Impacted Lower Third Molar Research Articles

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

BackgroundThe removal of impacted lower third molars (ILTM) is associated with bone defects in the distal area of second molars. Different methods have been described to minimize these defects. PurposeThe 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, sampleThis 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 variableThe 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 variablePD 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. CovariatesSex, age, surgical time, ILTM situation and position between groups were assessed. AnalysesANOVA 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 (CI) of 95% (p<0.05). ResultsThe 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<0.001, 95% CI) 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<0.001) and 0.54 ± 0.3 (p=0.43) were observed in test and control groups, respectively. Conclusions and relevanceATG 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.

Evaluation of the follicular space volume of lower third molars with different impaction positions and angulations: A cone-beam computed tomography and histopathological study

ObjectiveTo quantify the volume of the follicular spaces of impacted lower third molars (ILTMs) with different impaction positions and angulations using cone-beam computed tomography (CBCT) and to determine its association with the histopathological findings. Study designThis study included 103 ILTMs of 33 men and 70 women aged 18–46 years (mean age, 29.18 years). The follicular space volumes were measured on CBCT by manual segmentation and correlated with the histopathological diagnosis of each ILTM having different impaction positions and angulations. Statistical Product and Service Solutions, version 24, was used for statistical analyses by applying the t-test and binary logistic regression and multiple linear regression tests (p < 0.05). ResultsOverall, 83 (80.6%) dental follicles presented a non-pathological diagnosis (mean follicular volume, 0.10 cm3), whereas 20 (19.4%) presented a pathological diagnosis (mean follicular volume, 0.32 cm3; p = 0.001). Similarly, the impaction depth in Position C cases was associated with a pathological diagnosis (p = 0.010). ConclusionThe follicular volume of the ILTMs varied significantly in teeth with a histopathological diagnosis of a follicular cyst and was associated with the impaction depth, mainly in Position C cases, and its relationship with the mandibular ramus. A mean follicular volume of 0.32 cm3 was associated with a greater probability of a pathological diagnosis.

Influence of inflammation on bleeding and wound healing following surgical extraction of impacted lower third molars

ObjectiveThis study aimed to investigate the effect of inflammatory states following impacted lower third molar (ILTM) surgery regarding postoperative bleeding and wound healing.MethodsThe study included patients who underwent extraction of ILTMs associated with or without inflammatory conditions. Post-extraction bleeding and wound healing were assessed. In addition, mean grey values (MGVs) of alveolar bone and bone height using an orthopantomography radiograph were analyzed.ResultsA total of 376 patients were enrolled; 171 pericoronitis, 51 pulpitis, 44 chronic periapical periodontitis, 36 chronic periodontitis, and 74 control. The bleeding score in the control group was significantly lower than in the periapical periodontitis and periodontitis groups. Excellent wound healing for control, pericoronitis, pulpitis, periapical periodontitis, and periodontitis groups was (78.38%, 35.67%, 70.59%, 70.45%, and 33.33%, respectively). Patients with pericoronitis and periodontitis had significantly poorer wound healing (P < 0.01). The MGV in periapical periodontitis and periodontitis was considerably lower than in the control group.ConclusionsThe inflammatory conditions associated with ILTMs increase the risk of bleeding. So suturing with the placement of local hemostatic agents over a pressure pack alone is recommended. The poorest wound healing was in localized gingival inflammation. Furthermore, MGV was affected by age and was lower with periapical periodontitis.

Does dexmedetomidine combined with levobupivacaine in inferior alveolar nerve blocks among patients undergoing impacted third molar surgery control postoperative morbidity?

BackgroundPostoperative analgesia (POA) is an important determinant of successful treatment. Dexmedetomidine (DEX) has recently gained attention as a promising adjuvant to local anesthetics (LA). The present study aimed to evaluate the efficacy and safety of levobupivacaine (LB) as an adjuvant during inferior alveolar nerve block (IANB) in the extraction of lower impacted third molars (LITM).MethodsA prospective, randomized, placebo-controlled, triple-blind, parallel-arm, and clinical study was performed on 50 systemically healthy participants who required removal of an asymptomatic LITM. Using a 1:1 distribution, the participants were randomized into two groups (n = 25). Group L (control group) received 1.8 mL of 0.5% LB and 0.2 mL normal saline (placebo) and Group D (study group) received a blend of 1.8 mL of 0.5% LB and 0.2 mL (20 µg) DEX. The primary outcome variable was the duration of POA and hemodynamic stability, and the secondary variable was the total number of analgesics required postoperatively for up to 72 h. The participants were requested to record the time of rescue analgesic use and the total number of rescue analgesics taken. The area under the curve was plotted for the total number of analgesics administered. The pain was evaluated using the visual analog scale. Data analysis was performed using paired students and unpaired t-test, Mann–Whitney U test, Chi-square test, and receiver operating characteristic analysis. Statistical significance was set at P < 0.05.ResultsThe latency, profoundness of anesthesia, and duration of POA were statistically significant (P < 0.05). The differences between mean pain scores at 6, 12, 24, 48, and 72 h were found to be significant (each P = 0.0001). Fewer analgesics were required by participants in group D (2.12 ± 0.33) than in L (4.04 ± 0.67), with a significant difference (P = 0.0001).ConclusionPerineurally administered LA with DEX is a safe, effective, and therapeutic approach for improving latency, providing profound POA, and reducing the need for postoperative analgesia.

Effect of dexamethasone, ketoprofen and cold compress on postoperative sequelae in mandibular third molar surgery: A randomized clinical trial

PurposeThis is a single blinded, randomized clinical trial to assess and compare the effect of dexamethasone, icepack and ketoprofen on the postoperative pain, swelling and trismus following surgical removal of impacted lower third molar (ILTM). MethodologyConsecutive patients who require surgical extraction of ILTM with a modified Pederson difficulty index score of 5-6 were recruited. Ninety patients were randomly allocated into 3 groups. Group A received 100mg of ketoprofen and group C received 8mg of dexamethasone per-oral 1hr preoperatively. Subjects in group B used a pre-standardized ice pack held against the skin over the angle of the mandible for 6 hours postoperatively. Swelling, trismus and pain were recorded on postoperative day 1, 2 and 7. ResultA total of 78 subjects with mean age of 27.8 ± 4.9 years comprising of 59.0% males completed the study. There were no statistically significant difference found in the sociodemographics. Subjects in the dexamethasone group showed a significant reduction in pain on postoperative day 1 and 2, and in swelling on all postoperative days in review. ConclusionOral dexamethasone showed superior reduction in postoperative pain and swelling after ILTM surgery. It also offers an effective, painless, easy route of administration and single dose safety profile. However, icepack provides a low-cost option and may be of importance in low resource settings or in patients allergic to dexamethasone.

The prediction of impacted versus spontaneously erupted mandibular third molars

BackgroundTo evaluate the predictive capacity of orthodontists and oral maxillofacial surgeons (OMFSs) in anticipating the process of impaction or eruption of lower third molars (L3Ms) through the examination of serial panoramic radiographs.MethodsSixty-eight lower third molars (L3Ms) were analyzed in 34 orthodontically treated patients without extraction. Twenty-seven OMFSs and 27 orthodontists were randomized in order to analyze the radiographs. Initially, the evaluators issued the prognosis for the L3Ms in XR1, a posterior for the XR1 + XR2. Concordance of the diagnosis was examined using Kappa statistics, and the differences between the groups of evaluators were examined using the chi-square test at p<0.05.ResultsWhen examining XR1 in cases where the teeth erupted spontaneously, the prognostic accuracy rate for OMFSs and orthodontists was similar, 63 and 65.7%, respectively (p=0.19). When evaluating XR1 + XR2, the accuracy among orthodontists (60%) was similar to that reported for XR1 (p=0.19), while OMFSs presented a reduction in the accuracy (55.3%, p<0.0001). When the L3Ms remained impacted, accuracy in XR1 was lower than in spontaneously erupting L3Ms, although similar between OMFSs (50.1%) and orthodontists (49.1%). Furthermore, for impacted L3Ms, when examining XR1 + XR2, the OMFSs presented a significant higher accuracy (71.8%, p <0.0001).ConclusionsOrthodontists and OMFSs seem unable to predict spontaneous eruption or impaction of the lower third molars from single or longitudinal x-rays. When adding a second longitudinal x-ray, orthodontists and more significantly OMFSs tend to indicate more extractions.

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.

Effect of Genetic and Environmental Factors on the Impaction of Lower Third Molars

The aim of this retrospective study was to evaluate the impact of genetic and environmental factors on the impaction of lower third molars using a classical twin study by evaluation of the third molar eruption space and M3 angulation. The study group consisted of 212 twins: 80 dizygotic and 132 monozygotic twins with digital panoramic radiograms and lateral cephalograms. The zygosity of twins was determined using 15 highly polymorphic DNA regions from the venous blood of twins. The results showed that differences between siblings in the dizygotic and monozygotic twin pairs were not statistically significant. The most fitting model for the angulations of lower third molars was AE (additive genetic and specific environmental effect), where the additive genetic factors had up to 88% influence and the specific environment up to 27%. Therefore, the ACE( additive genetic, common and specific environmental effect), model showed higher significance for the lower third molar eruption level where additive genetic estimates reached 71%, a specific environment contributed up to 15% and the common environment reached 32%. The conclusion was that a considerable proportion of the third molar impaction could be attributed to additive genetic effects and the common environment, whereas the specific environment had a lower, but significant impact.

Can diagnostic changes caused by cone beam computed tomography alter the clinical decision in impacted lower third molar treatment plan?

This study observed whether changes in diagnosis caused by analysis of three-dimensional images can lead to alterations in the treatment plans of impacted lower third molars (ILTMs). Sets of panoramic (PAN) - cone beam computed tomography (CBCT) of 218 patients were assessed for ILTM classification, contact with mandibular canal, contact and resorption of the lower second molar (LSM), intraoperative planning and post-operative expectations. Percentage agreement and McNemar test compared PAN vs CBCT assessments. Logistic regression analyzed the dependency of change in surgical planning considering the changes in diagnostic features; descriptive statistics was used to observe the expectation of post-operative complications and paresthesia. Differences were found between PAN vs CBCT for classification of impaction and positioning, LSM relationship, choice for crown and root sectioning and expectation of post-operative complications (all with p < 0.001). Logistic regression indicated that the change in diagnosis caused by CBCT examination did not change the clinical decision to extract ILTM but altered the planning of intraoperative steps such as osteotomy, crown sectioning and relaxing incision. The expectation of post-operative complications decreased when professionals planned the ILTM removal using tri-dimensional images. We concluded that changes in the diagnosis after CBCT examination can lead to alterations in the treatment plan of impacted lower third molar.

The role of COX-2, caspase-1 and IL-17 in pericoronitis-related inflammation due to lower third molar impaction

Background: Inflammation of the pericorona due to lower third molar impaction (LTMI) is often diagnosed as pericoronitis. Expression of cyclooxigenase-2 (COX-2) and caspase-1 may be induced by lipopolysacharide (LPS) and cause pyroptosis with minimal inflammation. When LPS activates toll-like receptor (TLR-4), NOD-like receptors containing domain pyrin 3 (NLRP3) inflammasome will activate the release of pro-caspase-1 to caspase-1, followed by the secretion of interleukin (IL)-1β. IL-1β and IL-23 which induces CD4+ Tcells (Th17) to produce IL-17 as a pro-inflammation cytokine. Purpose: This study aimed to identify the respective roles of COX2, caspase-1 and IL-17 in pericoronitis inflammation of the pericorona due to LTMI. Methods: Frozen section samples were produced through LTMI pericorona tissue biopsy using material provided by the Dental and Oral Clinic at Muwardi Hospital, Surakarta. The paraffin block produced was subsequently cut using a clean microtome with the resulting thin slices being placed on an object glass coated with polylysine. A diagnosis of pericoronitis was subsequently made by a pathologist. Immunohistochemical staining for COX-2, caspase-1 and IL-17 was carried out by indirect tyramide signal amplification (TSA) method. Photos were obtained by means of 100X, 200X, 400X and 1000X objective lensed microscopes to qualitatively assess the above mentioned protein expressions. T-Test was conducted in order to establish the difference in expression between the control group and pericoronitis due to LTMI. Results: The presence of a brownish yellow color indicated the expression of COX-2, caspase-1 and IL-17 in pericorona epithelial cells which visible expression categorized as moderate (30-70%). The mean expression of COX-2, caspase-1 and IL-17 was categorized as mild and there was no significant difference between the expression of the three proteins. Conclusion: COX-2, caspase-1 and IL-17 play an important role in the phyroptosis signal of LTMI pericoronitis in cases of low inflammation.

Epidermal Growth Factor Receptor (EGFR) Expression and Incidence of Cystic Changes in Asymptomatic Dental Follicles in Smoking Patients

Background: Smoking is a well-known predisposing factor for pathological changes in oral tissues. Epithelial proliferation due to smoking is caused by the increased expression and activation of epidermal growth factor receptor (EGFR), which is a protooncogen. Aims: The objective of this study was to evaluate Epidermal Growth Factor Receptor (EGFR) expression and intensity and the incidence of histologically diagnosed cystic changes in asymptomatic impacted lower third molar (ILTM) follicles of smoking and non-smoking patients. Materials and Methods: A hundred dental follicles obtained from asymptomatic ILTMs were examined histopathologically and immunohistochemically using antibody against EGFR. After initial microscopic analyses, 18 specimens were excluded from the study because of lack of epithelium. The final EGFR expression intensity score of samples was determined by multiplying the percentage of positively stained cells by the staining intensity. Results: Cystic changes were detected with microscopic evaluation. In the smoking group, the relation between EGFR scores and cystic changes were found statistically significant (p<0.05). The relation of age and EGFR scores that showed cystic changes in the smoking group was also found statistically significant (p<0.05). Conclusion: Asymptomatic ILTMs of the smoker patients may be suspected for the higher possibility of cystic changes compared with the nonsmokers. Smoking may be considered as a factor for the decision of removal of an asymptomatic ILTM. Key Words: EGF Receptor, cystic changes, dental follicles, smoking

Impaction of lower third molars and their association with age: radiological perspectives

BackgroundThird molars are the most commonly impacted teeth, and their extraction is the most commonly performed procedure in oral and maxillofacial surgery. The aim of the present study is to describe the pattern of mandibular third molar impaction and to define the most appropriate age for prophylactic extraction of mandibular third molar teeth.MethodsA total of 1198 orthopantomographs (OPGs) with 1810 impacted lower third molars were reviewed by two authors. The pattern of eruption in relation to patient’s age was examined using standard radiographic points and angles. Statistical analysis was performed using SPSS for Windows release 16.0 (SPSS Inc., Chicago, IL, USA).ResultsIn patients older than 20 years, vertical pattern of impaction was the most common (21.4%); while in young patients; horizontal impaction was more common (21.3%). Furthermore, there was a constant pattern of increase in Pell-Gregory ramus class 1 with increasing age, as the prevalence of class 1 was 0% at age 18 years compared to 54.9% at the age of 26 years.ConclusionFrequency of vertical impaction of lower third molars was seen more at an older age (> 20 years) in this study, with an increase in the retromolar space. Late extraction of mandibular third molar teeth (i.e. after the age of 20) is therefore recommended when prophylactic extraction is considered.

Histopathological Evaluation of Dental Follicle Associated with Radiographically Normal Impacted Mandibular Third Molars.

Introduction:Removal of impacted mandibular third molar is a common procedure performed in oral surgery. Indications for removal of the third molar have generated much discussion in dentistry. The presence of pericoronal pathosis is generally accepted reason for the extraction of impacted mandibular third molars. Radiographic pathology is usually defined as a pericoronal radiolucency measuring about 2.5 mm or larger in any dimension.Purpose:This study aims to evaluate the histopathologic changes in radiographically normal dental follicles associated with impacted mandibular third molars.Methods:After extraction of 50 impacted mandibular third molars, dental follicle associated with extracted teeth was placed in 10% formalin solution. Histopathologic examination was done. The type of pathological changes was recorded based on histopathological reports. Patients’ gender, age, and radiographic parameters were recorded.Results:Cystic changes were found in 24% of radiographically normal impacted mandibular third molars. Significant cystic changes were observed in position A vertically impacted lower third molars (ILTMs). Male predominance for cystic change was seen with a male–female ratio of 2:1.Conclusion:The result of the present study shows that radiographic analysis may not be reliable technique for the diagnosis of cystic changes in ILTM. The presence of cystic changes can be found even in radiographically normal impacted mandibular third molars. Hence, we recommend that impacted mandibular third molars should be removed and histopathological analysis should be conducted on all surgically extracted dental follicles.

CBCT evaluation of the tridimensional relationship between impacted lower third molar and the inferior alveolar nerve position.

The aim of this study is to evaluate if the statistical significant relations between the measures taken exists or not and to show how the 3D reconstruction could be help the oral surgeon in all those instances in which it may have a direct impact on the planning of the surgical steps. Thanks to use of NobelClinician™ Software it was possible to analyze 200 mandibular tomography computerized, random selected, and create a 3D reconstruction of mandibular bone, point out dental structure of wisdom tooth and the way of IAN. Statistical analysis was performed using the Statistical Package for Social Sciences. One way ANOVA test was used to measure the association between each independent variable and the outcome variable, followed by the post-hoc least significant difference (LSD) test for intergroup differences. Two independent variables were significant predictors for risk to have the distance 0 mm from IAN to apex: "Ramus relationship/space available" and "depth". The 3D reconstruction software provide surgeons with an additional planning tool, offering: immediate and neat visualization of the noble structures that have to be respected and their localization in the three spatial planes; the exact morphology of the relevant root apex; a 360° view of the relationship between the IAN and the third molar and the exact point in which the root is in relationship with the canal.

Does Smoking Affect the Ki67 and p53 Expressions in Asymptomatic Fully Impacted Lower Third Molar Follicles?

Ki67 and p53 protein expressions are the most widely used markers to show the pathologic proliferation and early-stage tumoral alterations in vital tissues. The aim of this study was to compare Ki67 and p53 protein expressions in smokers' and nonsmokers' pericoronal follicles of asymptomatic impacted lower third molars (ILTMs). A cross-sectional study was planned. The study sample was derived from a population of patients who presented for evaluation and operative treatment of asymptomatic ILTMs. The predictor variable was smoking status, defined as smoker or nonsmoker. Outcome variables were Ki67 and p53 protein expressions in ILTM follicles. Other study variables were age, gender, tooth position, cigarette pack-year, epithelial layer staining, and inflammation. Independent-samples t test analyses were conducted with SPSS 10.0 (SPSS, Inc, Chicago, IL), with statistical significance set at a P value equal to .05. The study sample was composed of 70 patients (35 in the smoker group) who contributed 60 follicles. There were statistical differences between the 2 groups for variables Ki67 and p53. Mean expression levels of Ki67 were 3.93 ± 2.17 and 2.48 ± 2.09, respectively, for smokers and nonsmokers (P = .011). Mean expression levels of p53 were 5.32 ± 1.98 and 3.06 ± 2.34, respectively, for smokers and nonsmokers (P = .000). The present study showed that dental follicles of smokers have higher Ki67 and p53 protein expressions than nonsmokers' follicles.

Shear bond strength of orthodontic attachments bonded to impacted teeth under in vivo and in vitro conditions

To evaluate and compare the shear bond strength (SBS) of stainless steel and gold-plated attachments to impacted lower third molars in vivo and in vitro with a light-cured orthodontic resin. Sixteen patients with bilaterally full soft tissue impaction of lower third molars were recruited on a voluntary basis from an oral and maxillofacial surgery department. A split-arch technique was used. Following surgical exposure of the crown, the tooth was luxated but not extracted. Then, two attachments (one stainless steel button and one gold-plated eyelet) were bonded to the labial enamel surface of the loosened tooth. Five minutes later, the luxated tooth was removed from its socket. In each patient, the impacted tooth on the other side was extracted, and attachments were bonded in vitro. The SBSs of the attachments were evaluated. For comparison, analysis of variance and multiple range tests were used (α = 0.05). Statistically significant differences were evident in attachment adhesion to the impacted tooth surfaces among the four groups (p < 0.001). Superior SBS values were obtained for stainless steel button groups bonded in vitro. The mean bond strengths of the groups bonded in vitro were better than those of the same groups bonded in vivo. Although the in vitro-bonded groups showed higher SBS values, adequate bond strength is possible with stainless steel buttons bonded in vivo.

Incidence of cystic changes in impacted lower third molar

To assess the incidence of cystic changes in the impacted lower third molar (ILTM) in which the pericoronal (follicular) space is less than 2.5 mm as measured from the radiograph. The relationship between the cystic changes and patient's age, sex, and angular position and contact of ILTM with adjacent tooth was also evaluated. Follicular space less than 2.5 mm as measured from the panoramic radiograph was included in the study. A total of 73 tissue samples collected during the extraction ILTM were examined histopathologically. Then the data were analyzed for associations with age, sex, angular position, and contact of the ILTM with an adjacent tooth. There were 37 male and 36 female patients, age ranging from 17 to 35 years (mean 23.95 years). Out of 73 specimens, 17 (23.3%) showed cystic changes; among them 16 (22.1%) showed dentigerous cysts and 1 (1.2%) showed odontogenic keratocysts. Most of the cystic changes occurred in the 26-30 year age range. The cystic changes showed male predominance but could not gain statistical significance. The relationship between cystic changes and angular position was statistically significant (P < 0.05). Higher probability was found in distoangular positioned ILTM. The relationship between cystic changes and communication of ILTM with the second molar was not statistically significant. Incidence of cystic changes in ILTM justifies extraction of the impacted tooth associated with symptoms. The decision to extract or not to extract impacted third molar should be individualized, rather than generalized.

Histopathologic evaluation of follicular tissues associated with impacted lower third molars

Context:Previous studies have reported that the dental follicular tissues associated with impacted lower third molars (ILTMs) may undergo cystic degeneration and/or neoplastic transformation. This is especially likely when the pericoronal space is >2.5 mm on intraoral radiographs and >3 mm on panoramic radiographs and to examine dental follicular tissue for pathological changes in patients with ILTMs and pericoronal radiolucencies of <2.5 mm.Aim:Histopathological evaluation of follicular tissues associated with ILTMs.Materials and Methods:The morphology of the hematoxylin and eosin-stained follicular tissues of 146 such impactions were studied.Results:On microscopy, no cystic structures with fibrous walls were identified. 85 cases (58%) showed fibrous or myxomatous connective tissue and no epithelial elements. 61 cases (42%) showed epithelial elements in addition to fibrocollagenous tissue. Of these, 16 cases exhibited epithelium, of which 13 cases showed reduced enamel epithelium and three cases showed squamous metaplasia/non-keratinized stratified squamous epithelium.Conclusions:All asymptomatic unerupted third molars with pericoronal radiolucency of <2.5 mm should be retained since they do not exhibit cyst formation microscopically.

Effect of single dose preoperative intramuscular dexamethasone injection on lower impacted third molar surgery

This study aimed to investigate the effects of dexamethasone intramuscular injection 1h preoperatively, in reducing facial swelling, pain and trismus after lower impacted third molar (LITM) surgery. Twenty healthy Thai patients with both LITM surgical extraction were enrolled in the study. The washout period was 1 month after the first operation. Clinical assessment of the facial swelling, pain and trismus were measured before and after operation for 7 days and the patient's total analgesic consumption was recorded. The level of significance used in the statistical decisions was P<0.05. Preoperative intramuscular injection of single-dose 8mg dexamethasone reduced postoperative swelling after LITM surgical extraction significantly on the second postoperative day, but immediately after surgery and on day 7 after the surgical extraction, no significant difference was found between the dexamethasone and control groups. Dexamethasone also reduced postoperative pain after LITM surgical extraction significantly on postoperative days 2 and 7. Additionally, the amount of paracetamol decreased significantly. There were no significant differences in trismus in the study and control groups 7 days after LITM operation. Single-dose intramuscular injection of dexamethasone can reduce postoperative facial swelling and pain, without affecting trismus after LITM surgical extraction.

Unerupted lower third molars and their influence on fractures of the mandibular angle and condyle

Our aim was to assess the influence of the presence and state of impaction of mandibular third molars on the incidence of fractures of the mandibular angle and condyle. We designed a retrospective study of patients who presented for the treatment of mandibular fractures from January 2006 to April 2011. The independent variables were the presence and degree of impaction of lower third molars, and the outcome variables were the incidence of fractures of the mandibular angle and condyle. The information was acquired from hospital records and panoramic radiographs. Personal data included age, sex, mechanism of injuries, and number of fractures of the mandibular angle and condyle. We studied 110 fractures of the mandibular condyle and 80 of the angle. The incidence of fractures of the mandibular angle was higher in the group with incompletely erupted third molars (37/80, p<0.001) and that of condylar fractures was higher in the group without (67/110, p<0.001). An incompletely erupted third molar reduces the risk of condylar fractures and increases the risk of fractures of the mandibular angle.