Influence of mandibular third molar surgical extraction on the periodontal status of adjacent second molars

Effect of impacted mandibular third molar extraction on periodontal microbiota and clinical parameters of adjacent teeth: A randomized clinical trial

It is urgently necessary to clarify the effect of extraction of impacted mandibular third molar (IMTM) on the periodontal tissue of adjacent second molars (ASMs). In this study, the ASM periodontal condition and pathogenic microbes were assessed before IMTM extraction and at 1, 4, 8 and 12 weeks postoperatively. Based on the inclusion and exclusion criteria, our study revealed that IMTM extractions adversely affected distal － periodontal probing depth (dPPD), attachment loss (dAL), plaque index (dPLI) and bleeding on probing (dBOP) within 8 weeks, but these indices gradually normalize after 12 weeks. The subgingival pathogens near the ASMs distal surface, Porphyromonas and Pseudomonas, were significantly increased postoperatively. Moreover, relevance of ASMs clinical indices and subgingival microbes after IMTM extractions was found. In contrast to the situation in chronic periodontitis, the effects of IMTM extraction on dPPD, dAL, dPLI and dBOP of ASMs were mainly correlated with Pseudomonas. Additionally, while the IMTM extractions have adverse distal periodontal indices of ASMs within 8 weeks and increase subgingival pathogens, the modified triangular flap (MTF) had fewer distal periodontal indices and less Pseudomonas. Compared to the traditional envelope flap and triangular flap, the MTF benefits the periodontal health, which could be considered as the priority option for IMTM extractions.

Comparison of immediate vs. delayed guided tissue regeneration in Infrabony defect of second molars after adjacent third molar extraction: a retrospective study

BACKGROUND

The distal aspect of the second molar (d-M2) often exhibits infrabony defects due to the adjacent third molar. Although the defects can be treated by guided tissue regeneration (GTR) after removing the third molar, the optimal timing remains uncertain following third molar removal in clinical decision-making. This study aimed to compare delayed and immediate GTR treatments to assist in clinical decision-making.

METHODS

D-M2 infrabony defects with a minimum 1-year follow-up were collected and divided into three groups: Immediate GTR group, which underwent third molar extraction and received GTR simultaneously; Delayed GTR group, which underwent delayed GTR at least 3 months after third molar extraction; and Control group, which underwent only scaling and root planing during third molar extraction. The clinical and radiographic parameters related to the infrabony defect before GTR and post-surgery were evaluated using the Kruskal-Wallis test or one-way ANOVA, followed by post-hoc Dunn's test or the Bonferroni test for pairwise comparisons.

RESULTS

A total of 109 d-M2 infrabony defects were assessed. No significant differences were found between the two GTR groups, although both of them showed significant reductions in infrabony defect depth: the immediate GTR group (2.77 ± 1.97 mm vs. 0.68 ± 1.03 mm, p < 0.001) and the delayed GTR group (2.98 ± 1.08 mm vs. 0.68 ± 1.03 mm, p < 0.001) compared to the control group.

CONCLUSION

GTR can effectively improve d-M2 infrabony defects when the third molar is removed, whether simultaneously or delayed. Patients may experience less discomfort with immediate GTR treatment as it requires only one surgery.

Optimal tooth sectioning using a surgical handpiece and elevator: a finite element study of horizontally deeply impacted mandibular third molars

OBJECTIVES

To conduct a finite element analysis of the impact of different variables on tooth sectioning efficiency and trauma to surrounding tissues when utilizing high-speed surgical handpieces and elevators.

METHODS

CBCT data from the horizontally impacted third mandibular molar (M3M) of a patient were utilized to establish digital models of the M3M, adjacent M2M, and surrounding bone. To simulate tooth sectioning, a 3D finite element model was established with the following variables: remaining tooth tissue thickness (1-5 mm), tooth section fissure width (1-3 mm), elevator depth in fissure (2-6 mm), elevator position (buccal, lingual, central), elevator width (2-5 mm), and application of force (rotating, levering). Using this model, the distribution of stress on the M3M and the surrounding tissue was assessed while measuring tooth sectioning efficiency and trauma to the surrounding tissue.

RESULTS

Factors associated with uniform stress at the site of sectioning included thin (≤ 3 mm) remaining tooth tissue, appropriate fissure width (~ 2 mm), a wide (≥ 4 mm) elevator, and central elevator positioning. Levering the elevator yielded greater stress on the M3M than rotating force. Greater sectioning efficiency was associated with increased stress placed on the distobuccal side of M2M.

CONCLUSIONS

Tooth sectioning efficiency can be improved by adjusting the high-speed surgical handpiece and elevator. However, it is important to remain attentive to the trauma to which adjacent teeth are exposed during this process.

CLINICAL SIGNIFICANCE

These results offer guidance for approaches to improving operator efficiency and reducing trauma to surrounding tissues during tooth sectioning.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN, SETTING, SAMPLE

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

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

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

MAIN OUTCOME VARIABLE

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

COVARIATES

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

ANALYSES

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

RESULTS

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

CONCLUSION AND RELEVANCE

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

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.

Common Reasons for Permanent Tooth Extraction and Its Correlation with Demographical Factors in Kabul, Afghanistan

Objective

The aim of this survey was to investigate the main reasons for extraction of permanent teeth, and its correlation with age, gender, education level, smoking habits, and time of last dental visit, family income, and professions in Kabul, Afghanistan.

Subjects and Methods

The study proposal was approved by Research Ethics Committee of Khatam AL Nabieen and was conducted over a period of 5 months; its population consisted 594 patients, aged 10-70 years, who underwent extraction. The frequency distribution was calculated using X2 test, ANOVA and t-test for differences in mean number of patients.

Results

A total of 594 patients underwent extraction. The highest rate (53.8%) of extraction occurred for those 21-40 years old. Females compromised 51.3% of patients. Two hundred (33.6%) patients were uneducated. Tooth loss due to caries was 30.1%; patient-request was 18.3%; impacted teeth was 14.4%. Other causes were periodontal reasons, failed root canal therapy (RCT), Tooth mobility, and Root fractures.

Conclusion

The result of this survey indicated that caries, patient request, and impaction were the leading reasons for tooth extraction. The majority of patients were uneducated, and had insufficient family income. Most of the patients were housewives and laborers.

Mandibular Third Molar Impaction and Bone Change Distal to the Second Molar: A Panoramic Radiographic Study

Background: The mandibular third molar is the most frequently impacted tooth. An impacted mandibular third molar (IMTM) can have negative consequences on the adjacent mandibular second molar (MSM), such as bone loss. An IMTM can be identified using orthopantomography (OPG). Our objective is to compare changes in bone level distal to the mandibular second molar (MSM) in patients with an extracted IMTM versus non-extracted IMTM using OPG. Methods: In this retrospective case-control study, 160 orthopantomograms (OPGs) of 80 patients who attended Dental Hospital of the University of Barcelona (HOUB) were randomly selected. Participants were stratified into a study group and control group. Results: Males and females experienced bone gain in the study group and bone loss in the control group. However, the difference in bone-level change was not statistically significant regarding gender in the study group. Within the study group, the age group of 29-39 years demonstrated significant (p-value = 0.042) bone gain after extraction compared to other age groups. However, the control group demonstrated bone loss in all age groups in which the difference is not statistically significant (p-value 0.794). Conclusions: Bone improvements distal to the MSM were observed after the extraction of an IMTM compared to when an IMTM was not extracted.

Relationship between the Status of Third Molars and the Occurrence of Dental and Periodontal Lesions in Adjacent Second Molars in the Polish Population: A Radiological Retrospective Observational Study

The aim of this study was to evaluate the effect of third molars on caries, external root resorption, and alveolar bone loss on the distal surface of adjacent second molars. A total of 2488 panoramic radiographs of adult Poles were evaluated. Third molars were classified, according to eruption status, into non-impacted, partially, or completely impacted, and according to angulation into horizontal, mesioangular, vertical, and distoangular. Completely impacted third molars were assigned as reference group. The odds ratios (ORs) and 95% confidence intervals for the occurrence of the above-mentioned pathologies were 1.39 (1.09-2.21), 6.51 (3.72-10.11), and 2.42 (1.22-4.09), respectively, for second molars with adjacent erupted third molars and 1.54 (1.11-2.82), 10.65 (7.81-20.19), and 5.21 (3.38-10.81), respectively, when partially impacted third molars were next to second molars. The ORs of lesions were significantly higher for horizontally and mesioangularly impacted third molars. Within the limitation of a radiological study, it might be concluded that the presence of erupted third molars is a risk factor for caries, while the presence of impacted third molars increases the risk of root resorption and bone loss on the distal surface of second molars.

Six-Month Soft Tissues Healing after Lower Third Molar Extraction: Comparison of Two Different Access Flaps

BACKGROUND

As specific flap designs performed for lower third molar extractions usually influence periodontal healing of the adjacent first and second molars, this study aimed to evaluate the periodontal conditions of these sites after 6 months post-surgery.

METHODS

Forty patients, aged 14-30 years, were included. Surgical extraction of the lower third molar was performed through a flap with papilla detachment (a modified envelope technique with detachment of gingival papilla between the first and second molars) or a trapezoidal flap (characterized by mesial- and distal-releasing incisions). Periodontal parameters at the first and second molar sites were assessed for visible plaque index, bleeding on probing, recession, probing pocket depth, and clinical attachment loss before surgery (T0), one month (T1), and six months after extraction (T2).

RESULTS

No statistical differences were found for the plaque and bleeding indexes between the two flaps at each observation time and considering both time intervals. For recession, no statistical differences were found between the two flaps considering the final time interval. For probing pocket depth at the second molar site, both techniques registered a significant increase between T0 and T1, followed by a decrease up to T2. For clinical attachment loss, mean values assessed for the first and second molar sites demonstrated evidently increased values between T0 and T1, followed by moderate decreases up to T2.

CONCLUSIONS

Considering short (T1) and mid-term (T2) follow-ups, a specific flap design does not seem to particularly influence periodontal healing six months after surgery.

Oral microbiota in human health and disease: A perspective

The evolution of medical knowledge about oral microbiota has increased awareness of its important role for the entire human body health. A wide range of microbial species colonizing the oral cavity interact both with each other and with their host through complex pathways. Usually, these interactions lead to a harmonious coexistence (i.e. eubiosis). However, several factors - including diet, poor oral hygiene, tobacco smoking, and certain medications, among others - can disrupt this weak homeostatic balance (i.e. dysbiosis) with potential implications on both oral (i.e. development of caries and periodontal disease) and systemic health. This article is thus aimed at providing an overview on the importance of oral microbiota in mediating several physiological and pathological conditions affecting human health. In this context, strategies based on oral hygiene and diet as well as the role of probiotics supplementation are discussed.

Does surgical removal of mandibular third molar influence the periodontal status of the adjacent second molars? A systematic review

Objective: This study aimed to assess the influence of mandibular third molar surgical removal on the periodontal status of adjacent second molars and to investigate the potential impact of the flap design. Methods: A systematic review of the literature, registered in PROSPERO, has been carried out from Pubmed and Scopus databases following PRISMA guidelines from January 2010 to January 2022. PICO method was used to select the relevant articles. Studies comparing the periodontal status of the second molar before and after mandibular third molar removal were considered. Results: Twenty-three studies involving 1067 patients were included. The two main parameters studied were periodontal pocket depth and clinical attachment level. The envelope flap and the triangular flap were the most commonly used flap techniques. Periodontal health of adjacent second molar was maintained or improved in most of the included studies. The flap design did not seem to have a significant influence either. Conclusion: Avulsion of impacted third molar in healthy young adults does not impair the periodontal health of adjacent second molars. Further studies, with higher levels of evidence, are needed to confirm these results and to identify possible risk factors (such as age, impaction depth or periodontal disease) responsible for poorer healing.

How the Loss of Second Molars Corresponds with the Presence of Adjacent Third Molars in Chinese Adults: A Retrospective Study

Third molars (M3s) can increase the pathological risks of neighboring second molars (M2s). However, whether the M3 presence affects M2 loss remains unknown. This retrospective study aimed to reveal the reasons for M2 loss and how M2 loss relates to neighboring M3s. The medical records and radiographic images of patients with removed M2(s) were reviewed to analyze why the teeth were extracted and if those reasons were related to adjacent M3s. Ultimately, 800 patients with 908 removed M2s were included. In the included quadrants, 526 quadrants with M3s were termed the M3 (+) group, and the other 382 quadrants without M3s were termed the M3 (−) group. The average age of patients in the M3 (+) group was 52.4 ± 14.8 years and that of the M3 (−) group was 56.7 ± 14.9 years, and the difference between the two groups was statistically significant (p < 0.001). Of the 908 M2s, 433 (47.7%) were removed due to caries and sequelae and 300 (33.0%) were removed due to periodontal diseases. Meanwhile, 14.4% of the M2s with adjacent M3s were removed due to distal caries and periodontitis, which were closely related to the neighboring M3s; this percentage was much lower when M3 were absent (1.8%). Additionally, 42.2% of M3s were removed simultaneously with neighboring M2s. The presence of M3s, regardless of impaction status, was associated with an earlier loss of their neighboring M2s.

Effects of Flap Design on the Periodontal Health of Second Lower Molars after Impacted Third Molar Extraction

The purpose of this study was to compare the envelope flap and triangular flap for impacted lower third molar (M3) extraction and their effects on the periodontal health of adjacent second molars (M2). A population of 60 patients undergoing M3 extraction with the envelope flap (Group A) or triangular flap (Group B) was analyzed, comparing probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession (REC) recorded at six sites (disto-lingual, mid-lingual, mesio-lingual, disto-vestibular, mid-vestibular, and mesio-vestibular) before (T⁰) and 6 months after extraction (T¹). There was a statistically significant mean difference in PPD and CAL at two sites, disto-vestibular (dv) and disto-lingual (dl), between values recorded before and 6 months after surgery for either Group A or Group B. Furthermore, for the same periodontal records, at 6 months after surgery, a statistically significant difference was recorded between younger and older patients, implying that the healing process was more beneficial for younger patients. No significant differences were found between the two groups (A and B) in PPDdl, PPDdv, CALdl, and CALdv, confirming that the mucoperiosteal flap design does not influence the periodontal healing process of second molars.

Factors affecting periodontal healing of the adjacent second molar after lower third molar surgery: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aim to evaluate the effect modifiers which may influence the periodontal healing of the adjacent second molar after lower third molar surgery.

MATERIALS AND METHODS

Prospective studies including patients with third molars requiring removal, with at least 6 months follow-up were considered. Outcomes were periodontal probing depth (PPD) reduction, final PPD, clinical attachment level (CAL) change, final CAL, alveolar bone defect (ABD) reduction, and final ABD depth. Meta-regression was performed to identify factors.

RESULTS

Fourteen studies were included in the quantitative synthesis. At 6 months, the PPD reduction was 1.06 mm (95% CI, 0.72 to 1.39 mm) and the remaining PPD was 3.81 mm (95% CI, 3.00 to 4.62 mm). Baseline PPD was strongly correlated with the remaining PPD at 6 months (p < 0.001, adjusted R² = 70.05%).

CONCLUSIONS

Lower third molar surgery results in a modest reduction in PPD, CAL, and ABD; however, periodontal defects still remain at 6 months and beyond. Baseline PPD is strongly correlated with final PPD. While age is not shown to have effect on most of the periodontal parameters, a larger baseline PPD is more likely to manifest with increasing age and third molar surgery should be done before severe periodontitis occurs to avoid persistent periodontal defects.

CLINICAL RELEVANCE

This study shows that lower third molar surgery results in modest improvement in periodontal parameters on adjacent second molars and identified factors such as baseline PPD which may affect the healing, which may guide the pre-, peri-, and post-operative management of lower third molar surgery.

Influence of a novel suturing technique on periodontal health of mandibular second molar following impacted third molar surgery: a split-mouth randomized clinical trial

BACKGROUND

Surgical extraction of the third molar is the most common surgical procedure in the oral surgery field and is associated with several complications. This study aimed to compare the effects of a newly presented suturing technique with the routine suture after surgical removal of the third molar on the postoperative complications.

MATERIALS AND METHODS

This randomized clinical trial was designed as a split-mouth double-blinded investigation. Twenty patients were involved in the current study. After the surgical removal of the third molar, the new suturing technique was used to close the wound on one side of the patient randomly (case side), and the other side was sutured by the routine simple interrupted stitches (control side). Pain, edema, trismus, pocket depth, and the attachment loss of the distal of the second molar were assessed following the surgery. The data were statistically analyzed and compared between the sides.

RESULTS

Pain and edema following the surgery in the control side were significantly less than in the case side. The pocket depth and the gingival attachment loss of the distal aspect of the second molar in the case side were significantly less than in the control side. No case of dry socket was observed in the case side.

CONCLUSION

It seems that the newly presented suturing technique is able to keep the wound margins close to each other and may be helpful in reducing the periodontal complication of the second molar following the surgical removal of the impacted third molars.

Effects of Impacted Lower Third Molar Extraction on Periodontal Tissue of the Adjacent Second Molar

The extraction of impacted lower third molars (ILTM) is one of the most common procedures in oral-maxillofacial surgery. Being adjacent to lower second molars, most impacted lower third molars often lead to distal periodontal defects of adjacent second molars. Several symptoms may occur after extraction, such as periodontal pocket formation, loss of attachment, alveolar bone loss and even looseness of second molar resulting in extraction. The distal periodontal defects of second molars are affected by many factors, including periodontal conditions, age, impacted type of third molars, and intraoperative operations. At present, several studies have suggested that dentists can reduce the risk of periodontal defects of the second molar after ILTM extraction through preoperative evaluation, reasonable selection of flap design, extraction instruments and suture type, and necessary postoperative interventions. This review summarizes the research progress on the influence factors, interventions methods and some limitations of distal periodontal defects of adjacent second molar after extraction of impacted mandibular third molars, with the aim of opening up future directions for studying effects of ILTM extraction on periodontal tissue of the adjacent second molar.

Patient perception after oral biopsies: an observational outpatient study

OBJECTIVE

The aim of this study was to evaluate the postoperative course in patients undergoing oral mucosal biopsies, considering clinical and patient's perception variables potentially correlated to poor healing.

SUBJECTS AND METHODS

Eighty patients underwent oral biopsies. All the variables connected with the surgery were recorded, and the harvested volume was calculated through image software (ImageJ, NIH, Betesda, USA). To evaluate the postoperative discomfort, the OHIP-14 and the numeric rating scale of pain (NRS) were administered at 6 h, 7 days and 21 days after biopsy.

RESULTS

Six hours after the biopsy, 22 (OHIP-14 ≥ 20) and 24 (NRS ≥ 4) patients experienced a troublesome or painful healing, respectively. A significant statistical correlation between poor healing and high scores of NRS and OHIP was detected (Pearson's correlation test p < 0.05). Higher values of OHIP-14 were correlated to the type of lesion (OR = 1.165; p < 0.05), whereas high values of NRS were correlated to the use of systemic drugs (p < 0.05). No surgical variable had a significant statistical correlation with any of the outcomes.

CONCLUSIONS

The clinical evaluation was correlated with the patient's perception of pain and discomfort. This finding could be suggestive of the fact that wound healing can be reliably monitored with the help of these tools.

CLINICAL RELEVANCE

Patient perception can be a predictor of the healing of biopsied tissues.

Reasons for Extraction of Permanent Teeth in a University Dental Clinic Setting

Purpose

This study aimed to explore the reasons for tooth extraction and investigated the potential correlations between tooth loss and several variables including age, gender, education level, and other risk factors, such as diabetes and smoking habit.

Patients and Methods

The study retrospectively analyzed 1811 dental records of patients who underwent extraction procedure of at least one tooth. Patients’ variables included: age, gender, level of education, diabetes, and smoking habit. Reasons for extraction were recorded as follows: caries, periodontal disease, endodontic treatment complications, orthodontic treatment, impactions, trauma, pre-prosthetic, and others (esthetic reasons, tooth malposition, or unspecified reasons).

Statistical analysis

The significance of variables was analyzed by Chi square test, P < 0.05. The variances in the mean number of extracted teeth per patient were investigated using ANOVA. Pearson correlation test was used to test the strength of the association among the tested variables, P < 0.01.

Results

Out of 1811 reviewed patients’ records, 2654 extracted teeth were identified. Males had a higher number of extracted teeth, 1447 (54.5%), than females, 1207 (45.5%). Males had more extractions due to periodontal disease, while females had more extractions for orthodontic and pre-prosthetic reasons. The highest mean of extracted teeth was identified among the 51-year-old and above age groups (3.73 ± 0.53 teeth) where periodontal disease was shown to have a significant association (P < 0.05). Diabetic patients showed a significant association with periodontal diseases, while smokers showed a significant association with caries. Both diabetics and smokers had moderate correlation (0.055 and 0.04, respectively).

Conclusion

Caries, periodontal disease, and endodontic complications were the most common causes of tooth extraction. In addition, this study indicated that age, diabetes, and smoking habits were found to be suitable forecasters for permanent tooth loss as these variables displayed significant statistical association.

Removal of nonimpacted third molars alters the periodontal condition of their neighbors clinically, immunologically, and microbiologically

Considering the adverse effects of nonimpacted third molars (N-M3s) on the periodontal health of adjacent second molars (M2s), the removal of N-M3s may be beneficial to the periodontal health of their neighbors. This study aimed to investigate the clinical, immunological, and microbiological changes of the periodontal condition around M2s following removal of neighboring N-M3s across a 6-month period. Subjects with at least one quadrant containing an intact first molar (M1), M2, and N-M3 were screened and those who met the inclusion criteria and decided to receive N-M3 extraction were recruited in the following investigation. M2 periodontal condition was interrogated before M3 extraction (baseline) and at 3 and 6 months postoperatively. Improvements in clinical periodontal indexes of M2s in response to their adjacent N-M3 removal, along with changes in inflammatory biomarkers among gingival crevicular fluid (GCF) and the composition of subgingival plaque collected from the distal sites of the M2s of the targeted quadrant were parallelly analyzed. Complete data of 26 tooth extraction patients across the follow-up period were successfully obtained and subsequently applied for statistical analysis. Compared to the baseline, the periodontal condition of M2s was significantly changed 6 months after N-M3 removal; specifically, the probing depth of M2s significantly reduced (P < 0.001), the matrix metalloproteinase (MMP)-8 concentration involved in GCF significantly decreased (P = 0.025), and the abundance of the pathogenic genera unidentified Prevotellaceae and Streptococcus significantly decreased (P < 0.001 and P = 0.009, respectively). We concluded that N-M3 removal was associated with superior clinical indexes, decreased GCF inflammatory biomarkers, and reduced pathogenic microbiome distribution within the subgingival plaque. Although the retention or removal of N-M3s continues to be controversial, our findings provide additional evidence that medical decisions should be made as early as possible or at least before the neighboring teeth are irretrievably damaged.

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.

Five-Years Periodontal Outcomes of Early Removal of Unerupted Third Molars Referred for Orthodontic Purposes

PURPOSE

The removal of third molars (M3) is one of the most common oral-maxillofacial surgical procedures affecting periodontal tissues of neighboring second molars (M2). The aim of this study was to evaluate the periodontal status of lower M2 following the removal of unerupted lower M3 up to 5 years after removal.

PATIENTS AND METHODS

Primary predictor variable in this prospective cohort-study was time [baseline (BL; preoperatively), 6 and 60 months postoperatively]. The primary outcome variable was probing pocket depth (PPD). Clinical attachment level (CAL) was defined as a secondary outcome variable. Plaque index (PlI) and gingival index (GI) were assessed descriptively. All variables were compared using nonparametric tests. M3 were classified as either completely bony or partially bony unerupted. Risk factors (removed M3, type of impaction, mean BL PPD≥4 mm, gender, age) were analyzed (repeated measures ANCOVA). The significance level was set at 0.05.

RESULTS

From originally 91 subjects enrolled in this study, 39 subjects (22 females; mean age: 21.6 ± 2.5 years) contributing 39 M3 completed the study after 5 years. Average BL PPD significantly decreased at 6 (-0.50 ± 0.61 mm, P = .001), 60 months (-0.81 ± 0.56, P < .0001), as well as between 6 and 60 months (-0.31 ± 0.51 mm, P = .030). Corresponding CAL values decreased accordingly (BL-6 months: -0.37 ± 0.59 mm, P = .004; BL-60 months: -0.67 ± 0.55 mm, P < .0001; 6 to 60 months: -0.34 ± 0.48 mm, P = .004). The was confirmed as risk factor for PPD (P = .026) and CAL (P = .042) changes.

CONCLUSIONS

Average PPD and CAL of mandibular M2 in young subjects improved 5 years after early removal of unerupted M3 in favor of an initial partially bony unerupted type of impaction.

The beneficial effect of cold atmospheric plasma on parameters of molecules and cell function involved in wound healing in human osteoblast-like cells in vitro

The aim of this study was to analyse the effect of cold atmospheric plasma (CAP) on human osteoblast-like cells in vitro. Additionally, underlying intracellular mechanisms were to be studied. Human osteoblast-like (MG63) cells were exposed to CAP for 60 s. The effects of CAP on key molecules essential for the wound healing response were studied using real-time PCR, ELISA and immunocytochemistry. For studying intracellular signalling pathways, MAP kinase MEK 1/2 was blocked. Cell viability was analysed by an XTT assay and with an EVE automated cell counter. Cell migration was examined by an in vitro wound healing assay.CAP exposition on osteoblast-like cells caused a significant upregulation of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)α, cyclooxygenase (COX)2, collagen (COL) 1α, matrix metalloproteinase (MMP)1, Ki67, proliferating-cell-nuclear-antigen (PCNA) and chemokine ligand (CCL)2 mRNA expression at 1 day. Interestingly, after blocking of MAP kinase, CAP-induced upregulation of Ki67 was inhibited by 57%. Moreover, CAP treatment improved significantly osteoblast-like cell viability as compared to untreated cells at 1 day. Beneficial effect of CAP treatment was shown by an in vitro wound healing assay, displaying a significant faster wound closure. Our findings provide evidence that CAP exposure effects gene and protein regulation in human osteoblast-like cells. Furthermore, CAP treatment has a positive impact on wound closure in an in vitro setting and might improve existing concepts of hard tissue regeneration in the future.

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,

Prevention of Periodontal Pocket Formation after Mandibular Third Molar Extraction Using Dentin Autologous Graft: A Split Mouth Case Report

Surgical extraction of the third molar can often result in the development of a periodontal pocket distal to the second molar that could delay the healing, and the socket could be colonized by bacteria and lead to secondary abscesses, or it may cause mobility or hypersensitivity. The aim of this case report is to assess the efficacy of a dentin autograft in the prevention of periodontal dehiscences after the surgical extraction of the third molar, obtained by the immediate grinding of the extracted tooth. A healthy 18-year-old male patient underwent surgery of both impacted mandibular molars: right postextractive socket was filled with grinded dentin; then, the left one was filled with fibrin sponge. The patient was followed up for six months, and clinical and radiographic assessment were performed: measurements of plaque index (PI), bleeding on probing (BOP), gingival index (GI), clinical attachment level (CAL), and probing pocket depth (PPD) were done before surgery and repeated at 90 and 180 days after the extractions. Measurements made at six months after the surgery revealed that the grafted site was characterized by a minor depth of the pocket if compared with the nongrafted site, with no clinical/radiographic signs of complications.

Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth

BACKGROUND

Prophylactic removal of asymptomatic disease-free impacted wisdom teeth is the surgical removal of wisdom teeth in the absence of symptoms and with no evidence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as pericoronitis, root resorption, gum and alveolar bone disease (periodontitis), caries and the development of cysts and tumours. When surgical removal is performed in older people, the risk of postoperative complications, pain and discomfort is increased. Other reasons to justify prophylactic removal of asymptomatic disease-free impacted third molars have included preventing late lower incisor crowding, preventing damage to adjacent structures such as the second molar or the inferior alveolar nerve, in preparation for orthognathic surgery, in preparation for radiotherapy or during procedures to treat people with trauma to the affected area. Removal of asymptomatic disease-free wisdom teeth is a common procedure, and researchers must determine whether evidence supports this practice. This review is an update of an review originally published in 2005 and previously updated in 2012 and 2016.

OBJECTIVES

To evaluate the effects of removal compared with retention (conservative management) of asymptomatic disease-free impacted wisdom teeth in adolescents and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 10 May 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2019, Issue 4), MEDLINE Ovid (1946 to 10 May 2019), and Embase Ovid (1980 to 10 May 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov)and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. .

SELECTION CRITERIA

We included randomised controlled trials (RCTs), with no restriction on length of follow-up, comparing removal (or absence) with retention (or presence) of asymptomatic disease-free impacted wisdom teeth in adolescents or adults. We also considered quasi-RCTs and prospective cohort studies for inclusion if investigators measured outcomes with follow-up of five years or longer.

DATA COLLECTION AND ANALYSIS

Eight review authors screened search results and assessed the eligibility of studies for inclusion according to the review inclusion criteria. Eight review authors independently and in duplicate conducted the risk of bias assessments. When information was unclear, we contacted the study authors for additional information.

MAIN RESULTS

This review update includes the same two studies that were identified in our previous version of the review: one RCT with a parallel-group design, which was conducted in a dental hospital setting in the United Kingdom, and one prospective cohort study, which was conducted in the private sector in the USA. Primary outcome No eligible studies in this review reported the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth on health-related quality of life Secondary outcomes We found only low- to very low-certainty evidence of the effects of removal compared with retention of asymptomatic disease-free impacted wisdom teeth for a limited number of secondary outcome measures. One prospective cohort study, reporting data from a subgroup of 416 healthy male participants, aged 24 to 84 years, compared the effects of the absence (previous removal or agenesis) against the presence of asymptomatic disease-free impacted wisdom teeth on periodontitis and caries associated with the distal aspect of the adjacent second molar during a follow-up period of three to over 25 years. Very low-certainty evidence suggests that the presence of asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting the adjacent second molar in the long term. In the same study, which is at serious risk of bias, there is insufficient evidence to demonstrate a difference in caries risk associated with the presence or absence of impacted wisdom teeth. One RCT with 164 randomised and 77 analysed adolescent participants compared the effect of extraction with retention of asymptomatic disease-free impacted wisdom teeth on dimensional changes in the dental arch after five years. Participants (55% female) had previously undergone orthodontic treatment and had 'crowded' wisdom teeth. No evidence from this study, which was at high risk of bias, was found to suggest that removal of asymptomatic disease-free impacted wisdom teeth has a clinically significant effect on dimensional changes in the dental arch. The included studies did not measure any of our other secondary outcomes: costs, other adverse events associated with retention of asymptomatic disease-free impacted wisdom teeth (pericoronitis, root resorption, cyst formation, tumour formation, inflammation/infection) and adverse effects associated with their removal (alveolar osteitis/postoperative infection, nerve injury, damage to adjacent teeth during surgery, bleeding, osteonecrosis related to medication/radiotherapy, inflammation/infection).

AUTHORS' CONCLUSIONS

Insufficient evidence is available to determine whether asymptomatic disease-free impacted wisdom teeth should be removed or retained. Although retention of asymptomatic disease-free impacted wisdom teeth may be associated with increased risk of periodontitis affecting adjacent second molars in the long term, the evidence is very low certainty. Well-designed RCTs investigating long-term and rare effects of retention and removal of asymptomatic disease-free impacted wisdom teeth, in a representative group of individuals, are unlikely to be feasible. In their continuing absence, high quality, long-term prospective cohort studies may provide valuable evidence in the future. Given the current lack of available evidence, patient values should be considered and clinical expertise used to guide shared decision-making with people who have asymptomatic disease-free impacted wisdom teeth. If the decision is made to retain these teeth, clinical assessment at regular intervals to prevent undesirable outcomes is advisable.

Quality of Life of Patients with Mandibular Third Molars and Mild Pericoronitis. A Comparison between Two Different Treatments: Extraction or Periodontal Approach

Background: The extraction of the mandibular third molar is one of the most frequent intervention in oral surgery. A common indication for wisdom tooth extraction is represented by pericoronitis, which can determine discomfort and pain in patients. The present study aimed to evaluate the impact of patients’ quality of life by comparing a surgical approach with a periodontal approach. Methods: We evaluated 82 patients diagnosed with pericoronitis that occurred at the third molar site. In total, 41 of them received a periodontal treatment and 41 were treated by extraction. The quality of life (QoL) of the patients was assessed by using the Oral Health Impact Profile-14 (OHIP-14) index. Results: A total of 82 patients were included in the study and were followed up for 6 months. Of the patients, 41 received a periodontal treatment and 41 underwent surgical extraction. At the baseline, the OHIP-14 scores of the surgical group were higher (19.71, SD 9.90) than the periodontal group (14.41, SD 8.71). At 1 week, there was a reduction in terms of OHIP-14 in both groups, but the periodontal group showed lower values (12.3, SD 8.11). Long-term follow-up showed a reduction of the OHIP-14 values, with a difference in favor of the surgical group (0.10, SD 0.45). However, there was a reduction in OHIP-14 scores in both groups. Conclusion: Although the periodontal treatment offered a rapid improvement in terms of quality of life during the first week after the treatment, after 1 month and 6 months, the extraction of the mandibular third molar extraction remained the best treatment, removing the occurrence of re-inflammation of the site.

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.

Reasons for Tooth Extractions and Related Risk Factors in Adult Patients: A Cohort Study

Background: The aim of this study was to evaluate oral status, the reasons for tooth extractions and related risk factors in adult patients attending a hospital dental practice. Methods: 120 consecutive patients ranging from 23 to 91 years in age (mean age of 63.3 ± 15.8) having a total of 554 teeth extracted were included. Surveys about general health status were conducted and potential risk factors such as smoking, diabetes and age were investigated. Results: a total of 1795 teeth were missing after extraction procedures and the mean number of remaining teeth after the extraction process was 16.8 ± 9.1 per patient. Caries (52.2%) was the most common reason for extraction along with periodontal disease (35.7%). Males were more prone to extractions, with 394 of the teeth extracted out of the total of 554 (71.1%). Male sex (β = 2.89; 95% CI 1.26, 4.53; p = 0.001) and smoking habit (β = 2.95; 95% CI 1.12, 4.79; p = 0.002) were related to a higher number of teeth extracted. Age (β = −0.24; 95% CI −0.31, −0.16; p < 0.001) and diabetes (β = −4.47; 95% CI −7.61, −1.33; p = 0.006) were related to a higher number of missing teeth at evaluation time. Moreover, periodontal disease was more common as a reason of extraction among diabetic patients than among non-diabetic ones (p = 0.04). Conclusions: caries and periodontal disease were the most common causes of extraction in a relatively old study population: further screening strategies might be required for the early interception of caries and periodontal disease.

Impacts of non-impacted third molar removal on the periodontal condition of adjacent second molars

OBJECTIVE

The aim of this study was to determine how the removal of non-impacted third molars (N-M3s) affects the periodontal status of neighboring second molars (M2s).

SUBJECTS AND METHODS

The periodontal condition of M2s for which the neighboring N-M3s were removed (more than 6 months previously) and those with intact N-M3s was analyzed in a cross-sectional observation study. In an additional case series, periodontal changes in M2s in response to adjacent N-M3 removal were observed during a 6-month follow-up period.

RESULTS

A total of 457 patients with 1,301 M2s were enrolled in this cross-sectional observational study. Compared to M2s with neighboring N-M3s, M2s without neighboring N-M3s (teeth removed more than 6 months previously) exhibited a 0.27-mm reduction in the average pocket depth (PD) (p < .001) and a 0.38-fold reduced risk of at least one probing site with PD ≥5 mm (PD5+) (p < .001). Subsequently, a 41-case follow-up study showed that 6 months after neighboring N-M3 extraction, the PD of the M2s decreased by 0.31 mm (p < .001), while the incidence of PD5+ decreased by 21.9% when compared to the parameters detected before tooth extraction (p = .004).

CONCLUSIONS

Removing N-M3s was associated with an improved periodontal condition in neighboring M2s.

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.