retrospective evaluation of condylar morphology using panoramic radiography in a sample of Turkish population.

BACKGROUND: The temporomandibular joint is one of the most complex anatomic structures. It takes a great role in masticatory system and helps to make possible some functions such as speaking, chewing and swallowing. Clinicians should have sufficient anatomical knowledge to assess relationships of the hard and soft tissues, including the mandibular condyle, glenoid fossa, articular eminence of the temporal bone, the articular disc and its attachments. The aim of this study was to evaluate the frequency of different types of mandibular condyles and its distribution according to the age and gender. It was also evaluated whether the condyle types were bilaterally symmetrical or not. MATERIALS AND METHODS: A total of 1315 digital panoramic images which obtained from the patients suffering from the dental problems were assessed. Demographic data, condylar morphology were noted. All obtained data were analysed by using descriptive statistics. Morphology of mandibular condyles were classified into four shapes as identified in other studies, namely: type I - oval shape, type II - diamond shape, type III - bird beak shape, type IV - crooked finger shape. Two independent examiners, who have 19 and 7 years of experience in oral and dentomaxillofacial radiology, made a consensus and evaluated all images. RESULTS: A total of 1315 digital panoramic images were assessed. Seven hundred sixty-seven [58.3%] the patients were female and 548 [41.6%] were male. The age range of patients was from 18 to 84 years. Right-left condyle types were found to be symmetrical in the range of 67% of the subpopulation examined in the study. For the consensus, 'oval' condyle was common on both the right and left, while 'crooked finger' condyle was the rarest. CONCLUSIONS: The temporomandibular joint is the most important structure for all jaw functions such as speech, swallowing. In order for all these functions to continue in a healthy way, the anatomical structure should be known very well down to the finest detail. Identification of anatomical structures and their variations can play an important role in implant dentistry. Clinicians commonly prefer conventional radiologic methods to evaluate dentomaxillofacial region. Although the most of the variations are asymptomatic and require no treatment,correct identification of these findings will reduce unnecessary further diagnostic assessments and will provide more appropriate treatment plans.

Comparison of different 3D printers in terms of dimensional stability by image data of a dry human mandible obtained from CBCT and CT.

OBJECTIVES: To manage the mandibular traumas, for the expression of the complex anatomy or pathology in education of health sciences related branches, a model of the traumatized mandible is indispensable. For these, different 3D-print-technologies can be used. The aim of this study is, to measure how close these 3D-printed-models are to human-mandible (trueness) and the effectiveness of CT and CBCT at this point. STUDY DESIGN: One-dry-human-mandible and 10-models manufactured by five different 3D-printers in four different-kinds of additive-manufacturing technology (Fused-Deposition-Modeling (FDM), Stereolithography (SLA), Binder-jetting (BJ), Polyjet (PJ)) were used, five-anatomic-landmarks and eight-distances were measured and evaluated. Mandible's data were constructed based on DICOM-3.0 data from CBCT and CT scans. Images were opened in MIMICS (software-program). RESULTS: Study compared the devices that produced models with the same dry human-mandible. It was seen that the model with the highest margin of error (132.5 mm) was manufactured by Fused-deposition-modeling device using CT-data. In terms of distance to real-data, the model with the lowest error was generated by Binder-Jetting (ZCorp) with CBCT-data. Models produced with CBCT-data are closer to dry-human-mandible than models with CT-data. CONCLUSION: The current study shows that CBCT generates significantly better data than CT in producing mandibular models. The first choice for manufacturing of human mandible is BJ and the second choice is the technology of SLA.

Evaluation of a metal artifact reduction algorithm and an adaptive image noise optimization filter in the estimation of peri-implant fenestration defects using cone beam computed tomography: an in-vitro study.

OBJECTIVE: The aim of this study is to assess the effects of metal artifact reduction (MAR) and adaptive image noise enhancer (AINO) in CBCT imaging on the detection accuracy of artificially created fenestration defects in proximity to titanium and zirconium implants in sheep jaw. METHODS: Six zirconium and 10 titanium implants were planted on mandibular jaws of three sheep, and artificial defects were created. All images were obtained with a standard voxel size (0.150 mm3) and with 4 scan modes: (1) without MAR/without AINO; (2) with MAR/without AINO; (3) without MAR/with AINO; and (4) with MAR/with AINO during CBCT scanning. A total of 60 CBCT scans were produced. RESULTS: For all types of implants, intra- and inter-observer kappa values were the highest for MAR filter. The scan mode of with MAR filter was found to have the highest area under the curve (AUC), whereas the scan mode of without both MAR and AINO filters was found to have the lowest AUC values with statistical significance (p ≤ 0.05). Titanium implants were found to have higher AUC values than zirconium (p ≤ 0.05). CONCLUSION: Both MAR module and AINO filters enhance the accuracy of the detection of peri-implant fenestrations; however, the use of MAR filter solely can be recommended for detection of peri-implant fenestrations.