Retrospective evaluation and descriptive analysis of the prevalence of anatomical structures and variations in CBCT images before dental implant planning in a group Turkish population, part I.

PURPOSE: The aim of this study is to emphasize the importance of using cone-beam computed-tomography in order to determine the anatomical structures and their variations before the treatment in patients who apply to the dentist clinic for implant treatment. METHODS: In the study, CBCT images of 500 adult patients (240 female and 260 male), aged between 21 and 82 years, who applied for implant treatment due to missing teeth, were retrospectively analyzed. Anatomical structures and variations such as nasopalatine canal(NPC), canalis sinuosus(CS), antral alveolar artery(AAA), were evaluated in multiplanar reformation(MPR) sections which are axial, sagittal and coronal can be viewed in consistence with each other. RESULTS: The incidence of anatomical variation of CS in the right region was similar according to gender. The "Funnel" appearance of the NPC shape was found most common shape in both female and male patients (n = 89; 37.1% for females and n = 71; 27.3% for males). CONCLUSION: CBCT has become the most popular 3D imaging method in dental practice especially for planning dental implants. Understanding the relationship with important anatomical structures before implant applications is crucial in dealing with potential complications that may arise afterward. Assessing significant anatomical structures by CBCT and taking precautions against possible risks facilitate the work of dentists during and after procedures.

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.

Evaluation of mallear ligaments in different voxel resolutions using cone beam computed tomography.

OBJECTIVES:: The aim of this study was to assess the visibility of discomallear ligament and anterior mallear ligament together with anatomical morphometric measurements of petrotympanic fissure, and to determine whether the mallear ligaments correlate with the bone compartment changes of temporomandibular joint. METHODS:: Cone beam CT images of 275 patients were evaluated retrospectively. The visibility of discomallear and anterior mallear ligaments were evaluated by two observers. The petrotympanic fissure was classified into four groups. Morphologic features of petrotympanic fissure and mandibular fossa were also measured in sagittal, axial and three-dimensional cone beam CT reconstructed images. Pearson's χ2 test and Student's t-test were performed for statistical analysis of differences voxel sizes, age, gender, localization, temporomandibular joint and measurements (p < 0.05). Intra- and interobserver reliability was also performed. RESULTS:: Type 3 petrotympanic fissure was more frequent in male, whereas females showed Type 1 and Type 2 petrotympanic fissure structures (p < 0.05). Anterior mallear ligament visibility on cone beam CT images was statistically higher in bone compartment changes of temporomandibular joint. In cone beam CT images, petrotympanic fissure tunnel types 1, 2, 3 and 4 were seen in 11.5, 35.63, 51.34 and 1.53% of patients, respectively. CONCLUSIONS:: Knowledge of the anatomy may help in identifying temporomandibular joint pain and auditory symptoms due to temporomandibular disorder. Further cross-sectional studies with larger populations are needed to investigate the physiopathological relation of both disorders.