making changes to surgical practice is therefore limited. However, it is useful to describe the state of the research evidence supporting practice so that surgeons can make an informed choice in adopting new techniques, or continuing with established techniques.

Piezosurgery or conventional rotatory instruments for inferior third molar extractions?

PURPOSE

The purpose of this study was to compare the discomfort and surgical outcomes of a piezosurgery device with those of rotatory instruments in lower third molar extraction.

MATERIALS AND METHODS

A split-mouth, randomized, unblinded clinical study was designed; the 2 molars had to have the same extraction difficulty score. The test side was extracted using a piezosurgery technique and the control side was extracted using a conventional handpiece. The primary endpoint was patient discomfort evaluated with the Postoperative Symptom Severity (PoSSe) scale, which was administered to each patient; secondary endpoints were pain, trismus, swelling, and surgical time evaluation. Paired-samples t test and repeated-measures analysis of variance were used to compare outcomes within patients.

RESULTS

Ten consecutive patients (6 female, 4 male; mean age, 22.4 ± 2.3 yr) were recruited. The total score on the PoSSe scale was significantly lower for piezosurgery compared with the conventional rotating handpiece (24.7 ± 10.3 vs 36.0 ± 7.6; t = -4.27; P = .002). Moreover, postoperative swelling 1 week after surgery was significantly lower for piezosurgery than for the conventional rotating handpiece (2.75 ± 0.23 vs 3.1 ± 0.39 cm; t = -2.63; P = .027).

CONCLUSIONS

Piezosurgery was associated with less postoperative discomfort and yielded better results for swelling. Piezosurgery seems to be a good technique in daily surgical practice, especially if applied in the critical steps in which safety and respect for soft tissue, bone, and nerves are necessary.

Removal of impacted mandibular third molars using an inward fragmentation technique (IFT) - Method and first results

PURPOSE

Conventional surgical extraction of impacted mandibular third molars (M3M) requires a lateral flap reflection in conjunction with lateral bone removal for outward mobilization of the tooth. The aim of this report is to outline a novel inward fragmentation technique (IFT) in conjunction with an occlusal miniflap approach to reduce the amount of bone removal to a minimum.

PATIENTS AND METHODS

Seventeen consecutive patients (7 men and 10 women; mean age 24.4 years, range 18-36 years) required the extraction of 21-impacted M3M with a close relationship to the inferior alveolar nerve (IAN). Occlusal miniflaps were used and only occlusal bone removal was performed to expose the M3M under endoscopic vision. A central space-making cavity was created followed by inward fragmentation and mobilization of the crown and subsequent root removal through the space created.

RESULTS

20 of 21 sites healed uneventfully, one late infection was observed, no permanent neurosensory lesion occurred. The mean preoperative buccal bone height was 15.5 (11-18) mm and the postoperative buccal bone height 14.7 (11-17) mm. On the 2nd day, the mean swelling level was 1.38 (0-2) on a 4 point scale, the pain level was 2.30 (0-5) on a 10 cm VAS, mean pain duration was 2.04 days.

CONCLUSION

An inward fragmentation technique allows preservation of >90% of the buccal bone height adjacent to mandibular third molars and may reduce postoperative morbidity without raising the risk of IAN lesions.

Risk factors of neurosensory deficits in lower third molar surgery: an literature review of prospective studies

This literature review assessed the risk factors linked to inferior dental nerve (IDN) and lingual nerve (LN) deficits following lower wisdom tooth surgery. A computer search of several databases with specified key words was performed. 32 articles were selected; the risk factors for IDN deficit were reported in 4 articles, LN in 9 and both IDN and LN in 19. Data were analysed statistically to evaluate the potential risk factors. Literature review showed specific radiographic signs and intra-operative IDN exposure increased the risk of IDN deficit. Raising the lingual flap significantly increased the risk of LN deficit. Unerupted tooth and lingual split technique increased IDN and LN deficit risks significantly. Age was linked to IDN and LN deficits, and deep impaction was related to IDN deficit, but no statistical tests were performed on these two risk factors owing to the heterogeneity of data from the studies. This literature review found increased age, unerupted tooth, deep impaction, specific radiographic signs, intra-operative IDN exposure and lingual split technique were risk factors for IDN deficit; increased age, unerupted tooth, distal impaction, raising of lingual flap and lingual split technique were risks factors for LN deficit in lower wisdom tooth surgery.