Computed tomography of emphysema following tooth extraction

Subcutaneous and tissue space emphysema following surgical extraction of mandibular third molars is a rare and serious complication of dental surgery. Recognition of mediastinal emphysema following surgical extraction is difficult because there are no absolute clinical symptoms and signs. We present two cases of emphysema following extraction of a lower third molar and discuss the contribution of CT to the early recognition of the presence and spatial migration of air and to clinical management.     

Radiological age estimation: based on third molar mineralization and eruption in Turkish children and young adults

Radiographic evaluation of mineralization and eruption stages of third molars using dental panoramic radiographies can be an efficient tool for chronological age estimation in both forensic sciences and legal medicine. The third molar tooth is utilized for dental age estimation about the age span of 15–23?years because it represents the only tooth still in development. The aim of this study is to obtain and analyze data regarding third molar development and eruption in Turkish population for dental age estimation. A total of 744 dental panoramic radiographies of 394 female and 350 male subjects aged between 8 and 22?years were examined. Third molar development was determined according to the Nolla classification system, and eruption was assessed relative to the alveolar bone level. Mandibular and maxillary third molars were generally found at similar stages of development on both sides. Nolla stage 6 (completed crown calcification) was reached at around the age of 15 in both maxillary and mandibular third molars in both sexes. Alveolar emergence was at around the age of 16 in males and around age of 17 in females. Although third molars’ eruption shows greater variability than development of third molars, data which were obtained from this study about eruption of these teeth can be supportive to development data for age estimation.     

Dental emergency rates at an expeditionary medical support facility supporting Operation Enduring Freedom

The purpose of this study was to report the dental emergency rate and the distribution of cause of dental emergencies at an Expeditionary Medical Support +25 medical facility during a 6-month deployment in support of Operation Enduring Freedom. A retrospective cohort analysis of 1,972 soldiers stationed at Seeb Air Base, Sultanate of Oman, was accomplished from a phased deployment from March to September 2002. Procedures were divided into 11 categories: endodontic, extraction of teeth other than third molars, extraction of third molar teeth, restoration of teeth (caries), restoration of broken teeth (not caries), orthodontic bracket/wire problem, sensitive teeth, temperomandibular pain, periodontal, oral pathology, and prosthodontic. One hundred thirty-five dental emergency visits were recorded, corresponding to a rate of 137 dental emergencies per 1,000 soldiers per year. Most of the emergencies (34.8%) were due to caries. Pain from third molars was the second most common reason for visiting the dental clinic (19.3%).     

The influence of impaction to the third molar mineralization in northwestern Chinese population

Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C–H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C–H were 0.02–1.42 years higher in males and 0.04–1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation.     

Narrowing of the inferior dental canal in relation to the lower third molars

OBJECTIVES: To assess narrowing of the inferior dental canal in the lower third molar regions using computed tomography (CT) and to determine the value of radiographic markers on rotational panoramic radiographs in assessing the true relationships of the inferior dental canal. METHODS: Patients referred for CT assessment of impacted lower third molars were used in this study. The lower third molars were assessed using CT to determine the position and morphology of the inferior dental canal relative to the roots and the cortical plates. The radiographic markers on rotational panoramic radiographs were correlated with the CT findings when rotational panoramic radiographs were available. RESULTS: The patients referred had 202 lower third molars. Inferior positioning of the inferior dental canal was the most common location on CT. Narrowing of the inferior dental canal was found in relation to the lower third molars in 66.8% of cases. The chance of narrowing of the inferior dental canal as shown using CT increased when at least one of the radiographic markers, superimposition, narrowing, deviation or reduction in density was present on the rotational panoramic radiograph. Deviation of the inferior dental canal on rotational panoramic radiographs was found to be the most significant predictor of narrowing of the inferior dental canal and a close relationship to the roots, as shown in CT. CONCLUSIONS: Narrowing of the inferior dental canal is a common finding when impacted lower third molars are assessed using CT. On rotational panoramic radiographs deviation of the inferior dental canal is the best predictor of narrowing of the inferior dental canal and a close relationship to the roots.     

Accuracy of digital and film panoramic radiographs for assessment of position and morphology of mandibular third molars and prevalence of dental anomalies and pathologies

OBJECTIVES: To compare the accuracy of digital and film panoramic radiographs for determining (1) the position and morphology of mandibular third molars before surgical removal and (2) the prevalence of dental anomalies and pathologies. METHODS: Three hundred and eighty-eight third mandibular molars were available for examination. Position and morphology of third molars observed on film radiographs and on digital panoramic images from five systems (DenOptix, DigiDent, Digora, Dimax2 and Orthophos Plus) were recorded by two observers and were compared with surgeons' findings at the time of the operation (gold standard). One observer further recorded the prevalence of dental anomalies and pathologies on both imaging modalities. RESULTS: Few differences were found between the digital and film-based panoramic systems in the assessment of accuracy of position and morphology of mandibular third molars. The prevalence of dental anomalies and pathologies determined with the two modalities was roughly similar. CONCLUSION: The five digital panoramic systems evaluated in this study were equally as useful for third molar treatment planning and diagnosis of dental anomalies and pathologies as conventional film-based panoramic radiographs.     

Einfluss der Retention auf die Weisheitszahnmineralisation

In dental age diagnostics radiological evaluation of third molars is the most important criterion to establish whether an individual has attained 18 years of age. However, completed root development of third molars as the only criterion is insufficient for an establishment of legal certainty. In the present paper it was investigated whether root development is slowed down in impacted lower third molars and thereby increases the probability that 18 years of age has been attained. By means of logistic regression a delay of 0.6 years in male subjects and 0.7 years in female subjects was shown in impacted third molars with completed root development compared to cases with erupted third molars. There was no case in which an individual with impacted lower third molars with completed root development on both sides was under the age of 18. In the presence of impacted third molars with completed root development on one side only one subject was under 18 years of age (17 years and 11 months!). Conclusion: If two impacted third molars with completed root development in the lower jaw are determined in dental age diagnostics, a minimum age of 18 years in central Europeans can be suspected beyond any reasonable doubt. If one impacted mandibular third molar with completed root development is present it is very likely that 18 years of age have been attained.     

Dental age estimation from the developmental stage of the third molars in Iranian population

A sharp increase in forensic age estimation of living persons has been observed in recent years. However, ethnic populations residing in different countries have been insufficiently analyzed. The aim of this study was to achieve a referral database and regression equations for dental age estimation of unaccompanied minors of Iran nationality. A total of 1200 orthopantomograms were collected from original Iran and equally divided in age categories between 10 and 27 years. On the radiographs, the developmental stage of the third molars was scored applying a Demirjian et al. scoring technique. Inter- and intra-observer reliabilities were tested using kappa statistics. Correlation between the scores of all four wisdom maxillary and mandibular third molars teeth and left/right symmetry were evaluated with spearman correlation coefficient. Student’s t-test on asymmetry was performed and regression formulas were calculated. The present database was the first to assemble third molar developmental scores on radiographs of Iran individuals and provided more appropriate dental age estimation of unaccompanied Iran minors. To enhance the accuracy of forensic age estimates based on third molars mineralization, the use of population-specific standards is recommended.     

Dental emergency rates at two expeditionary medical support facilities supporting operations enduring and Iraqi Freedom

This study reports dental emergency rates and distribution of causes of dental emergencies at two expeditionary medical support facilities supporting operations Enduring Freedom/ Iraqi Freedom. A retrospective cohort analysis of 9948 soldiers deployed to Prince Sultan Air Base, Kingdom of Saudi Arabia, and 1467 soldiers at Baghdad International Airport, Iraq, was accomplished from a phased deployment from January 2003 to September 2003. Procedures were divided into 11 categories: endodontic, extraction of teeth other than third molars, extraction of third molar teeth, restoration of teeth (caries), restoration of broken teeth (not caries), orthodontic bracket/wire problem, sensitive teeth, temperomandibular pain, periodontal, oral pathology, and prosthodontic. The dental emergency rates for Prince Sultan Air Base and Baghdad International Airport were 153 and 145 dental emergencies per 1000 soldiers per year, respectively. Most of the emergencies were because of dental caries. Pain from third molars was the second most common reason for visiting the dental clinic.     

Are soldiers at increased risk of third molar symptoms when on operational tour in Iraq? A prospective cohort study

OBJECTIVE: Pain associated with third molar (wisdom) teeth is a common cause of morbidity for soldiers in the United Kingdom and on operational deployments. This study compared the incidence of third molar symptoms between soldiers serving in Iraq and soldiers stationed in barracks in Northern Ireland and assessed if pre-deployment screening could be improved. METHOD: Data was collected in a prospective cohort study over five consecutive months. Dental officers recorded each time an Army soldier presented with third molar related symptoms. RESULTS: 1% of soldiers in Iraq had third molar related symptoms in this time compared to 1.4% of those stationed in Northern Ireland. The range of pathologies and teeth affected were similar between locations. In both locations approximately 40% of teeth that caused problems had been symptomatic before and 13 -16% had untreated decay. CONCLUSIONS: This study suggests that soldiers experience a lower incidence of symptoms related to third molars when in Iraq compared to Northern Ireland (P < 0.033) possibly due to pre-deployment treatment. If ideal pre-deployment screening of third molars was carried out and National Institute of Clinical Excellence guidelines applied 38% of the Operation Telic group of patient's problems could have been prevented.     

The mandibular third molar position as a predictive criteria for risk for pericoronitis: a retrospective study.

During the 6-month period from mid February 1988 to mid August 1988, 148 patients presented with 154 diagnosed cases of mandibular third molar pericoronitis. All patients were members of the recruit population stationed at the Recruit Training Command, Great Lakes, Illinois. Selected clinical parameters relating to the orientation and eruption status of these third molars were collected and analyzed. The goal was to obtain a predictive clinical profile of the impacted mandibular third molar (MTM) at greatest risk for pericoronitis in the young naval and Marine Corps personnel. The majority of pericoronitis cases, 120 of 148 or 81.0%, involved vertically oriented MTMs; of this total, 79.1% were erupted to the approximate height of the occlusal plane of the arch. The remaining 20.9% were at or below the height of contour of the adjacent tooth. Mesioangular impacted MTMs accounted for only 11.2% of pericoronitis cases. The remaining cases comprised distoangular and horizontally impacted MTMs (3.4% and 3.8%, respectively). Involvement by impinging maxillary dentition was observed in 39.7% of the vertically oriented MTMs, 56.2% of the mesioangular oriented MTMs, 40.0% of the distoangular MTMs, and 14.0% of the horizontally impacted MTMs. The mean value for occlusal coverage by a soft tissue operculum observed for all MTMs in this study was 49%. In the population studied, risk for pericoronitis appears to increase with greater vertical orientation and height of eruption. The absence of impinging maxillary dentition did not eliminate the risk of mandibular third molar pericoronitis. These data have implications for targeting treatment needs of naval and Marine Corps personnel who may be without dental support for extended periods of time.     

Studies on the chronology of third molar mineralization in First Nations people of Canada

Forensic age estimation of living subjects has become increasingly important in recent years. One main criterion for dental age estimation in the relevant age group is the evaluation of third molar mineralization. In the present study, we determined the stages of third molar mineralization in 347 female and 258 male First Nations people of Canada aged 11 to 29 years based on radiological evidence from 605 conventional orthopantomograms. The results presented here provide useful data on the mineralization stages of third molars that can be used for forensic estimation of the minimum and most probable ages including the range of scatter of investigated persons.     

Dental emergencies during SFOR 8 in Bosnia

The purpose of this study was to report information regarding dental emergency rates, conditions that cause soldiers to present for care, and arrival patterns of dental emergency patients. Data came from a retrospective cohort analysis of dental emergencies experienced by the soldiers of the Third Infantry Division while deployed in the Multinational Division North area of Bosnia from September 2000 to March 2001. Defective restorations or caries accounted for 25% of the diagnoses prompting soldiers to report for dental sick call, third molar-related problems (pain or pericoronitis) were 19%, and periodontal conditions accounted for less than 5%. More aggressive treatment of unerupted or partially erupted third molars would appear to have the greatest potential for reducing the rate of emergencies.     

Economic and health implications of routine CBCT examination before surgical removal of the mandibular third molar in the Danish population

Objectives:

This epidemiological study aimed to analyse economical and societal consequences in Denmark if CBCT is used routinely as a diagnostic method before removal of the mandibular third molar. Furthermore, the aim was to calculate the excess cancer incidence from this practice.

Methods:

17 representative dental clinics in the regions of Denmark were visited by two observers, who registered the total number of patients in each clinic, the number of removed mandibular third molars from patients'' files together with the age and gender of these patients. The data were collected from 2008 to 2014. The total number of removed mandibular third molars in Denmark each year was derived from the collected data and information on patients'' contacts with dentists from Statistics Denmark as a sum of contributions from each region. The contribution of a region was obtained as the number of removed mandibular third molars in the selected clinics in the region times the ratio of the number of patients in the selected clinics in the region to the total number of patients with contact to a general practitioner in the region in 2011. Existing knowledge on the costs for panoramic and CBCT imaging was used to calculate total costs. The cancer incidence was calculated from lifetime attributable risk curves based on linear risk assumptions.

Results:

The selected clinics included 109,686 patients, and 1369 mandibular third molars had been surgically removed. Using data from Statistics Denmark gave an estimated annual number of removed mandibular third molars of 36,882 at a total cost of €6,633,400. The additional cancer incidence was estimated to be approximately 0.46 per year.

Conclusions:

The data should be used in a cost-effectiveness analysis of the clinical efficacy of CBCT imaging before removal of mandibular third molars.     

Rosette formation of impacted molar teeth in mucopolysaccharidoses and related disorders.

The radiographic features of the jaws in the mucopolysaccharidoses and related disorders (MPS) have been reviewed and three further cases are reported here, with particular reference to a novel dental anomaly, not previously described in detail, in two of them. The dental changes appear to be fully developed by the third decade and are characterized by bilateral multiple impacted molar teeth, which conglomerate in a single follicle to form a characteristic rosette of teeth. Rosetting was present only in relatively mature cases of MPS. However, it was also seen in the fourth patient, where we could not detect any other abnormal clinical or radiographic features. We therefore propose that since multiple rosetting of molar teeth can also occur in an isolated form, it is only suggestive of MPS.     

Evaluation of the effect of impaction on the mineralization of mandibular third molars and forensic age estimation in a sample of south Indian children

Assessment of third molar mineralization is a basic forensic odontological method available for age estimation in children and adolescents. Due to their protracted development into the late adolescence, their development has become the subject of interest and acquired great forensic importance. It is clearly evident in the literature that impaction factor has an influence on the rate of maturation of the third molars. In this regard, the present study was undertaken to test the relationship between impaction and its concomitant effect on the mineralization of the third molar and forensic age estimation. A total of 520 digital orthopantomograms (OPG) of 260 males and 260 females of south Indian origin were assessed retrospectively. Maturation of the third molars (I3M) was assessed using the method of Cameriere et al. (Int J Leg Med 122 (6):493–497, 2008). Impaction status was determined according to the position of lower right and left third molars in relation to the long axis of the second molars. Out of the total sample, 68.1% of lower left third molars and 71.2% of lower right molars were impacted. Statistical measures for I3M were calculated in the males and females for both impacted and non-impacted third molars. It was ascertained that the mean age and I3M values were higher in impacted third molars, indicating the slower rate of maturation than non-impacted ones. The sensitivity and specificity of the test (I3M < 0.08) was 96.2% and 72.4% for non-impacted third molars and 46.2% and 87% for impacted third molars, respectively. Our findings indicate that the cut-off value of I3M < 0.08 resulted in greater number of age misclassifications (false negatives) for impacted molars, highlighting the need for new cut-off value of I3M to meet the legal standards. It was concluded that the mineralization of impacted third molars was slower compared to non-impacted ones in south Indian males and females. Further studies are warranted to validate these findings among a larger and more diverse sample.

     

Age estimation of teenagers from Monterrey (Mexico) by the evaluation of dental mineralization after multi-slice helical computed tomography

Current social conditions require more accurate methods to determine the age of people, either living or deceased. The aim of this study was to determine chronological age by measuring the mineralization of third molars. Volunteers (n = 137), aged between 14 and 22 years and of either gender, were recruited from north-eastern Mexico. Sampling was probabilistic and at random. The mineralization stage of third molars was evaluated with the use of multi-slice helical computed tomography and the Mincer-modified Demirjian amended scale. The correlation coefficient, mean difference and linear estimation were determined. There was a linear correlation between age and the mineralization of third molars. Third molars of adults had a degree of mineralization above Demirjian stage F, whereas the third molars of minors had stages between A and F. Hence, a method was obtained to determine the chronological age from the evaluation of dental mineralization of third molars by multi-slice helical tomography. These results are useful as a diagnostic support in forensic dentistry.     

航海人员洁治术对干槽症的影响及原因分析

目的　探讨干槽症发病的相关因素和预防航海人员干槽症发生的方法。方法　对 4 6 8例需要拔除双侧下颌阻生智齿的航海人员在无拔牙禁忌证的情况下分次进行拔牙手术 (相隔时间 2个月以上 )。第 1次拔牙前不进行特殊术前准备 ,第 2次术前进行全口龈上下洁治术 ,术后 3～ 5 d拔牙。 2次拔牙前均牙菌斑取样检测幽门螺杆菌 (Helicobacter pylori,H.Pylori)。结果　第 1次拔牙后 78颗发生干槽症 ,占 16 .6 7% ;第 2次拔牙后仅 9颗发生干槽症 ,占 1.92 % ,差异非常显著 (P<0 .0 1)。牙菌斑 H.py-lori检测结果 2次拔牙前阳性率分别为 5 4 .2 7% (2 5 4 / 4 6 8)和 14 .74 % (6 9/ 4 6 8) ,差异亦有显著性 (P<0 .0 5 ) ,且所有发生干槽症的手术拔牙前牙菌斑 H.Pylori检测均为阳性。结论　口腔幽门螺杆菌感染可能是航海人员干槽症发病率高的原因 ,术前口腔洁治可以有效预防拔牙术后干槽症的发生。     

A study of sports-related mandibular angle fracture: relation to the position of the third molars

Mandibular angle fractures have been considered attributable to the presence of unerupted third molars. We examined the relationship between the incidence of sports-related mandibular angle fractures and the presence of a mandibular third molar with emphasis on the position of the third molar. The incidence of angle fracture was significantly higher in the sports-related injury group than in the group with fracture due to other causes ( P <0.05). The incidence of angle fracture in the athletes with higher impaction scores was significantly higher than that in the subjects with higher scores who did not have sports-related fractures ( P <0.05). The percentage of rugby athletes with third molars was significantly higher than that of those without third molars ( P <0.001), and a high proportion of young athletes (89.5%) was considered to belong to a potential high-risk group for angle fractures. Our findings suggest that mandibular angle fractures are influenced by the presence and characteristics of the third molar in sports-related injuries.