Comparison of Postoperative Outcomes Between Envelope and Triangular Flaps After Mandibular Third Molar Surgery: A Systematic Review and Meta-Analysis

Does the Lingual-Based Mucoperiosteal Flap Reduce Postoperative Morbidity Compared With the Buccal-Based Mucoperiosteal Flap After the Surgical Removal of Impacted Third Molars? A Meta-analysis Review

PURPOSE

The lingual-based mucoperiosteal flap, a novel flap, was unclear about the effects on the prognosis of surgery for impacted mandibular third molars. This study aimed to compare the lingual- and buccal-based mucoperiosteal flaps with respect to postoperative responses and complications.

MATERIALS AND METHODS

A systematic review with a meta-analysis was designed and the PubMed, Cochrane Library, EMBASE, and Web of Science databases and Google Scholar from January 1, 2000 to April 30, 2020 were searched for randomized clinical trials. The predictor variable was buccal- or lingual-based flap in the surgery, and the outcome variables were pain, swelling, trismus, operative time, and wound dehiscence. Other study variables were sex and retention depth of impacted teeth. RevMan 5.3 software was used for data analysis. Mean differences or standardized mean differences and risk ratios were computed to assess associations between 2 variables, where statistical significance was set at P < .05.

RESULTS

Seven publications met the inclusion criteria, contributing 370 subjects who had 590 teeth removed to sample. The lingual-based flap failed to significantly reduce postoperative discomfort. However, subgroup analysis revealed that subjects who underwent comma flap (a type of lingual-based flap) surgeries complained of milder pain than those who underwent buccal-based flap surgeries on day 1 (mean difference = -1.18, 95% confidence interval [CI] [-1.53, -0.83], P < .001) and day 7 (mean difference = -1.80, 95% CI [-2.13, -1.48], P < .001) after surgery. Significant differences were also observed on days 1, 3, and 7 regarding postoperative swelling and trismus (P < .01). In addition, the lingual-based flap was reported to cause a significantly lower rate of wound dehiscence (relative risk = 0.46, 95% CI [0.30, 0.69], P = .0002).

CONCLUSIONS

The lingual-based flap was associated with better primary wound closure in third molar removal. The comma flap, as a subtype, was preferable for relieving postoperative pain, swelling, and trismus over the buccal-based flap.

Effect of lingual-based flap design on postoperative pain of impacted mandibular third molar surgery: Split-mouth randomized clinical trial

Background

The extraction of third molars is one of the most common procedures in oral and maxillofacial surgery clinic. Surgical extraction involves the manipulation of both soft and hard tissues, so the patient usually experiences pain, swelling, and trismus in the immediate post-operative period. Several studies have been conducted using different types of surgical flaps to provide access with the least possible damage of soft tissues. Designing and implementing an optimum flap, which provides easier technique, better visibility, minimal post-operative complications, and best healing, is an aspired goal of every oral surgeon. This study aimed to compare lingual-based four-cornered flap with conventional triangular flap, and to evaluate its effect on post-operative pain after surgical extraction of impacted lower third molars.

Material and Methods

Seventeen patients (age ranged from 19 to 26 years) with bilateral, symmetrical impacted lower third molars (n=34) were included in the study. This was a randomized clinical trial with a split-mouth design. The impacted molars were assigned randomly, by coin flipping, to two groups: Case side with lingual-based four-cornered flap (Group A), and control side with conventional triangular flap (Group B). Away from the incision, the prognosis, surgical intervention, and postoperative procedures were exactly the same for the two groups. Postsurgical pain was assessed for 5 days using visual analogue scale (VAS) and by recording patients need for analgesics on a daily basis. Patients were also evaluated via a self-reporting questionnaire, i.e. Postoperative Symptoms Severity (PoSSe) scale, administered on the seventh postoperative day.

Results

Pain scores recorded in Group A were found to be significantly lower as compared to pain scores in Group B in the 5 postoperative days (P<0.05). Total analgesic intake in Group B was significantly higher (P<0.05). PoSSe scores were lower in Group A, however, this difference was insignificant (P>0.05).

Conclusions

According to the data of the current study and within its limits, it appeared that lingual-based four-cornered flap design was superior to the conventional triangular flap regarding the postsurgical discomfort and pain.

Key words:Impaction, third molar surgery, flap design, pain, PoSSe scale, split-mouth, RCT.

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.

Effect of drain application on postoperative complaints after surgical removal of impacted wisdom teeth-a randomized observer-blinded split-mouth clinical trial

OBJECTIVES

The aim of this randomized observer-blinded split-mouth-study is to objectively assess the influence of a rubber drain on postoperative swelling using 3D face scans as measurement method and additionally evaluate pain, trismus and complications after the osteotomy of lower third molars.

MATERIAL AND METHODS

Seventy-two patients with symmetrically impacted lower wisdom teeth were recruited. Before the operation, patients rated pain using the visual analogue scale, the interincisal distance was measured, and 3D face scans were taken with an optical scanner. Each patient underwent two procedures which were at least 30 days apart. On one side, a rubber drain was inserted randomly before closure, the contralateral control side was closed without drainage. On the third and tenth postoperative day, face scans to quantify the swelling, pain evaluation and trismus measurements were performed. Due to loss of follow-up, 32 patients were excluded which resulted in 40 out of 72 patients remaining in the study.

RESULTS

There was no statistical difference in using a drain on swelling and trismus on the third and tenth day (p > 0.05). Pain was slightly worse on the third day on the treatment side, but the difference was not significant (p > 0.05). We observed no differences in the number of wound infections.

CONCLUSIONS

The insertion of a rubber drain does not have any influence on swelling, pain or trismus and has no impact on the number of wound infections.

CLINICAL RELEVANCE

The use of a rubber drain cannot be recommended as no reduction of postoperative discomfort was detected.