فهرست مطالب

Dental Hypotheses
Volume:11 Issue: 2, Apr-Jun2020

  • تاریخ انتشار: 1399/04/08
  • تعداد عناوین: 6
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  • Rakesh Kumar Yadav*, Harsh Bhoot, Anil Chandra, Promila Verma, Ramesh Bharti, Vijay Kumar Shakya Pages 33-39
    Introduction

    Complete disinfection of root canal is one of the main objectives of root canal treatment. However, complete disinfection is only possible after correct determination of root canal working length. Thus, determining a correct working length is essential for endodontic success. Thus, the present study was conducted with the aim to comparatively evaluate the accuracy of four different techniques in determining root canal working length.

    Material and Methods

    30 freshly extracted human single-rooted teeth were taken. After sectioning the teeth at the cemento-enamel junction, K-Flexofile with size 10 was used to check the patency of canal and major foramen. Each sample was then subjected to all the four techniques. The four techniques used were conventional radiography, radivisiography, electronic apex locator (raypex 6) and cone beam-computed tomography. After calculating each root canal length of samples, their actual length was measured by using K- Flexofile until its tip became visible through the major foramen. The file was taken out when a magnifying glass showed its tip at the coronal border of major foramen. The adjustment of rubber stop was done according to the occlusal reference, and then the distance between the stop to the file tip was measured. Finally a comparison was done for each sample between the root canal length recorded with the four techniques and the actual length.

    Results

    Mean of absolute differences with respect to actual length was lowest in case of electronic apex locator whereas, it was highest in case of cone beam-computed tomography. Conventional radiography and Radiovisiography had negative mean difference values that showed overestimated canal length. A significant difference was observed between cone beam-computed tomography and the other three techniques respectively (P < 0.05).

    Conclusion

    Raypex 6 apex locator was more accurate than the other three techniques in determining root canal working length.

    Keywords: Apex locator, cone beam-computed tomography, digital dental radiography, radiography, root canal working length
  • Pranav Chhaliyil_Kael F Fischer_Bernd Schoel_Pradheep Chhalliyil* Pages 40-46
    Introduction

    Bedtime teeth cleaning is strongly recommended to limit overnight oral bacterial growth, but the impact of different cleaning methods on oral microbiota remains to be determined. Here we evaluated the efficiency of three oral cleaning methods in decreasing distinct subtypes of dental-damaging bacteria (DDB) using quantitative real-time PCR (qPCR) and 16s-based taxonomic profiling.

    Materials and Methods

    This was a randomized, controlled study of 58 healthy subjects who performed three timed oral cleaning methods for two consecutive nights: tooth brushing with sodium fluoride-containing toothpaste followed by tongue cleaning (BT); cleaning of gums and teeth by rubbing with an index finger followed by tongue cleaning (GIFT); and GIFT with the addition of rice husk activated charcoal (CT). Saliva samples were collected the following morning for qPCR and metagenomics analysis.

    Results

    All three oral cleaning methods resulted in a significant decrease (P < 0.006) in the quantity of DDB compared with no cleaning (NC) controls. Bonferroni post hoc analysis showed that GIFT and CT decreased Aggregatibacter actinomycetemcomitans and Streptococcus mutans levels compared to the BT method (P < 0.005). Metagenomics data also showed a more significant decrease in many pathogenic bacteria using the GIFT and CT methods compared to the BT method.

    Conclusion

    BT and GIFT are effective oral cleaning methods and reduce DDB levels. The greater flexibility of a finger to reach all areas of the teeth, gums, and inner cheeks that are inaccessible to a toothbrush to disturb biofilms makes GIFT a better method than traditional toothbrushing for bedtime oral cleaning.

    Keywords: Bedtime, biofilm, caries prevention, charcoal, dental cleaning, microbiota, sugar, tooth brushing, tongue cleaning, water swishing
  • Paridhi Gupta*, Bhagyalakshmi Avinash, Raghunath Nagasundara Rao Pages 47-51
    Introduction

    Several studies have found that certain diseases are associated with ABO blood groups. The aim of the present study was to investigate the correlation of ABO Rh blood group with dental malocclusion in the population of Mysuru.

    Materials and Methods

    In this study patients of 15–28 years of age will be selected, irrespective of gender from the hospital, Mysuru. It is an observational study with a duration of 3–4months. A total of 278 subjects between the age group of 15-28 years who visited the JSS hospital, Mysuru were recruited for this study. The maxillary and mandibular molar relation of teeth in maximum intercuspation using Angle’s classification were recorded. Blood group was evaluated using the ABO blood grouping system. Mean, Standard deviation, frequency, percentage were used for descriptive statistics. Chi-square test was used for inferential statistics. Statistical Package of Social Science (SPSS), version 16 was used for statistical
    analysis.

    Results

    Out of 278 people ‘O’ blood group was found to be most commonly associated with Angle’s Class I malocclusion (71.3%). Class II div I and div II was found to be more common in ‘A’ blood group (42.68%) and (4.9%) respectively. Class III being most common in ‘B’ blood group (6.5%).

    Conclusions

    A significant correlation exists between blood group and malocclusion. The prevalence of malocclusions being highest in blood group O, followed by A, B and AB in Mysuru. Class II div I malocclusion was more prevalent in ‘A’ followed by ‘B’ blood group.

    Keywords: ABO blood group, correlation, malocclusion, Mysuru population, Rh factor
  • Palle Svanholt, Michael Svanholt, Inger Kjær* Pages 52-61
    Introduction

    The hypothesis behind this study is that the ectopic mandibular canines move vertically in the mandibular bone during childhood and puberty. The aim was to evaluate interosseous vertical movements of the ectopic mandibular canines for improvement of diagnostic treatment and planning.

    Material and Methods

    The study had two parts: a cross-sectional study and a longitudinal study. The cross-sectional study included orthopantomograms from 54 patients (ages 9 years and 6 months to 16 years) with ectopic mandibular canines. The longitudinal study included series of orthopantomograms from 14 out of the 54 patients. Two methods were involved in both studies. 1) The canine angle expressing the vertical position (angle between canine axis and the vertical line perpendicular to the occlusal plane) was registered. 2) The crown morphology indicating rotation of the canine, as well as the maturity of the canine (Nolla Score System), were registered.

    Results

    The cross-sectional study demonstrated that the largest canine angles were observed in the most mature canines, often with the canine crown appearing in the lateral view. The longitudinal study demonstrated in 4 out of the 14 cases that the canines moved in the vertical plane towards a more upright position, resulting in a smaller angle, while the other ten cases moved during the observation period to a lower and more horizontal position, creating a larger angle. The crown morphology was unchanged in the uprighting cases, while rotation occurred in the ten cases undergoing increasing inclination. Maturity increased during all observation periods.

    Conclusions

    This study is the
    first study which demonstrates and accordingly proves the hypothesis that the vertical movements and rotation of mandibular canines can occur in children and young adults diagnosed with ectopic mandibular canine eruption. These spatio-temporal movements are believed to be of importance for diagnostics and treatment planning of ectopic mandibular canines

    Keywords: Canine, dentition, human, mandible, radiography
  • Mohammad Hasan Samandari, Milad Etemadi Shalamzari, Maryam Ghazizadeh*, Hooman Navaei Pages 62-68
    Introduction

    Restricted mouth opening (MO) is associated with the problems in intra/extra-articular components such as trauma to the articular bone component especially at the early ages, chronic displacement of the articular disk, tumors, condylar anomalies, coronoid hyperplasia and hyperactivity of jaw muscles. A pseudo-joint can form between the zygoma and the hyperplastic coronoid process (Jacob’s disease). Pseudo-joint restricts MO, it causes multiple problems for patients, and finally it decreases the quality of their or patients’ lives.
    Therefore, early diagnosis and treatment are very important. Case Report: Described here is a 28-year-old man that due to trauma in childhood, his coronoid process became hyperplastic. The pseudo-joint formed between coronoid process and zygomatic bone interfere with MO.

    Discussion

    The intraoral approach offers direct access without the risk of facial nerve injury or scars on the face

    Keywords: Coronoid hyperplasia, jacob’s disease, temporomandibular joint