Assessment of Convergence Angle of Tooth Preparations for Complete Crowns Among Dental Students: Typodont vs Simulator.

Introduction: The technology-enhanced learning and simulation-based learning are critically important pedagogic tools. They allow students to perfect their preclinical training by improving their skills and their manual dexterity while facilitating the acquisition of the know-how necessary for reproduction more realistically and faithfully of the behaviors required for a better dental practice. Retention is one of the mechanical fundamental principles of preparation of cemented fixed prostheses. It depends on several factors including the convergence of the axial walls. The undercut must be sparing in the reduction of tissue volume to obtain a low degree of convergence and a sufficient height of the preparation to comply with the retention and stabilization requirements of the prosthetic element. A draft value of 6° was recommended initially, but a range extending up to 16° has been accepted according to Weed et al. and Dodge et al., as being clinically achievable while providing good retention. Are students able to reproduce, in preclinical, total occlusal convergence (TOC) angles recommended on typodont and simulator? Objective: The evaluation of the TOC of the preparations made on typodont and simulator by the students in the 3rd year of the Faculty of Dental Medicine of Casablanca (FDMC). Material and Methods. A total of 140 dental preparations for cast crowns and metal-ceramics made by thirty-five 3rd year FDMC students were scanned by using the IDENTICA HYBRID optical scanner. The STL files were read by the 3D-TOOL-FREE software, two images were extracted for each preparation using the screen capture tool, and the two mediodistal (MD) and buccolingual angles (BL) were measured by the MB-RULER software. The statistical data were analyzed using the SPSS, software and comparisons were made by Student's t-test. Results: An overall average of 11.99° ± 4.48 was recorded for the preparations on the typodont with 11.40° ± 5.09 in the MD direction and 12.58° ± 4.74 in the BL direction. Concerning the simulator preparations, we recorded an overall average of 11.31° ± 4.16 with 10.81° ± 4.29 in the MD direction and 11.80° ± 5.44 in the BL direction. No significant difference was observed when comparing the preparations made on the typodont and the simulator. A percentage of 68.6% and 74.3% of the preparations made on the typodont and the simulators respectively fall within an acceptable range of 6 to 16°. Discussion. The TOC values achieved by the majority of students correspond to the recommended values which are 6 to 16° on average. The results of the simulator preparations are similar to the results of Marghalani for dental students at King Abdulaziz University, and Tiu et al., at the University of Otago in New Zealand. Conclusion: This study highlighted the difference between what is taught in dental schools, which is theoretically possible, and the academic results of actual practice. The generally recommended 6° tapers have proven difficult to achieve for many dental students. A margin of 6° to 16° of TOC angle is clinically achievable and allows sufficient retention. We can retain that most of the sample of our study had values that fall within the recommended range.

Periapical Status and Quality of Root Canal Fillings in a Moroccan Subpopulation.

AIM: The aim of the study was to assess the prevalence of apical periodontitis (AP) and quality of root canal fillings in an adult Moroccan subpopulation. METHODS: In the study 508 patients were included, attending the Conservative Dentistry Clinic at the Faculty of Dentistry of Casablanca. 508 panoramic and 709 periapical radiographs were observed. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's periapical index. The statistical analysis was performed with the software Epi Info Version 6.04dfr, April 2001. RESULTS: A total of 12719 teeth were examined. 45.3% of patients had apical periodontitis. 4.2% of teeth were treated endodontically and 70.4% of these treatments were inadequate. 91,5% with inadequate endodontic treatment presented apical periodontitis, while only 8,2% with adequate endodontic treatment had apical periodontitis. The lower molars and the upper premolars were the most affected teeth. The presence of apical periodontitis was correlated significantly with insufficient root canal fillings (p < 0.05). CONCLUSIONS: The present study found a high prevalence of apical periodontitis in this Moroccan population. Inadequate root canal fillings were associated with an increased prevalence of apical periodontitis.

Detection of potentially malignant lesions and squamous cell carcinomas in consultation of surgical denstitry.

UNLABELLED: Squamous cell carcinoma can occur on a apparently healthy mucosa or be preceded by lesions Chronic called potentially malignant, often asymptomatic, rarely showing the reason for consultation of patients, particularly in our Moroccan background which is  characterized by a care difficulty of access and the absence of priority to oral health. OBJECTIVE: To assess the prevalence of diseases potentially and malignant squamous cell carcinomas, and the role of certain risk factors in the onset of these lesions. METHODS: In the consultant population center Dental Consultation and Treatment of Casablanca CHU, we conducted a descriptive survey with 306 patients seen for different patterns between May and July 2010. RESULTS: 64.7% of the population had a defective hygiene. In addition, for 40 patients having an oral lesion mucosa, only 16 viewed for these lesions; the others were diagnosed incidentally. Five of these lesions were carcinomas, 32 white lesions of leukoplakia and 256 lichen planus. 7.2% of the population was smoking which nearly half were alcolo-smoking. The most risk factor according to this study significant is the alcohol and tobacco intoxication. CONCLUSION: This study confirms the importance of early screening of  symptomatic chronic lesions potentially malignant as well as squamous cell carcinoma which allows to improve prognosis.

Effect of orthodontic treatment on lip position.

UNLABELLED: Does an advanced or retracted position of the upper and lower incisors lead to modifications in lip position? The aim of our study was to evaluate modifications in lip position following orthodontic treatments. MATERIAL AND METHODS: This study concerned 100 patients who underwent treatment in the dento-facial orthopedic unit in Casablanca. Profile headfilms at the start and at the end of orthodontic treatment were compared using Frapier's analysis. The Student test was applied to evaluate the variations in the cephalometric measurements. RESULTS: We noted a non-significant increase in the nasolabial angle (P = 0.274), a significant decrease in the sagittal position of the lower vermillion border (PsVei) (P < 0.001) and the sagittal position of the soft-tissue supramentale (PsSmc) (P < 0.001), and a significant increase in the vertical position of the soft-tissue menton (PvMec) (P = 0.035). CONCLUSION: The results of this study demonstrate marked improvements in the situation of soft tissues. We suggest further investigation to throw light on the relationship between tooth movement and soft tissue, increasing the size of the sample and taking growth into account.

Prevalence of malocclusions and orthodontic treatment need in 8- to 12-year-old schoolchildren in Casablanca, Morocco.

OBJECTIVES: The purpose of this work was to evaluate the prevalence of malocclusions and orthodontic treatment need among schoolchildren in Casablanca, Morocco. MATERIALS AND METHODS: A sample of 1000 children aged between 8 and 12 years, with no history of orthodontic treatment, was chosen at random in state schools in different administrative areas of the city of Casablanca. Data was registered using the method of Bjork et al. (1964). Orthodontic treatment need was assessed with the index used by the Swedish National Board of Health (SweNBH). RESULTS: We found Angle Class I malocclusions in 61.4%, Class II in 24%, Class III in 10% and an indeterminate molar class with one or more missing molars in 4.6% of the children. Overjet was 1-4mm in 63.8%, 4-6 mm in 17.2% and >6 mm in 10%. Bite was normal in 65.4%, 23.6% presented an overbite greater than 4 mm, 1.7% an anterior open bite ≤3 mm, 1.2% an anterior open bite >3 mm and 0.2% a bilateral open bite. Half of the sample presented anterior crowding, while only 2.5% presented posterior crowding. In all, 84.2% of the subjects needed some orthodontic treatment, and 15.8% needed no treatment. No statistically significant difference was found between sex or age and orthodontic treatment need (P>0.05). CONCLUSIONS: This study found a strong need for orthodontic treatment, confirming the utility of implementing a programme of bucco-dental prevention and screening for malocclusion.

Tooth transposition: a descriptive study in a 547-patient sample.

INTRODUCTION: The aim of this investigation was to study the prevalence of tooth transposition in a population of orthodontic patients. MATERIALS AND METHODS: A total of 547 patient records from our dentofacial orthopedics department were consulted. Each file included clinical observations, panoramic radiography, lateral cephalograms and dental casts. Patients with incomplete or poorly kept orthodontic records were excluded from the sample, as were those with unreadable panoramic radiographs. The classification of tooth transpositions used in the study was that first proposed by S. Peck and L. Peck in 1995. Computerized statistical analysis was performed using Epi-Info 6.0. RESULTS: The prevalence of tooth transposition was 2%, with the female population more heavily affected (64%). Tooth transposition occurred only in the maxillary arch. Of all the teeth, the canines were the most involved in this anomaly (100%). Transposition was associated with tooth agenesis in 18% of cases, peg lateral incisors in 27%, and persistent deciduous teeth in 18%. CONCLUSION: The prevalence of tooth transposition in this study population remained low, but was nonetheless higher than that found in most published investigations.

Prevalence of temporomandibular dysfunction in orthodontic treatment.

UNLABELLED: The aim of our study was to investigate the prevalence of temporomandibular dysfunction (TMD) during orthodontic treatment. MATERIAL AND METHOD: the study investigated all the patients receiving orthodontic treatment in the dentofacial orthopedic department in Casablanca in the course of the different stages of treatment over a 4-month period. We looked for a possible association between the presence of at least one sign of TMD, the Helkimo anamnesis index, the clinical Helkimo index and the following factors: age, gender, extractions, or not, of premolars, duration, type and stage of orthodontic treatment, molar and canine class, crowding, overjet, overbite and unilateral crossbite. Data were analysed using Epi-info 6.0.fr software. The analysis of the results was done using the Chi(2) test (P<0.05). RESULTS AND CONCLUSION: no statistically significant association could be established between TMD and the various factors under investigation with the exception of the association between gender and the Helkimo anamnesis index, stage of treatment and the Helkimo anamnesis index and the Angle molar class and the Helkimo clinical index.

Surgical-orthodontic management of dental impaction.

UNLABELLED: The aim of this study was to assess the management of impacted teeth using surgical-orthodontic techniques at a dental treatment centre in Casablanca and to suggest strategies designed to enhance treatment of dental impaction. MATERIALS AND METHODS: The sample comprised 30 patients represented by their clinical files (mean age: 17 years; standard deviation: 8.141). RESULTS: Impaction most often involved a single tooth (56.7%), generally the upper canine (66%). The location was buccal in 43.3% of cases and generally high (63.3%). Presurgical orthodontic treatment was required in 80 of these cases. A closed eruption technique is reported in 93.1% of cases. Mean treatment duration was 11.4 months. The success rate of the surgical technical technique was 70%. DISCUSSION: A similarity exists between most of the variables studied and findings of other studies published on the same topic.