Inspektorische Beurteilung des Durchbruchs der bleibenden Zähne bei Kindern und Jugendlichen als forensisch-odontologisches Hilfmittel zur Bestimmung des chronologischen Alters

Aim: Age determination has become an ever increasing challenge in forensic odontology, both in the number of investigated subjects due to the worldwide migration and in the high level of scientific quality of the odontological judgement required in judicial processes. The aim of this study was to determine the eruption times of the permanent teeth in a longitudinal study and to compare the data with reports from the literature. The findings were further evaluated for their applicability to age determination of living individuals. Material and Methods: We evaluated the dental records of 477 male and 487 female school children recorded from 1969 to 1976 in a school in Stuttgart, Baden-Württemberg, a southwestern state of Germany. Sex, age and the presence of permanent teeth were recorded but wisdom teeth were excluded. Results: The sequence of tooth eruptions differed significantly between the lower and upper jaws, whereas no significant differences existed when comparing the different sides of each jaw. The calculated eruption times of the different types of teeth confirmed the known data from the dental literature. The acceleration of teeth emergence determined in German studies started after the World War II ranged from 1 to 9 months, computed on all teeth. Furthermore, we observed no relevant acceleration of the whole dentition but some differences to other international studies, concerning the sequence of tooth eruption. The computed differences for tooth eruption, as a mean value calculated for all teeth, was ±1 year at maximum when compared to studies from different continents. Conclusion: The genetic determinant for tooth eruption allows only a small time corridor for the penetration of the mucosa by individual teeth. These eruption times differ to results of studies generated during the first half of the last century. However, these differences are small, despite a remarkable increase in social standards during the second half of the century. The continuous checking of this simple to investigate feature is advisable in order to reveal factors that could possibly influence the teething period and to provide baseline data for ethnic comparisons. However our meta-analysis supports the view that the influence of ethnicity on the times of teeth emergence is poor as far as children and adolescents are concerned.     

Sexual differences in Turkish dentition

Sexual variation in the human skeleton and dentition is of great concern for both anthropologists and odontologists. Assessment of variation in dental size gives a clue about the behavior of a population, and also differences between the sexes. This study deals with sexual differences in a Turkish sample of individuals ranging in age from 20 to 29 years. The sample is composed of 28 buccolingual (BL) and mesiodistal (MD) dimensions of upper and lower dentition (I1 through M2). Dental casts of 50 males and 50 females were analyzed using discriminant function statistics. The results indicated that 8 of the upper and 7 of the lower dimensions were significantly greater in males. Many of the differences were located in the anterior teeth of both jaws. In a stepwise function applied to both arches, the lower and upper canine BL, lower canine and P1 MD, and lower I2 BL were used as the most discriminating variables. When the front teeth (i.e., I1, I2, and C) are used in separate functions, only the canine BL of the lower jaw and I2 and C BL of the upper jaw were found to have the discriminating variables. Classification accuracy was 81% for the total sample, 76% for upper front and 81% for lower front teeth. In conclusion, dentition in Turkish people seems to be less sexually dimorphic than the populations with which they were compared (Jordanians, Swedish and South Africans) as was determined by the percent of accuracy obtained. In comparison with other populations, as anticipated, Turkish dental size is closest to the Jordanian sample and farthest from the South African whites.     

Evaluation of intraoral CCD camera for dental examination in forensic inspection

This study was performed to assess the effectiveness of an intraoral CCD camera for dental examinations when sufficient jaw opening or adequate lighting cannot be obtained. A handpiece-type intraoral CCD camera (Crystal Cam; GC Corp., Japan) was used for the study. Because a full view taken by the intraoral CCD camera covers only one or two teeth, all the teeth were individually photographed and a view of the dentition assembled on a personal computer. Assuming that the jaw could not be opened widely enough to inspect an occlusal view, a dry skull and a volunteer were restricted to open the mouth and all the teeth were photographed with an intraoral CCD camera. These were compared to intraoral photographs taken by the conventional method using a single-lens reflex camera and mirror. When the intraoral CCD camera was used to photograph teeth, the color tone of metal restorations could be readily identified, but special care was required to identify carious lesions, discoloration of tooth structure, and esthetic restorations. The dentition photographs assembled from the original intraoral CCD images were transferred via the Internet as e-mail attachment files to allow preparation of the dental chart at the destination. Based on the transferred images, it was possible to prepare a dental chart agreeing satisfactorily with actual oral conditions. The easy transfer of digital images provides various advantages in evaluating and discussing certain cases in cooperation with other forensic odontologists via the Internet. The camera may be made more effective or useful through improvement of the tip portion of the camera and the entire system to achieve a more compact design and better portability.     

双生儿牙齿冠宽咬合特征遗传变异研究

对居住北京城区54对平均年龄21.3岁的同性别双生儿恒牙列牙齿冠宽、前牙覆、覆盖、第一恒磨牙关系进行测量,结果:同卵组与异卵组牙齿冠宽的对内之差、各牙齿的分散度和遗传度,均与遗传因素明显相关。同卵组双生儿的牙齿宽度无显著差异,异卵组双生儿的对内之差差异显著;各牙齿冠宽差异的分散度较大。但同卵组、异卵组前牙覆、覆盖、第一恒磨牙关系的一致率无显著性差异,表明咬合特征的形成受环境因素影响较大。     

A non-syndrome case with bilateral supernumerary canines: report of a rare case

Supernumerary teeth are described as the teeth formed in excess of the normal dental formula. Prevalence of supernumerary teeth varies between 0.1% and 3.8% in general Caucasian population. They have been reported in both the primary and the permanent dentition. Supernumerary teeth may occur in any region of the dental arch. However, a supernumerary tooth in the canine region is a rare condition and to our knowledge, a non-syndrome case with bilateral supplemental maxillary canines did not exist in the literature. It was the aim of this report to evaluate this rare case in view of both oral radiology and orthodontics.     

Cleidocranial dysplasia: radiological appearances on dental panoramic radiography.

OBJECTIVE: To report the effectiveness of dental panoramic radiography in identifying features pathognomonic for cleidocranial dysplasia. METHODS: Panoramic radiographs of nine male Caucasian patients with cleidocranial dysplasia are analysed. RESULTS: In addition to the established dental complications of failure of eruption of the permanent dentition and multiple supernumerary teeth, morphological abnormalities of the maxilla and mandible, particularly in the ascending ramus and coronoid process were present. CONCLUSION: Dental panoramic radiography is a valuable adjunct in confirming the diagnosis of cleidocranial dysplasia.     

64层螺旋CT多平面重建技术对颌骨埋伏牙的诊断价值

目的：探讨64层螺旋CT多平面重建技术在颌骨内埋伏牙的定位及临床应用价值。方法：对38例临床疑似埋伏牙患者行牙列轴面螺旋CT容积扫描,应用容积再现（VR）、最大密度投影（MIP）、多平面重建（MPR）、齿科软件获得牙体表面立体图像及任意平面、曲面断层图像。结果：38例患者阻生中切牙10颗,侧切牙8颗,尖牙14颗,第三磨牙6颗,多生牙13颗。结论：64层螺旋CT能清晰显示颌骨埋伏牙的形态,唇腭侧关系及与牙列、邻牙的关系,无论对于正畸牵引还是外科手术都具有极为重要的临床意义和发展前景。     

Development and evaluation of a standardized method and atlas for contouring primary and permanent dentition

Objectives:

Radiation toxicity of the dentition may present significant treatment-related morbidity in the paediatric head and neck cancer population. However, clear dose–effect relationships remain undetermined and must be predicated upon accurate structure delineation and dosimetry at the individual tooth level. Radiation oncologists generally have limited familiarity or experience with relevant dental anatomy.

Methods:

We therefore developed a detailed CT atlas of permanent and primary dentition. After studying this atlas, five radiation oncology clinicians delineated all teeth for each of eight different cases (selected for breadth of dental maturity and anatomical variability). They were asked to record confidence in their contours on a per-tooth basis as well as the duration of time required per case. Contour accuracy and interclinician variability were assessed by Hausdorff distance and Dice similarity coefficient. All analyses were performed using R v. 3.1.1 and the RadOnc v. 1.0.9 package.

Results:

Participating clinicians delineated teeth with varying degrees of completeness and accuracy, stratified primarily by the age of the subject. On a per-tooth basis, delineation of permanent dentition was feasible for incisors, canines, premolars and first molars among all subjects, even at the youngest ages. However, delineation of second and third molars was less consistent, commensurate with approximate timing of tooth development. Within each tooth contour, uncertainty was the greatest at the level of the dental roots.

Conclusions:

Delineation of individual teeth is feasible and serves as a necessary precursor for dental dose assessment and avoidance. Among the paediatric radiation oncology community in particular, this atlas may serve as a useful tool and reference.     

Dental radiographic information of term newborn babies within the first month: Analyzing five radiographic cases along with physical attributes in Japan

BackgroundAlthough dental radiography is a valuable tool for age estimation in forensic anthropology and odontology, very limited radiological data are available regarding tooth development in healthy newborn babies during the first month of life.AimThis study aimed to describe the radiological findings of tooth development in babies aged 0 days to 1 month.DesignWe analyzed the postmortem findings of five newborn babies with no known natural cause of death who had undergone autopsy, computed tomography (CT), and dental radiography. We estimated the gestational age for the babies aged 0 days and analyzed the condition of mandibular symphysis, existence of tooth germs, and presence or absence of calcification of the first permanent molars of all the babies.ResultsThe calcified form of 20 deciduous teeth, tooth germs of the permanent upper and lower first molars, and non-calcified mandibular symphysis were observed in each case. However, calcification of the first permanent molar was observed in only two 1-month-old babies.ConclusionThe dental radiographic findings and anthropometric measurements of non-skeletonized, non-mummified term babies confirmed calcification of all the deciduous teeth and the first permanent molar at the age of 0 days and 1 month, respectively.     

Eruption disturbances: an aetiological-cum-management perspective

Failure of permanent teeth to erupt without any known cause is a rare incident. We report a case of multiple unerupted permanent teeth and make an effort to predict all possible causes of non-eruption of permanent teeth clinically and radiographically. It is essential to diagnose and treat eruption disturbances as early as possible because treatment at a later stage is usually more complicated due to the tendency of malocclusion to increase with time and reduced ability of remaining dentition to adjust.     

Above or below 14 years? An orthopantomographic study based on chronological course of eruption of mandibular premolars and second molars in a sample of south Indian children

In the context of dental age assessment, two significant factors can be studied; tooth mineralisation and tooth emergence. Little is known about the role of a second molar eruption in forensic age estimation. This paper aims to contribute to forensic age estimation using an age threshold of 14 years, studying the eruption stages of permanent mandibular premolars and second molars. Totally 640 orthopantomograms (OPGs) of south Indian children, aged between 10 and 18 years, were evaluated using Olze et al. staging of tooth eruption stages (A–D). Spearman's rho correlation showed a strong, positive, and statistically significant correlation between the chronological age and the eruption stages of both sexes' teeth. Accuracy, sensitivity, specificity, likelihood ratios, and post-test probability values were calculated for all tested teeth. The best performance to discriminate individuals above or below 14 years showed stage D in second molars. The sensitivity varied between 89% and 94% and specificity between 75% and 84%, respectively. Receiver operating characteristic curve analysis revealed high diagnostic performance for stage D, with area under the ROC curve (AUC) values of 84% and 85% for tooth 37 and 85% and 83% for tooth 47 in males and females, respectively. In conclusion, it is possible to predict age over 14 years in south Indian children using tooth emergence stages from OPGs with a relatively high interobserver agreement and good diagnostic accuracy. However, there are some limitations and, therefore, must be used in conjunction with other methods.     

Die Zuordungswahrscheinlichkeit eines numerisch-topographischen Zahnstatus bei der Identifikation unbekannter Leichen

The numerical topographical dental findings of 29,862 adult patients from several German dental practices were evaluated. Taking into account the age-dependent loos of teeth the various decades were investigated separately for increased incidences of identical findings. The total number of teeth comprising the dental findings in the form of tooth number classes was a first-line criterion aiding classification. In accordance with an underlying binominal distribution, a raised incidence of identical dental findings was found both in patients edentulous jaws or few residual teeth and in patients with largly complete dentition. The raised incidence was confined to a few standard findings in each of these high or low tooth number classes. However, more than 50% of all cases were either in the intermediate tooth number classes, in which raised incidences of ≥ 0.2% generally do not occur, or showed correspondingly rare constellations of findings in the high or low tooth number classes. In more than half of all cases, there was therefore a numerical topographical dental status which can be used in identification with a matching probability of ≥ 99.8%. Dental findings which occur less frequently can be arranged clearly according to tooth number classes.     

Size of lower jaw as an early indicator of skeletal class III development

BACKGROUND/AIM: Malocclusion of skeletal class III is a complex abnormality, with a characteristic sagital position of the lower jaw in front of the upper one. A higher level of prognatism of the lower jaw in relation to the upper one can be the consequence of its excessive length. The aim of this study was to find the differences in the length of the lower jaw in the children with skeletal class III and the children with normal sagital interjaw relation (skeletal class I) in the period of mixed dentition. METHODS: After clinical and x-ray diagnostics, profile tele-x-rays of the head were analyzed in 60 examinees with mixed dentition, aged from 6 to 12 years. The examinees were divided into two groups: group 1--the children with skeletal class III and group 2--the children with skeletal class I. The length of the lower jaw, upper jaw and cranial base were measured. The proportional relations between the lengths measured within each group were established and the level of difference in the lengths measured and their proportions between the groups were estimated. RESULTS: No significant difference between the groups was found in the body length, ramus and the total length of the lower jaw. Proportional relation between the body length and the length of the lower jaw ramus and proportional relation between the forward cranial base and the lower jaw body were not significantly different. A significant difference was found in proportional relations of the total length of the lower jaw with the total lengths of cranial base and the upper jaw and proportional relation of the length of the lower and upper jaw body. CONCLUSION: Of all the analyzed parameters, the following were selected as the early indicators of the development of skeletal class III on the lower jaw: greater total length of the lower jaw, proportional to the total lengths of cranial base and theupper jaw, as well as greater length of the lower jaw body, proportional to the length of the upper jaw body.     

T4K矫治器治疗儿童替牙早期安氏Ⅱ类错合畸形的疗效观察

目的通过矫治前后对比,观察T4K矫治器对于儿童替牙早期安氏Ⅱ类错合畸形的治疗效果。方法抽取正畸门诊替牙早期安氏Ⅱ类错合畸形患者20例（男女各10例）,年龄6～10岁,在2012年11月～2013年3月戴用澳大利亚Myofunctional Research公司的T4K功能矫治器,治疗前后制取工作模型进行模型测量分析。结果 T4K矫治5个月后,20例患者的磨牙关系均由安氏Ⅱ类转为安氏Ⅰ类;前牙覆合平均减小3.00 mm,前牙覆盖平均减小2.25 mm;上牙弓后段宽度平均增加1.50 mm,下牙弓后段宽度平均增加2.50 mm;上前牙拥挤度平均减小2.75 mm,下前牙拥挤度平均减小3.00 mm。结论T4K矫治器用于儿童替牙早期安氏Ⅱ类错合畸形,能明显改善患者咬合关系,达到预期治疗目标,且易于被患者接受,值得临床推广应用。     

Dentascan软件在口腔正畸中的应用

目的探讨Dentascan软件在口腔正畸中的临床应用价值。方法对57例埋伏阻生牙患者行16层螺旋CT扫描，应用Dentascan软件重建出上、下颌的曲面全景体层图像及斜面体层图像，并与最大密度投影（MIP）、容积成像（VR）的图像进行对比。结果应用Dentascan软件生成的曲面体层图像及与其垂直的斜面体层图像可以清晰地显示埋伏阻生牙的位置、生长方向及与周围牙齿及颌骨的关系，并可显示埋伏牙的细节。而MIP及VR能直接显示立体三维图像，并且可以多角度旋转观察。结论Dentascan软件结合MIP及VR图像可以在任意方向获得直观清晰的二维及三维图像，对于口腔正畸具有重要的指导意义。     

Contrast-enhanced dental MRI for visualization of the teeth and jaw.

A technique for contrast-enhanced dental MRI is described that enables 3D visualization of the oral cavity, including the jaw and teeth. Since teeth are MR-invisible, the basic principle of this technique is that the teeth and jaw can be observed indirectly through contrast with a surrounding MR-visible medium. For this purpose, the oral cavity is filled with a nontoxic substance, such as water or MR contrast media, that gives a high MR signal. A 3D data set covering the entire buccal space is acquired, and the image intensities are inverted. Since isosurface reconstructions of the teeth and jaw, as well as panoramic views analogous to orthopantomography, can be extracted from these data, contrast-enhanced dental MRI may be useful as a flexible tool for dentistry and orthodontics. Moreover, contrast-enhanced dental MRI works without radiation exposure, and therefore it is an interesting alternative to X-ray-based imaging modalities such as conventional radiography and dental CT. In this article, some preliminary results obtained with contrast-enhanced dental MRI are shown in order to demonstrate the feasibility and performance of this new approach.     

数字化断层融合在颌骨疾病诊断中的应用

目的：探讨数字化断层融合技术在颌骨疾病诊断中的优势。方法：搜集牙科患者,行数字化断层融合检查,对牙周炎,颌骨囊肿,根尖脓肿,阻生齿,牙源性肿瘤,下颌骨骨折,赘生齿等疾病做出影像诊断,分析数字化断层融合技术在颌骨疾病诊断中的应用优势。结果：46例颌骨断层融合图像显示,牙周炎3例,颌骨囊肿4例,根尖脓肿3例,阻生齿19例,颌骨骨髓炎1例,赘生齿2例,断齿2例,牙源性肿瘤2例,上颌窦炎6例,下颌骨骨折3例,颞下颌关节脱位1例。随诊观察断层融合技术诊断与临床诊断相符。结论：数字化断层融合技术在颌骨疾病上均能作出正确诊断。简便,快捷,价格低,辐射少,不受体位限制,更能体现它的优点。     

Odontometric sex assessment from logistic regression analysis

Odontometric sex assessment is considered a useful adjunct to more robust predictors such as pelvic and cranial bones, and discriminant function analysis (DA) has been widely applied in dental sex assessment. Logistic regression analysis (LRA) is considered a better alternative, although still untested in odontometric sex prediction. This study examines the use of LRA in dental sex assessment and compares its success to DA. Mesiodistal and buccolingual dimensions of all teeth, except third molars, were obtained on dental stone casts of 105 young adults (52 females, 53 males) using digital caliper. Application of LRA to teeth of both jaws combined and to maxillary and mandibular teeth separately yielded correct sex allocation rates ranging from 76% to 100%, which proved superior to sex assessment using DA (∼52–71%). LRA enabled optimal sex prediction (100%) when all teeth in both the jaws were included. Results were not as accurate when only maxillary (76.2%) or mandibular (84.8%) teeth were used. To assess and compare the use of these multivariate techniques in practical forensic casework, >25% of tooth variables were randomly deleted. LRA still performed better (∼91% sex allocation accuracy vs. 62.9% for DA), indicating that LRA may be superior in its ability to predict sex irrespective of the presence of complete or incomplete sets of dentitions and should be preferred in dental sex assessment. The 100% success rate of LRA in correctly assigning sex is also noteworthy considering that, in general, tooth measurements have yielded sub-optimal sex prediction levels. However, unambiguous sex assessment is possible only when the entire dentition is available and correct sex allocation levels decreases when teeth are missing.     

螺旋CT三维重建在上颌骨正畸埋伏牙诊断中的临床应用

目的评价CT三维重建在上颌骨正畸埋伏牙中的诊断价值。方法对常规口腔全景片和咬合片不能清楚判断的47例上颌骨内埋伏牙患者行螺旋CT扫描和图像三维重建,并采用多平面重建(MPR)、三维牙体表面成像(SSD)及上颌骨和牙体容积成像(VR)显示埋伏牙的形态、位置及与邻牙的关系。结果47例均清楚显示了埋伏牙的形态、唇腭向位置、萌出方向及与邻牙的关系,MPR可测出埋伏牙的高度,SSD能清晰地显示骨内埋伏牙的形态、在牙列唇侧或腭侧的位置及与牙列牙根的关系,VR可展现埋伏牙的萌出方向及与邻牙的空间关系。结论SSD和VR成像对上颌骨埋伏牙可互为补充,立体直观地、完整地显示其病理解剖关系,是一种准确有效的检查方法。     

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.