Pattern of third molar impaction in a Singapore Chinese population: a retrospective radiographic survey

Are There Differences in the Causes and Complications of Mandibular Third Molar Extraction in Older Patients Compared to Younger Patients?

BACKGROUND

Although most impacted third molars (ITMs) are extracted in the teens and early 20s, some undergo extractions after their 40s. It is unclear whether the reasons for extraction, the degree of impaction, and complications differ in patients in an older age group compared with a younger age group.

PURPOSE

The purpose of this study was to measure the association between age and 1) reason for extraction and 2) postoperative complications.

STUDY DESIGN, SETTING, SAMPLE

This was a retrospective cohort study of patients who had undergone surgical extraction of at least one mandibular ITM at a single institution. We excluded 1) age under 20 years, 2) follow-up period of less than 1 week, and 3) tooth extraction under general anesthesia.

PREDICTOR VARIABLE

The primary predictor variable was age, classified into 3 groups (20s:20-29; 30s:30-39; over 40s: 40 and greater).

MAIN OUTCOME VARIABLE(S)

The primary outcome variables were the reason for extraction (prophylactic or symptomatic) and the presence of complications. The secondary outcome variable was type of complication (postoperative infection, dry socket, neurosensory disturbance, presenting pain over 1 month, retained root requiring secondary treatment).

COVARIATES

The covariates were sex, laterality of ITM, and difficulty of extraction as measured by the difficulty index, a measure based on depth, orientation, and ramus relationship/space available, with a higher score indicating greater difficulty.

ANALYSES

χ2 test was performed to analyze the association of categorical outcome variables and covariates. Level of statistical significance was set at P < .05.

RESULTS

Of a total of 831 eligible subjects, there were 555 (66.8%), 159 (19.1%), and 117 (14.1%) in the 20s, 30s, and over 40s age groups, respectively. The percentage of symptomatic extraction of ITM was significantly higher in the over-40 age group compared with the 20s group (92.3 vs 69.4%, (P < .001). Complication rate also significantly differed between over 40s group and the 20s group (7.7 vs 1.8%, P < .001). Difficulty index and indications for ITM extraction were significantly different between groups (P < .001).

CONCLUSION AND RELEVANCE

Symptoms, difficulty, and complications related to ITM increase at over 40 years of age. This should be taken into consideration during the joint clinical decision-making process with patients with ITM.

The Accuracy of Bone Assessment Distal to Lower Second Molars Using Panoramic Radiography: A Systematic Review and Meta-Analysis

Panoramic radiography (OPG) evaluates mandibular third molar impaction (MTMI). This systematic review aimed to investigate the diagnostic accuracy of OPG in detecting bone loss distal to the lower second molars. The associated bone loss with different impaction positions and the most prevalent positions of MTMI were investigated as secondary outcomes. In January 2023, PubMed, Scopus, and Cochrane were searched to identify studies published between January 2012 and January 2023. Two examiners blindly selected the eligible studies for data extraction and quality assessment. Of 427 studies, 8 were suitable for data extraction. All studies reported bone loss distal to the second molar using OPG, ranging from 4.9 to 62.9%. The most frequent position of MTMI is mesioangular. The distal bone loss in the vertical and horizontal positions is statistically significant compared to typically positioned third molars and those that are fully erupted or impacted, but in a normal orientation (p-value 0.005 and 0.02, respectively). Bone loss was not statistically significant in the mesioangular position compared to other impacted positions (p-value 0.14). The risk of bias ranges between 66 and 88%. Despite its limitations, OPG is still considered a valuable tool to assess bone loss distal to the lower second molar in cases of an impacted mandibular third molar.

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

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

Prevalence of Impacted Teeth: A Radiographical Retrospective Rio de Janeiro Population-Based Study

Background

The early detection of impacted teeth is essential for the prevention of future malocclusions and possible lesions. The aim of this study is to assess the prevalence of impacted teeth and associated pathological lesions.

Methods

One thousand six hundred and two panoramic radiographs were analyzed for this retrospective study. The prevalence of impacted teeth, the presence of supernumerary teeth and cystic or tumoral lesions associated, and the type of angulation of third molars using Winter's classification were accessed. The descriptive statistics and the Chi-squared test were performed (P < 0.05).

Results

One thousand three hundred and ninety-seven panoramic radiographs fulfilled impacted criteria. A prevalence of 541 (38.7%) impacted teeth was observed, with the female gender significantly higher (P < 000.1). Of the total impacted teeth (n = 541), the overall mean impacted of lower third molars was 55.6%. Twenty-nine (5.3%) supernumerary teeth and four lesions were verified. The angulations most observed in the upper (76.6%) and lower (39.2%) third molars were vertical (P < 000.1) and mesioangulated (P < 000.1), respectively.

Conclusion

The impacted tooth prevalence was 38.7%, more common in females than in males. The lower third molars presented the highest prevalence of impacted, and the most common angulations were vertical and mesioangulated. Only four associated lesions were observed.

Mandibular Second Molars and Their Pathologies Related to the Position of the Mandibular Third Molar: A Radiographic Study

Objective

The aim of this study was to determine the prevalence of mandibular third molar malposition and its impact in relation to the lower second molar using panoramic radiography.

Methods and Materials

This was a cross-sectional descriptive study of 353 panoramic images of patients who visited the Dental Clinic of the International University of Rabat. Panoramic images were analyzed in order to determine the number of second molar pathologies associated with the positions of third molars. The following radiographic lesions on the second molar were recorded: caries, root resorption and distal alveolysis. The Chi-square test was used to assess the association between different variables.

Results

Of these 353 radiographies, 169 were males, ie, 48%, and 184 were females, ie, 52%. The age range was from 18 to 63 years. The prevalence of the impacted position of the lower third molar was noted in 60%. Distal caries on the second mandibular molar was present in 47.5% of instances having an impacted third molar. Caries was present in 65.5% of wisdom teeth in a normal position and was also present in 79.6% of the impacted teeth. This difference was statistically significant with p = 0.01. The angulation of the third molar is a factor of caries of the second molar: 58.56% of them were carious. Of all the teeth in association with an angulation, 72.03% showed distal alveolysis in the second molar. In addition, root resorption was found in 20.4% of second molars linked to a wisdom tooth in all angulation occurrences.

Conclusion

It has been noted that among the pathologies seen on the mandibular second molar, distal alveolysis accounts for the majority of cases (58%), followed by caries (47.5%) and root resorption (13.3%). This study illustrated the importance of performing Orthopantomogram X-rays at each new consultation in patients over the age of 18.

The perception and practice of routine lingual flap retraction in lower third molar surgery among oral and maxillofacial surgeons in Nigeria

Background

Lingual nerve injury is a known complication of mandibular third molar (M3M) surgery, and retraction of the lingual flap is reported to reduce the incidence of this complication. However, there is no global consensus on the routine retraction of lingual flap.

Aim

The aim of the study was to assess the perception and practice of lingual flap retraction amongst oral and maxillofacial surgeons in Nigeria.

Materials and Methods

This cross-sectional national survey was conducted amongst 122 oral and maxillofacial surgeons in Nigeria from January 2023 to March 2023 using a validated, structured, self-administered questionnaire. The questionnaire had three sections and 14-item questions. Section A consists of the sociodemographic questions, Section B comprises questions on perception towards lingual flap retraction, whereas Section C consists of questions on the practice of lingual flap retraction. These questionnaires were deployed as an online survey and as hard copies. Both qualitative and quantitative data were analysed. A critical probability level (P < 0.05) was used as the cut-off level for statistical significance.

Results

Most of the participants (47.6%) belong to the age group of 31-40 years. The male-to-female ratio was 6:1. Only 12 (9.8%) participants had a positive perception towards routine lingual flap retractions following M3M surgery. Perception of lingual flap retraction was found not to be associated with the demographic variables of the participants (P > 0.05). A total of 95 participants (77.9%) did not raise nor retract the lingual flap during lower third molar surgery. The rate of practice of lingual flap retraction during third molar surgery was not influenced by any of the factors studied (P > 0.05).

Conclusion

The majority of oral and maxillofacial surgeons in Nigeria do not agree that routine retraction of the lingual flap is necessary to reduce lingual nerve injury and majority, too, do not practice this in their management of impacted lower third molar.

Mandibular Third Molar Impaction among Patients Visiting Outpatient Dental Department of a Tertiary Care Centre

Introduction

Mandibular third molar impaction is the most common impaction as third molars are last to erupt at the age of 17-25 years. Despite its high prevalence and negative impacts, there is limited study about mandibular third molar impaction. The aim of this study is to find out the prevalence of mandibular third molar impaction among patients visiting the outpatient Dental Department of a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted among patients visiting the Outpatient Dental Department of a tertiary care centre from 1 January 2023 to 30 June 2023. Ethical approval was taken from the Institutional Review Committee of the same institute. A total of 414 orthopantomograms were prospectively reviewed for the angulation of impaction, depth and position. The indication for extraction was recorded from patients' cards during the time of extraction. Convenience sampling method was used. The point estimate at a 95% confidence interval was calculated.

Results

The prevalence of mandibular third molar impaction was 37.13% (34.29-39.97, 95% Confidence Interval). There was a high prevalence of mesioangular 344 (45.38%) pattern followed by vertical 249 (32.85%) for mandibular third molar impaction, the most commonly involved group was 20-30 years, with female 247 (59.70%) predominance. Bilateral impaction 344 (83.10%) was more prevalent than unilateral. Depth A, 639 (84.3%), ramus relation level I, 602 (79.42%) was the most common level of impaction. Recurrent pericoronitis 160 (38.6%) was the common indication for extraction followed by dental caries 145 (35%).

Conclusions

The prevalence of mandibular third molar impaction was lower than other similar studies done in similar settings.

Keywords

impacted tooth; pericoronitis; prevalence; third molar.

Three-dimensional relationship between the degree of bilateral impacted mandibular third molars angulation and the mandibular dental arch parameters: a cross-sectional comparative study

OBJECTIVE

The purpose of this study was to three-dimensionally evaluate the relationship between the degree of bilateral impacted mandibular third molar (IM3M) angulation and the mandibular dental arch parameters in normal skeletal and dental malocclusion patients.

MATERIALS AND METHODS

In this retrospective cross-sectional comparative study, 120 adult subjects' cone-beam computed tomography (CBCT) images were three-dimensionally analyzed. The sample included 120 adults aged 20-30 years, with a gender distribution of 51 male and 69 female participants. The sample was divided into 100 adults with bilateral IM3M (study group) and 20 adults with normal bilateral erupted M3M (control group). The study group was sub-divided into three groups according to the degree of IM3M buccolingual angulation (BL°): group A, < 12° on the center of the ridge (N = 30), group B, 12-24° off-center of the ridge (N = 40), group C, > 24° off-center of the ridge (N = 30). The study group was also sub-divided into two groups according to IM3M mesiodistal angulation (MD°): group 1 from 10 to 45° (N = 36), group 2 > 45° (N = 64). Comparison within and between groups was performed using one-way ANOVA followed by Tukey's post hoc test. The correlation between IM3M, BL, and MD angulation and the mandibular arch parameter was calculated using Pearson's correlation coefficient.

RESULTS

Statistically significant differences (P < 0.001) were found between the IM3M BL° and anterior teeth inclination, arch length (AL), and inter-second molar width (inter 2nd MW) as well as between the IM3M MD° with anterior crowding and the arch length (P < 0.001). A significant positive correlation was found between IM3M BL° and anterior teeth inclination and between IM3M MD° and anterior teeth crowding and inter 2nd MW. A significant negative correlation was observed between IM3M BL° and inter 1st MW and 2nd MW.

CONCLUSION

The degree of buccolingual and mesiodistal angulation of the impacted mandibular third molars was related with mandibular dentoalveolar changes. Increased buccolingual angulation is generally associated with increased anterior teeth inclination and decreased 1st and 2nd inter-molar width. The increase in mesiodistal angulations was generally related with increased anterior teeth crowding and 2nd inter-molar width.

CLINICAL RELEVANCE

Assessment of the relationship between the impacted mandibular third molars and the degree of arch discrepancy, and the position of mandibular incisors in the three planes of space might help in the decision-making process for the extraction of the impacted third molars in adult patients.

The pattern of mandibular third molar impaction and its relationship with the development of distal caries in adjacent second molars among Emiratis: a retrospective study

Objectives

The purpose of this study was to investigate the pattern of mandibular third molar (MTM) impaction and associated carious lesions in adjacent mandibular second molars (MSMs) in a sample of Emirati individuals.

Methods

This retrospective study assessed 2000 orthopantomograms of Emirati patients who visited the Specialized Fujairah Dental Center between 2015 and 2020. The depth, ramus relation and angulation of the impacted MTMs were assessed according to the Pell and Gregory classification and Winter’s classification. In addition, carious lesions in adjacent MSMs associated with the evaluated parameters were identified.

Results

A total of 461 (23.05%) of the patients had at least one impacted MTM. The mean age of the study population was 26.24 years. Mesioangular, level B, and class II impactions were the most common, at 47.37% (χ² = 382.134; p < 0.001), 45.48% (χ² = 56.889; p < 0.001), and 74.05% (χ² = 513.099; p < 0.001), respectively. There was a higher percentage of level C impaction among females than among males (χ² = 19.178; p < 0.001). A total of 126 impacted teeth (18.36%) had associated carious lesions. These carious lesions were predominantly found in teeth with mesioangular impactions (χ² = 59.430; p < 0.001), level A and B impactions (χ² = 23.301; p < 0.001), and class II and I impactions (χ² = 17.918; p = 0.006).

Conclusions

It is imperative to raise awareness of soft tissue mesioangular-impacted MTMs, as they are the most frequently associated with the development of carious lesions in adjacent MSMs. Approximately one quarter of evaluated Emiratis had at least one impacted MTM, with the most prevalent pattern being class II, level B, and mesioangular impactions. Furthermore, surgical removal is expected to be more challenging for females than for males.

Is it necessary to remove bone-impacted teeth? A retrospective study

BACKGROUND

In clinical practice, it is risky to extract bone-impacted teeth and they're prone to a variety of complications, such as pathological fracture, adjacent tooth fracture, maxillary sinus perforation, and so on, making it difficult for clinicians to decide whether to extract them.

PURPOSE

In order to illustrate our opinions on the possibility of extracting full third molars (M3), 360 examples of complete third molars were analyzed in this study.

MATERIALS AND METHOD

We investigated 2189 patients, and 261 of them provided CBCT images of 360 teeth. assessing the degree of second molar(M2) root absorption in connection to age, impacted relationship, contact part, calculating the odds ratio (OR) and 95% confidence interval using the Logistic regression analysis equation.

RESULT

Bone-impacted M3 occurred in 11.92% (261/2189) of patients with "impacted teeth" diagnoses. There was a significant difference between the occurrence of M2ERR and the contact parts (P value<0.001), and only the type of vertical impaction differed significantly from Level 3 (P < 0.05).

CONCLUSIONS

1) M3 should be removed if root resorption has not occurred in M2. 2) Root resorption is more likely to occur when M3 crown and M2 apical contact. 3) Enough experience, precise preoperative assessment can reduce the dangers to a minimum.

Can lower third molar position indicate the need for preoperative cone beam computed tomography exploration of retromolar canal?

OBJECTIVES

This study aims to reveal whether and which position of lower third molar (M3), assessed on a 2D image, indicates or potentially exclude the need for the CBCT exploration of the retromolar canal (RMC). We hypothesized that some positions of M3 are associated with overall higher incidence of the RMC, and particularly clinically relevant ones, thus justifying additional CBCT diagnostics.

METHODS

CBCT exam of 186 hemi-mandibles with present M3 were selected for the study. Explorations were made during the 2-year period from January 1th 2018 to December 31th 2019 with Scanora 3Dx Sorodex (Tussula, Finland). The following variables were assessed: the presence and width of the RMC, eruption status, and angulation of the M3. The RMC presence in relation to the M3 eruption status and angulation was analyzed using appropriate statistical tests.

RESULTS

RMC was present in 89 (47.8%) out of 186 hemi-mandibles. Mean canal width was 1.51 mm. 22.5% of detected canals had the diameter exceeding 2 mm. Third molar's eruption status showed no statistical correlation with the occurrence of RMC. We observed significantly higher occurrence of RMC in the hemi-mandibles containing distally angulated M3 in comparison to other orientations (p = 0.025).

CONCLUSION

Based upon our findings, we recommend preoperative CBCT in cases where distal angulation of M3 is observed on 2D images, for the purpose of RMC exploration. Lower resolution CBCT mode and limited field of view (XS or S) are sufficient for the visualization of potentially clinically relevant RMCs, with as much reducing the patient dose.

Evaluation of the Position and Incidence of Impaction of Mandibular Third Molars in Different Anteroposterior and Vertical Skeletal Patterns: A Retrospective Study

Aim: To evaluate the incidence of impacted mandibular third molar in different anteroposterior and vertical facial skeletal patterns and to evaluate the angle of impaction of mandibular third molar. Methodology: 207 Panoramic and lateral cephalometric radiographs for patients above 20 years old with impacted mandibular third molar were recruited from the orthodontic department clinics in multiple universities in Egypt and traced using WebCeph ™ software. From the lateral cephalograms, three anteroposterior measurements were taken which were termed as ANB, A-B difference and Wits appraisal and three vertical angles were measured which were SN/MP, MMPA and FMPA to determine different skeletal facial types. The angulation of mandibular third molar impaction was determined by β angle according to Winter’s classification from the orthopantomogram. Results: Among all 207 analyzed cases, impacted third molars were detected in (38.6%) cases unilaterally and (61.4%) bilaterally. Anteroposteriorly, the higher percentage of total impactions was found in subjects with a class 2 skeletal pattern (97.2%). Vertically, the higher percentage of total impactions was found in subjects with a mesocephalic facial pattern (45.9%). The most common type of impaction was mesioangular based on Winter’s classification. Conclusions: A higher incidence of lower third molar impaction was found in subjects with a class 2 skeletal pattern. A higher incidence of lower third molar impaction was found in subjects with a mesocephalic facial pattern. In almost all skeletal facial types, the mesioangular position of the impacted mandibular third molar was the most prevalent position.

Maxillary and Mandibular Third Molars Impaction with Associated Pathologies in a North Cyprus Population: A Retrospective Study

This study aimed to find out the incidence of impacted third molars and associated pathologies in people who live in the North Cyprus population. Dr. Burhan Nalbantoglu State Hospital is the only hospital that has an oral and maxillofacial surgery department among the state hospitals in North Cyprus. Patients who were referred to this department during a one-year period due to the complaints regarding their third molar were included in our study. This retrospective study involved 550 patients aged 16 to 65 years (1752 third molars). Chi-square tests were done for bilateral comparison between age, gender, and third molar (p < 0.05). Among the groups included in the study, the highest number of third molars originated from the 20–29 age group (n = 1050). Among all 1752 third molars, 716 (40%) of them erupted, while 1036 (60%) were impacted molar teeth, with significant differences between genders (p > 0.05). The most often impacted position in the mandible was the mesioangular type (42%) and in the maxilla was the vertical type (62%). Partially and completely impacted mandibular third molars showed a significant difference between the left and right sides (p < 0.05). A huge proportion of third molars are impacted in the North Cyprus population. The degree of impaction of wisdom teeth and the problems they cause should be well evaluated, and the surgical approach should be considered according to the baseline of this data.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Automated Prediction of Extraction Difficulty and Inferior Alveolar Nerve Injury for Mandibular Third Molar Using a Deep Neural Network

Extraction of mandibular third molars is a common procedure in oral and maxillofacial surgery. There are studies that simultaneously predict the extraction difficulty of mandibular third molar and the complications that may occur. Thus, we propose a method of automatically detecting mandibular third molars in the panoramic radiographic images and predicting the extraction difficulty and likelihood of inferior alveolar nerve (IAN) injury. Our dataset consists of 4903 panoramic radiographic images acquired from various dental hospitals. Seven dentists annotated detection and classification labels. The detection model determines the mandibular third molar in the panoramic radiographic image. The region of interest (ROI) includes the detected mandibular third molar, adjacent teeth, and IAN, which is cropped in the panoramic radiographic image. The classification models use ROI as input to predict the extraction difficulty and likelihood of IAN injury. The achieved detection performance was 99.0% mAP over the intersection of union (IOU) 0.5. In addition, we achieved an 83.5% accuracy for the prediction of extraction difficulty and an 81.1% accuracy for the prediction of the likelihood of IAN injury. We demonstrated that a deep learning method can support the diagnosis for extracting the mandibular third molar.

Comparison of Digital OPG and CBCT in Assessment of Risk Factors Associated with Inferior Nerve Injury during Mandibular Third Molar Surgery

Background: Pre-operative radiographic assessment of the anatomical relationship between the roots of the mandibular third molar and the inferior alveolar nerve (IAN) is a must to minimize the risk of IAN injury during surgery. Objectives: To compare the radiographic signs of digital orthopantomogram (OPG) and cone-beam computed tomography (CBCT). An additional objective was to assess the cortex status between the mandibular canal and third molar on CBCT images in relation to the demographic characteristics, region (right or left side), and angulation of mandibular molar. Methodology: In this retrospective study, a total of 350 impacted mandibular third molars with a close relationship between the inferior alveolar canal (IAC) and impacted mandibular third molars on digital OPG were further referred for CBCT imaging for assessment of the position of the mandibular canal. The study was conducted between August 2018 and February 2020. Digital OPGs were evaluated for radiographic signs like interruption of the mandibular canal wall, darkening of the roots, diversion of the mandibular canal, and narrowing of the mandibular canal. The age and sex of patients, site of impacted third molar, Winter’s classification of mandibular third molar, position of IAC relative to impacted molar, and the radiographic markers of OPG were assessed for cortical integrity using CBCT. Chi square testing was applied to study the values of difference and binomial logistic regression was done to assess the factors associated with cortication. Statistical significance was set at p ≤ 0.05. Results: Among 350 patients, 207 (59.1%) were male and 143 (40.9%) were female with a mean age of 36.8 years. The most common OPG sign was interruption of white line, seen in 179 (51.1%) cases. In total, 246 cases (70.3%) showed an absence of canal cortication between the mandibular canal and the impacted third molar on CBCT images. Cortication was observed in all cases with a combination of panoramic signs which was statistically significant (p = 0.047). Cortication was observed in 85 (50.6%) cases where IAC was positioned on the buccal side, 11 (16.9%) in cases of inferiorly positioned IAC, and just 8 (7.6%) for cases of lingually positioned IAC which was statistically significant (p = 0.003). Statistically insignificant (p > 0.05) results were noted for cortex status in CBCT images with regards to the age, sex, site, and angulation of impacted third molars. Conclusion: CBCT imaging is highly recommended for those cases where diversion of the mandibular canal is observed on OPG and when the roots are present between canals.

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.

Pattern of Mandibular Third Molar Impaction in Nonsyndromic 17760 Patients: A Retrospective Study among Saudi Population in Central Region, Saudi Arabia

The objective of this study was to study the incidence of type of impaction of mandibular third molars based on the classifications of Pell and Gregory and Winter, which included angulation of the tooth and level of the occlusal surface of the third molar with respect to the second molar, respectively, in a sample of Saudi population in central region. In this retrospective study, orthopantomograms (OPGs) of 17760 patients were examined, who were reported by the Dental University Hospital (DUH) at King Saud University, Riyadh, Saudi Arabia, between the years 2016 and 2020. Out of 17760 radiographs, 2187 (12.31%) patients presented with at least one impacted third molar. Out of which, 1337 (7.52%) patients had bilateral impaction and 850 (4.78%) patients had unilateral impaction (p < 0.001). No gender predominance was noted in the impaction status (p > 0.05). In bilateral impaction, 671 were male (50.2%) and 666 were female (49.8%). Among unilateral impaction, 394 (46.4%) were male and 456 (53.6%) were female. Mesioangular angulation was the most common pattern of impaction (65%) followed by vertical angulation in both bilateral and unilateral impactions. Level A impaction was found to be highest in both bilateral and unilateral impactions which are 48.02% and 54.0%, respectively (p < 0.05). Our study highlights mesioangular impaction and level "A" as the most frequently encountered angulation and level of impaction in impacted teeth. This study result provides us useful data regarding the radiographic status of mandibular third molars in the population of Saudi Arabia.

Correlation of Variables for WHARFE Assessment and Pederson Difficulty Index for Impacted Mandibular Third Molar Surgery-A Prospective Clinical Study

Objectives

To assess the correlation of factors of WHARFE assessment and Pederson difficulty index for impacted mandibular third molar surgery.

Study Design

A comparative study of difficult factors utilizing Pederson WHARFE and WAR lines was performed involving patients undergoing surgical removal of mandibular third molars for 100 such teeth.

Results

The Spearman's rho correlation run to determine the relationship between Pederson difficulty index and WHARFE assessment values showed a strong, positive monotonic correlation at the 0.05 level (2-tailed; rs = 0.242, n = 100, p = 0.015 < 0.05).

Conclusion

The study has revealed WHARFE assessment to be a more reliable and consistent measure for the radiological evaluation of surgical difficulty over the contemporary Pederson difficulty index.

Evaluation the relationship between the position and impaction level of the impacted maxillary third molar teeth and marginal bone loss, caries and resorption findings of the second molar teeth with CBCT scans

OBJECTIVE

To evaluate the relationship between the position and impaction level of the impacted maxillary third molar teeth and marginal bone loss, caries and resorption findings on the distal surface of the second molar teeth with cone beam computerized tomography (CBCT) scans.

METHODS

All CBCT images of 189 impacted maxillary teeth belonging to 121 patients were examined by an observer. After determining the position and impaction level of the impacted maxillary third molar teeth, presence of caries, resorption and marginal bone loss in the distal of the second molar tooth were evaluated. IBM SPSS Statistics 22.0 (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.) was used for statistical analyses and calculations. Data were analysed using the Chi-square test and Fisher's exact test.

RESULTS

A statistically significant difference was found in terms of the impaction level of the impacted maxillary third molar tooth and the presence of caries in the distal surface of the second molar tooth, in terms of the impaction level of the impacted third molar tooth and the presence of marginal bone loss in the distal surface of the second molar tooth. A similar difference was found in terms of the impaction level of the impacted third molar tooth and the presence of root resorption in the distal surface of the second molar tooth.

CONCLUSION

These data on the natural history of impacted maxillary third molars may contribute to both more accurate estimates of the risk of complications associated with these teeth and determination of the prophylactic approach to asymptomatic impacted third molars.

The Pattern of Mandibular Third Molar Impaction and Assessment of Surgery Difficulty: A Retrospective Study of Radiographs in East Baltic Population

Classifications of impacted teeth allow defining the type and degree of retention, as well as assessing the degree of difficulty of the procedure. The aim of this study was to conduct retrospective analysis of the degree of retention and difficulty in the surgical removal of impacted mandibular third molars in the clinical material of the Department of Oral Surgery in 2013–2018. This study included 1585 dental panoramic radiographs of patients of the Department of Oral Surgery, who reported in 2013–2018, in order to perform surgical removal of the impacted mandibular third molar. Based on dental panoramic radiographs, the degree of retention was determined based on classifications according to Winter, according to Pell and Gregory, according to Tetsch and Wagner, and according to Asanami and Kasazaki. The difficulty of the procedure was also assessed based on the Pederson index. The most common types of lower wisdom tooth impaction are as follows: in Winter’s classification, mesial-angular impaction; in Tetsch and Wagner’s classification, oblique medial-angular impaction; in Pell and Gregory’s classification, impaction grade 2A; and in Asanami and Kasazaki’s classification, 3A and anterior inclination. In most cases of surgical removal of an impacted tooth, the anticipated difficulty of the procedure was rated as very difficult.

A novel method for measuring tooth angulation in permanent mandibular second molars with delayed tooth eruption

OBJECTIVE

To investigate the effect of angulation of permanent mandibular second molars (MM2) on eruption problems and investigate a new method of measuring MM2 angulation for the diagnosis and evaluation of delayed tooth eruption (DTE) for easy use in dental practice.

DESIGN

Retrospective study.

SETTING

Department of Orthodontics, Necmettin Erbakan University.

PARTICIPANTS

A total of 98 patients aged 9-18 years.

METHODS

Patients with 64 permanent MM2s with delayed eruption problems were included in the study group. The control group consisted of patients with 83 normally erupted teeth. In addition, a sub-group, consisting of 23 patients showing unilaterally delayed eruption of the same teeth, was set as a split-mouth group. All patients with unilateral delayed eruption of second molar teeth were selected from the study group to form the sub-group. Angulations of permanent MM2s were measured on panoramic radiographs with two measurement methods: (1) a new method; and (2) a previously accepted method. The comparison of the study and control groups was performed by Mann-Whitney U-test and the split-mouth group was analysed with the paired t-test. The P value was set at 0.05 for statistical significance.

RESULTS

Measurements of the tooth angulation values of the study group were significantly higher than in the control group for both measurement methods (P < 0.001). In addition, in the split-mouth group, angulation values of delayed eruption side were significantly higher than the erupted side (P < 0.001).

CONCLUSION

Increased angulations of permanent MM2s could be associated with delayed eruption problems of these teeth. This new method could be useful in clinical dentistry to determine the eruption evaluation of lower second molars.

Anatomical Risk Factors of Inferior Alveolar Nerve Injury Association with Surgical Extraction of Mandibular Third Molar in Korean Population

The purpose of this study was to analyze the incidence and risk factors of possible inferior alveolar nerve (IAN) injury after extraction of the mandibular third molars. A total of 6182 patients were examined for 10,310 mandibular third molar teeth. Panoramic radiography and patients’ medical records were used to analyze age, gender, and impaction pattern of the mandibular third molar. Cone beam computed tomography (CBCT) was used to investigate the detailed pathway of the inferior alveolar nerve and evaluated the presence of symptoms of nerve damage after tooth extraction. In CBCT, 6283 cases (61%) of the inferior alveolar nerve were actually in contact with the root of the mandibular third molar. The correlation with the panoramic signs of root darkening (p < 0.001), root deflection (p < 0.001), interruption of the IAN (p < 0.001), diversion of the IAN (p < 0.001), and narrowing of the IAN (p < 0.001) had statistical significance. Of the 4708 patients who underwent surgical extraction, 31 (0.658%) complained of nerve damage. Among them, 30 patients (0.637%) complained of symptoms of inferior alveolar nerve damage, and 1 patient (0.02%) complained of symptoms of lingual nerve damage. There was a significant correlation with IAN injury in cases where the roots became dark at the IAN area (p = 0.018) and there was diversion of the IAN at the root area (p = 0.041). When the narrowing of the IAN and the lingual driving pathway of the inferior alveolar nerve appeared simultaneously in CBCT, the risk of IAN injury was high.

Evaluation of Panoramic Radiographs in Relation to the Mandibular Third Molar and to Incidental Findings in an Adult Population

OBJECTIVES

 The aim was to evaluate the characteristics of the mandibular third molars, especially in relation to the inferior alveolar nerve. Further aims were to investigate incidental findings in panoramic radiographs in an adult population, and to investigate image quality related to patient positioning.

MATERIALS AND METHODS

 From a previous study with 451 randomly selected adult participants who lived in Sweden, 442 panoramic radiographs from four dental public health clinics were used. The third molars' characteristics and relation to inferior alveolar nerve were evaluated. Incidental findings and patient positioning were recorded.

STATISTICAL ANALYSIS

 Frequency analysis was used to investigate the occurrence of all findings and their possible interconnections. Whether the patients' age or gender had an impact or not was also analyzed.

RESULTS

 The third molars were erupted in vertical position among 73% regardless of age. When retained or semi-retained, they were most commonly in mesioangular positions. The inferior alveolar nerve was located inferior to the roots in 52%, whereas an overlapped position was most common if the third molar was retained (90%), semi-retained (83%) or the age was less than 30 years (66%). Common incidental findings were apical radiolucencies, idiopathic osteosclerosis, and tooth fragments. Suboptimal patient positioning was found in one-third of the radiographs.

CONCLUSIONS

 Panoramic radiography is a useful method to evaluate third molar prior to surgical removal and may be the only image required. Most incidental findings on panoramic radiographs does not seem to require any further odontological management.

Prevalence and Pattern of Impacted Mandibular Third Molar: An Institution-based Retrospective Study

Introduction:

The third molar is the most frequently impacted tooth with a frequency of occurrence generally reported to be from 18 to 32%. It is considered impacted when its eruption into normal functional occlusion has been interfered with by other teeth, overlying bone or soft tissue and when it is not fully erupted by its expected age of around 20 years. Racial differences affect the pattern of impaction. There is a lacunae of literature on the pattern of mandibular third molar impaction in Tamil population. Aim: To investigate the prevalence of pattern of third molar impaction among the population in Madurai.

Materials and Methods:

A retrospective cohort study was conducted. The first 1000 OPGs (Orthopantamograms) were taken at the Department of Oral Medicine and Radiology, CSI College of Dental Sciences and Research from August to December 2018 of Madurai population aged between 20 and 40 years old. Data include angle, level and position of impaction, proximity to inferior alveolar nerve and dental caries in second molar and/or third molar.

Results:

The average age of subject with mandibular third molar impaction is 30.5 years. The most common occurring mandibular impaction is mesioanglar (60%), Level A (71%), Class II (50%) without involving the inferior alveolar nerve (33%) and dental caries in 20% of second and/ or third molar.

Conclusion:

Mandibular third molar impactions are one of the common developmental condition in this modern civilization. Assessing the third molar and prognosis of its eruption is mandatory for better patient management because of numerous complications associated with unerupted third molar.

Digital Assessment of Difficulty in Impacted Mandibular Third Molar Extraction

PURPOSE

In recent era of computer and software technology, it is necessary to introduce software which helps in routine assessment of surgical procedures practiced in oral surgery. Removal of impacted third molar is a common procedure. It is hard to evaluate factors that complicate removal of impacted third molars because of the large variation among patients and the difficulty in creating a study design. In this article, we have described about our newly designed software developed in order to assess the difficulty in extracting impacted mandibular third molars accurately, thereby reducing the bias faced during the assessment of difficulty in removing impacted mandibular third molar.

MATERIALS AND METHOD

A software is designed using C# computer language and Windows Presentation Foundation Framework.

RESULTS

The measurements and angulations are accurately calculated by this software which helps to bring about uniformity in results, thus minimizing the bias during clinical as well as study purposes.

CONCLUSION

Mandibular third molar difficulty level calculator can be useful software for dental practitioners in day-to-day practice. Dental students and professionals should be made aware of this software so as to utilize it to the utmost possible level.

Evidence-based clinical decision making for the management of patients with periodontal osseous defect after impacted third molar extraction: A systematic review and meta-analysis

Background/purpose

Extraction of impacted mandibular third molar (MTM) is one of the most common procedures in clinical dental treatment; building a decision tree to perform MTM extraction can be prudent in alleviating periodontal diseases. This study is to review the latest research on the management of periodontal osseous defect (POD) after MTM extraction and rebuild a new clinical decision tree.

Materials and methods

Current study was conducted according to PRISMA statement. Medline, Embase, Scopus, and Google Scholar were searched concerning treatment of MTM extraction up to Oct.2019. Three focused questions revolving around asymptomatic versus disease site, age, and necessity of ridge preservation after >6 months follow up will be answered.

Results

A total of 7 studies were included for meta-analysis. Evidences were inadequate in regards to asymptomatic vs disease site of MTM extraction in the long-term follow-up. For patients with age <25 years, postoperative probing depth (PD) always remained at < 4 mm. However, for patients with age >25 years with initial PD > 7 mm, residual pockets still remained at 5 mm. For ridge preservation, significant positive effect in reduction of second molar distal site PD was observed, regardless of different biomaterials being placed (z = 4.69, p < 0.00001).

Conclusion

Age is of utmost importance in preoperative evaluation during impacted MTM extraction. The timing for ridge preservation is essential determinant for achieving optimal treatment outcome. The clinical decision tree as proposed could serve as guidance when dealing with POD after impacted MTM extraction.

Third molar impaction in the Jazan Region: Evaluation of the prevalence and clinical presentation

Objective

To provide information on the prevalence and clinical features of impacted third molar teeth in the South-Western region of Saudi Arabia.

Material and methods

In this cross-sectional study, 1200 panoramic radiographs (50% males and 50% females) were retrieved from the electronic clinical records of patients at the College of Dentistry, Jazan University from December 2014 to December 2016, and impacted third molars were evaluated. Data on clinical and radiographic presentation were analyzed.

Results

Overall, there were 291 (24.3%) patients with impacted third molars among 1200 radiographs. The distribution of impacted third molars according to the number of impacted teeth was as follows: one impaction in 121 (41.6%); two impactions in 90 (30.9%); three impactions in 42 (14.4%); and four impactions in 38 (13.1%) patients. There was a high prevalence of all impaction types among females (54.5%). Maxillary vertical angulation was most common (50%) followed by mandibular mesioangular angulation (48.3%). The depth of impaction in maxillary teeth was higher than in mandibular teeth. Pain was uncommon (4.5% of patients).

Discussion

Clinically, vertical impaction in the maxilla was present in 50% of patients because of limited posterior space, and mesioangular angulation in the mandible was present in 48% of patients because of inadequate space between the ramus and the second molar. These findings are similar to other reports. Vertical impaction of the maxillary wisdom tooth is mostly related to the discrepancy between the mesiodistal size of the tooth crown and the limited retromolar space.

Conclusion

Noiseless presentation of an impacted third molar requires raising the population’s awareness about the need for diagnosis and treatment of the problem to avoid any further complications. The study can be to guide surgical procedures. This study documented the prevalence, pattern, and clinical features of impacted third molars in South Western region of Saudi Arabia.

Modified difficult index adding extremely difficult for fully impacted mandibular third molar extraction

Objectives

The aim of this study was to evaluate the validity of the existing classification and difficulty index of impacted mandibular third molars in clinical situations and propose a more practical classification system.

Materials and Methods

This study included 204 impacted mandibular third molars in 154 patients; panoramic x-ray images were obtained before tooth extraction. Factors including age, sex, and pattern of impaction were investigated. All impacted third molars were classified and scored for spatial relationship (1–5 points), depth (1–4 points), and ramus relationship (1–3 points). All variables were measured twice by the same observer at a minimum interval of one month. Finally, the difficulty index was defined based on the total points scored as slightly difficult (3–4 points), moderately difficult (5–7 points), very difficult (8–10 points), and extremely difficult (11–12 points).

Results

The strength of agreement of the total points scored and difficulty index were 0.855 and 0.746, respectively. Most cases were classified as moderately difficult (73.0%). Although only 13 out of 204 cases (6.4%) were classified as extremely difficult, patients classified as extremely difficult were the oldest (P<0.05).

Conclusion

For difficulty classification, the authors propose one more difficult category beyond the existing three-step difficulty index: the clinician should consider the patient's age in the difficulty index evaluation.

Does craniofacial morphology affect third molars impaction? Results from a population-based study in northeastern Germany

Objectives

It is still not clear why impaction of third molars occurs. Craniofacial morphology and facial parameters have been discussed to be strong predictors for third molar impaction. Thus, this study aimed to investigate the effect of craniofacial morphology on erupted or impacted third molars in a German population sample.

Materials and methods

Erupted and impacted third molars in 2,484 participants from the Study of Health in Pomerania were assessed by whole-body magnetic resonance imaging. Markers of facial morphology were determined in 619 individuals of those participants in whose 421 participants (16.7%) had at least one impacted third molar. Craniofacial morphology was estimated as linear measurements and was associated in a cross-sectional study design with impacted and erupted third molars by multinomial logistic regression models. Erupted third molars were used as reference outcome category and regression models were adjusted for age and sex.

Results

Maximum Cranial Width (Eurion-Eurion distance) was significantly associated with impacted third molars (RR: 1.079; 95% confidence interval 1.028–1.132). This association was even more pronounced in the mandible. Individuals with a lower total anterior facial height (Nasion-Menton distance) and a lower facial index also have an increased risk for impacted third molars in the mandible (RR 0.953; 95% confidence interval 0.913–0.996 and RR: 0.943; 95% confidence interval 0.894–0.995). No significant associations of third molar status with facial width (Zygion-Zygion distance), and sagittal cranial dimension (Nasion-Sella distance; Sella-Basion distance) were observed.

Conclusion

Individuals with an increased maximal cranial width have a higher risk for impaction of third molars in the mandible and in the maxilla. Individuals with a lower anterior total anterior facial height and lower facial index also have an increased risk for third molars impaction in the mandible. These findings could help orthodontic dentists, oral surgeons and oral and maxillofacial surgeons in decision-making for third molars removal in their treatment. These findings highlight the necessity of an additional analysis of the maximal cranial width by the Eurion- Eurion distance.

Prevalence of impacted teeth among a sample of Yemeni population and their association with sex and age

Aim: the aim of the study was to assess the prevalence of impacted teeth and its association with sex and age among a sample of the Yemeni population. Materials and Methods: A cross sectional study design was employed. The study included 999 radiographical records of patients who had panoramic X- rays previously done. All radiographs were assessed for the number and type of impacted teeth, pathology-associated impaction, sex, age and location (mandible and/or maxilla). The collected data was analyzed using SPSS®version21 software. Results: The study sample comprised digital panoramic radiographs of Yemeni patients aged 17 to 54 years (mean 26.6 years). The present study found 542 patients (54.3%) presented with at least one impacted tooth. The 17 to 25 years age group of the study sample had the highest prevalence of tooth impaction (28.6%). Only 10 (1.0%) case presented pathologies associated with the impacted teeth. There was a significant difference in the number of male 203 (20.3%) and female 339 (33.9%) patients with impacted teeth (p=0.031). Impacted teeth occurred slightly more often in the mandible (42.8%) compared to the maxilla (42.4%). Conclusion: The prevalence of impacted teeth among a sample of Yemeni population was high. Third molars and canines were the most common impacted teeth. The prevalence of impacted teeth in females was higher than in males and it was higher in the mandible than in the maxilla, with the younger patients with a higher prevalence of impaction.

Preoperative Anatomic Evaluation of the Relationship Between Inferior Alveolar Nerve Canal and Impacted Mandibular Third Molar in a Population of Bhubaneswar, Odisha, Using CBCT: A Hospital-Based Study

Purpose

To evaluate the correlation between the position of inferior alveolar nerve canal and the angulation of impacted mandibular third molars using cone beam computed tomography (CBCT) in a hospital-based study in the state of Odisha, India.

Materials and Methodology

Three hundred cases of impacted third molars in 200 patients (154 males; 46 females) were included in the study, for whom an initial periapical or panoramic radiograph had revealed that the mandibular canal and the lower third molars were in close proximity. A CBCT scan of each patient was carried out to assess how the canal position influenced the class and position of impaction, angulation of impaction and bone contact.

Results

Class II position B impactions were found in 78.37% cases where the position of ID canal was approximate to the lingual plate and inferior to third molar (73.75%). The results were statistically significant (p = 0.00). 80% of the ID canals showed bone contact. Of these 73.75% ID canals showed lingual bone contact. Mesioangular impactions were most common in mandible and significantly associated with lingual and inferior positioning of the canal.

Conclusions

The study mostly exhibited patients having mesioangular class II position B third molar impactions of the mandible. The position of the canal has a significant influence on the type of impaction and the bone contact.

An Analysis of Dentigerous Cysts Developed around a Mandibular Third Molar by Panoramic Radiographs

Dentigerous cysts are one of the most prevalent types of odontogenic cysts and are associated with the crown of an unerupted tooth, especially of the mandibular third molar. In this study, the characteristics of a dentigerous cyst developed around a mandibular third molar on panoramic radiographs were investigated. The panoramic images of 257 consecutive dentigerous cyst cases associated with a mandibular third molar were analyzed. The mean age of the patients was 45.9 ± 13.3 years. The size of the cyst did not significantly correlate to the age of the patient. The unilocular type (89.1%) and the crown side type (68.5%) were significant. The associated mandibular third molars had a high frequency of class III (64.6%) and position B (48.3%) in Pell and Gregory classification and of horizontal position (36.3%) in angulation. Dentigerous cysts were thought to originate and grow commonly around deeply impacted third molars. The associated third molar with dentigerous cyst tends to have a mesial inclination. Dentigerous cysts do not appear to develop gradually after the crown formation has finished, but arise at various periods randomly.

Contribution of third molar eruption to the estimation of the forensic age of living individuals

Forensic age estimation of a living individual is frequently performed in clinical forensic medicine. Medicolegal physicians are usually called upon by the authorities to estimate the age of a living person requesting asylum or to determine whether a suspected offender is subject to juvenile or adult criminal law. Dental age is one of the parameters studied to estimate biological age. Several methods are used, and among these, analysis of the eruption of the third molar (M3) on an orthopantomogram (OPG) is one of the common methods. The objective of the study was to analyse the contribution of M3 eruption to age estimation, in particular with regard to the threshold of 18 years of age, in a sample of individuals examined in a French university hospital. The stage of wisdom tooth eruption of all individuals aged between 15 and 24 years, who had an OPG performed between 1 January 2013 and 31 December 2015, was interpreted using a three-stage scoring system. In total, 557 OPGs (340 males and 217 females) were included. None of the stage scores allowed a distinction between minors and majors, for either sex. Overall, 85% of females and 98% of males with four M3s in stage 3 (complete emergence in the occlusal plane) were majors.

Third molar tooth agenesis and pattern of impaction in patients with palatally displaced canines

OBJECTIVES

To investigate the association between third molar agenesis and pattern of impaction, missing teeth, and peg-shaped lateral incisor with palatal canine displacement (PDC).

MATERIALS AND METHODS

The pretreatment orthodontic orthopantomograms of 438 patients (122 males and 316 females) diagnosed with PDC were included. A total of 338 patients with normally erupted canines who had a preexisting radiograph as part of their orthodontic treatment (125 males and 313 females) served as controls. Orthopantomograms were evaluated for missing third molars, third molar eruption status, and type of impaction, third molar spaces, third molar width, and angulation.

RESULTS

In the PDC group, at least one third molar was missing in 48% and 19% in the upper and lower arches, respectively. Also, 38% and 67% of PDC patients had at least one third molar impaction in the upper and lower arches, respectively. The difference between the PDC and control groups was significant for both missing and impacted third molars ( P < .001 for each). The most common type of third molar impaction in the upper arch was vertical and distoangular in the PDC and control groups, respectively. Upper and lower third molar width and spaces were reduced in PDC patients when compared with the control group ( P < .001). In PDC patients, missing teeth and peg-shaped lateral incisors were recorded in 5.6% and 9.1%, respectively.

CONCLUSIONS

PDC patients showed a high prevalence of third molar agenesis and impaction. Upper and lower third molar width and space were reduced in the PDC patients. There were no significant associations between tooth agenesis (other than third molars) and the PDC anomaly.

Permanent tooth emergence: Timing and sequence in a sample of Black Southern African children

OBJECTIVES

This study investigates mean age, sequence, and temporal trends of permanent tooth emergence in Black Southern African children and compares the findings with other population samples.

MATERIALS AND METHODS

This community-based cross-sectional study involved 639 Black Southern African children between 5 and 20 years of age. Probit analysis was used to derive the mean age at emergence of the permanent teeth. Sex and cross-population comparisons were undertaken to determine similarities and differences in emergence timing and sequence.

RESULTS

Females emerged all teeth earlier except for M3s (p < .05). Black Southern Africans have earlier mean ages of emergence compared to population samples from the USA, Europe, Australia, and Asia. Sexual dimorphism was detected in the mandibular I1/M1 emergence sequence (females, M₁ I₁ ; males, I₁ M₁ ). The sequence in males is similar in both jaws to males from other sub-Saharan African, USA, and European samples. Females show a similar sequence pattern in the maxilla with other sub-Saharan African, and also Australian and US females of European ancestry. There is a high frequency of polymorphism in the P1P2C1 emergence sequence, with significantly more P2P1C1 maxillary sequences seen among males. Polymorphic variation was common for the I₁ M₁ sequence in both males and females.

DISCUSSION

Mean age of tooth emergence among Black Southern African children is similar to children from most other sub-Saharan African populations. No temporal change was seen in the mean age of emergence. Earlier permanent tooth emergence in Black Southern Africans is part of a general sub-Saharan pattern that is distinct from European and Asian populations.

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

Background

Third 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.

Methods

A 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).

Results

In 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.

Conclusion

Frequency 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.

Anatomical and Radiological Investigation of Dry Bone Adult Mandibles Having Impacted Third Molar Teeth

OBJECTIVE

To investigate the incidence of the impacted mandibular third molars in dry bones adult mandibles.

METHODS

The 198 dry bones adult mandibles gathered from the bone collections in Laboratory of the Anatomy Department of Dokuz Eylul University School of Medicine were macroscopically examined for the presence of impacted mandibular third molars. The genders of the adult bones were unknown. The adult mandibles having impacted third molars were photographed with Canon 400B (55 mm objective). The mandibles having impacted third molars were also radiographically examined with orthopantomography (a dental radiographic technique, kV 60, mA 2.0) in radiology unit of Faculty of Dentistry, Ege University. The impacted teeth were grouped according to their position and degree of impaction.

RESULTS

The each of 2 of 198 adult mandibles (2/198; 1.01%) was having an impacted 3rd molar teeth. These 2 molar teeth were belonged to class 1, B and partially buried, vertically oriented. The first impacted 3rd molar teeth was located on the left side of the one mandible and the second one on the right side of the other mandible.

CONCLUSION

The present study provides information about impacted mandibular 3rd molar in dry bones.

A Cohort Study of the Patterns of Third Molar Impaction in Panoramic Radiographs in Saudi Population

Objectives

To evaluate the epidemiological patterns of third molar impaction in a cohort of patients living in the north of Saudi Arabia.

Materials and Methods

A retrospective cohort study comprised of analysing 2550 Orthopantomograms (OPGs) belonging to patients who attended Aljouf University College of Dentistry between September 2013 and December 2015. OPGs were examined to determine the frequency of third molar impaction, their levels of eruption and angulations. Mixed effects logistic regression analysis was performed to calculate adjusted odds ratios. Data were weighted by age and sex based on population regional estimates.

Results

1551 patients (60.8%) with a mean age of 33.5 years-old (95%CI: 32.9 to 34) demonstrated 2650 impacted third molars. Third molars were more likely present in patients aged from 20 to 39 years-old (p<0.001); and in mandible more than maxilla (p<0.001). It showed highest vertical impaction and higher impaction rate in mandible than maxilla. Level A impaction was the most common among other levels by 1365 (53.5%). Vertical impaction was the most common pattern (1354 patients; 53.1%). Mesioangular impaction ranked second in mandible, while distoangular impaction ranked second in maxilla. There was no statistically significant difference between males and females concerning impaction frequency, depth levels and angulations.

Conclusion

Impacted third molars is still a public health concern among youth and young adults. Vertically impacted mandibular third molars with their occlusal plane at the same level as the occlusal plane of adjacent tooth is the most prevalent pattern of third molar impaction in the northern region of Saudi Arabia.

Prevalence and Pattern of Mandibular Third Molar Impaction in Eritrean Population: A Retrospective Study

INTRODUCTION

The most commonly impacted tooth in the oral cavity is the mandibular third molar. Various etiologic factors have been suggested for impacted mandibular third molars. The pattern and prevalence of impacted mandibular third molars vary with different population and region. This study throws light on the prevalence and pattern of impacted mandibular third molars in Eritrea, East Africa. This is the first reported study regarding the same from Eritrea.

AIM

To assess the prevalence and pattern of impacted mandibu-lar third molars in the population of Eritrea, East Africa by conducting a retrospective study from January 2009 to January 2014.

MATERIALS AND METHODS

This study was conducted in the Department of Oral and Maxillofacial Surgery, Orotta School of Medicine and Dental Medicine and the Orotta Referral Medical and Surgical Hospital, Asmara, Eritrea. A total of 1,813 clinical and radiographic records [orthopantomograms] were assessed and 276 cases were selected for the study as per the inclusion criteria. They were evaluated for the frequency among the various age groups, gender and region along with the sides affected, angulation and level of impaction. The presence of systemic conditions and associated pathologies was also assessed according to the type of impaction.

RESULTS

The average age of these patients in the study was found to be 30 years, with the 20 to 30 years age group being the most affected (67.4%). Females (53.3%) were affected more than the males (46.7%). People from the Asmara region showed significantly more prevalence (79.7%) than the adjoining areas (20.3%). Mesioangular impaction was the most common angulation with a definite relationship to the age groups (p = 0.032). The level of impaction had no significant relationship to the age groups, gender, or region, although class I position A was found to be the most common type. Mesioangular class I position A impac-tion showed an apparent relationship with underlying systemic conditions, but it was statistically insignificant. Mesioangular impaction was found to be associated with the most number of pathologies (p = 0.001).

CONCLUSION

The prevalence of mandibular impaction was less in Eritrea (15.2%) compared with other populations. This study provides useful baseline data for the prevalence and pattern of mandibular impaction in the Eritrean population.

CLINICAL SIGNIFICANCE

This study throws light on the pattern, type, and frequency of mandibular impacted teeth as per age, sex, and region among the population of Eritrea.

Third molar impaction and agenesis: influence on anterior crowding

Background Third molar influence on anterior crowding is controversial, but they are assumed to play a major role in compromising dental arch space. Aim To evaluate the relationship among impaction, agenesis and crowding in black South African males. Subjects and method Mandibles and maxillae of 535 black South African males in the Raymond A. Dart Collection of Human Skeletons, University of the Witwatersrand were examined for anterior crowding and third molar agenesis and impaction. Dental crowding was determined using Little's irregularity index. Results Individuals with impaction showed more moderate-to-extreme crowding than those with agenesis. Bilateral third molar presence was more frequently associated with ideal-to-minimal crowding. Weak positive but significant correlations between crowding and impaction were found (mandible, ρ = 0.154, p = 0.000; maxilla ρ = 0.130, p = 0.000). The direction was the opposite for bilateral presence of molars (mandible, ρ = -0.135, p = 0.02; maxilla, ρ = -0.111, p = 0.010). Odds of mandibular crowding were greatest in individuals with impaction (OR = 3.22, CI = 1.716-6.05, p < 0.001). Maxillary results were similar. Conclusion Third molar impaction plays a role in anterior crowding. Third molar presence was not associated with anterior crowding, while agenesis did not explain absence of crowding.