Failure rates and factors associated with infrazygomatic crestal orthodontic implants - A prospective study.

Objective: Infrazygomatic crestal (IZC) implants have gained increased popularity over the past few years. Hardly any studies have been done to assess the rate and reasons for failure of IZCs. This prospective study was planned and designed with the primary objective of assessing the rate of failure of bone-screws (BS) placed in the infrazygomatic crest. In continuation, the secondary objective was to assess the factors that were associated with the failure. Materials and methods: The study was carried out by taking a detailed case history, (age, gender, vertical skeletal pattern, medical history), photographic records, radiographs, and clinical examination of a total of 32 randomly selected. patients of south indian origin who required infrazygomatic implants bilaterally as the choice of anchorage conservation to retract their incisors. All selected subjects were required to take a PA Cephalogram after the implant placement. The age of the patients ranged from 18 to 33 with an average age of 25 years. The patient log was maintained which included the treatment mechanics, status of oral hygiene, stability of implants, time of loading of the implant, presence of inflammation and time of failure of implant. The angulation of implant was measured on a digital PA cephalogram using Nemoceph software. These parameters were examined to evaluate independent and dependent variables using the Chi-Square test and Fischer's exact test. Result: A failure rate 28.1% for IZC placed in the infrazygomatic crest region was observed. Patients with a high mandibular plane angle, poor oral hygiene, immediately loaded implant, peri-implantitis, and severe clinical mobility showed higher failure rates. Variables such as age, gender, sagittal skeletal pattern, length of the implant, type of movement, occluso-gingival position, method of force application, and angle of placement were not significantly associated with implant failure. Conclusion: Oral hygiene and peri-screw inflammation must be controlled to minimize the failure of bone screws placed in the infrazygomatic crest region. Loading of the implant should be done after a latent period of two weeks. A higher failure rate was observed in patients with vertical growth pattern.

Safe sites for buccal shelf bone screw placement in various skeletal malocclusions: A CBCT study.

INTRODUCTION: The mandibular buccal shelf area is an extra-alveolar anchorage site that has high quality and quantity of bone, provides biomechanical benefits and has low failure rates. It is essential to place the implant in the region of bone with optimal thickness. The aim of this study was to determine the suitable site of the mandibular buccal shelf for bone screw insertion at 90 degrees and 30 degrees angles of insertion and various heights, angulations, areas of the buccal shelf in prognathic and retrognathic mandibles, and vertical and horizontal growth patterns. METHODS: In this retrospective study, we evaluated the cone-beam computed tomography (CBCT) images of 48 patients in the age range of 18-30 years, divided into four groups. Seven sectional sites were examined at 3, 5, and 7 mm from the alveolar crest at 90 degrees and 30 degrees. The angulation and area of the buccal shelf were examined. RESULTS: Cortical bone thickness increased distally from the first to the second molar in all four groups. CONCLUSIONS: The preferred site for buccal shelf implant placement was distal to the mandibular second molar. The maximum amount of cortical bone was observed distal to the second molar, 7 mm vertically from the alveolar crest, when the buccal shelf implant was placed at 30 degrees angulation to the long axis of the tooth.

Soft tissue and incisor position changes in class I bimaxillary subjects after retraction using friction and frictionless mechanics

Aim: Bimaxillary protrusion is a common condition observed irrespective of race and ethnicity and is a chief concern for patients who seek orthodontic treatment. The aim of this study was to compare and evaluate changes in soft tissue structures and incisor positions in class I bimaxillary protrusion subjects undergoing orthodontic therapy when friction and frictionless mechanics were used. Methods: Two groups with a total of 40 patients aged 18­30 years diagnosed with class I bimaxillary protrusion treated by extracting first premolars were considered for this study. Patients treated with friction mechanics were included in Group 1 and those treated with frictionless mechanics in Group 2. The digital lateral cephalograms were calibrated and analyzed using Nemoceph software. Selected landmarks were marked on pre- and post-treatment cephalograms and assessed for intra- and inter-group soft tissue and incisor position changes. Student's t-test was used to analyze the collected data using SPSS 20 software. Result: Intragroup comparison revealed significant changes in both groups. Inter-group comparison of the selected parameters between groups 1 and 2 showed differences but without any statistical significance, except for the inter-incisal angle. Conclusion: Pre- and post-treatment comparison analysis revealed significant soft tissue changes in both groups. However, the comparison between friction and frictionless mechanics showed no statistically significant changes

Comparative evaluation of dermatoglyphic patterns between skeletal class I and skeletal class III malocclusion.

Background: Dermatoglyphics is the study of various dermal configurations on the fingers, palms, and soles. These appear during the 12th week of intrauterine life and develop completely by the 24th week. It is said that they remain constant thereafter. The aim of the present study was to compare and assess the association of dermatoglyphic patterns between skeletal class I and skeletal class III malocclusion. Methods: Finger and palm prints were collected using the ink and roller method from 604 subjects who were divided into skeletal class I, class III with maxillary retrognathism and class III with mandibular prognathism based on lateral cephalogram assessment. Results: Loop pattern was more predominant in skeletal class I malocclusion subjects and whorl pattern was more frequent in the other two groups. Total finger ridge count and atd angle also showed significant difference between the study groups. Conclusions: The present study attempted in assessing the association between dermatoglyphic patterns and skeletal malocclusion. Analysing dermal configurations may aid in indicating the type of developing malocclusion and thus help in interceptive and preventive orthodontics.

Association between dermatoglyphic patterns and growth patterns of subjects with skeletal class I relation: A cross sectional study.

Background: To assess the relationship between dermatoglyphic patterns and various growth patterns of the mandible. Methods: Patients with Class I Skeletal relation were selected after clinical diagnosis followed by digitally tracing the cephalogram. The patients were subdivided into three groups of mandibular divergence patterns ie Average, Horizontal and Vertical. 90 samples ie 30 in each group were selected for the study. The fingerprints of all the selected subjects were then extracted digitally and analysed for the most dominant pattern in each hand. Results: For the left hand, there was a statistically significant (P<0.05) association between fingerprint pattern and growth pattern when Horizontal growers were compared to Average and Vertical Growers. For the right hand, there was a statistically significant (P<0.05) association between fingerprint pattern and growth pattern when Horizontal growers were compared to Average Growers. A significant association (P<0.05) between fingerprint pattern and growth pattern was also found when average growers were compared to vertical growers. Conclusions: Horizontal growers had 80% frequency of appearance of whorls in their left hand and 67% in their right hand. Horizontal growers could easily be differentiated from the average and vertical growers because of the dominance of whorl pattern in their hands. Composite and arch pattern were more frequent in vertical growers when compared to horizontal and average growers.

Comparison of Cellular and Differentiation Characteristics of Mesenchymal Stem Cells Derived from Human Gingiva and Periodontal Ligament.

Objectives: Dental tissues possess multipotent stem cells with varying biological properties. The present study was aimed to establish a primary culture of human gingiva-derived mesenchymal stem cells (GMSCs) and periodontal ligament-derived stem cells (PDLSCs) from periodontally healthy subjects and compare their biological characteristics. Materials and Methods: Gingival and periodontal ligament (PDL) tissues were collected from extracted premolar teeth of five healthy subjects and primary cultures were established. Basic biological characteristics, such as cell morphology, viability, proliferation capacity, and colony-forming units, and in vitro osteogenic and adipogenic differentiation potential were performed at passage 3 of GMSCs and PDLSCs. This was followed by immuno-phenotyping and flow cytometric analysis for identification of positive mesenchymal stem cell (MSC) markers, such as CD73, CD90, and CD105, and negative markers CD45 and CD34. Statistical Analysis Used: One-way analysis of variance (ANOVA). Results: Primary cultures of GMSCs and PDLSCs were successfully established. Cells exhibited a fibroblast-like morphology with a homogeneous population at passage 3. Cells derived from both tissues were highly viable (>95%), proliferative, and capable of forming colonies. Both cells did not exhibit any noticeable differences in cellular properties. Immunofluorescence and flow cytometric analyses showed positivity for MSC markers, CD73, CD90, and CD105, and negativity for CD34 and CD45. Furthermore, GMSCs and PDLSCs were capable of differentiating in vitro into osteocytes as evidenced by Alizarin red-S staining, and adipocytes as demonstrated by oil red O staining. Conclusions: The results of the present study indicate that both GMSCs and PDLSCs have similar cellular characteristics and mesenchymal differentiation potential. Therefore, they may serve as an equally potent source of stem cells for use in cell-based periodontal therapies.

Knowledge, attitude and practice on exposure to Bisphenol A among dental surgeons in Southern India.

BACKGROUND: Bisphenol A (BPA) is a product in the manufacture of Bis-GMA, which is commonly used in dentistry, and is known to have a number of adverse effects. OBJECTIVES: The aim of this study is to evaluate to assess the knowledge, attitude and practice based on exposure and handling of BPA containing materials among dental surgeons for better understanding about the level of care rendered to the patients. MATERIAL AND METHODS: A questionnaire survey was conducted on 400 dental surgeons in Southern India. The questionnaire consisted of 20 objective type questions out of which ten questions assessed knowledge and five questions assessed the attitude and five questions to understand the practice related measures taken by the dentist. The data collected were analysed using SPSS version 23. RESULTS: A total of 402 responses were collected for this online questionnaire survey over a period of 2 months. It was found that females showed higher knowledge and attitude towards exposure to BPA which was statistically significant when compared to males. It showed that dentists with more than 20 years of practice had a higher level of knowledge. Though most of the groups agreed fairly on safety practice to be undertaken related to BPA exposure in their clinics, the ones with experience more than 20 years displayed the least positive attitude and dentists with 6-10 years of practice had the least positive behaviour among all. CONCLUSIONS: In spite of having a good knowledge regarding the harmful effects of BPA, dental surgeons are not very cautious while using materials containing them on a regular basis. Therefore, there is a need to enhance the awareness with the help of Continuing Dental Education programs or proper instructions on the packaging.

Third Molar Angulation Changes in Class II Div I Malocclusion Subjects Treated with Extraction of Four Premolars: A Retrospective Study.

AIM: The aim of this study was to assess the changes in maxillary and mandibular third molar inclinations in individuals with class II div 1 malocclusion, before and after orthodontic treatment with extraction of all four first premolars. MATERIALS AND METHODS: This retrospective study consisted of the pretreatment and posttreatment records of 30 patients that were obtained from the archives of the department of orthodontics and dentofacial orthopedics in A B Shetty Memorial Institute of Dental Sciences. The maxillary third molar's relation to the palatal plane and the mandibular third molar's relation to the mandibular plane were measured. The paired t test was used to calculate pre- and posttreatment changes. A value of P < 0.05 was considered to be statistically significant. RESULTS: The maxillary third molars showed a mean correction of 6.15° (P < 0.001) and the mandibular third molars showed a mean correction of 5.10° (P < 0.001). CONCLUSION: Maxillary third molars showed more uprighting when compared to the mandibular third molars and that both maxillary and mandibular third molars showed an improvement in their angulations to their respective planes after extraction of the first premolars. However, the results of the study cannot be analyzed to state if the third molars do become fully functional.

Prevalence of Molar Incisor Hypomineralization among School Children Aged 9 to 12 Years in Virajpet, Karnataka, India.

BACKGROUND: The molar incisor hypomineralization (MIH) is defined as a qualitative defect of the enamel characterised by the progressive and simultaneous hypomineralization of the enamel structure of the first permanent molars which is of systemic origin, which may be associated frequently with incisors. Although the reported prevalence of MIH ranges from 2.4% to 40.2% worldwide, very little data is available from India. AIM: To determine the prevalence of molar incisor hypomineralization among school children aged 9 to 12 years in virajpet, Karnataka. METHODS: This cross-sectional descriptive study consisted of 1600 school children aged 9-12 years selected by stratified cluster sampling procedure. The European Academy of Pediatric Dentistry criteria were followed for MIH diagnosis. Chi-square test was used to analyse the categorical data. P ≤ 0.05 was considered for statistical significance. RESULTS: The prevalence of MIH is 13.12% with no gender predilection. Ten-year-old children showed the highest prevalence (15%) among all the age group. Majority of children with MIH (70.2%) have lesions in both molars and incisors with demarcated opacities and atypical restorations being the most frequent defect type. CONCLUSION: Prevalence of MIH was 13.12% in the 9-12-year child population in Virajpet. There is a need for a proper planned preventive and restorative program about the increasing prevalence of MIH.