Comparison of Occlusal Parameters between Open Bite and Nonopen Bite Patients Using the T-Scan III System: A Pilot Study

Objective To evaluate and compare the first tooth contact region, occlusion time, time to generate total force, and force distribution between open bite (OB) and non-OB (NOB) patients at the maximum intercuspation position using the T-Scan III system. Materials and Methods Sixteen patients were divided into the OB and NOB groups (n = 8 for each group). The T-Scan III system was used to evaluate the first tooth contact region, occlusion time, time to generate total force, and force distribution. Statistical Analysis The mean patient age, overjet, overbite, occlusion time, and time to generate total force were compared between the groups by independent samples t-test. Relative force distributions between groups and among regions were compared by the Mann–Whitney U- and Kruskal–Wallis H-tests, respectively. A probability value of less than 5% (p < 0.05) was considered significant. Results Differences in the first tooth contact region between groups were observed. The molar region was the first tooth contact region in the OB group, while first tooth contact was observed in all regions in the NOB group. Neither the occlusion time nor the time to generate total force was significantly different between the groups (p > 0.05). The highest force distributions were observed in the molar regions in both groups. Significant intragroup differences were found among all regions (p < 0.05), except between the anterior and premolar regions in the NOB group (p = 0.317). Intergroup differences in the force distributions in the anterior (p = 0.000), premolar (p = 0.038), and molar (p = 0.007) regions were significant. Conclusion Unlike in the NOB group, in which first tooth contact occurred in every region, in the OB group, first tooth contact occurred only in the molar region. Compared with those in the NOB group, the force distributions in the OB group were approximately 1.5 times higher in the molar region but were significantly lower in the anterior and premolar regions.

Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues

Background This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. Methods Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar’s socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. Results In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). Conclusions AEC’s performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

Twist and chew: three-dimensional tongue kinematics during chewing in macaque primates

Three-dimensional (3D) tongue movements are central to performance of feeding functions by mammals and other tetrapods, but 3D tongue kinematics during feeding are poorly understood. Tongue kinematics were recorded during grape chewing by macaque primates using biplanar videoradiography. Complex shape changes in the tongue during chewing are dominated by a combination of flexion in the tongue's sagittal planes and roll about its long axis. As hypothesized for humans, in macaques during tongue retraction, the middle (molar region) of the tongue rolls to the chewing (working) side simultaneous with sagittal flexion, while the tongue tip flexes to the other (balancing) side. Twisting and flexion reach their maxima early in the fast close phase of chewing cycles, positioning the food bolus between the approaching teeth prior to the power stroke. Although 3D tongue kinematics undoubtedly vary with food type, the mechanical role of this movement—placing the food bolus on the post-canine teeth for breakdown—is likely to be a powerful constraint on tongue kinematics during this phase of the chewing cycle. The muscular drivers of these movements are likely to include a combination of intrinsic and extrinsic tongue muscles.

Conduction of Third Molar Extraction with the Presence of Retromolar Canal: A Case Report

Introduction: The retromolar canal is a structure rarely identified in clinical practice. The content of this canal is composed of nerves, arteries and venous plexus that give innervation and irrigation to the third molar region and the vestibular mucosa of molars and lower premolars. Thus, knowledge of the presence of this structure is important in dental procedures, due to the complications that damage to this structure can cause. Methods: In this report, a 19-year-old patient sought dental care at a clinic, Dentistry course at the Federal University of Santa Maria for the extraction of third molars due to hygiene difficulties. On radiographic examination, a retromolar canal was identified at the distal of the left mandibular third molar. With the identification of this structure, preventive measures were performed during the procedure to avoid complications. Results: With adequate planning and prevention measures, the trans and postoperative periods occurred without any complications. Conclusion: The foramen and the retromolar canal may occasionally appear in the clinic radiographic routine of the Dentist, and the professional should be attentive to the management of these anatomical structures during surgical procedures to avoid accidents and complications.

Comparative evaluation of biting force in 2mm locking plates with 2mm miniplates in the treatment of mandible fractures: A clinical study

1. To compare efficacy of 2mm locking plates with 2mm miniplates in the fixation of mandible fractures and 2. To evaluate and compare the biomechanical function by measuring the bite force at 1st week, 3rd week, 6th week and 3rd month postoperatively in 20 patients divided equally into two study groups.A prospective randomized study was carried out at Department of Oral and Maxillofacial Surgery, Meghna Institute of Dental Sciences, Nizamabad from 2019 to 2021 to treat consecutive mandibular fractures where patients were randomly divided into two groups each composed of 10 patients where Group A were treated with single 4 holed stainless-steel locking miniplates and Group B with two 4 holed stainless steel conventional mini plates both maintaining a gap of 2.0 mm system. Later assessment was done using bite force recording postoperatively at 1st week, 3rd week, 6th week and 3rd month and with the associated complications like Swelling, Infection, Paresthesia, Mobility between fracture fragments and Hardware failure.When the mean bite force values in right molar region of group A and group B were compared at 1st week, 3rd week, 6th week and 3rd month, there was statistically significant increase in bite force noted in group A when compared to group B at 1st week and 3rd week (P&#60;0.05). But no statistically significant differences were observed at 6th week and 3rd month (P&#62;0.05).When the mean bite force values in the central incisor region of group A and group B were compared at 1st week, 3rd week, 6th week and 3rd month, there was statistically significant increase in bite force noted in group A compared to group B at 1st week and 3rd week (P&#60;0.05). But no statistically significant differences were observed at 6th week and 3rd month (P&#62;0.05).When the mean bite force values in left molar region of group A and group B were compared at 1st week, 3rd week, 6th week and 3rd month, there was statistically significant increase in bite force noted in group A when compared group B at 3rd week (P&#60;0.05). But no statistically significant differences were observed at 1st week, 6th week and 3rd month (P&#62;0.05).The study signifies that both the fixation systems were able to provide stability to fracture segments, but locking plate system has provided better stability when compared to miniplates system, hence recommending for more elaborative studies to arrive at definitive conclusion.

Three-dimensional alveolar bone assessment of mandibular molars for immediate implant placement: a virtual implant placement study

Background To elucidate the anatomical features of the mandibular molar region to allow safe immediate implant placement. Methods Cone-beam computed tomography images of 150 patients (600 teeth) were reviewed retrospectively. The virtual implants were placed in the mandibular first and second molar region. The anatomic structures of the mandible and inter-radicular septum were both categorized into three types. The relationship between implant and inferior alveolar nerve (IAN), and the horizontal distance from the implant surface to the bone wall were analyzed. Variables were compared using a student’s t-test, or Mann–Whitney U test. Results Type U (39.0%) and type S (56.0%) were the most common in the first molar, while type U (67.7%) and type M (54.7%) had the highest prevalence rate in the second molar. The mean distance from the level where the virtual implant was completely surrounded by bone to IAN was 7.06 mm. The mean horizontal widths from the implant to the mesial and distal socket wall were 1.59 mm and 1.89 mm. The widths of the inter-radicular septum and the distances from implant to the buccal and lingual plate on different sections were significantly associated with tooth position (P < .05). Conclusions In the first molar region, the implant is suggested to be placed in the center of the inter-radicular septum, while in the second molar region, the mesial root socket could be considered. Immediate implant placement in the mandibular second molar sockets shows a high risk of IAN injury, lingual perforation, and inadequate primary stability.

Effects of Induced Malocclusion on Vertebral Alignment in Rats: A Controlled Study by CBCTs

This study aimed to evaluate with CBCTs the alteration of vertebral alignment over time of induced malocclusion in rats. Crown pads increasing the vertical dimension of 0.5 mm were applied on the upper molars at one randomly selected side of the maxilla in rats (premature contact side) while the opposite side was left untreated (control side). Four groups were organized, ten animals each. In groups A, B, and C, the crowns were applied at time 0 (t-0). In group A, the crowns were removed after 2 weeks (t-2w) and euthanized after two more weeks, while in groups B and C, the animals were euthanized after 2 and 4 weeks (t-4w), respectively. No premature contacts were applied in group D. CBCTs were taken at t-0 in all animals before applying the crowns, at t-2w in group A before removing the crowns, and in all groups before the euthanasia. The changes in the iliac crest angle (ICA) that formed between the superior external margin of the iliac crest and the vertebral spine were evaluated. In groups A and B, after 2 weeks, the changes in ICA were statistically significant at p = 0.028 and p = 0.042, respectively. In group C, and in the control group D, the changes of ICA were not statistically significant (p = 0.058 and p = 0.414, respectively). In conclusion, the incease in monolateral occlusion in the molar region yielded a rotation of the lumbo-sacral segment towards the same side of the occlusal bite-raising.

Periodontal Clinical Parameters as a Predictor of Bite Force: A Cross-Sectional Study

Objective. To investigate the correlation of periodontal parameters and bite force in different stages of periodontitis after phase I periodontal therapy. Methods. Periodontal clinical parameters such as mobility, attachment loss, gingival recession, and percentage of bone remaining were recorded at the mandibular first molar region after phase I therapy in subjects categorized according to the stage of periodontitis. Corresponding bite force was recorded at the first mandibular molar region using a bite force device after phase I therapy. ANOVA test was used to assess the significant difference among different groups. Pearson correlation coefficient was used to assess the correlation between measured variables. Results. The ANOVA test represents that there is no statistical significant difference between the bite force in stage I, stage II, and stage III type of periodontitis. A strong positive correlation was found ( r = 0.537 ) between bite force and percentage of remaining alveolar bone support whereas negative correlation was observed in measured parameters such as mobility ( r = − 0.0181 ), attachment loss ( r = − 0.608 ), and gingival recession ( r = − 0.435 ). Conclusion. Among all periodontal clinical parameters, the percentage of remaining alveolar bone is the strong predictor of bite force and mobility; attachment loss and gingival recession cannot predict the bite force in the first molar region. Bite force is variable in different stages of periodontitis.