scholarly journals TO JUSTIFY A DIFFERENTIATED APPROACH TO PRESERVATION OF THIRD MOLARS DURING ORTHODONTIC TREATMENT BY DETERMINING THEIR CONDITION AND POSITION IN THE JAW

2021 ◽  
pp. 76-82
Author(s):  
S.І. Doroshenko ◽  
I.S. Kuzmenko ◽  
K.V. Storozhenko ◽  
S.V. Irkha ◽  
Kh.M. Demianchuk
Keyword(s):  
Orthodontic Treatment ◽  
Measurement Data ◽  
Diagnostic Model ◽  
Third Molars ◽  
X Ray ◽  
The Mean ◽  
The Difference ◽  
The Right ◽  
Distal Occlusion ◽  
Upper Third

No tooth is as problematic for patients as it is for third molars. After erupting later than all teeth, they often have little space in the dentition, or rather in the retromolar space, which should appear, above all, with further growth of the jaws. Therefore, the timing of their eruption varies considerably and is often accompanied by the appearance of significant morphological and functional disorders. That is why it is necessary to take a balanced approach to the preservation of third molars in the dental arch, providing them with a place in the retromolar space by timely detecting their condition and position in the jawbones and thus preserving the integrity of the dentition and implementing the fourth and last stage of bite raising in orthodontic patients with dental anomalies. The purpose of the study. To substantiate a differentiated approach to the preservation of third molars in orthodontic treatment by determining their condition and position in the jaw. Material and methods of research. For this purpose, 44 patients aged 15-30 years with different dentofacial anomalies having full permanent dentition including third molars confirmed by clinical and X-ray data were examined and given orthodontic treatment. Additional methods of the study included analysis of diagnostic model measurements (by Pont Korkhaus method). Furthermore, retromolar space was measured to find out if there is a space for third molars in the row of teeth by measuring its length and height using a silicone index (by S.I. Doroshenko and Ye.A. Kulhinskyi's method, 2009). X-ray studies included analysis of orthopantomograms (OPG), teleradiography (TRG), computed tomography (CT) scan, etc. The OPG analysis was conducted using K.V. Storozhenko's method (2013) which involved measuring the inclination of teeth, especially third and second molars relative to the jaw base. OPG showed a lack of space for third molars using S.I. Doroshenko and Ye.A. Kulhinskyi's method (2009). Measurement data were processed using mathematical statistics. The mean and the confidence interval for the data sample were calculated according to GOST R 8.736 – 2011. Results. The analysis of data showed significant variability in inclination of third molars relative to the jaw base and second molars on both sides of the jaws (on the left and the right). The largest difference in inclinations of third and second molars was observed in the lower jaw (LJ) both on the left and the right, with an insignificant deviation of 0.3° ± 0.2°, and the least difference was in the upper jaw (UJ), especially on the left, but with a larger deviation of 3.6° ± 0.2°. The conducted studies suggested that the larger the difference in inclinations of third lower molars relative to second ones is, the more problematic their eruption is, since they erupt later. Lower third molars incline medially at their crowns and therefore they have a smaller angle of inclination relative to the LJ base. While erupting upper third molars incline distally at their crown with an increased angle of inclination relative to the UJ base. In 44 patients aged 15-30 years, 106 (60.2%) third molars were in retention, including 35 (33.1%) teeth in physiological retention in younger people, 40 (37,7%) teeth in half-retention, and 31 (29.2%) third molars in constant retention. An important factor in predicting the eruption of third molars became the presence of space for them in retromolar space, both sagittally and vertically. The presence of space in the row of teeth, i. e. sagittally, was observed in 25 (14.2%) of 176 third molars: in LJ in 15 (8.5%) molars, especially on the left in 7 (4.0%), and on the right in 8 (4.5%) teeth; in UJ in 10 (5.7%) teeth – 6 (3.4%) and 4 (2.3%) respectively. The presence of space for the third molars also depended on width at the equator, which appeared to be the smallest in UJ and varied from 10 mm to 15 mm with a mean of 11.7 mm, and the largest in LJ – from 12 mm to 19 mm, the mean was 14.17 mm. Differences in the means between left and right UJ third molars were not detected (11.8 mm and 11.8 mm respectively), and in LJ it was insignificant (14.2 mm and 14.1 mm). In individual cases, the difference was 2.0-4.0 mm, and 1.0 mm in LJ. The latter confirms some scientists’ conclusions that the sizes of upper third molars vary more widely. Retention of third molars in the subjects was associated with different dentofacial anomalies most commonly reported in 17 (38.6%) patients with distal occlusion (class ІІ) and in 13 (29.5%) persons with deep occlusion, and more rarely seen with medial (class ІІІ) – 4 (9.1%) – and open occlusion – 4 (9.1%). Clinical studies suggested that when selecting a tactic for treatment of retained teeth, apart from determining their position in jawbones and the presence of a sagittal space in the row of teeth, it is also necessary to determine the size of vertical retromolar space for them which was measured using silicone indexes. Persons with deep and distal occlusion had the narrowest alveolar space from 0.5 mm to 4 mm, while in those with neutral occlusion it was from 5 mm to 7 mm. Thus, the conducted studies showed the importance of the differentiated approach to the preservation of third molars, especially during orthodontic treatment.

The empirical formula for calculating the incident air Kerma in intraoral radiographic imaging

2021 ◽  
pp. 20210117
Author(s):  
Zoran Mirkov ◽  
Katarina M Rajković ◽  
Jovan B Stanković ◽  
Dario Faj
Keyword(s):  
Empirical Formula ◽  
Measurement Data ◽  
Radiographic Imaging ◽  
Relative Percentage ◽  
X Ray ◽  
Air Kerma ◽  
Final Formula ◽  
Average Patient ◽  
The Mean ◽  
Fitted Function

Objectives: The aim of this paper is to determine the empirical formula for calculating the incident air kerma (Ki), used as a patient dose descriptor in the intraoral radiographic imaging. Methods: The data for the formula were collected during the regular annual inspection of intraoral dental X-ray units in 2018, 2019 and early 2020. The measurement data of 50 X-ray units were processed to develop the formula. Exposure factors for imaging molars of the upper jaw of an average patient in a clinical setting were used in the measurement. The formula validity was statistically evaluated using coefficient of correlation, standard error of the fitted function and the mean relative percentage deviation. Results: measurement values of the radiation doses and calculated values obtained by using the final formula showed good agreement - the mean relative percentage deviation values less than ±15%. Conclusions: Although there are differences in X-ray units, voltages, manufacturers and device architectures (single-phase and high-frequency), the measurement data comply well with computed ones in all cases.

scholarly journals Orthodontic treatment stability predictors: A retrospective longitudinal study

2016 ◽  
Vol 87 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Paloma González-Gil de Bernabé ◽  
José María Montiel-Company ◽  
Vanessa Paredes-Gallardo ◽  
Jose Luis Gandía-Franco ◽  
Carlos Bellot-Arcís
Keyword(s):  
Longitudinal Study ◽  
Orthodontic Treatment ◽  
Protective Factor ◽  
Peer Assessment ◽  
Anterior Segment ◽  
End Of Treatment ◽  
The Mean ◽  
The Difference ◽  
The Stability

ABSTRACTObjective: To examine medium- to long-term orthodontic treatment stability and its possible association with certain variables.Materials and Methods: In a retrospective longitudinal study of 70 postretention patients, the Peer Assessment Rating (PAR) index was measured at the start (T1) and end (T2) of treatment and between 4 and 10 years afterwards (T3). The stability was considered absolute when the T2 and T3 values were identical and relative when the difference was within the ±5 range.Results: Among the 70 patients, 65.8% were female and 34.2% were male. Their mean age was 14.5 years. The mean treatment length was 2.4 years. The mean retention phase was 3.3 years. The mean pre- and posttreatment PAR scores were 29.8 (T1) and 6.3 (T2). The mean T1–T2 difference was 23.6. The mean T2–T3 difference was −0.39.Conclusions: Within the study, 7.1% presented absolute stability and 68.6% presented relative stability. Lower anterior segment alignment and overbite were the most unstable occlusal features and tended to worsen. Fixed retainer (odds ratio [OR] 0.31; 95% confidence interval [CI] 0.10–0.98) as a protective factor and years without retention (OR 1.32; 95% CI 1.03–1.68) as a risk factor are predictor variables of instability in the case of lower anterior segment alignment. The PAR value at the end of treatment (OR 1.29; 95% CI 1.08–1.54) and extractions (OR 4.76; 95% CI 1.05–21.6) before treatment are predictors for midline instability.

(Ph4P)2 Mn2Br6 und (Ph3PCH2Ph)2Mn2I6 (Ph = C6H5) / (Ph4P)2Mn2Br6 and (Ph 3PCH2Ph)2Mn2I6 (Ph = C6H5

1988 ◽  
Vol 43 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Peter Stolz
Keyword(s):  
Single Crystal ◽  
Diffraction Data ◽  
Unit Cell ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
The Mean ◽  
The Difference

(Ph4P)2Mn2Br6 (1) and (Ph3PCH2Ph)2Mn2I6 (2) were prepared from the reaction of manganese dihalide with the corresponding phosphonium halide in CH2Cl2.The structures of 1 and 2 were determined from single crystal X-ray diffraction data.Both compounds crystallize in the triclinic space group P 1 with one formula unit per unit cell.1:a = 998.1(1), b = 1005.7(1), c = 1313.3(2) pm, α = 108.51(1), β = 94.25(1), γ = 100.36(1)°.2: a = 1058.6(2), b = 1236.3(2), c = 1248.4(3) pm, α = 63.53(1), β = 74.15(1), γ = 74.65(1)°.The structures of 1 and 2 exhibit discrete, dimeric anions formed by the fusion of two identical tetrahedral-like units with a common halogen-halogen edge. The mean Mn-Hal bond lengths were found to be 251.8 pm (Mn-Br) and 272.2 pm (Mn-I). The difference between the bridging and terminal Mn-Hal bond lengths is about 12-13 pm in both compounds

scholarly journals A Case of Surgical Extraction of the Lower Third Molars in a Cranial Series from the Pucará de Tilcara Fortress (Jujuy Province, Argentina)

2020 ◽  
Vol 48 (2) ◽  
pp. 149-156
Author(s):  
A. V. Zubova ◽  
O. L. Pikhur ◽  
A. V. Obodovskiy ◽  
A. A. Malyutina ◽  
L. M. Dmitrenko ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Third Molar ◽  
Pathological Process ◽  
Stone Tool ◽  
Third Molars ◽  
Dental Surgery ◽  
X Ray ◽  
Surgical Extraction ◽  
Ct Analysis ◽  
The Right

This study analyzes the earliest known case of surgical extraction of the lower third molars, observed in a cranial series from Pucará de Tilcara fortress (15th–16th centuries AD), northwestern Argentina, excavated in 1908–1910. Crania were transported to the Kunstkamera in 1910 under an exchange project. Traces of dental surgery were registered in the mandible of a male aged ~40. Both third molars had been extracted after the removal of soft tissues and parts of the alveoli. Teeth were extracted by scraping alveolar walls with semicircular movements. The results of scanning electron microscopy, X-ray fluorescence, and X-ray microanalysis suggest that a stone tool was used. The results of macroscopic and CT analysis suggest that the surgery was motivated by the exacerbation of chronic periodontal disease and probably by caries. The left third molar was extracted without complications 2–3 months before the individual’s death. On the right side, the pathological process continued, culminating in osteomyelitis and its complications. The surgeon’s skill notwithstanding, the extraction of the right third molar did not cure the patient, who died, apparently following the destructive stage of acute osteomyelitis complicated by orofacial phlegmon. Our findings suggest that the level of dental surgery practiced in the Inca Empire was ahead of the diagnostic expertise.

scholarly journals Results of orthodontic treatment of a child with asymmetrical micrognathia and the congenital mandibular condylar hyperplasia

2021 ◽  
Vol 102 (1) ◽  
pp. 92-99
Author(s):  
F S Ayupova ◽  
R A Khotko ◽  
E L Vinichenko ◽  
V N Lovlin
Keyword(s):  
Computed Tomography ◽  
Orthodontic Treatment ◽  
Permanent Dentition ◽  
Mixed Dentition ◽  
Functional Disorders ◽  
Facial Aesthetics ◽  
Condylar Hyperplasia ◽  
Comprehensive Rehabilitation ◽  
The Right ◽  
Distal Occlusion

Aim. To analyze the results of orthodontic treatment of a child with asymmetrical micrognathia and mandiblar condylar hyperplasia. Methods. The configuration of a face in the photos was evaluated and diagnostic models of the jaws were analyzed by using the Ponts and Korkhaus methods in treatment dynamics. The physiological status of bone tissue, temporomandibular joints and teeth was studied by using orthopantomography and computed tomography. Functional disorders were detected by using special tests, including EschlerBittner's test and Ilyina-Markosyans test. Orthodontic treatment and stimulation of mandibular growth in the mixed dentition stage were undertaken with the single jaw removable appliances and the appliance improved by us for correction of the distal occlusion. The Damon Q bracket system with archwires was used in permanent dentition period. Results. The child's convex facial profile was typical for distal occlusion and micrognathia. The facial asymmetry, increasing with mouth opening, and a decrease in mandibular range of motion indicated lesion of the right temporomandibular joint. The right condyle was enlarged on the orthopantomogram. The computed tomography showed that it was asymmetrically enlarged and had a cellular structure. There was detected asymmetric micrognathia. The comprehensive rehabilitation plan included orthodontic treatment, myotherapy, speech therapy, mechanotherapy. The use of removable orthodontic appliances led to the normal size of the dentition and their relation, significantly reduced functional disorders and improved facial aesthetics. Five years after completion of orthodontic treatment, the physiological occlusion and amplitude of the mandibular movements remained, but the right mandibular angle was flattened. Conclusion. The comprehensive rehabilitation of a child with asymmetrical micrognathia and mandibular condylar hyperplasia started in mixed dentition stage provided conditions for the formation of normal permanent dentition and the improvement of functional disorders and facial aesthetics; our results allow us to suggest the positive effect of our tactics for treatment of the patient.

scholarly journals Histological study of proportion of cortex and medulla of the ovary in Bangladeshi women

2016 ◽  
Vol 44 (1) ◽  
pp. 8-10
Author(s):  
Hosna Ara Perven ◽  
Abu Sadat Mohammad Nurunnabi ◽  
Dilruba Siddiqua ◽  
Fatema Johora ◽  
Halima Afroz ◽  
...  
Keyword(s):  
Histological Study ◽  
Age Groups ◽  
Age Group ◽  
Cross Sectional ◽  
Medical College ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Group B ◽  
The Right

This cross sectional, descriptive study was done in the Department of Anatomy, Dhaka Medical College, Dhaka from January to December 2009, to determine the proportion of cortex and medulla of the ovary in di_erent age group of Bangladeshi women. This study was based on collection of 140 ovaries of 70 unclaimed female dead bodies from the morgue of Dhaka Medical College, Dhaka. The samples were divided into three age-groups including A (10-13 years), B (14-45 years) & C (46-52 years). Histological slides were prepared by using routine haematoxylin and eosin stain. Ten best prepared histological slides from each age group were examined to determine the thickness of the cortex and medulla & proportion of the thickness of the cortex and the medulla of the ovary were expressed in percentages. The mean proportion of the cortex and the medulla of the right ovary were found 80.83±0.58% and 19.17±0.58% in group A, 86.95±1.14% and 13.05±1.14% in group B, 70.53±1.53% and 29.47±1.53% in group C respectively. The mean proportion of the cortex and the medulla of the left ovary were found 80.63±0.58% and 19.37±0.58% in group A, 86.78±1.14% and 13.22±1.14% in group B, 70.41±1.50% and 29.59±1.50% in group C respectively. The difference in mean proportion of the cortex and the medulla was not signi_cant in between the ovaries. However, the difference in mean proportion of the cortex and the medulla of the ovary between group A & group B, group A & group C and group B & group C were statistically significant.Bangladesh Med J. 2015 Jan; 44 (1): 8-10

scholarly journals Radiological Assessment of Femoral Bicondylar Angle among Persons Attending a Tertiary Health Care

2019 ◽  
Vol 21 (1) ◽  
pp. 44-47
Author(s):  
Allin Pradhan ◽  
CP Lama ◽  
S Dhungel ◽  
SK Ghosh
Keyword(s):  
Health Care ◽  
Knee Joint ◽  
Left Knee ◽  
Knee Joints ◽  
Teaching Hospitals ◽  
Radiological Assessment ◽  
Left Femur ◽  
The Mean ◽  
The Difference ◽  
The Right

 Femoral bicondylar angle is the angle between an axis through the shaft of the femur and a line perpendicular to the infracondylar plane. This study aims to assess femoral bicondylar angle measured from radiograph of femur and knee joints obtained from teaching hospitals in Kathmandu Nepal. Total of two hundred AP view radiograph of knee joint were collected, out of which, 50 each were of male right and left knee joint and 50 each were of female right and left knee joint. The mean angle for the right male femur was 7.86° with the range of 5°-10° and mean angle for the right female femur was 8.82° with the range of 6°-11°. On the left side, bicondylar angle ranged in male from 6° -10° with the average of 7.46° and in female range was 6°-11° and average was 8.66°. The bicondylar angle was higher in female on both the side, the difference was statistically significant on the left side (P=0.004) and significant on the right side (P=0.001). The finding of the study showed the femoral bicondylar angles were greater in right femur than left femur in both sexes. The difference in the bicondylar angle between the right and left femur was statistically insignificant in both sexes. (male p=0.144, female p=0.541). The result from this study has shown that femoral bicondylar angles were generally greater amongst the females as compared to the males; greater in right femur than left femur in both sexes.

Preoperative imaging assessment for third molars

2015 ◽  
Vol 61 (1) ◽  
pp. 77-83
Author(s):  
Florian-C. Dogioiu ◽  
◽  
Rodica Luca ◽  
Marinela Tonea ◽  
Consuela E. Ghiuţă ◽  
...  
Keyword(s):  
Postoperative Complications ◽  
Panoramic Radiography ◽  
Third Molar ◽  
Preoperative Imaging ◽  
Third Molars ◽  
X Ray ◽  
Dental Practitioners ◽  
Digital Panoramic Radiography ◽  
Upper Third ◽  
Clinical Cases

Objectives. The comparative evaluation of the role and information contribution brought by panoramic radiography (X-ray) and CT to the preoperative assessment of third molars, found in different stages of eruption. This assessment is useful both for certifying the diagnosis and for establishing the proper surgical strategy adapted to specific clinical cases, in order to avoid undesirable surgical incidents and postoperative complications. Patients and method. This is a retrospective study in which 23 patients were enrolled, on whom 79 third molars were identified. All these molars had, for various (historical and clinical) reasons, removal indications. Sex distribution of the patients was: 6 (26%) men and 17 (74%) women. After a detailed clinical examination, a digital panoramic radiography was performed on all patients, which provided additional useful information. This imaging investigation allowed a sorting out of the cases in which an additional preoperative imaging investigation, such as CT, was required. CT information was compared with that obtained from panoramic radiography (X-ray) and surgery intervention data. Results. In this study imaging investigation was performed on 79 third molars: 41 (51.9%) on upper third molars and 38 (48.1%) on lower molars. As concerning the stage of impaction, 22 (27.84%) were impacted and the same percent was found for those partially impacted. In 22.5 (28.48%) cases root dilacerations were identified. Special attention has been granted to the anatomical relationship of third molar roots with nearby structures: maxillary sinuses and the mandibular canal. So, from the upper third molars, 13 (31.7%) were in the sinus and so were those which were in close relationship with the sinus. Conclusion. Panoramic radiography (X-ray) provides orientative and often insufficient information about root morphology and anatomical relationships of third molars. In the clinical cases which required a comprehensive imaging assessment, CT data were crucial for adapting surgical procedures to specific clinical situations, minimizing surgical incidents and postoperative complications. Discerning recourse to 3D imaging ensures net benefits for patients as well as for dental practitioners.

scholarly journals Abdominal pain and two x-rays: spot the difference

2012 ◽  
Vol 94 (2) ◽  
pp. e95-e95 ◽  
Author(s):  
Z Rajković ◽  
D Papeš ◽  
S Altarac ◽  
N Arslani
Keyword(s):  
Abdominal Pain ◽  
Portal Vein ◽  
Elective Surgery ◽  
Exploratory Laparotomy ◽  
X Rays ◽  
X Ray ◽  
Artery Embolism ◽  
The Difference ◽  
Bilioenteric Fistula ◽  
The Right

We present two patients with air found in the right upper quadrant on standard abdominal x-ray. One was diagnosed with pneumobilia and underwent elective surgery for a bilioenteric fistula. The other was diagnosed with portal vein gas and underwent an emergency exploratory laparotomy at which a superior mesenteric artery embolism was found. The differential diagnostic criteria for pneumobilia and portal vein gas are described. If portal venous gas is found on x-ray in patients with abdominal pain, it is recommended that management is aggressive, meaning an emergency exploratory laparotomy, because mortality in such cases is approximately 75%.

scholarly journals Analysis of hard tissue facial symmetry after unilateral mandibular reconstruction

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Mohamad Saleh Khaghaninejad ◽  
Leila Khojastepour ◽  
Hanie Ahmadi ◽  
Saeid Tavanafar ◽  
Alireza Ebrahimi ◽  
...  
Keyword(s):  
Bilateral Symmetry ◽  
Asymmetry Index ◽  
Mandibular Reconstruction ◽  
Control Group ◽  
Study Group ◽  
The Mean ◽  
The Difference ◽  
Bilateral Differences ◽  
Mean Differences ◽  
The Right

Abstract Background This study aimed to determine how successful reconstruction of the mandible can recover the symmetry. Materials and methods All patients who underwent surgical treatment for unilateral mandibular reconstruction in 4 years were retrospectively examined. Bilateral differences of gonion (GO) positions were measured in 3 dimensions based on immediate postoperative computed tomography. The data collected was analyzed in 3 ways: First, the comparison of bilateral differences of GO in 3 dimensions. Second, the mean Asymmetry Index in control subjects was used to divide all cases into three groups: “Symmetry,” “Asymmetry,” and “Marked asymmetry.” Third, “maximum normal asymmetry” was calculated, and all cases were categorized as below and above maximum normal asymmetry. The difference between two gonial angles was used to determine the amount of asymmetry. Results Forty-seven patients and 47 normal adults were enrolled. The mean bilateral GO difference in the control group was higher than in the study group patients, but it was not statistically significant. The mean Asymmetry Index for the control group was not also significantly higher than the study cases. The study group was “Symmetric” in 78.7% of the cases whereas the control group in 91.4%, 19.1% of the study group and 8.5% of controls were “Asymmetric,” and 2.1% of study cases and 0% of controls were “Markedly Asymmetric.” Maximum normal asymmetry was 82.9% in the study group and 97.8% in the control group. The mean differences between the right and left gonial angles were higher in the study group, but it was not significant (P = 0.1). Conclusions Our study’s results showed that bilateral symmetry in mandibular reconstruction patients was satisfactory and similar to the normal individuals.

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