Age estimation from developing third molars

2021 ◽  
pp. 002581722110529
Author(s):  
Yvonne Padmini Wilson ◽  
Phrabhakaran Nambiar ◽  
Hashim Yaacob ◽  
Muhammad Khan Asif

We investigated the development of third molars among Malaysians (including variations between jaws and genders) using Demirjian’s method. Dental panoramic radiographs of 1224 subjects aged 8 to 24 years were examined, and the molars were assigned Demirjian et al.’s development grades (A–H). Results indicated that 18.8% had congenitally missing or extracted third molars. Development of molars begins earlier in females (also in the mandible), but by age 9, male children's molar development speeds up with more advanced grades in their middle teens than females. Grade C indicates the subject is a juvenile, while initiation of root development (Grade E), was observed from 13 years on. Grade H can occur in a child aged 18 years who technically is still a juvenile. We compared the development and growth patterns of the third molar from both the maxilla and the mandible.

Author(s):  
Josefine Cederhag ◽  
Nina Lundegren ◽  
Per Alstergren ◽  
Xie-Qi Shi ◽  
Kristina Hellén-Halme

Abstract 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.


Author(s):  
Myrthel Vranckx ◽  
Adriaan Van Gerven ◽  
Holger Willems ◽  
Arne Vandemeulebroucke ◽  
André Ferreira Leite ◽  
...  

The purpose of the presented Artificial Intelligence (AI)-tool was to automatically segment the mandibular molars on panoramic radiographs and extract the molar orientations in order to predict the third molars’ eruption potential. In total, 838 panoramic radiographs were used for training (n = 588) and validation (n = 250) of the network. A fully convolutional neural network with ResNet-101 backbone jointly predicted the molar segmentation maps and an estimate of the orientation lines, which was then iteratively refined by regression on the mesial and distal sides of the segmentation contours. Accuracy was quantified as the fraction of correct angulations (with predefined error intervals) compared to human reference measurements. Performance differences between the network and reference measurements were visually assessed using Bland−Altman plots. The quantitative analysis for automatic molar segmentation resulted in mean IoUs approximating 90%. Mean Hausdorff distances were lowest for first and second molars. The network angulation measurements reached accuracies of 79.7% [−2.5°; 2.5°] and 98.1% [−5°; 5°], combined with a clinically significant reduction in user-time of >53%. In conclusion, this study validated a new and unique AI-driven tool for fast, accurate, and consistent automated measurement of molar angulations on panoramic radiographs. Complementing the dental practitioner with accurate AI-tools will facilitate and optimize dental care and synergistically lead to ever-increasing diagnostic accuracies.


2016 ◽  
Vol 28 (3) ◽  
Author(s):  
Tan Chun Wei ◽  
Eky Setiawan Soeria Soemantri ◽  
Iwa Rahmat Sunaryo

Introduction: Third molar impaction has been a controversial topic among clinician when it comes to mandibular anterior teeth crowding. The aim is to know the prevalence of third molar impaction in patient with mandibular anterior teeth crowding in Orthodontic Department, RSGM UNPAD, Indonesia. Methods: This was a descriptive research, with non-probability sampling obtained from a population with full arch 32 teeth. Totaling 54 samples from year 2011 to 2014 were obtained. The age of sample range from 15 to 25 years old. Also all panoramic radiographs taken from the year 2011 to 2014 were examined using a computer. The position of third molars were determined by Winter’s classification using angle formed between the intersected longitudinal axes of the second and third molars and anterior teeth status by using Little’s irregularities index. Results: This study obtained data that as much as 68.52% mesioangular third molar, 19.44% distoangular, 4.63% horizontal, 1.85% buccolingual and 0% others. In mesioangular impaction condition there was crowding 83.78%, in distoangular condition there was 100% crowding, in horizontal position crowding found 100%, while at buccolingual crowding found 100%.Conclusion: In all positions the third molar impaction was accompanied by crowding of the mandible anterior teeth, with the largest percentage of impaction was the mesioangular position


2015 ◽  
Vol 18 (1) ◽  
pp. 51 ◽  
Author(s):  
Hudson Oliveira Silva ◽  
Antonione Santos Bezerra Pinto ◽  
Moara E Silva Conceição Pinto ◽  
Marconi Raphael de Siqueira Rego ◽  
Jamyra Ferreira Gois ◽  
...  

<p><strong>Objective: </strong>The aim of the study was to evaluate the frequency of distal caries in the second molar influenced by the angulation of the third molar adjacent on panoramic radiographs in a clinical dental radiology. <strong>Material and</strong><strong> Methods: </strong>A descriptive and quantitative study that examined 750 panoramic radiographs, of this total, 120 were in accordance with the inclusion criteria of the study was conducted.<strong> Results: </strong>157 seconds and third molars analyzed the prevalence of caries in the distal of the second molar was 25.5%. The most prevalent angle position of the third molar was 57.3% with the vertical, but the position with the highest percentage of decayed molar second distal mesioangular was 50% of the cases. The elements listed, males obtained 40% of second molar distal caries versus 17% for females. People aged 35 or older had the highest incidence with 50% distal caries while other bands obtained 16.21% in the group 18-24 years, and 23.52% in 25-34 years. <strong> Conclusion: </strong>It was possible to establish a sliding scale on the indication for prophylactic removal of mandibular third molar according to the angulation of Winter: horizontal, mesioangular, vertical and distoangular. One can also see a greater relevance to the indication of prophylactic removal of male individuals aged over 35 years.</p>


2013 ◽  
Vol 25 (1) ◽  
Author(s):  
Sanjit Singh Munjit Singh ◽  
Suhardjo Sitam ◽  
Belly Sam

Introduction: The third molar is undoubtedly the most variable tooth in the human dentition, and also the most common tooth to become impacted due to it being the last tooth to erupt into the dental arch The aim of research is to obtain the prevalence of the mandibular third molar (M3) impaction among the patients attending the Radiology Clinic. Methods: The type of research conducted was a descriptive research. The sampling was purposive, drawn from a population of 1451 digital panoramic radiographs taken from January – December in the year 2010, of which 392 samples were included in the survey, with patient ages ranging between 18 – 59 years at time of exposure. The position of the M3’s was assessed using the Pell and Gregory and, Winter’s impaction classification. Results: The prevalence of impacted mandibular M3’s in this study is 76.8% overall. Of the impacted mandibular M3’s present, 76.1% were bilateral impactions and of these bilateral impactions 50.7% are similar in impaction classification. Of the mandibular M3’s examined, 40.1% are in a vertical angulation, 33.3% mesioangular, 23.5% horizontal and 3.1% distoangular. The three most common types of impaction according to the Pell and Gregory classification are IIB at 38.5%, IA at 36.8% and IIA at 18.8%. Conclusion: Prevalence of  mandibular third molar of the patients attending the Radiology Clinic is 76.8%.


2021 ◽  
Vol 15 (1) ◽  
pp. 591-594
Author(s):  
Weeraya Tantanapornkul ◽  
Ruchadaporn Kaomongkolgit ◽  
Sirilawan Tohnak ◽  
Chutamas Deepho ◽  
Ronnayut Chansamat

Background: Radiographic visibility of the root pulp in lower third molars is one of the reliable methodologies for chronological age estimation. Objective: To evaluate the radiographic visibility of the lower third molar root pulp using digital panoramic radiographs of the Thai population, and determine the appropriation of this technique in age assessment, especially at the age of 18 years. Methods: A total of 746 digital panoramic radiographs of the Thai population aged from 16 to 26 years were recruited for the present study. The visibility of root pulp of lower third molars with completed root formation was recorded in the four stages. Descriptive statistics were performed for each stage in both males and females. Results: The first appearance of stage 0 is 16.71 years in males and 17.00 years in females. The minimum age of stage 1 was found at 17.08 years in males and 17.18 years in females. The beginning of stage 2 was 18.33 years in males and 18.17 years in females. For stage 3, the earliest presence was started at 18.58 years in males and 18.83 years in females. Conclusion: The occurrence of stages 2 or 3 in both males and females indicated that the subject is over 18 years of age. Further study on the Thai population should be conducted to confirm the results of the present study.


Objectives: The objectives of this study were to assess the relationship between the third molar and the mandibular canal, to identify the radiographic markers most prevalent in predicting connectivity between these structures, and to associate these signs and proximity with the position of the third molar according to Bell, Gregory’s and Winter’s classifications. Subjects and methods: A retrospective cross-sectional study was conducted in the city of Sana’a on a sample of Yemeni patients in Ammar Dental Clinics who underwent panoramic radiography in the year 2019 until September 2020. The study consisted of panoramic radiographs of 597 patients with third molars with a total of 1017 third molars; the number of males was 216 (36.2%) and 381 females (63.8%). The panoramic radiographs were evaluated for proximity signs. Inclusion criteria were patients of both sexes who had at least a fully formed third molar of the mandible that was adjacent to the second molar. The radiographs were excluded if evidence of cystic, neoplastic, or extensive caries processes was detected. Seven radiological signs were used to determine if there was contact between the third molar and the mandibular canal. Results: A proximity to the mandibular canal was verified for 620 (61%) of 1017 third molars. The most frequent radiographic signs of proximity were darkened roots (315 teeth [31%]) and discontinuity of the mandibular canal (267 teeth [26.3%]). Third molar/mandibular canal proximity was found significantly more frequently in female patients and in patients aged 24 years and younger (P < 0.001). The tooth positions most frequently associated with proximity between the third molar and the mandibular canal were position C (highest point of the third molar located at or below the cervical margin of the second molar) and the mesioangular position (long axis of the third molar angled mesially toward the second molar). Conclusions: The frequency of third molar/ mandibular canal proximity was greater in female patients and patients aged 24 years or younger. The most frequently observed signs of proximity were darkening of the roots and discontinuity of the mandibular canal. The tooth positions most frequently associated with proximity of the third molar to the mandibular canal were position C and the mesioangular position.


2012 ◽  
Vol 219 (1-3) ◽  
pp. 158-164 ◽  
Author(s):  
Guo Li ◽  
Jiayin Ren ◽  
Shuping Zhao ◽  
Yuanyuan Liu ◽  
Na Li ◽  
...  

Author(s):  
А. . Atyakshev ◽  
N. . Tekoutieva

Extraction of the third molars from the upper jaw can cause somatic dysfunctions and changes in cerebral hemodynamics in patients. Rehabilitation measures aimed to correct somatic dysfunctions and restore cerebral hemodynamics are necessary for these patients.


2018 ◽  
Vol 1 (2) ◽  
pp. 98
Author(s):  
Bunga Fatimah ◽  
I Gusti Aju Wahju Ardani

Background: Dental agenesis is a term that refers to the absence of one or more teeth, and hypodontia refers to a severe type of tooth agenesis involving less than six or more than one congenitally missing teeth, excluding the third molars. Purpose: This aimed to report the correction of overbite by using intrusion archwires. Case: A 20-year-old female patient had class I malocclusion and deep overbite, incisor retroclination, mild mandibular crowding and agenesis of 12, 13, 14, 15, and 24. Case management: The case was treated with non-extraction using 0.022 pre-adjusted technique to level and unravel using intrusion archwires to correct the deep overbite. Conclusion: The 17-month treatment resulted in a corrected overbite, good occlusion, and good facial aesthetics.


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