Direct-Acting Oral Anticoagulant/Vitamin K Antagonists: Do They Affect the Trabecular and Cortical Structure of the Mandible?

BACKGROUND: This study aimed to evaluate the mandibular bone structure of patients using oral anticoagulants (OACs) vitamin K antagonist drugs (warfarin) and other OACs including direct oral anticoagulants [(DOACs) apixaban, rivaroxaban, dabigatran, edoxaban]. Analyses were based upon the fractal dimension (FD), the panoramic mandibular index (PMI) and the Klemetti index (KI), which is also known as the mandibular cortical index (MCI). METHODOLOGY: Ninety participants were divided into three groups: group 1: 30 systemically healthy individuals who had not used any anticoagulants before, group 2: 30 individuals using warfarin, and group 3: 30 individuals using DOACs. FD was used to analyze trabecular bone architecture in the condyle, angle, and two sites in the alveolar bone. PMI was used to evaluate the quantity of cortical bone and KI was used to evaluate the cortical bone quality. RESULTS: There was no difference between the groups regarding FD analysis and KI; however, a difference was found between groups 1, 2, and 3 in the PMI (P≤ 0.001). The PMI in group 1 was higher than in groups 2 and 3. CONCLUSION: Mandibular radiomorphometric indices can be used on panoramic radiographs to evaluate the quantity of mandibular cortical bone in patients using oral anticoagulants.

Determination of growth and developmental stages in hand-wrist radiographs : Can fractal analysis in combination with artificial intelligence be used?

PURPOSE: The goal of this work was to assess the classification of maturation stage using artificial intelligence (AI) classifiers. METHODS: Hand-wrist radiographs (HWRs) from 1067 individuals aged between 7 and 18 years were included. Fifteen regions of interest were selected for fractal dimension (FD) analysis. Five predictive models with different inputs were created (model 1: only FD; model 2: FD and Chapman sesamoid stage; model 3: FD, age, and sex; model 4: FD, Chapman sesamoid stage, age, and sex; model 5: Chapman sesamoid stage, age, and sex). The target diagnoses were accelerating growth velocity, very high growth velocity, and decreasing growth velocity. Four AI algorithms were applied: multilayer perceptron (MLP), support vector machine (SVM), gradient boosting machine (GBM) and C 5.0 decision tree classifier. RESULTS: All AI algorithms except for C 5.0 yielded similar overall predictive accuracies for the five models. In order from lowest to highest, the predictive accuracies of the models were as follows: model 1 < model 3 < model 2 < model 5 < model 4. The highest overall F1 score, which was used instead of accuracy especially for models with unbalanced data, was obtained for models 1, 2, and 3 based on SVM, for model 4 based on MLP, and for model 5 based on C 5.0. Adding Chapman sesamoid stage, chronologic age, and sex as additional inputs to the FD values significantly increased the F1 score. CONCLUSION: Applying FD analysis to HWRs is not sufficient to predict maturation stage in growing patients but can be considered a growth rate prediction method if combined with the Chapman sesamoid stage, age, and sex.

Effects of aligner activation and power arm length and material on canine displacement and periodontal ligament stress: a finite element analysis.

BACKGROUND: This study aimed to assess the impact of aligner activation and power arm length and material on canine and aligner displacement, von Mises stress in the power arm, and principal stress in the periodontal ligament (PDL) during canine tooth distalization using finite element analysis (FEA). The effects of aligner activation and power arm length were primary outcomes, while the effect of the power arm material was a secondary outcome. METHODS: Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis. RESULTS: Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm. CONCLUSION: Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.

Evaluation of trabecular bone and mandibular cortical thickness in adults with different vertical facial types.

OBJECTIVES: This study investigated differences in trabecular structure and mandibular cortical thickness in adults related to vertical facial type (VFT), sex, and their interactions. STUDY DESIGN: Lateral cephalometric radiographs (LCRs) and panoramic radiographs (PRs) of 256 patients were reviewed. The VFT classification into low-angle, normal, and high-angle groups was determined using angular and linear measurements on LCRs. Fractal dimension (FD) values and mandibular radiomorphometric indices (RMIs) were calculated on PRs. RESULTS: Two-way analysis of variance revealed significant differences in FD overall among VFT groups in all sites (P < .001), with pairwise comparisons indicating the greatest values in the high-angle group in the condyle (P < .05) but in the low-angle group elsewhere (P < .001). RMIs were significantly different overall regarding VFT only in the posterior mandible (P = .004), with pairwise comparisons revealing low-angle and normal group values greater than high-angle group values (P < .05). Patient sex and the interaction of facial type and sex had no significant effect on any bone measurements. CONCLUSIONS: VFT had significant effects on trabecular structure at all measured sites, but cortical thickness was affected only in 1 location.

Evaluation of mandibular morphologic measurements and trabecular structure among subgroups of impacted mandibular third molars.

OBJECTIVE: To investigate mandibular morphologic measurements and trabecular structures that may cause mandibular third molar (MM3) impaction according to MM3 subgroups. METHODS: A total of 150 MM3 of 2175 panoramic radiographs (PRs) were reviewed. MM3s according to Winter (vertical), Pell & Gregory Class 1 and group: A, B, C on PRs were included in the study group. Fractal dimensions (FD) and mandibular morphologic measurements were evaluated. Statistical analysis for parametric values was performed using one-way analysis of variance (ANOVA). Statistical analysis for non-parametric values was performed using the Kruskal-Wallis H test. RESULTS: Statistically, a significant difference was found only in terms of angle of impaction among the groups of MM3 (p < 0.05) [Winter (vertical), and Pell & Gregory Class 1 and group A, B, C]. There was no difference among groups A, B, C in mandibular morphology and trabecular structure, but group C showed different characteristics than the other groups only in terms of impaction angle. CONCLUSION: The trabecular structure and morphometric properties except for the angle of impaction do not affect impacted MM3s with adequate retromolar space and vertical angle.

Occipital spurs on lateral cephalometric radiographs: morphologic and morphometric features.

OBJECTIVE: To evaluate the presence of occipital spurs, morphologic/morphometric features, and the presence of ossification of ligamentum nuchae (ONL) on lateral cephalometric radiographs of individuals aged under and over 18 years. METHODS: Lateral cephalometric radiographs of 1430 individuals aged between 14-50 years were scanned. The presence of ONL and occipital spurs was evaluated in 1312 patients who met the inclusion criteria, and existing occipital spurs were measured and their types (flat/crest/spine) were recorded. RESULTS: Occipital spurs were detected in 63 patients aged over 18 years (63/120; 52.5%) and 57 patients aged under 18 years (57/120; 47.5%). When the spur length by age category and sex was evaluated, no statistically significant difference was observed. The spur types seen were flat (40.8%; 49/120), crest (30%; 36/120) and spine (29.2%; 35/120), respectively. Although there was no statistically significant difference between the spur types seen in terms of age, a significant difference was observed between the sexes in the total group (p < 0.001). Spine-type spurs (66.7%; 18/27) were the most common in females, and flat-type spurs (45.2%; 42/39) were the most common in males. ONL was detected in only three individuals. CONCLUSION: No relationship was found between the presence of occipital spurs and ONL. Although spur length was not affected by age and sex, spur types were found to vary according to sex. Occipital spurs are mostly asymptomatic and detected incidentally on lateral cephalometric radiographs. They are one of the important anatomic formations that should be diagnosed by physicians.

A modified presurgical alveolar molding technique for treatment of cleft in Down syndrome.

Craniofacial clefts are extremely rare deformities. Tessier's classification is a widely accepted system that is based on clinical, radiographical, and surgical observations. The Tessier No. 0 cleft most commonly affects the upper lip, nose, and palate. This case presentation aims to report the outcome of a modified presurgical alveolar molding (PAM) appliance used in the treatment of an infant with Tessier No. 0 cleft as an alternate approach to mold such defects before surgery. The modified PAM appliance consisted of reciprocal parts connected by a helix. The segments were approximated by stripping the appliance at the midline in a V-shaped manner and the force was exerted by the extraoral elastics. The procedure gave results in 8 weeks, which may be regarded as a reasonable duration. The anterior cleft gap, which was 13 mm before the treatment, was reduced to 3 mm after the treatment by using modified PAM appliance. On a 21-month follow-up period, oral reshaping was regarded successful due to stability of the improved oral mold.