scholarly journals Prior Probabilities and the Age Threshold Problem: First and Second Molar Development

Human Biology ◽  
2021 ◽  
Vol 93 (1) ◽  
pp. 1
Author(s):  
Konigsberg ◽  
Frankenberg ◽  
Sgheiza ◽  
Liversidge
2019 ◽  
Vol 9 (4) ◽  
pp. 238-248
Author(s):  
Sun-mi Lee ◽  
Seong-Ryeol Bae ◽  
Hee-Moon Kyung ◽  
Mi-hee Hong ◽  
Hyo-Sang Park

2011 ◽  
Vol 3 (9) ◽  
pp. 417-418
Author(s):  
Dr Veerendra M Uppin ◽  
◽  
Dr Priyanka Sarangi ◽  
Dr Sukanta Kumar Satapathy

2020 ◽  
Vol 46 (4) ◽  
pp. 415-422
Author(s):  
Junho Jung ◽  
Jung Soo Park ◽  
Seoung-Jin Hong ◽  
Gyu-Tae Kim ◽  
Yong-Dae Kwon

The aim of this study was to measure the convexity of the lateral wall of the maxillary (Mx) sinus and identify the locational distribution of antral septa in relation to the zygomaticomaxillary buttress (ZMB), in order to suggest another anatomical consideration and surgical modification of sinus floor elevation procedures. This study was designed as a cross-sectional study, and a total of 134 patients and 161 sinuses containing edentulous alveolar ridges were analyzed. The angle between the anterior and lateral walls of the Mx sinus (lateral sinus angle [LSA]), and the angle between the midpalatal line and the anterior sinus wall (anterior sinus angle [ASA]) were measured. Mean LSAs and ASAs were 105.9° ± 9.86° and 58.4° ± 6.43°, respectively. No significant difference between left and right sides was found (LSA, P = .420; right = 105.5° ± 9.27°; left = 105.5° ± 9.27° and ASA, P = .564; right = 57.9° ± 6.80°; left = 58.8° ± 6.02°). The prevalence of septa was 37.3%, and it was most frequently noted in the second molar region (32.8%), followed by the first molar (20.9%), retromolar (16.4%), and second premolar regions (14.9%). Septa were most frequently located posterior to the ZMB (49.2%), while ZMB was mostly located in the first molar region (66.4%). Narrow LSAs may complicate the surgical approach to the posterior maxilla, especially when sinus elevation should be used in the second molar region. Considering the occasional presence of antral septa, membrane elevation may be complicated when a septum is encountered during the procedure. These results suggest that 3-dimensional examination of the convexity of the Mx sinus should be performed preoperatively to choose proper surgical techniques and minimize surgical complications.


Author(s):  
Deepashri H Kambalimath

Congenital missing permanent second molar is an extremely rare condition. Non syndromic mandibular second molar agenesis associated with other anomalies has occasionally been reported in literature, but isolated sporadic cases are rarely observed. Number of interactions between genetic and environmental factors during the process of tooth development might be the causative etiology for agenesis. This report presents an isolated case of hypodontia with absence of bilateral mandibular second molar agenesis in a healthy 18 year old female patient is presented and literature review on prevalence of most missing teeth with incidence of missing second molar in various regions of the world and in various regions of Indian continent is presented. No such case has been reported in Indian literature so far.


Author(s):  
Jessica Brown

This chapter distinguishes between fallibilism and infallibilism by appeal to entailment: infallibilists hold that knowledge that p requires evidence which entails that p; fallibilists deny that. It outlines some of the recent motivations for infallibilism, including the infelicity of concessive knowledge attributions, the threshold problem, closure, and the knowledge norm of practical reasoning. Further, we see how contemporary infallibilists attempt to avoid scepticism by appeal either to a generous conception of evidence or a shifty view of knowledge, such as contextualism. The chapter explains the book’s focus on non-shifty versions of infallibilism which defend a generous conception of evidence. It ends by defending the entailment definition of infallibilism over other potential definitions, and outlining the chapters to come.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Kamontip Sujaritwanid ◽  
Boonsiva Suzuki ◽  
Eduardo Yugo Suzuki

Abstract Background The purpose of this study was to compare the stress distribution and displacement patterns of the one versus two maxillary molars distalization with iPanda and to evaluate the biomechanical effect of distalization on the iPanda using the finite element method. Methods The finite element models of a maxillary arch with complete dentition, periodontal ligament, palatal and alveolar bone, and an iPanda connected to a pair of midpalatal miniscrews were created. Two models were created to simulate maxillary molar distalization. In the first model, the iPanda was connected to the second molar to simulate a single molar distalization. In the second model, the iPanda was connected to the first molar to simulate “en-masse” first and second molar distalization. A varying force from 50 to 200 g was applied. The stress distribution and displacement patterns were analyzed. Results For one molar, the stress was concentrated at the furcation and along the distal surface in all roots with a large amount of distalization and distobuccal crown tipping. For two molars, the stress in the first molar was 10 times higher than in the second molar with a great tendency for buccal tipping and a minimal amount of distalization. Moreover, the stress concentration on the distal miniscrew was six times higher than in the mesial miniscrew with an extrusive and intrusive vector, respectively. Conclusions Individual molar distalization provides the most effective stress distribution and displacement patterns with reduced force levels. In contrast, the en-masse distalization of two molars results in increased force levels with undesirable effects in the transverse and vertical direction.


Reports ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 4
Author(s):  
Sawako Ono ◽  
Hotaka Kawai ◽  
Shintaro Sukegawa ◽  
Kiyofumi Takabatake ◽  
Keisuke Nakano ◽  
...  

Primordial odontogenic tumor (POT) is a rare odontogenic tumor characterized by a variably cellular loose fibrous tissue with areas similar to the dental papilla and covered by cuboidal to columnar epithelium. We herein report a case of POT in a 14-year-old boy. Computed tomography (CT) exhibited a round cavity with a defined cortical border circumscribing the tooth of the second molar. However, the gross finding was a solid mass, not a cyst. Histologically, the tumor consisted of dental papillalike myxoid connective tissue covered by columnar epithelium. Therefore, although the clinical diagnosis was dentigerous cyst (DC), we diagnosed POT based on histologic findings. Clinical findings of POT resemble DC, but the clinical behavior of POT is different to DC, such as cortical expansion and root resorption of teeth. Therefore, histological differentiation of POT from DC is critical for accurate diagnosis.


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