ABSTRACT
Purpose@#This study aimed to identify the prevalence and extension of the anterior loop (AL) of the mental nerve in different populations and according to different cone-beam computed tomography (CBCT) imaging settings. @*Materials and Methods@#Medline/PubMed, Embase, Scopus, Web of Science, and ProQuest were searched. The main inclusion criterion was ALs evaluated in CBCT images. The quality of studies was assessed with the Joanna Briggs Institute risk of bias checklist. Subgroup analyses were conducted for sex, side, continent, voxel size, field of view, and type of CBCT-reconstruction images with a random-effects model. @*Results@#Sixty-three studies with 13,743 participants (27,075 hemimandibles) were included. An AL was found in 40.6% (95% CI: 32.8%-48.9%, P<0.05) of participants and 36.0% (95% CI: 27.5%-45.5%, P<0.05) of hemimandibles, in 34.9% (95% CI: 25.1%-46.2%, P<0.05) of males and 34.5% (95% CI: 23.5%-47.4%, P<0.05) of females. The average length of ALs was 2.39 mm (95% CI: 2.07-2.70 mm, P<0.05). Their extension was 2.13 mm (95% CI: 1.54-2.73 mm, P<0.05) in males and 1.85 mm (95% CI: 1.35-2.36 mm, P<0.05) in females. Significant differences were observed regarding the prevalence and length of ALs among continents and for its measured length on different CBCT-reconstruction images, but not between other subgroups. @*Conclusion@#AL was a relatively common finding. The voxel size and fields of view of CBCT devices were adequate for assessing AL; however, a 2-mm safety margin from anatomical structures (such as the AL) could be recommended to be considered when using CBCT imaging.
ABSTRACT
Objective: The aim was to evaluate the survival time and success rates of dental implants in warfare victims and factors that affect implant success
Subjects and Methods: This retrospective study involved 250 Iranian warfare victims who received dental implants from 2003 to 2013. Patients' demographic characteristics, as well as the brand, diameter, length, location and failure rate of the implants were retrieved from patients' dental records and radiographs. The associations between these data and the survival rate were analyzed. Statistical analysis was carried out with X2 and log-rank tests
Results: Overall, out of the 1,533 dental implants, 61 [4%] failed. The maxillary canine area had the highest failure rate [9 of 132 implants [6.8%]], while the mandibular incisor region had the least number of failures [3 of 147 implants [2.0%]] and the longest survival time [approximately 3,182 days]. Maxillary canine areas had the shortest survival [about 2,996 days]. The longest survival time was observed in implants with 11 mm length [3,179.72 +/- 30.139 days] and 3.75-4 mm diameter [3,131.161 +/- 35.96 days], and the shortest survival was found in implants with 11.5 mm length [2,317.79 +/- 18.71 days] and 6.5 mm diameter [2,241.45 +/- 182.21 days]. Moreover, implants with 10 mm length [10.7%] and 5.5-6 mm diameter [22.2%] had the highest failure rate; however, the least failure rate occurred when the implants were 11.5 mm in length [1.9%] and 3-3.5 mm in diameter [3.1%]
Conclusions: The brand, length and diameter of implants affected the survival time, failure rate and time to failure. The location of the implant was not statistically significant regarding the mentioned factors, although it has clinical significance
ABSTRACT
PURPOSE: This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. MATERIALS AND METHODS: Two acrylic models were fabricated from a cast with normal occlusion. Straight and 75degrees mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an 8degrees downward tilt of the occlusal plane compared to the standard position, at an 8degrees upward tilt of the anterior occlusal plane, and at a 10degrees downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. RESULTS: Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. CONCLUSION: Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than 10degrees had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and 8degrees upward tilt of the anterior part of the occlusal plane compared to other positions.
Subject(s)
Dental Occlusion , Dimensional Measurement Accuracy , Head , Lysergic Acid Diethylamide , Posture , Radiography, PanoramicABSTRACT
Local bone augmentation in the posterior maxilla [sinus lift] before the placement of dental implants has become an acceptable treatment technique in implant dentistry. However, limited documented data are available on the results of this technique and relevant issues in Iran. The present study aimed at evaluating the surgical outcome of sinus lift and implant placement in warfare victims presenting to Ghazi Tabatabai Clinic during 2001-2008. In this retrospective study, 50 patients that had undergone sinus lift surgery were evaluated. All warfare victims presenting to the clinic who had a medical record and undergone sinus lift treatment were enrolled. Those with incomplete medical files were excluded from the study. The required data were extracted from patients' medical records and entered into a questionnaire. The mean duration of follow up was 53.32 +/- 23.05 months. The surgical success criterion was presence of osseointegrated implants in the oral cavity during the follow up period. Statistical analysis was performed using t-test and Fisher's exact test. Failed out of which 5 were in the sinus-lift area. Thus, the total success rate, the success rate of implants placed in the sinus lift area and the success rate of those out of the sinus lift area were 96.6%, 93.9% and 98%, respectively. The study results demonstrated high success rates for implants placed in sinus lift and non-sinus lift areas in warfare victims