Mandibular third molar impaction: review of literature and a proposal of a classification

Lingual nerve revisited-A comprehensive review Part II: Surgery and radiology

The lingual nerve (LN) is a branch of the mandibular division of the fifth cranial nerve, the trigeminal nerve, arising in the infratemporal fossa. It provides sensory fibers to the mucous membranes of the floor of the mouth, the lingual gingiva, and the anterior two-thirds of the tongue. Although the LN should rarely be encountered during routine and basic oral surgical procedures in daily dental practice, its anatomical location occasionally poses the risk of iatrogenic injury. The purpose of this section is to consider this potential LN injury risk and to educate readers about the anatomy of this nerve and how to treat it.

Retrospective study of the morphology of third maxillary molars among the population of Lower Silesia based on analysis of cone beam computed tomography

INTRODUCTION

Understanding the anatomy of root canal systems and being aware of their variations is crucial for successful endodontic treatment. Specifically, the intricate and diverse nature of the root anatomy in maxillary third molars poses a significant challenge for dental clinicians. The study analyzed the morphology of the root canal system in maxillary third molars among residents of the Lower Silesia region in Poland using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

This retrospective cross-sectional imaging study was conducted at the X-Ray Diagnostics Laboratory of the Academic Dental Polyclinic of Wroclaw Medical University, Poland. The study evaluated 316 CBCT scans and included 196 maxillary third molars. They were obtained from 118 females and 78 males over the age of 18, in the period from January to April 2022 (three consecutive months). The number of roots, root canals, and root canal configurations according to Vertucci's classification were analyzed.

RESULTS

Three-rooted maxillary molars were found most often (64.29%), followed by single-rooted (24.49%), two-rooted (7.65%), and four-rooted (3.57%) teeth. Among all the roots examined, Vertucci Type I root canals were the most prevalent. Our research found that single-rooted forms (40 teeth, 33.89% vs. 8 teeth, 10.26%, p = 0.0013) of maxillary third molars were significantly more common in females than in males. However, three-rooted forms (62 teeth, 79.49% vs. 64 teeth, 54.24%, p = 0.0013) of maxillary third molars were significantly more common in males than in females.

DISCUSSION

In the Lower Silesia region, the typical maxillary third molar in the Polish population has a three-rooted structure with Vertucci Type I root canal configuration. We noted a sex-dependent correlation in maxillary third molar morphology, with single-rooted forms more prevalent in women and three-rooted forms in men.

Awareness of patients with impacted teeth about impacted teeth in Turkey: A questionnaire study

Objective

The aim of this study is to evaluate the knowledge and awareness levels of patients who have at least one impacted tooth and who had previously applied to the dentist.

Study design

This study was conducted in patients aged 15 years and older who applied to Ordu University Faculty of Dentistry for routine examination and agreed to fill out the questionnaire form. A total of 325 people participated in the survey conducted to determine the awareness of patients applying to the faculty of dentistry about their existing impacted teeth. A Pearson's chi-square test was used for hypothesis testing when expected frequencies exceeded 5.

Results

It was determined that 56.9 % (185) of the participants were aware of their existing teeth, while 43.1 % (140) were not aware. When the patients were evaluated according to the institutions they had visited, it was seen that the group who were most aware of the presence of impacted tooth were those who apply to the faculty of dentistry (74.4 %). The rate of being informed by dentists in the institutions that they had previously visited was higher in patients with university or post-university graduates (p < 0.05). The most common information given by the dentists to the patients about their impacted dental problems was that the tooth should be followed up (40.4 %), while the removal of the tooth constituted 28.4 % of the information given.

Conclusion

This study showed that although patients are aware of their existing impacted teeth, their level of knowledge about the risks it may pose is low. For a healthy oral care and health, patients should be adequately informed about impacted teeth.

An Observational Study on Cystic Alterations in Normal Dental Follicles Associated with Impacted Lower Third Molar for Early Intervention

AIM

To evaluate the cystic changes in the radiographically normal dental follicle associated with impacted mandibular third molar.

MATERIALS AND METHODS

This study was conducted on 80 patients. Samples were selected using a convenient sampling technique from the patients who had impacted mandibular third molars in Pell and Gregory's positions B and C, with follicular space less than 2.5 mm in diameter. After surgical removal of an impacted tooth, the dental follicle was sent for histopathologic evaluation.

RESULTS

Pathologic alterations were found in 19% of cases out of 80 samples. Odontogenic keratocystic and dentigerous cystic changes were found in 7% of cases. A statistically significant cystic alteration was found in female patients and distoangular impacted teeth.

CONCLUSION

This study shows a significant cystic alteration in the radiologically normal dental follicles. Clinical and radiographic features alone may not be a reliable indicator of the absence of pathology. Early intervention of impacted teeth will help to reduce morbidity due to the development of pathology.

CLINICAL SIGNIFICANCE

This study will help educate patients on the risks of retaining impacted teeth, based on scientific facts, in order to minimize the risks and to assess the correlation of pathologic alterations with the depth of impaction and angular position of the impacted tooth.

Criteria for early diagnosis of mandibular third molar agenesis based on the developmental stages of mandibular canine, first and second premolars, and second molar: a retrospective cohort study

BACKGROUND

Permanent first molars with severe dental caries, developmental defects, or involved in oral pathologies are at risk of poor prognosis in children. Accordingly, using the third molar to replace the first molar can be a good treatment option when third molar agenesis is predicted early. Thus, this retrospective cohort study aimed to develop criteria for early detection of mandibular third molar (L8) agenesis based on the developmental stages of mandibular canine (L3), first premolar (L4), second premolar (L5), and second molar (L7).

METHOD

Overall, 1,044 and 919 panoramic radiographs of 343 males and 317 females, respectively, taken between the ages of 6 and 12 years were included. All developmental stages of L3, L4, L5, L7, and L8 were analyzed based on the dental age, as suggested by Demirjian et al. The independent t-test was used to assess age differences between males and females. The rank correlation coefficients were examined using Kendall's tau with bootstrap analysis and Bonferroni's correction to confirm the teeth showing developmental stages most similar to those of L8s. Finally, a survival analysis was performed to determine the criteria for the early diagnosis of mandibular third molar agenesis.

RESULTS

Some age differences were found in dental developmental stages between males and females. Correlation coefficients between all stages of L3, L4, L5, and L7 and L8 were high. In particular, the correlation coefficient between L7 and L8 was the highest, whereas that between L3 and L8 was the lowest.

CONCLUSION

If at least two of the following criteria (F stage of L3, F stage of L4, F stage of L5, and E stage of L7) are met in the absence of L8 crypt, agenesis of L8 can be confirmed.

Three-dimensional facial swelling evaluation of pre-operative single-dose of prednisone in third molar surgery: a split-mouth randomized controlled trial

BACKGROUND

Facial swelling, pain, and trismus are the most common postoperative sequelae after mandibular third molar (M3M) surgery. Corticosteroids are the most used drugs to reduce the severity of inflammatory symptoms after M3M surgery. This study aimed to evaluate the effect of a single pre-operative dose of prednisone on pain, trismus, and swelling after M3M surgery.

METHODS

This study was designed as a split-mouth randomized, controlled, triple-blind trial with two treatment groups, prednisone (PG) and control (CG). All the parameters were assessed before the extraction (T0), two days (T1), and seven days after surgery (T2). Three-dimensional evaluation of facial swelling was performed with Bellus 3D Face App. A visual analogue scale (VAS) was used to assess pain. The maximum incisal distance was recorded with a calibrated rule to evaluate the trismus. The Shapiro-Wilk test was used to evaluate the normal distribution of each variable. To compare the two study groups, the analysis of variance was performed using a two-tailed Student t-test for normal distributions. The level of significance was set at a = 0.05. Statistical analysis was conducted using the software STATA (STATA 11, StataCorp, College Station, TX).

RESULTS

Thirty-two patients were recruited with a mean age of 23.6 ± 3.7 years, with a male-to-female ratio of 1:3. A total of 64 M3Ms (32 right and 32 left) were randomly assigned to PG or CG. Surgery time recorded a mean value of 15.6 ± 3.7 min, without statistically significant difference between the groups. At T1, PG showed a significantly lower facial swelling compared to CG (PG: 3.3 ± 2.1 mm; CG: 4.2 ± 1.7 mm; p = 0.02). Similar results were recorded comparing the groups one week after surgery (PG: 1.2 ± 1.2; CG: 2.1 ± 1.3; p = 0.0005). All patients reported a decrease in facial swelling from T1 to T2 without differences between the two groups. At T1, the maximum buccal opening was significantly reduced than T0, and no difference between PG (35.6 ± 8.2 mm) and CG (33.7 ± 7.3 mm) (p > 0.05) was shown. Similar results were reported one week after surgery (PG: 33.2 ± 14.4 mm; CG: 33.7 ± 13.1 mm; p > 0.05). PG showed significantly lower pain values compared to CG, both at T1 (PG: 3.1 ± 1.5; CG: 4.6 ± 1.8; p = 0.0006) and T2 (PG: 1.0 ± 0.8; CG: 1.9 ± 1.4; p = 0.0063).

CONCLUSION

Our results showed that pre-operative low-dose prednisone administration could reduce postoperative sequelae by improving patient comfort after M3M surgery and reducing facial swelling two days and one week after surgical procedures.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov - NCT05830747 retrospectively recorded-Date of registration: 26/04/2023.

Can the Position of the Impacted Third Molars Be an Early Risk Indicator of Pathological Conditions? A Retrospective Cone-Beam Computed Tomography Study

Objectives

The aim of this retrospective study was to evaluate the prevalence of pathologies associated with impacted third molars in relation to tooth position on cone-beam computed tomography images.

Material and Methods

In 348 cone-beam computed tomography images, the position of 640 impacted third molars (mesiodistal angulation, buccolingual inclination, impaction depth, and contact point localization) and the presence of pathologies (distal caries, external root resorption, marginal bone loss, and pathological follicular space) were evaluated. The data were analysed statistically with a significance level set at P < 0.05.

Results

Distal caries was mostly detected in relation to Class A (20.4%) and contact point at (12.5%) and above (10.5%) the cementoenamel junction (CEJ) (P = 0.000; P < 0.05). External root resorption and marginal bone loss were more common in mesioangular angulation (52.3% and 80.1%, respectively), Class C (53% and 73.8%, respectively), and contact point below the CEJ (53.2% and 73.3%, respectively) (P = 0.000; P < 0.05). Lingual inclination was identified as a new risk factor for associated pathologies (P < 0.05). Pathological follicular space was significantly more likely to occur in those with inverted angulation (100%) and absence of contact (31.5%) (P = 0.000 and P = 0.010, respectively; P < 0.05).

Conclusions

Pathologies arising in second molars in relation to impacted third molars are significantly associated with the three-dimensional position of impacted third molars, and watchful monitoring or prophylactic removal of impacted third molars should be considered, taking into account the relevant risk parameters for the related pathologies.

[Classification of lower impacted third molars position and their interrelationship with mandibular canal]

Classification of lower Impacted third molars position and their interrelationship with mandibular canal have a great scientific, theoretical and practical importance. An attempt to systematize and classify all anatomical impacted third molars position has been made by many authors. Based on our scientific literature search, we found: 8 impacted third molars classifications, 7 third molars and mandibular canal interposition classifications, as well as 5 classifications of mandibular canal anatomical branching variants. Most classifications are proposed by the author to predict third molar eruption perspective, determine level of operation complexity and prevent mandibular canal damage. New clinical classification development of impacted third molars interrelationship with mandibular canal, which combined the radiological PR, CBCT criteria, neurovascular bundle trauma prognosis, and operative technic choice can be actual.

[General ideas about the stages, classifications, pathological conditions during the lower third molars eruption in humans. Literature review. Part 2]

The article is a review of literature data on the stages, classifications, pathological conditions during the eruption of the lower third molars in humans. The authors analyzed the established knowledge about clinical and morphological changes at various stages of eruption of the lower third molars, studied new data describing the pathogenetic, histological and biochemical features of their development, packaging, movement to the occlusal plane. The literature review helped to identify a series of current trends that define a number of key hypotheses that summarize the accumulated material and indicate different opinions on the topic under study, which confirms the prospects and relevance of continuing research.

Impacted Mandibular First Molar: A Rare Riddle

Tooth impaction incidence is in the range of 5.6 to 18.8% of the population. Eruption failure of the first permanent molar is very rare; the prevalence is 0.01% of the population. The permanent molars are of particular importance in providing adequate occlusal support as well as coordinating facial growth. Failure of the eruption of permanent molars might lead to an array of complications like a reduction in the vertical dimension, extrusion of the antagonist teeth, a posterior open bite, inclination and resorption of adjacent teeth, and cyst formation. Various treatment modalities for impacted teeth include periodic observation, orthodontic relocation, and partial dislocation. More invasively, surgical exposure and extraction of teeth before prosthetic treatment may be performed. It is imperative to diagnose and manage the condition early, as delayed treatment may result in a myriad of problems, like a decreased force of the spontaneous eruption, a decreased percentage of treatment success, and a prolonged period of treatment, increasing the complications furthermore. Because of the importance of permanent molars, eruptive guidance is required before impacted tooth extraction. This article summarizes a case in which the surgical-orthodontic combined approach to the impacted mandibular first molar avoided the need for prolonged orthodontic treatment that would have required repositioning the deeply impacted first molar to the dental arch. As an outcome, patient satisfaction improves.

Compression of the Inferior Alveolar Canal by Mandibular Third Molar among Images Taken from Patients Visiting Dental Imaging Centres of Kathmandu: A Descriptive Cross-sectional Study

INTRODUCTION

Third molars are common teeth to be impacted. The position of mandibular third molar is such that it is in close contact with inferior alveolar canal which may lead to nerve damage during its removal. So, this study was conducted to find out the prevalence of compression of inferior alveolar canal by mandibular third molars.

METHODS

This descriptive cross-sectional study was conducted on images collected from Dental Imaging Centers of Nepal from 25th June 2020 to 15th February 2021 after obtaining ethical clearance from Nepal Health Research Council (Reference number: 2100). A convenience sampling method was used to collect 433 cone-beam computed tomography images showing the relation between the third molars and inferior alveolar canal. Data were analyzed using the Statistical Package for the Social Sciences version 16. Point estimate at 95% confidence interval was calculated along with frequency and proportion for the binary data.

RESULTS

Out of 433 images, 135 (31.17%) (26.80-35.53 at 95% Confidence Interval) images showed compression of inferior alveolar nerve by mandibular third molar. The study result indicated that 16 (11.85%) buccally placed, 50 (37.03%) lingually placed and 69 (51.11%) inferiorly placed inferior alveolar canal were compressed by apices of mandibular third molars.

CONCLUSIONS

The prevalence of compression of inferior alveolar canal by mandibular third molar was found to be similar to other studies done in similar settings. Compression of the canal was more evident when inferior alveolar canal is situated lingually.

The Correlation between Impacted Third Molar and Blood Group

Background

Blood type is among the most important genetical characteristics of any individual and is shown to be correlated with the development of a variety of illnesses including dental diseases. Finding the association of ABO and Rh blood groups and impacted tooth is important in order to predict which population is more vulnerable to grow impacted third molars that could lead to making better intervention. The present investigation tried to take a small step in that regard, by evaluating the correlation between ABO and Rh blood groups and the most commonly impacted tooth, bony impacted third molars among Iranian individuals.

Methods

The investigation was done retrospectively on patients who were referred to the Department of Oral Radiology, Shiraz University of Medical Science, Shiraz, Iran. The patients were classified according to their blood groups, and 40 patients were randomly selected for each blood type. Therefore, the impaction of their third molars was evaluated, and statistical analyses were done in order to find any association.

Results

A total of 320 participants contributed to the study; 136 (42%) were males and 184 (57%) were females. The mean age was 29 ± 6 years. Among all participants, 205 (64%) had no impacted third molar, 26 (8%) had one impacted third molar, 43 (13%) had 2 impacted third molars, 5 (1%) had 3 impacted third molars, and 41 (12%) had 4 impacted molars.

Conclusion

According to the results of the present study, nearly one out of three individuals has at least an impacted third molar in the Iranian population, being more prevalent in individuals between 20 and 30 years old. The evaluation of the relationship between the blood group and impacted third molar revealed that blood groups have no association with the impacted third molars. However, more studies with higher and diversified participants should be done to find comprehensive results.

Differences in third molar development and angulation in class II subdivision malocclusions

PURPOSE

To assess and compare the developmental stages and angulations of third molars between the class II and class I sides in class II subdivision malocclusions.

METHODS

This retrospective study was performed using panoramic x‑rays of 38 individuals (mean age: 15.5 years; 24 females, 14 males) with class II subdivision malocclusions, which were further divided into type 1 and 2 subgroups according to midline deviation, and a control group of 42 individuals (mean age: 17.0 years; 30 females, 12 males) with normal occlusion. Third molars were categorized using the developmental stages defined by the Demirjian method. Angles between the third molars and horizontal reference lines and also to the second molars were measured.

RESULTS

No difference was found in developmental stages or angulations between the left and right third molars in the control group. In the class II subdivision malocclusion cases, no difference in third molar developmental stages was observed, but the angle between the long axes of the mandibular third and second molars was significantly greater on the class II side. In the type 2 subgroup, developmental stage of the maxillary third molar was more advanced on the class II side. In both subgroups, the angles of the maxillary third molars' long axis to the interorbital plane differed significantly between the two sides.

CONCLUSION

Class II subdivision malocclusion may cause differences in third molar development and angulations between the two sides. Orthodontic treatment should be planned considering the third molars in this malocclusion.

Does Mandibular Gonial Angle Influence the Eruption Pattern of the Lower Third Molar? A Three-Dimensional Study

Lower third molars (M3M) are the most frequent impacted teeth. The aim of this study was to evaluate the correlation between M3M position and gonial angle. A retrospective cross-sectional study was conducted. The study population included patients with unilateral or bilateral M3M and underwent Cone Beam Computed Tomography. A morphometric analysis of the mandible was performed after three-dimensional reconstruction, recording gonial angle (GA), ramus high, ramus width, ramus divergency, and retromolar space. GA was the primary predictor variable. The primary outcome variable was the position of M3M analyzed in sagittal, axial, and coronal planes. Descriptive, bivariate, and multiple regression statistics were performed (p < 0.05). Study sample included 172 patients (mean age: 26.3 ± 4.6 years); 266 M3Ms were analyzed. The average GA was 122.6° ± 4.8°. A reduced GA value was significantly associated with a deeply impacted M3M in the ramus. With a progressive decrease of GA, M3M assumed a more horizontal position closer to the mandibular canal (p < 0.05). A lower GA showed a reduced retromolar space with more complex impacted M3M (p < 0.05). The results confirm a statistically significant correlation between GA and the position of M3M. Higher incidence of impacted M3M was related to a reduction of the GA value.

Piezo-surgery technique and intramuscular dexamethasone injection to reduce postoperative pain after impacted mandibular third molar surgery: a randomized clinical trial

Background

Surgical extraction of the impacted mandibular third molar is commonly associated with postoperative pain, swelling, and trismus. Usually, rotatory instruments like burs have been used for osteotomy, while Piezosurgery is an innovative technique introduced to overcome the weaknesses related to the conventional technique. In addition, Dexamethasone administration before the extraction of impacted third molars is an efficient way to reduce postoperative pain due to robust anti-inflammatory activity. The purpose of the study is to evaluate the effect of piezo-surgery and dexamethasone injection on postoperative sequelae after the surgical extraction of impacted mandibular third molars, and ultimately to compare their effect on reducing postoperative pain.

Methods

A randomized controlled clinical trial was conducted with a sample of 80 patients. Participants were divided into four groups: Group 1 (Conventional rotatory), Group 2 (Conventional rotatory with 8 mg dose of dexamethasone 30 min before surgery), Group 3 (Piezo-surgery), and Group 4 (Piezo-surgery with 8 mg dose of dexamethasone 30 min before surgery). The outcome variables were surgical working time calculated in minutes, maximal mouth opening measured in millimeters using Vernier Caliper at baseline and day 3 and postoperative pain assessed using a Visual Analog Scale (VAS) on days 1, 3, and 7.

Results

The surgical working time was longer in piezo-surgery groups compared with the conventional rotatory instruments groups (15.82 ± 3.47 vs 23.33 ± 2.54; p value < 0.0001). The lowest reduction in mouth opening between baseline and 3rd-day post-op was found in the Piezo-surgery with Dexamethasone group (mean difference = 5.0, SD = 3.9, p value < 0.0001) followed by the Piezosurgery without Dexamethasone group (mean difference = 5.8, SD = 4.5, p value < 0.0001) and the highest average was reported by the Conventional rotatory without Dexamethasone (mean difference = 9.7, SD = 4.5, p value < 0.0001. In the four groups, the mean pain score was highest on the 1st day and gradually decreased over the following days. Comparison of the 1st and 3rd postoperative pain between groups revealed a lowest mean pain score in the Piezo-surgery with Dexamethasone group, followed by Conventional rotatory with Dexamethasone group and a highest mean score in the Conventional rotatory without Dexamethasone group (p value < 0.0001).

Conclusion

The association of Piezosurgery osteotomy and Dexamethasone intramuscular injection could be an effective combination to reduce postoperative pain and trismus after impacted third molar surgery.

Trial registration: NCT04889781 (https://clinicaltrials.gov/), Date of Registration: 17/05/2021 (retrospectively registered), https://clinicaltrials.gov/ct2/show/NCT04889781?term=NCT04889781&draw=2&rank=1

Evaluation of the Effect of Surgical Extraction of an Impacted Mandibular Third Molar on the Periodontal Status of the Second Molar-Prospective Study

Dental injury to the second molar (SM) caused by the surgical extraction of the impacted third molar tends to be underestimated. The necessity of assessment of the impact of the removal of the wisdom tooth in the mandible on the second molar arose. The study group (n = 60) was the one with the second molar on the surgical side, and the control group (n = 60) was the one with the tooth on the opposite side of the alveolar arch. Before the surgery, the difficulty level was assessed according to the Pederson scale. The periodontal status of the SM was assessed by probing depth (PD), gingival index (GI), tooth mobility (TM) examination by the percussion method and resonance frequency. Measurements were taken before and after the surgery, 7 days and 8 weeks after the surgery. The study demonstrated the significant impact of the surgical removal of the wisdom tooth on the PD, GI and TM of the SM. The predicted degree of difficulty of the very difficult surgery had an influence on the increase in PD on the distal buccal and lingual surface of the SM, and on the GI in the proximity of the examined tooth. The results of the presented research confirm the necessity of the clinical assessment of the lower SM before and after the surgical removal of the impacted wisdom tooth in the mandible.

Evaluation of Vitamin D (25OHD), Bone Alkaline Phosphatase (BALP), Serum Calcium, Serum Phosphorus, Ionized Calcium in Patients with Mandibular Third Molar Impaction. An Observational Study

The aim of this study was to evaluate the levels of vitamin D (25OHD) and other bone biomarkers in patients with third molar impaction (TMI). Thirty males and 30 females with unilateral or bilateral impacted mandibular third molar, and 15 males and 15 females as a control group (CG) were recruited. Rx-OPT was used to evaluate dental position and Pederson index to measure the difficulty of the intervention. Bone biomarkers were measured through blood venous sample in TMI group and CG. Mann-Whitney test, Pearson’s correlation coefficient, linear regression model were used to compare the different parameters in the two groups. 25OHD showed lower values in TMI group than in CG (p < 0.05) with values significantly lower in bilateral impaction (p < 0.05). Pearson’s coefficient for 25OHD presented a negative correlation with the Pederson index (ρ = −0.75). Bone alkaline phosphatase (BALP) showed significantly lower dosage in TMI group than CG (p = 0.02), Pearson’s coefficient for BALP presented a negative correlation with the Pederson index. Serum calcium, serum phosphorus, ionized calcium levels in TMI and CG groups were similar and Mann-Whitney test did not significantly differ between TMI and CG. TMI could be a sign of vitamin D deficiency and of low BALP levels that should be investigated.

Review of Difficulty Indices for Removal of Impacted Third Molars and a New Classification of Difficulty Indices

BACKGROUND

A number of efforts have been made to establish a reliable assessment model for the surgical removal of impacted third molars. Although many such models have been proposed, none is considered universally applicable, and controversy remains. The earlier attempts were based exclusively on radiographic variables, whereas recent evidence is associated with nonradiographic and demographic variables.

PURPOSE

This article aimed to prepare review of the relevant literature to summarize the important indices given till date, tabulating only new indices as old indices are mentioned in almost all text books, their merits and demerits and their specificity and sensitivity (if assessed in the literature). In addition to it, authors also aimed to introduce a new descriptive classification of all indices based on pre- and postoperative assessment and further classify based on clinical, radiographic and demographic factors, surgical technique and time. This article will be of academic and practical help for residents and clinicians.

METHOD

A literature search was conducted in Medline, PubMed, Google Scholar, Science Direct and Cochrane electronic database with keywords-impacted mandibular third molar, difficulty indices, validity of, sensitivity, specificity. No publication year limit was used. The abstracts of the articles were retrieved, reviewed and sorted based on the following inclusion and exclusion criteria. Articles which include a new index, validate difficulty index, compare two or more difficulty indices, specificity and sensitivity of particular index are included. Duplicate articles, articles on complication, flap design, drug study, radiographic relation of inferior alveolar nerve, suturing, classification, only assessing factor affecting difficulty of third molar surgery are not included.

RESULTS

Total 39 (36 articles + 3 books) are included. A total of 20 individual indices were found in the literature; each has been described in brief in this review. These indices are also listed in chronological order with their specificity and sensitivity if accessed in the literature.

CONCLUSION

There is a definite need to derive and validate an user-friendly index that could be used for preoperative prediction of difficulty. To the best of our knowledge, this review including all indices till date and classification proposed is the first on this subject.

Evaluation of mandibular morphologic measurements and trabecular structure among subgroups of impacted mandibular third molars

OBJECTIVE

To investigate mandibular morphologic measurements and trabecular structures that may cause mandibular third molar (MM3) impaction according to MM3 subgroups.

METHODS

A total of 150 MM3 of 2175 panoramic radiographs (PRs) were reviewed. MM3s according to Winter (vertical), Pell & Gregory Class 1 and group: A, B, C on PRs were included in the study group. Fractal dimensions (FD) and mandibular morphologic measurements were evaluated. Statistical analysis for parametric values was performed using one-way analysis of variance (ANOVA). Statistical analysis for non-parametric values was performed using the Kruskal-Wallis H test.

RESULTS

Statistically, a significant difference was found only in terms of angle of impaction among the groups of MM3 (p < 0.05) [Winter (vertical), and Pell & Gregory Class 1 and group A, B, C]. There was no difference among groups A, B, C in mandibular morphology and trabecular structure, but group C showed different characteristics than the other groups only in terms of impaction angle.

CONCLUSION

The trabecular structure and morphometric properties except for the angle of impaction do not affect impacted MM3s with adequate retromolar space and vertical angle.

Ultrasonic techniques to obtain dental pulp from impacted third molars

Background

In the dental clinic impacted teeth are frequent findings, especially upper and lower third molars, leading to their exodontia. Among surgical techniques piezosurgery is advantageous for delicate structures in the oral cavity. Extracted teeth, usually discarded, have been revalued as biological material, providing living tissues with possible applications in regenerative dentistry. The aim was to compare cross-section methods of upper included third molars by ultrasonic piezoelectric technique to obtain dental pulp, with diamond-coated tip (DT) against titanium nitride-coated tip (TN), according to the pulp tissue cell viability and the section surface characteristics.

Material and Methods

Patients attending dental consultation were evaluated. Upper third molars (n= 24) were avulsed from 15 patients with exodontia indication, age 18-26 years old, who agreed to participate of the study. Third molars were cross-sectioned at amelocemental junction level with piezoelectric device using DT or TN inserts. Pulps were mechanic and enzymatically treated, and tissue viability determined by Trypan Blue test. Sectioned teeth were visualized using Scanning Electron Microscope (SEM). Ethical principles of biomedical research were respected; all patients gave their informed consent.

Results

Viability of pulp tissue was 84.71% not associated to sex (p= 0.141) nor to teeth position, upper right third molar or upper left third molar (p= 0.580). According to the insert used, pulp tissue viability was 85.21% with TN, similar to 84.00% with DT (p= 0.611). By SEM, cut performed by TN insert showed smooth and uniform surfaces, while DT insert surfaces were irregular, porous, with fissures.

Conclusions

Piezosurgery applied to cross-section upper third molars with both types of inserts showed differences in the cut surfaces but similar effectiveness regarding preservation of pulp tissue with high viability, thus, they could be allocated for further cellular developments. Key words:Impacted teeth, third molars, piezosurgery, regenerative dentistry.

Does the Presence of Impacted Mandibular Third Molars Increase the Risk of Bad Split Incidence During Bilateral Sagittal Split Osteotomy?

BACKGROUND

The possibility of mandibular bad spilt might happen during bilateral sagittal split osteotomy (BSSO). This study investigated the effect of impacted mandibular third molars on bad spilt incidence during BSSO.

METHODS

Totally, 140 patients under 40 years old who were candidates for BSSO surgery due to class 3 skeletal discrepancy were divided randomly into two equal groups. The impacted mandibular third molars were presented in one group during BSSO (Exposed), and the third molars were removed at least six months before surgery for the other group (Unexposed). All cases underwent BSSO using the same technique by a single surgeon. A bad split was diagnosed by inter-operative clinical examination and postoperative panoramic radiography.

RESULTS

Four bad split occurrences were observed including three patients in the group which impacted mandibular third molars were presented and one patient in the group without impacted mandibular third molars. The incidence of bad fracture in the exposed group was 3.7 times more than the unexposed group. The incidence of the bad fracture in exposed group was 3.7 times more than unexposed group. The chance of fractures in females was 1.7 times higher than males. With one year addition to the patient's age, chance of fracture increased 0.985 times more.

CONCLUSION

Overall incidence of bad split fracture in presence of mandibular third molars in females and at older ages increased during BSSO. The extraction of impacted mandibular third molars, six months before the BSSO is recommended to prevent the bad split incidence during the operation.

Reliability of Orthopantamogram in Lower Third Molar Surgery: Inter- and Intra-observer Agreement

Context:

The evaluation of relationship between the roots of impacted lower third molar (IL3M) and inferior alveolar nerve injury (IAN) with orthopantamogram (OPG) is mandatory before performing de-impaction surgery. An investigation is considered reliable if it can be reproduced by various examiners. Assessment of OPG is subjective and varies among examiners. OPG is reliable to clinicians if the interpretation is not a product of guess work.

Aim:

The aim of this study was to evaluate the magnitude of agreement among oral surgeons and oral radiologist in observing intimate relationship between IL3M and mandibular canal.

Materials and Methods:

OPGs were evaluated by two oral surgeons and one oral radiologist for nerve root relationship. All the three were from different institutions with 10–15 years of experience. The three observers were blinded from each other’s findings. A total of 127 OPGs were evaluated for inter-observer agreement. Fifty OPGs were evaluated after 60 days for intra-observer agreement.

The agreement was evaluated based on Cohen’s κ statistics.

Results:

Our results denote that the interpretation of OPG among specialists is not in good agreement. We suggest development of methods to standardize evaluation of OPG and the exposure technique to improve inter-observer agreement among the dental specialists.

Cross-Sectional Imaging of Third Molar-Related Abnormalities

Third molars may be associated with a wide range of pathologic conditions, including mechanical, inflammatory, infectious, cystic, neoplastic, and iatrogenic. Diagnosis of third molar-related conditions can be challenging for radiologists who lack experience in dental imaging. Appropriate imaging evaluation can help practicing radiologists arrive at correct diagnoses, thus improving patient care. This review discusses the imaging findings of various conditions related to third molars, highlighting relevant anatomy and cross-sectional imaging techniques. In addition, key imaging findings of complications of third molar extraction are presented.

Combined inferior alveolar nerve block anaesthesia and local infiltration anaesthesia in extraction of impacted mandibular third molars: a randomised controlled trial

Aim To compare the anaesthetic effect of combination of inferior alveolar nerve block anaesthesia and local infiltration anaesthesia with nerve block anaesthesia techniques in the extraction of mandibular third molars.Materials and methods One hundred and fifty healthy adult volunteers were divided into three groups and were administered three different local anaesthetic techniques before tooth extractions: group A (inferior alveolar nerve, lingual nerve and buccal nerve block anaesthesia with lidocaine), group B (inferior alveolar nerve, lingual nerve and buccal nerve block anaesthesia with mepivacaine) and group C (inferior alveolar nerve block anaesthesia with lidocaine and infiltration anaesthesia with mepivacaine). The patients' reported pain on anaesthesia injection and tooth extraction, the surgeon's assessment of anaesthetic effect, the severity of intra-operative bleeding and post-operative complications were evaluated.Results There was no significant difference in visual analogue scale (VAS)-pain of anaesthesia among the three groups. Compared with groups A and B, group C had reduced VAS-pain of tooth extraction scores. Additionally, the surgeon's assessment of anaesthetic effect improved and intra-operative bleeding decreased.Conclusions The combination of inferior alveolar nerve block and infiltration anaesthesia provides a stronger anaesthetic effect in the extraction of mandibular third molars.

Comparison of efficacy of ozonated water, normal saline, and povidone-iodine after surgical removal of impacted mandibular third molars: A cross-sectional study

Background:

Surgical extraction of mandibular third molars is an important and one of the most frequently performed operative procedures in dentistry. There are a variety of postoperative complications that may follow this procedure. These include pain, trismus, infection, dry socket, or alveolar osteitis. Numerous techniques have been used for reducing these morbid conditions. These range from flap designs, suture placement, use of various irrigating solutions, etc.,

Aim:

The present study aimed to compare the effectiveness of three irrigating solutions: Ozonated water, normal saline, and povidone-iodine in reducing postoperative complications following surgical removal of impacted mandibular third molars.

Materials and Methods:

A total of 100 study participants formed the sample size of this study. Study subjects were categorized into three groups: Group I (third molar surgeries using ozonated water), Group II (third molar surgeries with normal saline irrigation), and Group III (third molar surgeries using povidone-iodine irrigation). Parameters studied postoperatively were alveolar osteitis (dry socket), pain, trismus, and infection after a week interval. All data obtained were entered in Microsoft Excel 2007 worksheets and Analysis of Variance (ANOVA) as a statistical tool was employed. A P value of < 0.01 was considered statistically significant.

Results:

It was found that ozonated water provided the best statistically proven results with comparison to normal saline and povidone-iodine in reducing the incidence of alveolar osteitis or dry socket and pain. No statistically significant difference was observed in the incidence of trismus and infection rate among three studied groups.

Conclusion:

Ozonated water is the best irrigating solution when compared to normal saline and povidone-iodine in terms of reduction in pain and dry socket after a 1-week duration.

Three-dimensional measurement and analysis of mandibular characteristics in subjects with impacted mandibular second molars

OBJECTIVE

To investigate the morphological characteristics of the mandible in subjects with impacted mandibular second molars by measuring and analysing the mandible in three dimensions.

SETTING AND SAMPLE POPULATION

In this retrospective study, the data of a total of 52 609 subjects who underwent cone-beam computed tomography (CBCT) for diagnosis and treatment were reviewed. According to the inclusion and exclusion criteria, 183 subjects with impacted mandibular second molars and 176 age- and sex-matched controls were included.

METHODS

A retrospective case-control study was designed. The 183 subjects were divided into two groups: group 1 (G1) comprised 120 patients with unilaterally impacted mandibular second molars, and group 2 (G2) comprised 63 patients with bilaterally impacted mandibular second molars. Group 3 (G3) contained 176 age- and sex-matched controls. The mandible was reconstructed with nineteen landmarks using Mimics software. Twelve linear lengths and 3 angles were measured.

RESULTS

The bilateral germination gap, mandibular body width and gonion width in G1 were significantly lower than those in G3 (P < .05), while the gnathion angle and first molar width values in G1 were significantly higher than those in G3 (P < .05). The results in G2 were similar to those in G1, but the differences between G2 and G3 were greater than those between G1 and G3. There were no significant differences in the other measurements among the groups.

CONCLUSION

The mandibles of the subjects with impacted second molars were constricted in terms of the sagittal length and transverse width.

[Three-dimensional analysis of the mandible with impacted mandibular second molar]

OBJECTIVE

To study the developmental and morphological characteristics of the mandible in patients with impacted mandibular second molar and to predict the possible trend of mandibular development via three-dimensional (3D) measurement and analysis.

METHODS

A total of 88 cases of impacted group and 88 cases of control group were screened out. 3D measurements were performed by using Mimics software. A total of 23 landmark points and 17 measurements were determined. The measurements were analyzed by t-test.

RESULTS

The mandible length, the space between the first molars, the space between mandibular angles, and the width between the first molars in the impacted group were lower than those in the control group (P<0.05). Moreover, the value of the submandibular angle was higher than that in the control group (P<0.05).

CONCLUSIONS

The impacted mandible of patients with mandibular second molar showed lack of sagittal and width development, and the impacted mandibular second molar was a manifestation of its degeneration.

A Clinical, Radiographic and Histological Study of Unerupted Teeth in Dogs and Cats: 73 Cases (2001-2018)

Lack of dental eruption may be accompanied by development of dentigerous cysts and has also been rarely associated with neoplasia. However, little information is available on prevalence of unerupted teeth and associated lesions in dogs and cats. The main objective of this study was to describe the epidemiologic data of canine and feline dental patients with unerupted teeth, and assess the prevalence of associated dentigerous cysts and tumors. Secondary aims included the evaluation of possible factors implicated in cystic development, and description of the histological features of dentigerous cysts. Medical and dental records, intraoral photographs, intraoral radiographs of client-owned dogs and cats with clinically missing teeth examined between 2001 and March 2018 were reviewed. Collected data included signalment, reason for presentation, number, type, depth of inclusion and angulation of unerupted teeth, presence of cystic lesions or tumors, abnormalities affecting involved teeth, histopathological findings, performed treatment and outcome. Seventy-three animals (69 dogs and 4 cats) with 113 unerupted teeth were included. The most frequent unerupted tooth in dogs was the first premolar teeth (78%), followed by the canine and third molar teeth. Dentigerous cysts were diagnosed associated with 48 (44.4%) teeth in dogs and one out of five unerupted teeth in cats. The affected teeth in dogs were predominantly in horizontal inclination (40%) and in soft tissue inclusion (77%). Brachycephalic canine breeds were overrepresented. The only unerupted tooth in boxer dogs was the first premolar tooth (32 teeth). Ninety percentage of boxers with unerupted teeth developed associated lesions (25 dentigerous cysts and one tumor). Two ameloblastomas (one in a dog and one in a cat) and one osteosarcoma (in a dog) were diagnosed in association with three unerupted teeth. Histology was essential in diagnosing two odontogenic cysts not evident on radiographs. In all cases that were followed-up, treatment (i.e., extraction, extraction and surgical curettage, or operculectomy) appeared successful. Untreated dentigerous cysts showed progression at re-examination. None of the unerupted teeth without evidence of cyst at the time of diagnosis showed incipient cystic development. None of the evaluated factors were associated with lack of eruption and/or development of associated lesions.

Risk of lingual nerve injuries in removal of mandibular third molars: a retrospective case-control study

Background

Through the analysis of clinical data, we attempted to investigate the etiology and determine the risk of severe iatrogenic lingual nerve injuries in the removal of the mandibular third molar.

Methods

A retrospective chart review was performed for patients who had undergone microsurgical repair of lingual nerve injuries. The following data were collected and analyzed: patient sex, age, nerve injury side, type of impaction (Winter’s classification, Pell and Gregory’s classification). Ratios for the respective lingual nerve injury group data were compared with the ratios of the respective data for the control group, which consisted of data collected from the literature. The data for the control group included previous patients that encountered various complications during the removal of the mandibular third molar.

Results

The lingual nerve injury group consisted of 24 males and 58 females. The rate of female patients with iatrogenic lingual nerve injuries was significantly higher than the control groups. Ages ranged from 15 to 67 years, with a mean age of 36.5 years old. Lingual nerve injury was significantly higher in the patient versus the control groups in age. The lingual nerve injury was on the right side in 46 and on the left side in 36 patients. There was no significant difference for the injury side. The distoangular and horizontal ratios were the highest in our lingual nerve injury group. The distoangular impaction rate in our lingual nerve injury group was significantly higher than the rate for the control groups.

Conclusion

Distoangular impaction of the mandibular third molar in female patients in their 30s, 40s, and 50s may be a higher risk factor of severe lingual nerve injury in the removal of mandibular third molars.

Use of piezoelectric surgery and Er:YAG laser:which one is more effective during impacted third molar surgery?

Background

Reduction in postoperative complications is of vital considerations in impacted third molar teeth surgery. The aim of this study was to compare postoperative complications of impacted third molar surgeries for bone removal using laser, piezoelectric equipment, and conventional rotary instruments.

Methods

To address the research purpose, the investigator designed the prospective double-blind clinical trial study. The sample size was determined 20 (40 teeth) by sampling formula in any kind of operation. The data of patients were obtained in the different periods in terms of pain, trismus, swelling, ecchymosis, and patient's satisfaction and then analyzed using SPSS 20 software via paired t test and Wilcoxon and McNemar's tests.

Results

The pain immediately after surgery and 2 days and 7 days after surgery was higher in the laser group. The swelling immediately after surgery was more in the laser group but not significant. The amount of mouth opening immediately after surgery and 2 days and 7 days after surgery was significantly lower in the laser group than in the piezosurgery group. The total duration of surgery and duration of osteotomy were significantly longer in the laser group. The patient's satisfaction from surgery with piezosurgery was more than that with laser, but this difference was not significant.

Conclusion

Due to the rising demand for impacted wisdom tooth surgery, the present study suggests that hard tissue laser surgery and piezosurgery can clear the future of impacted molar surgery, and these approaches are more efficient in reducing postoperative complications compared to the conventional surgeries.

Preoperative informed consent for mandibular third molar surgeries: A survey analysis in a subset of dentists and oral surgeons in Saudi Arabia

Objectives

The objective of this study was to identify patterns of obtaining preoperative informed consent from patients undergoing mandibular third molar surgeries, in a subset of general dentists and oral surgeons in Saudi Arabia, and to compare the consenting patterns based on the clinician’s rank, years of experience, place of work and gender.

Methods

A prospective questionnaire based study was designed and data was obtained through an online survey from 102 participants who were selected for the study. Demographic information, clinician experience, type of informed consent obtained and information related to discussion of legal implications and complications were collected. Descriptive analysis of the obtained data and statistical comparisons using cross tabulation and Pearson Chi-Square test with a 95% significance level (P < 0.05) were done between the independents demographic variables and dependent variables pertaining to patterns of preoperative consenting.

Results

The survey response rate was 81.3% (n = 83), with 59.04% general dentists and 40.96% oral surgeons. The ratio of male to female respondents was approximately 3:1. Majority of the respondents reported a clinical experience of less than 10 years (77.11%) and were reportedly working in the private sector (73.49%). Nearly 80% of the respondents (79.52%) mentioned obtaining preoperative consent for mandibular third molar surgeries and was significantly higher (p-value – 0.018) among clinicians with more than 5 years of experience (90%). While 38.5% of the respondents indicated obtaining both a written and verbal consent, 53.01% obtained only a verbal consent. Majority of the respondents were aware of the legal implications of obtaining informed consent (81.93%) and disclosed incidental complications to their patients (91.57%). However, differences in the perceived post-operative complications associated with mandibular third molar surgeries were observed between general dentists and oral surgeons.

Conclusion

The results of this study indicate a good level of knowledge about informed consent for mandibular third molar surgery and its legal implications among the dentists and oral surgeons who were surveyed. However, to avoid painful medico-legal disputes, a written informed consent signed by patients along with a witness should be considered mandatory.

Computer-Aided Design/Computer-Aided Manufacturing Cutting Guides for Odontectomy of Deeply Impacted Mandibular Third Molars

AIM:

To evaluate a new technique for surgical removal of deeply impacted mandibular third molars (DIMTM), using computer-guided cutting guide to maintain inferior alveolar nerve (IAN) integrity and the covering buccal bone.

PATIENTS AND METHODS:

Eighteen cases indicated for removal of DIMTM. Cone-beam Computed Tomography (CBCTs) used to determine the tooth’s relation to the IAN. Computer-guided software used for fabrication of surgical cutting guide stent to expose the impacted tooth and repositioning of bone after odontectomy without fixation. Clinical assessment included a neurosensory deficit of IAN, pain using a visual analogue scale (VAS), facial swelling, and maximal mouth opening (MMO). CBCTs were taken immediately and six months postoperatively to evaluate position and healing of bone.

RESULTS:

None of the patients showed a permanent neurological deficit of IAN while all patients showed normal parameters of pain, facial swelling and MMO.

CONCLUSION:

this technique has shown the accurate determination of the bony window cuts with subsequent preservation of IAN and external oblique ridge.

Effects of facemask therapy on the mandibular retromolar space. A follow-up study

Objectives:

To evaluate the mandibular retromolar space after facemask therapy and a follow-up period.

Methods:

This retrospective study was conducted between May and September in 2014. The sample consisted of pre-treatment (T1), post-treatment (T2), and follow-up(T3) panoramic radiographs of 19 skeletal and dental Class III patients (7 female, 12 male; mean age: 10.5 years) treated with facemask and a removable intraoral upper appliance in the Faculty of Dentistry Gazi University, Ankara, Turkey. Each patient’s lower arches were evaluated as right and left segments. As third molars were congenitally absent in 3 segments, a total of 35 segments were evaluated. The average treatment time was one year. The average follow-up period was 2.4 years. The positions, angulations, dental maturations of lower third molars, and mandibular retromolar spaces (DJ) were assessed. Friedman’s 2-way Analysis of Variance, multiple-comparison, Pearson’s correlation, and Chi-square tests were used for statistical evaluation. A p<0.05 was considered as significant.

Results:

The angulation of the first molar (¡) increased significantly only in the follow-up period (T3). Mandibular retromolar spaces were increased significantly during all periods. The most commonly determined position of the third molar, by Winter’s classification, was vertical angulation in all periods. Moderate and significant correlations were found between third molar angulation(ß) and DJ at T2 and T3. Significant correlations were also found between DJ and Demirjian classification stages during all periods.

Conclusion:

Facemask therapy did not have an adverse effect on the mandibular retromolar space during treatment and follow up periods.

Tridimensional assessment of the dental follicle dimensions of impacted mandibular third molars using cone-beam CT

Background

The present study was performed to compare follicle dimensions of impacted mandibular third molar (IMTM) with different impaction angulations using cone beam computed tomography (CBCT).

Material and Methods

Forty-nine individuals with IMTM (24 male, 25 female) were selected. Their age range was 25-55 years. The sample was divided into three IMTM groups either vertical (n=16), mesioangular (n=18) or horizontal (n=15) position based on Winter’s classification (the angle between the longitudinal axis of the second and third molars). Follicular spaces (FS) from available CBCT imaging were measured from the midpoint of the teeth’s crown in several dimensions (mesial, distal, occlusal, apical, vestibular and lingual) in axial, sagittal and coronal planes. An ANOVA, T-student, Kruskal–Wallis and Mann-Whitney U tests were used.

Results

A comparison of the mesial FS for all groups revealed significant differences (p<0.001). Significant difference was also found for vestibular FS between the vertical and mesioangular IMTM groups (p=0.04). Buccolingual FS for all groups revealed no significant differences (p=0.074), whereas significant difference was found for the vertical and horizontal IMTM groups (p=0.02). No significant statistical differences were found for occlusal (p=0.54), apical (p=0.06), and lingual (p=0.64) FS.

Conclusions

In this sample IMTM follicles have different dimensions according to their degree of angulation. Mesioagulated and horizontally positioned IMTMs seems to consistently have some increased FS dimensions (mesial and vestibular aspects).

Key words:Dental follicle, impacted tooth, third molar, cone-beam computed tomography.

Comparison of Articaine and Lidocaine for Buccal Infiltration After Inferior Alveolar Nerve Block For Intraoperative Pain Control During Impacted Mandibular Third Molar Surgery

In order to compare the efficacy of lidocaine and articaine for pain control during third molar surgery, 160 patients presenting bilateral asymptomatic impacted mandibular third molars were selected. They received 1.8 mL of 2% lidocaine with epinephrine 1:100,000 during inferior alveolar nerve block. In group 1 (n = 80), an infiltrative injection of 0.9 mL of 2% lidocaine with epinephrine 1:100,000 was performed in buccal-distal mucosa of the third molar. Group 2 (n = 80) received 0.9 mL of 4% articaine with epinephrine 1:100,000 in the contralateral side. All procedures were performed at the same visit, by a single operator, in a double-blind and parallel design. The duration of each surgery and the moment when the patient expressed pain were noted. Data were analyzed by nonpaired t test and chi-square test (alpha = 5%). Duration of surgery did not differ (p = .83) between Groups 1 (19.8 ± 2.3 minutes) and 2 (19.7 ± 3.0 minutes). Pain was expressed more in group 1 (26.3%) than in group 2 (10%) (odds ratio = 3.2, p = .0138). In both groups, tooth sectioning was the most painful event (p < .0001). No influence of gender (p = .85) or age (p = .96) was observed in pain response. Buccal infiltration of 4% articaine with epinephrine 1:100,000 showed more efficacy than 2% lidocaine with epinephrine 1:100,000 when used in combination with inferior alveolar nerve block in controlling intraoperative pain related to impacted mandibular third molar surgery.

Clinical and Radiographic Characteristics as Predictive Factors of Swelling and Trismus after Mandibular Third Molar Surgery: A Longitudinal Approach

Introduction

Factors that contribute to swelling and trismus are complex, and they are originated by surgical trauma. The aim of the present study was to determine whether clinical and radiographic factors could predict the level of swelling and trismus after lower third molar surgery, through longitudinal approach.

Methodology

A prospective longitudinal trial was carried out. Forty-five patients of both genders with clinical and radiographic diagnosis of asymptomatic mandibular impacted third molar and with no intake of analgesic or anti-inflammatory drugs 12 h prior to surgery were recruited and evaluated in a 72 h follow-up period. A mixed repeated measures model and backward and restricted maximal likelihood methods were used to analyze the data.

Results

Male gender, body mass index (BMI), the relation to the lingual and buccal walls, and age were determinants for predicting postoperative swelling and for exerting a significant influence (P < 0.05).

Conclusions

This study suggests the association of male gender, the relation to lingual and buccal walls, BMI, and age with measurement of swelling.

Assessment of impacted and partially impacted lower third molars with panoramic radiography compared to MRI-a proof of principle study

OBJECTIVES

Third molars often require surgical removal. Since three-dimensional radiological assessment is often indicated in difficult cases to avoid surgical complications, the radiation burden has to be considered. Here, MRI may offer a dose-free alternative to conventional X-ray techniques. The aim of this retrospective analysis was to evaluate the assessment quality of MRI compared to panoramic radiography in impacted and partially impacted lower third molars.

METHODS

Panoramic radiographs and MRI scans of 28 Caucasian patients were assessed twice by four investigators. Wisdom teeth were classified according to Juodzbalys and Daugela 2013.

RESULTS

When radiological lower third molar assessments with panoramic radiography and MRI were compared, staging concurred in 73% in the first round of assessments and 77% in the second.

CONCLUSIONS

The presented study demonstrates that MRI not only provides much the same information that panoramic radiography usually does, but also has the advantages of a dose-free three-dimensional view. This may facilitate and shorten third molar surgery. Image interpretation, however, can differ depending on training and experience.

Comparison of Surgical Outcome after Impacted Third Molar Surgery Using Piezotome and a Conventional Rotary Handpiece

Background and Aim:

One of the most commonly performed surgical procedures by oral and maxillofacial surgeons all over the world is the removal of impacted teeth. The most critical and important steps in third molar extraction are bone cutting or osteotomy. Many techniques are used for this purpose including chisels and mallet, rotary instruments, and ultrasonic-based bone cutting instruments. Piezotome is newer and innovative device for osteotomy based on piezoelectric vibrations. Piezotome is considered very efficient in performing osteotomy because of its selective cutting; being inert against soft tissues, including nerves and blood vessels. The aim of this study was to compare the surgical outcome of third molar surgery using conventional handpiece and piezotome with all other criteria remaining same for all the individuals.

Materials and Methods:

All patients reporting to the Department of Oral and Maxillofacial surgery, Manipal College of Dental Sciences, Mangalore, for impacted mandibular third molar removal were screened. A total of 30 patients with same Pederson difficulty index for bilateral impacted third molar were selected for the study. The study involved the use of piezotome on one side (Side A) and rotary technique (Side B) on the other side for osteotomy on the same patient with an interval of 1 month. Therapeutic management was same for both the sides. Operating time was recorded in each surgery. Patients were examined postoperatively on 1^st, 3^rd, and 7^th day and pain, edema, trismus, paresthesia, and dry socket were evaluated and compared on both the sides. Data collected were analyzed statistically.

Results:

The mean operating time was 48.13 min in piezotome (Side A) and 32.90 min in conventional handpiece (Side B) which was statistically significant (P < 0.001). Furthermore, there was statistically significant difference (P < 0.001) in the level of pain (P < 0.001), number of analgesics taken (P < 0.001), and trismus (P < 0.01) on 1^st, 3^rd, and 7^th days postoperatively. There was no statistically significant difference in edema between the two sides. Paresthesia was present in one patient (3.3%) in Side B, while no paresthesia was present in Side A. No incidence of alveolar osteitis was reported on both the sides.

Conclusion:

Operating time with piezotome was more than that of conventional handpiece, but the postoperative responses such as pain, trismus, and edema were less in piezotome. Hence, despite being a slower procedure, piezotome can be an effective alternative for osteotomy in impacted third molar surgery. We recommend using piezotome for bone cutting and conventional rotary handpiece for tooth sectioning in order to obtain favorable outcomes as well as decreasing the operating time.

Evaluation of Kharma scale as a predictor of lower third molar extraction difficulty

Background

The Evaluation of the degree of lower third molar (L3M) extraction difficulty is extremely important for both clinicians and patients. This study aimed to evaluate the validity of a new index (Kharma scale) as a preoperative predictor index of the difficulty of surgical removal of impacted L3M.

Material and Methods

Extraction difficulty of a series of 49-impacted L3M was predicted preoperatively by Kharma scale, and postoperative difficulty was assessed with a modified Parant scale.

Results

The sensitivity of Kharma scale, as a predictor of difficulty, was 18.2% and the specificity was 68.4%. Likelihood ratios for the Kharma categories also indicated that the scale is of little value for predicting a difficult extraction. There was no significant association between the Kharma score and duration of operation, but high-modified Parant scores were significantly associated with longer operations.

Conclusions

The proposed Kharma scale was unreliable as preoperative predictor of the L3M extraction difficulty, and both radiological and clinical information must be taken into account.

Key words:Kharma scale, prediction scale, lower third molar, extraction difficulty.

Mesiolingual root rotation for horizontal mandibular third molar extraction: position classification and surgical simulation

Extracting horizontal mandibular 3rd molars face considerable difficulty due to the large bone and adjacent tooth resistances. This study aims at evaluating the effectiveness of a novel method-mesiolingual root rotation to extract wisdom teeth of this type. In this study, 73 horizontal teeth extracted using piezosurgery were reviewed and classified based on impaction depth: position I, II, III refers to the highest portion of the crown on a level with upper 1/3, middle 1/3, lower 1/3 of the 2rd molar’s root. Based on the surgical simulations on their 3D CBCT reconstructions, traditional method(crown distal rotation) and novel method(root mesiolingual rotation) are applied. 79.17% of teeth in position I and 57.89% of teeth in position II were designed using traditional method, 83.33% teeth in position III were designed using the novel method(p < 0.05). The surgeries were performed according to the designs. Two cases in position II using traditional method were found temporary inferior alveolar nerve(IAN) injury; while only one case in position III using novel method got temporary IAN and lingual nerve injury. Our study suggested that root mesiolingual rotation is an effective method to extract the horizontal mandibular 3rd molars, especially the deep impacted ones.

Clinician-related factors behind the decision to extract an asymptomatic lower third molar. A cross-sectional study based on Spanish and Portuguese dentists

BACKGROUND

Scientific literature estimates that around 18 to 40 % of asymptomatic third molars are extracted. The aims of the present study were to determine the indications for extraction of asymptomatic lower third molars in a sample of Spanish and Portuguese dentists, and to relate these indications to the clinicians' training and professional experience.

MATERIAL AND METHODS

A survey consisting of 15 cases of asymptomatic lower third molars was emailed to Portuguese and Spanish dentists. The clinicians were asked to assess the level of difficulty of the extractions and to make a reasoned recommendation based on the panoramic radiographs, gender and age of the patients.

RESULTS

381 clinicians filled in the questionnaires. Most of the professionals had over 13 years of clinical experience. The number of Spanish clinicians with postgraduate degrees in Oral Surgery was significantly higher. On average, 42% of respondents recommended extraction of asymptomatic third molars. The indication for extraction was significantly higher among Portuguese dentists. Clinical experience was negatively correlated with the perceived extraction difficulty (p<0.05). The main reason given for extracting was the prevention of pericoronitis, whereas that for not extracting was the absence of a clear indication and the risk of injuring the inferior alveolar nerve.

CONCLUSIONS

The Portuguese dentists were more in favour of removing asymptomatic lower third molars than the Spanish dentists, although the latter had a higher proportion of professionals with postgraduate studies in Oral Surgery.

Low-level Laser Therapy on Postoperative Pain after Mandibular Third Molar Surgery

Introduction:

The analgesic effect of low-level laser therapy (LLLT) after mandibular third molar (MTM) extraction is controversial. The aim is to evaluate the effect of intraoral LLLT on postoperative pain after MTMs extraction.

Methods:

Thirty patients with bilateral symmetrical impacted MTMs underwent surgical extractions. Experimental and control sides were randomly selected to receive LLLT or placebo. Following suturing, a dental assistant applied 810 nm gallium aluminum arsenide (GaAlAs) at three points for 30 s each with a total energy of 9 J. Pain was recorded on a visual analog scale on the 7 successive days.

Results:

Data analyzed by IBM SPSS Statistics 23 for Windows with P ≤ 0.05 significance level. LLLT appeared to have a high significant effect on pain reduction; however, there was a mild increase in pain after the 4^th day.

Conclusion:

Intraoral 810 nm GaAlAs is effective in reducing postoperative pain when a dose of 32.86 J/cm² is used.

Analysis of potential dynamic concealed factors in the difficulty of lower third molar extraction

BACKGROUND

The purpose of this study was to identify potential concealed variables associated with the difficulty of lower third molar (M3) extractions.

MATERIAL AND METHODS

To address the research purpose, we implemented a prospective study and enrolled a sample of subjects presenting for M3 removal. Predictor variables were categorized into Group-I and Group-II, based on predetermined criteria. The primary outcome variable was the difficulty of extraction, measured as extraction time. Appropriate univariate and multivariate statistics were computed using ordinal logistic regression.

RESULTS

The sample comprised of 1235 subjects with a mean age of 29.49 +/- 8.92 years in Group-I and 26.20 +/- 11.55 years in Group-II subjects. The mean operating time per M3 extraction was 21.24 +/- 12.80 and 20.24 +/- 12.50 minutes for Group-I and Group-II subjects respectively. Three linear parameters including B-M2 height (distance between imaginary point B on the inferior border of mandibular body, and M2), lingual cortical thickness, bone density and one angular parameter including Rc-Cs angle (angle between ramus curvature and curve of spee), in addition to patient's age, profile type, facial type, cant of occlusal plane, and decreased overbite, were found to be statistically associated ( p < or = 0.05) with extraction difficulty under regression models.

CONCLUSIONS

In conclusion, our study indicates that the difficulty of lower M3 extractions is possibly governed by morphological and biomechanical factors with substantial influence of myofunctional factors.

PRACTICAL IMPLICATIONS

Preoperative evaluation of dynamic concealed factors may not only help in envisaging the difficulty and planning of surgical approach but might also help in better time management in clinical practice.

Which factors are associated with difficult surgical extraction of impacted lower third molars?

Objectives

The aim of this retrospective study was to investigate factors associated with increased difficulty in the surgical extraction of impacted lower third molars and to improve identification of difficult cases.

Materials and Methods

A total of 680 patients who required 762 surgical extractions of impacted lower third molars from 2009 to 2014 were enrolled in the study. Demographic factors, clinical factors, radiographic factors, surgical extraction difficulty, and presumed causes of difficulty were collected. Data were statistically analyzed using IBM SPSS Statistics version 23.

Results

Age, sex, depth of impaction, and blurred radiographic image influenced difficulty in surgical extraction. The position of the impacted tooth influenced surgical difficulty, especially when it was accompanied by other factors.

Conclusion

It is challenging to design a reliable and practical instrument to predict difficulty in surgical extraction of impacted lower third molars. To identify very difficult cases, root investigation using computed tomography is advised when impacted tooth position suggests difficult extraction.

Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as "jaw lesion", "jaw disease", "impacted tooth", and "unerupted tooth". More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs.

Comparison of Piezosurgery and Conventional Rotary Instruments for Removal of Impacted Mandibular Third Molars: A Randomized Controlled Clinical and Radiographic Trial

The purpose of this study was to test the effect of the surgical removal of impacted mandibular third molars using piezosurgery versus the conventional surgical technique on postoperative sequelae and bone healing. Material and Methods. This study was carried out as a randomized controlled clinical trial: split mouth design. Twenty patients with bilateral mandibular third molar mesioangular impaction class II position B indicated for surgical extraction were treated randomly using either the piezosurgery or the conventional bur technique on each site. Duration of the procedure, postoperative edema, trismus, pain, healing, and bone density and quantity were evaluated up to 6 months postoperatively. Results. Test and control sites were compared using paired t-test. There was statistical significance in reduction of pain and swelling in test sites, where the time of the procedure was statistically increased in test site. For bone quantity and quality, statistical difference was found where test site showed better results. Conclusion. Piezosurgery technique improves quality of patient's life in form of decrease of postoperative pain, trismus, and swelling. Furthermore, it enhances bone quality within the extraction socket and bone quantity along the distal aspect of the mandibular second molar.

Evaluation of Outcome Following Coronectomy for the Management of Mandibular Third Molars in Close Proximity to Inferior Alveolar Nerve

INTRODUCTION

Iatrogenic damage to Inferior Alveolar Nerve (IAN) is a significant risk factor following prophylactic or therapeutic removal of impacted mandibular third molar. The risk to IAN injury increases many fold, when the third molar root overlaps the nerve canal as identified by the radiographic imaging. Various methods like orthodontic assisted extraction, staged removal of tooth or coronectomy have been advocated to reduce the incidence of IAN injury in high risk cases with variable outcome.

AIM

The aim of present study was to evaluate the fate of the root (resorbed, exfoliated, covered by bone) after coronectomy or intentional root retention of impacted mandibular 3(rd) molars in patients with high risk for inferior alveolar nerve damage as evaluated by the intra oral periapical radiograph.

MATERIALS AND METHODS

Twenty impacted mandibular third molar teeth, in 18 patients with high risk of injury to IAN based on Rood's Criteria in an intra oral periapical radiographic examination, between the age group of 18 to 40 years, were included in the study. Preoperatively the impacted third molars were evaluated clinically as well as radiographically. Pederson Difficulty Index and Winter's Classification of impacted tooth was recorded. Coronectomy was done at the cemento enamel junction leaving the roots 2-3mm below the alveolar crest and primary closure was done. Patients were evaluated periodically for two years at six months interval. Post operative pain, swelling, IAN injury or any other complications were observed and recorded.

RESULTS

None of the patients had IAN injury and none required second surgical removal. There was no incidence of post-operative infection and none required second surgical intervention. However, two of our patients had failed coronectomy (10%) due to mobilization of roots intra operatively and the roots were removed. One patient developed profuse bleeding intra-operatively in the failed coronectomy case. One patient had temporary lingual nerve paresthesia.

CONCLUSION

Coronectomy procedure is effective in controlling inferior alveolar nerve injury following third molar surgery, in radiographically evaluated high risk cases and it has very low incidence of complications.

Piezosurgery for the Lingual Split Technique in Lingual Positioned Impacted Mandibular Third Molar Removal: A Retrospective Study

The aim of this study was to evaluate the effect and safety of lingual split technique using piezosurgery for the extraction of lingual positioned impacted mandibular 3rd molars with the goal of proposing a more minimally invasive choice for this common surgery.Eighty-nine consecutive patients with 110 lingual positioned impacted mandibular 3rd molars requiring extraction were performed the lingual split technique using piezosurgery. One sagittal osteotomy line and 2 transverse osteotomy line were designed for lingual and occlusal bone removal. The success rate, operative time, postoperative outcome, and major complications (including nerve injury, mandible fracture, severe hematoma or edema, and severe pyogenic infection) were documented and analyzed.All impacted mandibular 3rd molars were successfully removed (110/110). The average time of operation was 14.6 minutes (ranged from 7 to 28 minutes). One hundred and seven extraction sites (97.3%) were primary healing. Pain, mouth opening, swelling, and PoSSe scores on postoperative 7-day were 0.34 ± 0.63, 3.88 ± 0.66(cm), 2.4 ± 0.2(cm), and 23.7 ± 5.9, respectively. There were 6 cases (5.5%) had lingual nerve disturbance and 3 cases (2.7%) developed inferior alveolar nerve impairment, and achieved full recovery within 2 months by neurotrophic drug treatment.Our study suggested piezosurgery for lingual split technique provided an effective way for the extraction of lingual positioned and deeply impacted mandibular 3rd molar.

Influence of two different surgical techniques on the difficulty of impacted lower third molar extraction and their post-operative complications

BACKGROUND

Post-operative complications of various degrees of severity are commonly observed in third molar impaction surgery. For this reason, a surgical procedure that decreases the trauma of bone and soft tissues should be a priority for surgeons. In the present study, we compare the efficacy and the post-operative complications of patients to whom two different surgical techniques were applied for impacted lower third molar extraction.

MATERIAL AND METHODS

Patients of the first group underwent the classical bur technique, while patients of the second group underwent another technique, in which an elevator was placed on the buccal surface of the impacted molar in order to luxate the alveolar socket more easily.

RESULTS

Comparing the two techniques, we observed a statistically significant decrease in the duration of the procedure and in the need for tooth sectioning when applying the second surgical technique, while the post-operative complications were similar in the two groups. We also found a statistically significant lower incidence of lingual nerve lesions and only a slightly higher frequency of sharp mandibular bone irregularities in the second group, which however was not statistically significant.

CONCLUSIONS

The results of our study indicate that the surgical technique using an elevator on the buccal surface of the tooth seems to be a reliable method to extract impacted third molars safely, easily, quickly and with the minimum trauma to the surrounding tissues.

Impacted Mandibular Third Molars: Review of Literature and a Proposal of a Combined Clinical and Radiological Classification

Tooth impaction is a pathological situation where a tooth fails to attain its normal functional position. Impacted third molars are commonly encountered in routine dental practice. The impaction rate is higher for third molars when compared with other teeth. The mandibular third molar impaction is said to be due to the inadequate space between the distal of the second mandibular molar and the anterior border of the ascending ramus of the mandible. Impacted teeth may remain asymptomatic or may be associated with various pathologies such as caries, pericoronitis, cysts, tumors, and also root resorption of the adjacent tooth. Even though various classifications exist in the literature, none of those address the combined clinical and radiologic assessment of the impacted third molar. Literature search using the advanced features of various databases such as PubMed, Scopus, Embase, Google Scholar, Directory of Open Access Journals and Cochrane electronic databases was carried out. Keywords like impaction, mandibular third molar, impacted mandibular third molar, complications, anatomy, inferior alveolar nerve injury, lingual nerve injury were used to search the databases. A total of 826 articles were screened, and 50 articles were included in the review which was obtained from 1980 to February 2015. In the present paper, the authors have proposed a classification based on clinical and radiological assessment of the impacted mandibular third molar.