https://www.research.manchester.ac.uk/portal/files/45988550/wang_MIA2016.pdf

A benchmark for comparison of dental radiography analysis algorithms

Cascaded convolutional networks for automatic cephalometric landmark detection.

Objective: The aim of this study was to assess the morphology of the sella turcica and measure its size in cleft and noncleft subjects. Material

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Evaluation of Sella Turcica Shape and Dimensions in Cleft Subjects Using Cone-Beam Computed Tomography.

The purpose of this study was to analyse the linear and area dimensions and morphological shape of sella turcica to determine if differences exist due to gender or age and compared with available global data. A total of 183 (113 men and 70 women) Malay subjects who had their computed tomography (CT) scan at the Radiology Department, Hospital University Sains Malaysia (HUSM) for ordinary diagnosis not related to craniofacial deformities. The selected age groups were divided into four groups as children (0-6 years), preadolescents (7-12 years), adolescents (13-20 years) and adults (21-35 years). The images were processed using Mimics V17.0 software. Conventional measurements included three different heights of the sella turcica (anterior, posterior, median), its length, diameter, area and width, measured in relation to the Frankfort reference line (FH). Morphometric methods were used to assess shape. No significant differences in size of the sella were found except at sella height anterior between genders. When age was evaluated, significant differences were found among all age groups. The study found that sella turcica presented with a three different shapes: in a U shape (57.9 %), in a J shape (24.5 %) and shallow (17.5 %). Sella shape and dimensions reported in the current study can be used for discovering Pathological enlargement of the pituitary fossa and may also be helpful in providing reference data in the assessment of racial, gender and age specific variation in Malay population.

Size and Morphology of Sella Turcica in Malay populations: A 3D CT Study

Purpose Based on the evidence of the embryonic origin of the sella turcica and the teeth, this retrospective study evaluated the association between sella turcica bridging and palatal canine impaction in skeletal Class I and Class II orthodontic patients. Methods Sixty-two orthodontic patients with palatally impacted canines and 54 controls with erupted canines (aged 12-25 years) were classified into skeletal Class I and Class II (according to ANB angle and Wits analysis). The length, depth, and diameter of the sella turcica were measured, and the shape was described. The difference in linear dimensions between the study and control groups was calculated using two-way analysis of variance and Student's t-test. The interrelationship of the variables, subject groups, skeletal type, and age, with the linear dimensions of sella turcica, was tested using regression analyses. The association between sella turcica, bridging and palatally impacted canines was determined in skeletal type using a chi-square test. Results Highly significant differences were found in the length, diameter, and depth of the sella turcica between the study sample and the control (P<0.001, P=0.015, P<0.0001, respectively). There was a highly significant frequency of bridging in cases with palatally impacted canines (P<0.0001). An increasing incidence of bridging was found in subjects with palatally impacted canines and skeletal Class I (P<0.0001) and Class II (P=0.044) relationships. Regression analysis showed that the age was significantly related to a change in length (P=0.025), diameter (P<0.0001), and depth (P<0.0001). The normal sella turcica morphology was present in most subjects (56.4%), and no significant association was found in subjects with palatally impacted canines in terms of the shape of the sella turcica. Conclusion Sella turcica bridging is frequently seen in patients with impacted canines. The findings suggest that careful monitoring of canine eruption is required in patients diagnosed with sella turcica bridging at an early age.

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Association of sella turcica bridging with palatal canine impaction in skeletal Class I and Class II.

In orthodontic science, diagnosis of facial skeletal type (class I, II, and III) is essential to make the correct treatment plan that is usually expensive and complicated. Sometimes results from analysis of lateral cephalometry radiographies are not enough to discriminate facial skeletal types. In this situation, knowledge about the relationship between the shape and size of the sella turcica and the type of facial skeletal class can help to make a more definitive decision for treatment plan.The present study was designed to investigate this relationship in patients referred to a dental school in Iran.In this descriptive-analytical study, cephalometric radiographies of 90 candidates for orthodontic treatment (44 females and 46 males) with an age range of 14 - 26 years and equal distribution in terms of class I, class II, and class III facial skeletal classification were selected. The shape, length, diameter, and depth of the sella turcica were determined on the radiographs. Linear dimensions were assessed by one-way analysis of variance while the correlation between the dimensions and age was investigated using Pearson's correlation coefficient.Sella turcica had normal morphology in 24.4% of the patients while irregularity (notching) in the posterior part of the dorsum sella was observed in 15.6%, double contour of sellar floor in 5.6%, sella turcica bridge in 23.3%, oblique anterior wall in 20% and pyramidal shape of the dorsum sella in 11.1% of the subjects. In total, 46.7% of class I patients had a normal shape of sella turcica, 23.3% of class II patients had an oblique anterior wall and a pyramidal shape of the dorsum sella, and 43.3% of class III individuals had sella turcica bridge (the greatest values). Sella turcica length was significantly greater in class III patients compared to class II and class I (P < 0.0001). However, depth and diameter of sella turcica were similar in class I, class II, and class III patients. Furthermore, age was significantly correlated to the diameter of sella turcica as greater diameters were observed in older ages (P < 0.04).A significant relationship exists between the type of facial skeletal classification and the shape of the sella turcica; as in class III patients, sella turcica bridge was reported with a higher frequency. Also, sella turcica had a significantly higher length in these patients than in those with class I and class II facial skeletal types.

Correlation of Shape and Size of Sella Turcica With the Type of Facial Skeletal Class in an Iranian Group

Background: Evaluation of the craniofacial bones is the oldest method to measure the facial proportion ratio in orthodontics. Objectives: The purpose of this study was to evaluate the effect of emboss enhancement on the reliability of landmark identification in digital lateral cephalometric images. Materials and Methods: Ten digital lateral cephalograms were selected from the archive of an oral and maxillofacial radiology center. Using DIGORA software, these images were saved in two formats; common images and 3D emboss images. On these images, 32 skeletal, dental, and soft tissue landmarks were marked at least twice with a 2-week interval by four observers (two radiologists and two orthodontists). In order to determine the position of the marked landmarks (in x and y coordinates), a software was designed. The statistical analysis was performed in SPSS software and the reliability of each observer was obtained by means of intraclass correlation coefficient (ICC). Results: In three skeletal landmarks [Orbit (Or), condyl top (Cond), and pogonion (Pog)], the enhancement caused significant reduction in the reliability, and in four skeletal [Anterior Nasal Spine (ANS), B, A, and Basion (Ba)], two dental (U1 root, L1 incisal), and one soft tissue landmark (Menton soft tissue), the enhancement increased the reliability of landmark detection between the two phases of the study. Totally, ICC of embossed images in both x and y coordinates were greater than the typical images, but the difference was not statistically significant. However, the effect of enhancement on the improvement of the reliability of landmark identification was higher in the x-axis than the y-axis. Conclusions: Using embossed images is only effective in increasing the reliability of detection in a few numbers of cephalometric landmarks.

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The Effect of Emboss Enhancement on Reliability of Landmark Identification in Digital Lateral Cephalometric Images.

BACKGROUND AND AIM : It is required in many young patients that permanent first molars (PFMs) be extracted due to poor prognosis. This study investigates whether the extraction of such teeth is effective on the development of third molars and even their crown and root morphologies. METHODS : A total of 7000 panoramic radiographs were evaluated and 128 radiographs showing a history of extraction of PFMs on one side in one jaw or both jaws, with the third molars present in the same jaw on both sides, were selected. The third molar on the first molar extraction side was considered the case and the third molar on the other side was considered the control. The case and control third molars were compared in relation to their development, impaction, number of roots, mesiodistal width, root length, and curvature of apex. P < 0.05 was considered significant. Data were analyzed using SPSS software. RESULTS : On 128 panoramic radiographs evaluated, Olze and Demirjian factors showed that in most cases the crown development of the third molars on the control side lagged behind that on the case side. On the control side, the third molars had two roots in 66.9% and on the case side had two roots in 75.8%. CONCLUSION : Extraction of PFMs at a proper time might accelerate the development of the third molars on the same side and affect the morphologies of the crown and root(s) of third molars.

http://johoe.kmu.ac.ir/article_87173_f6d34f2406b00a41a6a2720483dc8412.pdf

Effect of extraction of permanent first molars on the development and eruption of third molars

Introduction: Maxillary sinuses have variable sizes. Knowledge of anatomic correlation between maxillary molars and sinus floor is essential for preoperative assessment in maxillary essment of posterior teeth. Aim: To assess maxillary sinus floor topography and root position of maxillary impacted third molar position using Cone Beam Computed Tomography (CBCT) imaging. Materials and Methods: This retrospective study was conducted on the 1080 CBCT images of the upper jaw of patients admitted to Oral and Dental Diseases Research Center, Kerman University of Medical Sciences, Kerman, Iran, from March 2015 to December 2018. Among these, CBCT images that had atleast one maxillary impacted third molar were evaluated for the position, number and shape of roots and distance from the sinus floor. Data were analysed by Statistical Package for Social Sciences (SPSS) version 26.0, using the Pearson Chi-square test. Results: In the present study, of 1080 CBCT, 100 (9.26%) showed atleast one maxillary impacted third molar. Of 100 patients, 62% were women and the mean age of samples was 35.73±10.27 year. The roots of 17 impacted molars (13.1%), protruded into the sinus cavity, and 18 (13.84%) of teeth had four roots. Distance from the sinus floor in the left and rightsides were 2.38±0.15 and 2.33±0.17 mm, respectively. Root distance from the alveolar crest in the left and right-sides were 3.40±0.22 and 3.51±0.27 mm, respectively. Conclusion: The results of the present study showed that roots of 51% of impacted third maxillary molars had a relation with the sinus floor. The most frequent tooth position was mesioangular.

Sudeh Mohseni

Papers

Correlation of Shape and Size of Sella Turcica With the Type of Facial Skeletal Class in an Iranian Group

The Effect of Emboss Enhancement on Reliability of Landmark Identification in Digital Lateral Cephalometric Images.

Effect of extraction of permanent first molars on the development and eruption of third molars

Assessment of Maxillary Sinus Floor Topography and Root Position of Maxillary Third Molars using Cone Beam Computed Tomography