Periodontal Healing Distally to Second Mandibular Molar After Third Molar Coronectomy

Third Molar Coronectomy vs Total Removal in Second Molar Periodontal Healing

OBJECTIVES

The objective of this randomised controlled trial was to compare the periodontal healing at the distal of the adjacent second molar after coronectomy or surgical removal and the surgical morbidities of the 2 techniques.

METHODS

This is a pilot study of a split-mouth randomised clinical trial comparing the periodontal healing of the adjacent second molar after coronectomy or total removal of lower third molars, which was registered with the University of Hong Kong Clinical Trial Centre as HKUCTR-2948 on 21 February 2020. Cone beam computed tomography (CBCT) scans were taken preoperatively and at 6 months postoperatively. Changes in the bone level from the cemento-enamel junction, periodontal probing depth (PPD), and clinical attachment level (CAL) at the distal of the adjacent second molar were compared. Surgical morbidities in terms of pain, infection, neurologic deficit, root exposure, and need for second surgery for removal were assessed.

RESULTS

Forty patients (22 male, 18 female) with mean age of 26.7 years were evaluated at 6 months postoperatively. Both coronectomy and total removal groups demonstrated statistically significant reduction in PPD and CAL. There was an alveolar bone gain of 1.28 ± 0.88 mm in the coronectomy group and 1.13 ± 0.73mm in the control group, which was statistically significant (P < .001 for both groups).

CONCLUSIONS

Early findings show the periodontal healing at the adjacent second molar of coronectomy was as good as that of total removal of lower third molar. There were no differences in terms of surgical morbidities between both groups.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effectiveness of Bone Graft for an Alveolar Defect on Adjacent Second Molar After Impacted Mandibular Third Molar Extraction

PURPOSE

This retrospective study examined distal bone healing on the adjacent second molar between the demineralized bone matrix incorporated with recombinant human bone morphogenetic protein-2 (DBM/rhBMP-2) and a collagen sponge in the mandibular third molar extraction socket.

MATERIALS AND METHODS

From 2018 to 2020, 26 extraction patients (male, average 21.5 years), who received a graft (each of 13 using DBM/rhBMP-2 and collagen plug, respectively) on the extraction socket without primary closure, were enrolled in this study. The bony defect was measured by computed tomography before and 6 months after the extraction. The difference in the bone healing was analyzed between the DBM/rhBMP-2 and collagen plug groups using a Mann-Whitney U test.

RESULTS

No complications, such as infection and food packing, were encountered. The DBM/rhBMP-2 and collagen plug groups showed a similar distribution of preoperative bony defect (median 5.8 and 5.0 mm, respectively). After 6 months, more bone healing was observed in the DBM/rhBMP-2 group than in the collagen plug group (median 3.85 and 2.37 mm, respectively, P = .029) CONCLUSIONS: A DBM/rhBMP-2 graft after a third molar extraction does significantly alter the bony defect on the distal aspect of the second molar compared with a collagen plug.

Computer-aided three-dimensional assessment of periodontal healing distal to the mandibular second molar after coronectomy of the mandibular third molar: a prospective study

Background

The periodontal healing distal to the mandibular second molar (M2M) after coronectomy of the M3M has shown controversial results. We aimed to combine a digital method with cone-beam computed tomography (CBCT) and estimate periodontal healing of M2M after M3M coronectomy. An accurate and stable indicator in three dimensions was also explored tentatively.

Methods

Patients with a M3M in contact with the inferior alveolar canal were included. CBCT was applied immediately after coronectomy (baseline) and 6-months later. Data were investigated with digital software for registration. Previously reported and coronectomy-related factors were included for univariate and multivariate analyses.

Results

A total of 181 patients (213 M3Ms) completed 6-month follow-up. Significant reduction in the distal intra-bony defect (DBD) depth of the M2M was shown (1.28 ± 1.24 mm, P < 0.001). DBD depth of the M2M at baseline was the most influential factor (r = 0.59), followed by preoperative M3M condition, age, rotation and migration of the root complex. Remaining enamel (OR = 6.93) and small retromolar space (0.67) contributed to re-contact of the root complex and M2M. Bone volume regenerated in the distal 2 mm was associated significantly with DBD-depth reduction (r = 0.74, P < 0.001).

Conclusions

Bone volume regenerated in the distal 2 mm of the M2M denoted stability of distal periodontal healing of the M2M. DBD depth at baseline was the most influential factor for healing of a DBD of the M2M after M3M coronectomy. The remaining enamel and a small retromolar space could contribute to re-contact of the root complex and the M2M.

Trial registration

China Clinical Trial Center, ChiCTR1800014862. Registered 10 February 2018,

Bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy: a long-term analysis

A residual bone defect at the distal aspect of the adjacent second molar may occur after total removal of the lower third molar. Lower third molar coronectomy has been proved to be a safe alternative to total removal, but the extent of bone regeneration at the adjacent tooth after coronectomy is not well reported. The aim of this prospective study was to investigate the long-term bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy. Preoperative and postoperative cone beam computed tomography scans were measured to assess bone regeneration at the distobuccal (DB), mid-distal (MD), and distolingual (DL) aspects of the lower second molar. Forty-eight coronectomies in 37 patients (23 female) with a mean±standard deviation age of 29.1±7.2 years were assessed. The mean follow-up was 93.2±8.7 months. The mean bone level increase at DB, MD, and DL aspects was 3.2±1.6mm, 3.5±1.5mm, and 3.2±1.6mm, respectively; the bone levels were significantly higher than the preoperative measurements (P<0.001). Age and impaction patterns were not factors affecting bone regeneration. Based on this study, it appears that coronectomy of the lower third molar brings favourable bone regeneration at the distal aspect of the adjacent second molar.

Third mandibular molar coronectomy: a way to prevent iatrogenic inferior alveolar nerve injuries—an systematic review

Introduction: In the field of oral and maxillo-facial surgery, the avulsion of third mandibular molar is a very common procedure. However, and although the injury on the alveolar inferior nerve is very rare, the neurological risk must not be underestimated. Indeed, it may lower the patient’s quality of life in a significant way. The coronectomy is a technique that allows us to avoid this risk. It consists in remaining in place the third mandibular molar’s roots. Educational objectives: After a clinical introduction to this surgical technique, the main characteristics of this type of procedure will be presented with the help of an exhaustive literature review. Thus, we will refer to the following subjects: the obvious decrease of neurological risks, the potential pre and post-operating complications, the potential necessity of an endodontic treatment for the residual roots, the becoming of these same roots, and finally the bony and mucosal cicatrization of the operated area. Conclusion: Every oral surgeon should have in mind this technique of coronectomy and master it. Indeed, when the case justifies it, the benefits are numerous for the patient.