Maxillary 1st Molar Research Articles

Clinical Accuracy of Bimaxillary Surgery Completed with Custom Prefabricated Splints vs. Patient-specific Surgical Guides and Plates

Abstract Purpose Virtual surgical planning (VSP) has improved outcomes in bimaxillary orthognathic surgery when compared to traditional cephalometric analysis and model surgery. However, several studies have shown discrepancies between the planned and post-operative position of the maxilla with the use of VSP and splints. Patient-specific Implants (PSIs) have the maxillary movement and final position built into them as dictated by the virtual surgical plan, completely independent of the mandibular position and have shown promising results, but are limited in number and by sample size and no study to date has directly compared the accuracy of splints versus PSIs. The purpose of our study was to determine the accuracy of splints versus PSIs in executing a virtual surgical plan. Materials and Methods A retrospective analysis of patients who underwent bimaxillary orthognathic surgery with splints or PSIs planned with VSP at our institution from 2017 to present was completed. The difference in maxillary positions from the VSP to the post-operative CBCT were evaluated in both cohorts. The primary predictor variable was the planned 3D position of the maxillary mid-incisors, and right and left first molars in the antero-posterior, transverse, and vertical dimensions. The primary outcome variable was the post-operative 3D position of these points. The root mean square deviation (RMSD) was used to calculate the absolute value of the mean differences. A paired t test was used to determine if there were statistically significant differences between the predicted and observed positions with p < 0.05 Results A total of 65 patients (46 female, 19 male) aged 14 to 58 years (mean age, 23.3 years). 10 patients (8 female, 2 male) aged 14 to 54 years (mean age, 24.8 years) underwent bimaxillary surgery with a Le Fort 1 osteotomy and a mandibular sagittal split osteotomy or intraoral vertical ramus osteotomy and were rigidly fixated after the use of a splint to facilitate the final maxillary position, whereas 55 patients (38 female, 17 male) aged 14 to 58 years (mean age, 22.7 years) were rigidly fixated with the use of a PSI. The difference between the planned and actual movements varied in all dimensions in the splint cohort but was greatest in the anteroposterior dimension for all points in the PSI cohort. The only statistically significant differences in pre-operative and post-operative position of the splint group were the mid-incisor transverse and vertical dimensions, whereas all differences in the PSI cohort were found to be statistically significant with the exception of the maxillary right 1st molar in the transverse dimension and the maxillary left 1st molar in the vertical dimension. There was an overall tendency for undertreatment in all directions as shown in the deviation from 0 toward under (-) or over (+) correction, regardless of type of surgery performed. Also, there was no indication that posterior or anterior movements were more or less accurate in either group. The PSI group was more accurate at all 3 maxillary points in all 3 dimensions, ranging from 1% to 62.8% more accurate than the splint group. Conclusion The use of a PSI allows for greater control of the post-operative position of the maxilla when planned via VSP and is more accurate than the use of a splint.

Relation of Facial Growth Pattern with Molar’s Axial Inclination

OBJECTIVE: To investigate the relationship between mesiodistal angulation of maxillary and mandibular 1st molar to different facial growth patterns.METHODOLOGY: This cross-sectional study was conducted from January to February 2021 at theJinnah Sindh Medical University, Karachi, Sindh. According to the non-probability consecutive samplingtechnique, a lateral cephalogram of 90 individuals (55 female and 35 male) with mean age 19.7±4.38 wasanalyzed for the vertical growth pattern. Only those patients with age between 14 to 30, teeth inpermanent dentition, and presence of teeth posteriorly from 1st premolar to 2nd molar were included.Mesiodistal angle was measured of the maxillary and mandibular molar to the palatal plane (PP),mandibular plane(MP), and occlusal plane(OP). The findings were then related to the facial growthpattern. Data were analyzed utilizing SPSSversion 20. RESULTS: Molar’s angulation was significantly (P<0.001) related to the change in facial growth pattern.The mesiodistal angle of the molar increased with an increase in facial divergence and was relativelyupright in patients with low-angle individuals. However, there was a decrease in both maxillary andmandibular molar’s inclination on the occlusal plane with an increase in facial divergence.CONCLUSION: A strong relationship exists between the molar mesiodistal inclination and facial growthpattern. This research presents relative information that can help the clinician in better diagnosis andtreatment plan based on the pattern of individual’s vertical growth. KEYWORDS: Facial divergence, growth pattern, mandibular plane, masticatory force, molar inclination,occlusal plane, palatal plane

Assessment of post-operative pain with use of rotary and conventional root canal instruments in single and multiple visit root canal treatment

Aim: To compare the post-operative pain after the use of rotary and conventional root canal instruments in single and multiple visit root canal treatment Materials and Method: 168 patients requiring Root Canal Treatment [RCT] in maxillary and mandibular 1st molar were involved in the study. On the basis of vitality and radiographic features two groups were made, multiple visit (Group A n=72), single visit (Group B n=96). Then the patients were randomly divided into 4 subgroups. Subgroup I n=36 (multiple visit conventional RCT), Subgroup II n=36 (multiple visit rotary RCT), Subgroup III n=48 (single visit Conventional RCT) and Subgroup IV n=48 (single visit rotary RCT). In subgroup I &amp; Subgroup III Canal preparation was done with stainless steel K files in step back manner. In subgroup II &amp; Subgroup IV, rotary Protaper Next was used. Irrigation was done with 3 % NaOCl and Ethylenediamine tetraacetic acid (EDTA) alternatively followed by obturation. The postobturation pain was recorded at 6hr, 12hr, 24hr, 1 week using visual analogue scale. Statistical Analysis was done using Tukey HSD Post Hoc Test and ANOVA Test. Results: Within 24 hours there was statistically significant difference between the groups (p&lt; 0.05) but after 7 days no statistically significant difference was there (p&gt;0.05). Conclusion: Patients in the groups either in single and multiple visit experience less postobturation pain if the canal preparation was done with the rotary files at all the time intervals (6hrs, 12hrs, 24hrs ) but after 7 days no statistical difference was found.

Cone Beam Computed Tomography of Mesiobuccal Root and Canal Morphology of Maxillary Molars in Delhi-NCR Population- A Retrospective Study

Introduction: Adequate knowledge of the anatomic variation and root canal morphology is paramount for long term endodontic success. The presence of two canals in Mesiobuccal (MB) root is commonly associated with maxillary molars in various populations. Aim: To retrospectively evaluate the prevalence of a second mesiobuccal canal (MB2) in maxillary first and second molars in Delhi-National Capital Region (NCR) population using Cone Beam Computed Tomography (CBCT) analysis. Materials and Methods: This retrospective study evaluated the records of complete maxillary CBCT scans of 204 maxillary first and second molars from January 2016 till May 2019 from different CBCT centres in Delhi-NCR region to determine the anatomy and morphology in June 2019. The prevalence of second MB2 canals was recorded and associated with age, gender and symmetry. The z-test for proportions was used to assess the differences among the subgroups. Results: The number of roots in 204 teeth in both maxillary molars were determined. The prevalence of 3-rooted configuration was 98.55% in maxillary first molars and 79.4% in maxillary 2nd molars. Also, in maxillary 2nd molars, 7.4% were single rooted and 13.2% had 2-rooted configuration. Three rooted configuration and variable canal number was commonly reported in maxillary molars. Prevalence of MB2 canal was 87.2% in maxillary 1st molars and 64.2% in maxillary 2nd molars. Also, the prevalence was 87.2% bilaterally in maxillary first molars and 65.7% on the right and 53.9% on the left in maxillary second molars respectively. Type IV canal configuration was most prevalent in 44.60% of maxillary first molars and type 1 configuration (35.78%) for the maxillary second molars. Conclusion: Prevalence of MB2 canals in maxillary first and second molars was found to be high in North Indian population and the clinician should suspect its presence in all cases. Prevalence of MB2 had bilaterally symmetrical distribution without any association with age or gender. The MB roots were more likely to exhibit type IV and type II canal configurations in maxillary first molars and type I and type II configurations in second molars.

Outcome of first-time surgical closures of oroantral communications due to tooth extractions. A retrospective analysis of 162 cases.

The objective of this study was to analyze the outcome of first-time surgical closures of oroantral communications (OAC) after tooth extractions. Using a billing software, all patients treated in a surgery department were filtered for interventions of the maxillary sinus indicative of OAC therapy. Out of 221 initially eligible cases, the charts of 162 cases fulfilling the inclusion criteria were retrospectively evaluated for the outcome in terms of symptom-free OAC closure as well as possibly influencing patient and treatment factors. The analyzed cohort included 98 males (60.5%) and 64 females (39.5%) with a mean age of 48.6 years (range 17 to 86 years). The maxillary 1st molar (38.3%) was the most common site requiring OAC closure. In 60.5% of the cases, surgical OAC closure was performed immediately after tooth extraction. The Rehrmann flap (72.2%) was the most frequently used technique for surgical OAC closure. 94.4% of surgical OAC closures were successful. Gender and age did not influence the outcome. In contrast, the site of OAC and the time interval from tooth extraction to OAC closure affected the results. Furthermore, the Rehrmann flap, alone or in combination with biomaterials, was superior to the mere suturing (with or without biomaterials) of the OAC site. In conclusion, the Rehrmann flap alone or in combination with biomaterials provided high success rates for first-time surgical OAC closure. With regard to the study parameters, an OAC in the 3rd molar area and an extended interval from tooth extraction to OAC closure negatively influenced the resolution of OAC. However, results must be interpreted cautiously considering the retrospective study design and the limited number of cases.

Outcome of first-time surgical closures of oroantral communications due to tooth extractions. A retrospective analysis of 162 cases.

The objective of this study was to analyze the outcome of first-time surgical closures of oroantral communications (OAC) after tooth extractions. Using a billing software, all patients treated in a surgery department were filtered for interventions of the maxillary sinus indicative of OAC therapy. Out of 221 initially eligible cases, the charts of 162 cases fulfilling the inclusion criteria were retrospectively evaluated for the outcome in terms of symptom-free OAC closure as well as possibly influencing patient and treatment factors. The analyzed cohort included 98 males (60.5%) and 64 females (39.5%) with a mean age of 48.6 years (range 17 to 86 years). The maxillary 1st molar (38.3%) was the most common site requiring OAC closure. In 60.5% of the cases, surgical OAC closure was performed immediately after tooth extraction. The Rehrmann flap (72.2%) was the most frequently used technique for surgical OAC closure. 94.4% of surgical OAC closures were successful. Gender and age did not influence the outcome. In contrast, the site of OAC and the time interval from tooth extraction to OAC closure affected the results. Furthermore, the Rehrmann flap, alone or in combination with biomaterials, was superior to the mere suturing (with or without biomaterials) of the OAC site. In conclusion, the Rehrmann flap alone or in combination with biomaterials provided high success rates for first-time surgical OAC closure. With regard to the study parameters, an OAC in the 3rd molar area and an extended interval from tooth extraction to OAC closure negatively influenced the resolution of OAC. However, results must be interpreted cautiously considering the retrospective study design and the limited number of cases.

Frontal and Axial Evaluation of Craniofacial Morphology in Repaired Unilateral Cleft Lip and Palate Patients Utilizing Cone Beam Computed Tomography; An Observational Study.

The current study was conducted to assess the extent of maxillary arch collapse on the cleft vis-a-vis non-cleft sides in the same individual presenting withunilateral cleft lip and palate (UCLP), using cone-beam computed tomography (CBCT). Thirty-one children (eighteen boys andthirteen girls) with surgically repaired UCLP, who met the inclusion criteria, were selected. Following the acquisition of CBCT scans, fourteen bilateral landmarks were selected. The distance of the bilateral landmark was calculated from the midsagittal plane on the cleft and non-cleft sides for both frontal and axial views. Tracings were done;the data obtained was subjected to statistical analysis;and intra-observer variability was checked with intraclass correlation coefficient (ICC) and two-way ANOVA. Subsequently, the measurements were subjected to paired t-tests at the 95% level of significance with Bonferroni correction. A significant reduction of pyriforme and an alveolar crest above the maxillary 1st molar were discerned in frontal analysis on the cleft side. In the axial view, the zygomatic arch, malar, porion and alveolar crest at the molar region were non-significant, but the alveolar crest at the premolar region (p < 0.004)) was significantly decreased. In the frontal analysis, pyriforme and the alveolar crest above the maxillary 1st molar, and, in the axial view, premolar widths, showed significant reduction when comparing the cleft vis-a-vis non-cleft sides.

A Comparative Evaluation of Grades Obtained for Placement of Stainless Steel Crowns on Maxillary Molars Among Post Graduate Students

Success of any restoration depends on the material used and the skill of the operator. This study aims to compare the clinical efficiency of postgraduates of various years in placing stainless steel crowns in maxillary 1st molars and thereby finding how operator skills affect the placement by analyzing their grades. In this retrospective study the dental records of pediatric patients who had visited the dental hospital located in Chennai, Tamil Nadu, India from June 2019 to March 2020 were reviewed. Patients who underwent stainless steel crown placement of at least one primary maxillary 1st molar teeth under local or general anesthesia of 2-6 years of age by postgraduates were included in the study. Out of the 467 teeth treated 268 (57.38%) were of males and 199 (42.61%) females. The percentage of treatment done at various ages were at 2 years: 33(7.06%), 3 years: 110(23.55%), 4 years: 150(32.11%), 5 years: 102(21.84%), 6 years: 71(15.20%). The percentage of crowns placed by postgraduates of various years were 1st year postgraduates: 86(18.41%), 2nd year postgraduates: 170(36.40%), 3rd year postgraduates: 211(45.18%). Chi-square test was done and the association was found to be not significant( p-value = 0.139). The frequency of each tooth treated being primary right 1st molar: 164(35.11%), primary right 2nd molar: 56(11.99%), primary left 1st molar: 180(38.54%), and primary left 2nd molar: 67(14.34%). This data showed that the 3rd year postgraduates got the most number of high grades 211(45.18%). Chi-square test was done and the association was found to be significant (p-value = 0.000). There is a significant difference in the placement of stainless steel crowns among the various postgraduates. There was a gradual increase in the clinical performance with the 3rd years performing the best among the three years.

Estimation of the frequency of second mesiobuccal root canal in maxillary first permanent molar teeth in subjects visiting teaching dental hospitals of Peshawar.

Objectives: To determine the frequency of second mesiobuccal canal (MB2) in a sample of 223 extracted maxillary permanent 1st molars. Study Design: In-vitro Cross-sectional study. Setting: Department of Endodontic at Peshawar Dental Hospital. Period: June 2019-Nov 2019. Material &amp; Methods: The samples were processed with application of the Clearing Technique which includes demineralization with nitric acid, dehydration with ethanol and clearing with methyl salicylate. The samples were classified according to Weine’s system of root canal classification. Results: Among the 223 samples, 30% were found to have Weine’s type1 root canal in the mesiobuccal root (second mesiobuccal canal absent). Second mesiobuccal canal was present in majority of the samples (70%) with Weines type2 (2-1) predominant with 23.32%, Weines type3 (2-2) present in 15.7% and Weines type 4 (1-2) present in 21% of the samples. 9% of the samples could not fit into Weines classification so they were placed in Vertuccis classification for root canal system type 6 (2-1-2). Conclusion: The present study concludes that the second mesiobuccal canal is more frequently found in maxillary permanent 1st molar teeth than our textbooks report, irrespective of quadrant and gender. Therefore, time should be given to evaluation of its anatomy by the clinician before starting the root canal treatment for the greater good of the community.

Modified Keles TPA –An Effective Method for Molar Derotation

Mesio-palatal rotation of maxillary 1st molars is commonly encountered in clinical practice and this results in a Class I molar relation becoming end on. Traditionally transpalatal arches (TPA) fabricated with 0.036” stainless steel wires have been used for correction of molar rotation in fixed orthodontic treatment. They are not very efficient in correcting the mesio-palatal rotations and require frequent activations. This article describes a modified Keles TPA as an easy, effective method for rapid and precise correction of unilateral or bilateral mesio-palatal molar rotations

SECOND MESIOBUCCAL CANALS IN MAXILLARY FIRST MOLARS DETECTED USING CONE-BEAM COMPUTED TOMOGRAPHY

OBJECTIVE: To determine the numbers of second mesiobuccal canals of first permanent maxillary molars by Cone-Beam Computed Tomography (CBCT).METHODS: In this cross-sectional study, data of patients requiring CBCT images as part of their dental procedures were retrieved from the database of the radiology department of Sardar Begum Dental College, Peshawar, Pakistan. CBCT images of 100 maxillary 1st molars from 2016 to 2018 were selected by using consecutive sampling technique. Selection criteria for teeth were no prior endodontic treatment and roots formation completed, while teeth with open root apices and pathology were excluded. All teeth were analyzed in three planes (sagittal, axial, and coronal) and canal numbers per root were recorded. Descriptive statistics were computed in SPSS 20.0. Stratification was done for canals number in maxillary 1st molar among genders and age groups. Post, stratification Chi-Square test was applied to see effect modification.RESULTS: The mean age of patients was 27.41±13.22 years. Second mesiobuccal canal (MB2) was present in 56 (56%) cases. Frequency of second mesiobuccal canal was more in female patients (n=29/40; 72.5%) than male patients (n=27/60; 45%) [p=0.007]. Overall, the most common age group was 10-25 years (57%) followed by 26-50 years (34%). Frequency of second mesiobuccal canal was 45.6% (n=26/57), 38.2% (n=13/34) & 33.3% (n=3/9) in age groups 10-25 years, 26-50 years & >50 years, respectively (p=.004).CONCLUSION: A high frequency was recorded for second mesiobuccal canal in upper first molars and a significant association was noted for second mesiobuccal canal with gender and age group.

In vitro precision evaluation of blue light scanning of abutment teeth made with impressions and dental stone casts according to different 3D superimposition methods

PurposeThe purpose of this in vitro study was to determine the precision evaluation of blue light scanning of abutment teeth impressions and dental stone casts according to different 3D superimposition methods. MethodsImpressions and dental stone casts of the maxillary canine, 1st premolar, and 1st molar were fixed; they were repeatedly scanned 11 times, (6 types, total n = 66). Stereolithography (STL) files were superimposed one by one, and used to obtain 10 root mean square (RMS) values with the 2 superimposition methods (best-fit-alignment, no control). Statistical analysis included the independent t test and one-way ANOVA with Tukey honest significant differences (α = 0.05). ResultsRMS ± Standard Deviation (SD) values for the best-fit-alignment method of the abutment teeth impressions of the maxillary canine, 1st premolar, and 1st molar was 8.07 ± 0.76, 5.03 ± 0.23, and 6.59 ± 0.24, respectively, and those of the no control method were 9.36 ± 0.82, 7.10 ± 1.14, and 8.17 ± 0.36 respectively. RMS ± SD values for the best-fit-alignment method for the dental stone casts were 4.07 ± 0.27, 3.39 ± 0.07, and 3.29 ± 0.07, respectively, and those for the no control method were 6.26 ± 2.50, 4.98 ± 1.16, and 4.55± 0.74, respectively. ConclusionsUsing different 3D superimposition methods, blue light scanning of abutment teeth impressions and dental stone casts shows high precision. The no control method showed lower precision best-fit-alignment. However, the results may help advance the digital dental CAD/CAM research and the clinical field of Prosthodontics.

The Effect of First Permanent Tooth Eruption on Dental Arch Dimension

Background: Crowding is one of the most prevalent types of malocclusion as well as a major problem in clinical orthodontics. It is essential to know the cause of crowding in order to achieve a better treatment. Objectives: A longitudinal analysis of arch dimension changes in late primary and early mixed dentition periods in children was designed and investigated the effect of eruption of precedence on the arch size in the samples under study. Methods: This longitudinal study was carried out on 32 children aged 5.5 - 6.5 years who had no erupted permanent dentition. Impression was taken and the arch perimeter, depth and width as well as tooth size were measured by a digital calliper and a brass wire on casts. After eruption of the first permanent tooth, the second impression was taken; the above-mentioned parameters were measured on the second casts. Data were analysed by ANOVA test. Results: Four pattern of eruption of precedence were as follows: maxillary 1st molar, mandibular incisors, Mandibular 1st molars and simultaneous eruption of maxillary and mandibular 1st molars. With eruption of mandibular central incisors, inter canine width and overjet increased by 0.81 and 0.27 mm, respectively. The mandibular arch perimeter increased by 2.25 mm with simultaneous eruption of maxillary and mandibular permanent first molars. The maxillary arch perimeter increased by 1.25 mm and 1.50 mm with eruption of maxillary first molars and simultaneous eruption of maxillary permanent first molars, respectively. Conclusions: Eruption precedence had a significant effect on changing mandibular inter canine width, maxillary arch perimeter, mandibular arch perimeter and overjet.

Comparative evaluation of incidence of separation of three different endodontic reciprocating files (manufactured from Ni-Ti) using scanning electron microscope: An in vitro study

Background and Objectives: The most significant objective of this in vitro study was to analyze the incidence of separation of three different endodontic Ni-Ti manufactured files using a scanning electron microscope (SEM) used in root canal shaping. Materials and Methods: Freshly extracted teeth (maxillary 1st molars and mandibular 1st molars) were obtained from the Department of Oral and Maxillofacial Surgery, People's Dental Academy, Bhopal, India, and selected for root canal shaping with Ni-Ti manufactured three types of endodontic file. Ninety canals determined for root canal shaping with three different endodontic files were divided into three equal groups (WaveOne, Reciproc instruments, and WaveOne Gold during biomechanical preparation) to know the number of canals prepared before separation (i.e., lifespan). The data were recorded using a SEM and analyzed using analysis of variance, followed by Tukey's post hoc test. Results: The mean score between the three files used was for the WaveOne file system was 5.40 ± 0.89, for Reciproc file system was 5.90 ± 1.19, and for WaveOne Gold file was 9.33 ± 1.58. Statistically, it shows a significant difference in the mean number of canals prepared before separation among three file systems (F = 87.46, P Conclusion: According to the outcome of this in vitro study, the longest existence span was found in WaveOne Gold file system, accompanied by Reciproc file, and WaveOne file was found with the shortest existence span.

Laser-Assisted Orthodontic Tooth Movement in Saudi Population: A Prospective Clinical Intervention of Low-Level Laser Therapy in the 1st Week of Pain Perception in Four Treatment Modalities.

Background This first-in-human study in Saudi orthodontic patients has evaluated the role of low-level laser therapy (LLLT) in pain perception (PP). The outcome of single application of LLLT with 4 different treatment modalities (TM) on PP are evaluated following orthodontic bracket bonding on maxilla. Materials and Methods A prospective clinical intervention with implementation of parallel technique in each group, 32 orthodontic patients with ectopic canine requiring fixed orthodontic appliance were enrolled and randomly allocated to the 4 groups: LLLT + self-ligating (SL) bracket, LLLT + conventional (Conv.) bracket, non-LLLT + SL bracket, and non-LLLT + Conv. bracket. Orthodontic bracket bonding from 1st molar to 1st molar and superelastic 0.012 inch NiTi were applied for the maxilla. For each patient, maxillary 1st molar to molar received a single application of LLLT using a 940 nm Ga-Al-As laser device on 5 different points labially/buccally and palatally. Main outcome measure was the degree of PP score during the 1st week of orthodontic tooth movement (OTM) after 4 hours, 24 hours, 3 days, and 7 days of both LLLT and non-LLLT treatment applications. A questionnaire with an 11-point numeric rating scale (NRS) was used for PP. Results Mean ± SD of PP in the LLLT + SL group was 3.33 ± 1.4, 3.58 ± 1.06, 2.31 ± 0.67, and 1.89 ± 0.54 in 4 hours, 24 hours, 3 days, and 7 days, respectively. Compared to all 4 TM groups, LLLT groups showed better PP. More statistically significant differences were found in LLLT groups. No harms were encountered. Limitations The intervention provider and the patient were not blinded to the intervention. Conclusion The LLLT + SL group revealed significantly promising benefits on PP during OTM.

Removal Torque Analyses of Two Self-drilling Orthodontic Temporary Anchorage Devices (TADs)

Stability of miniscrews or Temporary Anchorage Devices (TADs) is an essential factor for successful application in orthodontics. Miniscrews removal torque can be used as an indicator of miniscrews stability. The objective of this work was to compare removal torque between self-drilling tapered mini-screws and cylindrical miniscrews. Materials and Methods: Two groups of TADs were inserted in the maxillae of orthodontic patients to provide stationary anchorage for front teeth retraction. Group 1: 20 tapered self-drilling miniscrews, Group 2: 20 cylindrical self-drilling miniscrew. Split mouth technique was used. All of the TADs were inserted parallel to the occlusal plane, between roots of the 2nd maxillary premolar and 1st maxillary molar. The TADs were immediately loaded with constant and continuous load using 8 mm long heavy short Nickel Titanium coil spring. The coil spring was stretched between the heads of the two types of TADs and crimpable hooks that fixed on arch wire just distal to the anterior six maxillary teeth. After complete retraction of the anterior maxillary teeth, TADs were removed using torque adjustable screw-removal. At the moment of movement of the TAD the torque was recorded in Newton Centimeter (Ncm). Results: Mann Whitney U Test resulted in a significant difference between the two groups, indicating that cylindrical TADs had significantly higher removal torque than tapered TADs (means were 3.20 Ncm ± 0.20 and 2.70 Ncm ± 0.10 respectively). Conclusion: Physical properties have a considerable influence on the stability of the TADs. Cylindrical TADs are showed more mechanical interlock into the bone.

Assessment of Proximity of Maxillary Molars Roots to the Maxillary Sinus Floor in a Sample from the Egyptian Population using Cone-beam Computed Tomography (Hospital Based Study)

Aim: To assess the proximity between the roots of maxillary molars and Maxillary Sinus Floor ‘MSF’ using CBCT in a sample from the Egyptian population.Materials and Methods: Eighty seven CBCT scans of adult Egyptians (29 males and 58 females) involving 135 maxillary 1st molars, 168 maxillary 2nd molars and 107 maxillary 3rd molars, were collected from patients’ data base of Planmeca Promax 3D Mid CBCT machine available at the Department of Oral &Maxillofacial Radiology, Faculty of Dentistry, Cairo University. The vertical relation between MSF and examined teeth roots was assessed on cross sectional CBCT images based on Jung classification 2009 Results: In all mesio-buccal “MB’, disto-buccal ‘DB’& palatal ‘P’ roots of the examined teeth, the 1st molars showed the highest prevalence of class (0) in the 3 roots, while the 2nd molars showed the highest prevalence of class (3) among both MB & DB roots, and the highest prevalence of class (2) among P roots, finally 3rd molars showed the highest prevalence of class (1) among DB roots, and the highest prevalence of class (3) among P roots. There was a significant inverse correlation between age and vertical relationship classes of only the first maxillary molars roots. Males showed higher prevalence of Class (2) and Class (3) while females showed higher prevalence of Class (0) and Class (1) in the 3rd molars.Conclusion: In the investigated Egyptian subjects, maxillary 1st molars’ roots are the least close to the MSF compared to the other molars roots, while buccal roots of maxillary 2nd molars are highly anticipated for MSF invagination. The lower the age is, the closer are the maxillary 1st molar roots to the MSF, and males’ maxillary 3rd molars are more frequently approximating MSF than females.

A novel hypothesis based on clinical, radiological, and histological data to explain the dentinogenesis imperfecta type II phenotype

ABSTRACT Purpose/Aim: The aim of this study was to explore whether dentinogenesis imperfecta (DGI)-related aberrations are detectable in odontogenic tissues. Materials and Methods: Morphological and histological analyses were carried out on 3 teeth (two maxillary 1st molars, one maxillary central incisor) extracted from a patient with DGI Type II. A maxillary 2nd molar teeth extracted from a healthy patient was used as control. A micro-computed tomographic (μCT) data-acquisition system was used to scan and reconstruct samples. Pentachrome and picrosirius red histologic stains were used to analyze odontogenic tissues and their collagenous matrices. Results: Our findings corroborate DGI effects on molar and incisor root elongation, and the hypo-mineralized state of DGI dentin. In addition to these findings, we discovered changes to the DGI pulp cavity: Reactionary dentin formation, which we theorize is exacerbated by the early loss of enamel, nearly obliterated an acellular but still-vascularized DGI pulp cavity. We also discovered an accumulation of lamellated cellular cementum at the root apices, which we hypothesize compensates for the severe and rapid attrition of the DGI tooth. Conclusions: Based on imaging and histological data, we propose a novel hypothesis to explain the complex dental phenotypes observed in patients with DGI Type II.

CBCT assessment of relationship between maxillary sinus floor and maxillary posterior teeth: A retrospective study

Introduction: Aim of the study was to assess the relationship between maxillary sinus floor and maxillary posterior teeth. Materials and Methods: Retrospectively 50 cone beam computed tomographic images in the age group of 20 to 60 years were procured from CBCT archives randomly, based on the inclusion and exclusion criteria set forth for the study. Results: Palatal root of right maxillary 1st premolar was farthest & mesiobuccal root of maxillary right 2nd molar was nearest to maxillary sinus (MS). Mean thickness of the distobuccal root for left maxillary 2nd molar with buccal cortical was maximum whereas mean thickness for the mesiobuccal root with buccal cortical plate for left maxillary 1st molar was minimum. Conclusion: Adequate radiographic investigations are required before any surgical procedure in maxillary posterior teeth region. We recommend to use CBCT a 3-dimensional imaging modality when required. Keywords: Cone beam computed tomography (CBCT), Maxillary posterior teeth, Maxillary sinus floor (MSF).

Assessing peculiarity of molar root trunk dimensions in a sample of Saudi population – A radiographic analysis

ObjectiveTo assess the dimensions of root trunk lengths (RTL) in maxillary and mandibular molars and evaluate their correlation with the mesio-distal (MD) width of the tooth at the level of cemento enamel junction and Inter-Radicular Angle (IRA) at the point of roots separation. Materials and methodsRadiographic measurements of a total of 955 molars from 120 study subjects satisfying the inclusion criteria were analyzed. The sampling frame consisted of radiographs from the outpatient dental clinic of the College of Dentistry, King Saud University, Riyadh, Saudi Arabia. The linear measurements, including the width, length and depth of the root trunks under investigation were made using flexible translucent plastic grid while; the angles were measured by rotary German caliper protractor. ResultThe mean RTL dimension for molars were 4.31 mm (3–8 mm). The mean MD width of the molars was 10.02 mm and the mean measured IRA was 34.12°. The longest RT was observed in maxillary 1st molar (4.40 mm) while the shortest radiographic RT length was recorded for the mandibular 2nd molars (4.13 mm). Statictically insignificant correlation (p = 0.090) was observed between RTL with the MD width of the tooth, whereas appreciable significance resulted between RTL and IRA (p < 0.001). ConclusionKnowledge about the molar teeth RT length of the study population will aid the dental clinician in better decision making during management of periodontal disease conditions.