Cone-Beam Computerized Tomography Evaluation of the Relationship between Orthodontic Vertical Direction Parameters and the Distance from the Apex of the Upper Central Tooth to the Nasal Floor and Anterior Nasal Spine.

The aim of this study was to examine the relationship between the vertical cephalometric values and the distance from the apex tip of the upper central tooth (U1A) to the anterior nasal spine (ANS) and nasal floor (NF) using cone-beam computerized tomography (CBCT). One hundred and twenty-two patients who applied to the Department of Orthodontics between January 2011 and June 2019 were included. The distances between the U1A and the NF and ANS were measured using CBCT. Statistical significance was considered as p < 0.05. Of the 122 individuals, 73.8% (n = 90) were female and 26.2% (n = 32) were male, with a mean age of 22.8 ± 3.3 years. A statistically significant moderate positive correlation was found between the mean NF-U1A values and the N-Me, ANS-Me, ANS-Gn, S-Go, and N-ANS measurements (p < 0.01). A statistically significant positive correlation was found between the mean ANS-U1A values and the Ar-Go-Me, total posterior angles, N-Me, SN/GoGn and Y-axis angle, ANS-Me, and ANS-Gn measurements (p < 0.01). The distance from the U1A to the ANS and NF was related to the orthodontic vertical direction parameters. The ANS-U1A and NF-U1A distances can serve as reference points for identifying the orthodontic vertical growth pattern from CBCT scans.

Comparison of zygoma plates and infrazygomatic crest miniscrews used open bite treatment: A 3-dimensional finite element study.

INTRODUCTION: This study aimed to evaluate infrazygomatic crest (IZC) miniscrews, which represent a new approach to maxillary posterior tooth intrusion and extra-alveolar skeletal anchorage, using 3-dimensional finite element stress analysis to predict the clinical usability instead of zygoma plates. METHODS: Six different models were developed. The direction of the intrusion force was generated parallel to the maxillary first molar, and the posterior bite-block intrusion appliance was connected with 2 steel arches. A zygoma plate, stainless steel (SS)-IZC miniscrew, and a titanium alloy (TiA)-IZC miniscrew were used as anchorage units, and 200 g and 400 g of intrusion forces were applied. The cortical bone, spongious bone, stress values, and displacements in the anchorage unit were examined. The anchored materials were considered nonosseointegrated. RESULTS: Zygoma plates formed low-stress values under 200 g and 400 g of force. The greatest stress and displacement occurred in the first miniscrew that fixed the plate. SS-IZC miniscrews gave lower stress and displacement values than TiA-IZC miniscrews. The most stress was detected inferior to the screw-to-bone contact in IZC miniscrews. CONCLUSIONS: Considering the initial value of resorption in cortical bone, it is predicted that SS-IZC and TiA-IZC miniscrews can be used in the clinic under 200 g of intrusion force, although there is not as little stress and displacement as for zygoma plates. Under 400 g of intrusion force, clinical use cannot be recommended because of the critical stress value they generate in the cortical bone.

Assessment of soft tissue changes after LeFort I advancement.

PURPOSE: The aim of this retrospective study was to investigate the soft tissue changes after maxillary advancement in class III patients. METHODS: Pre- and post-operative lateral cephalometric radiographs of 20 patients treated with maxillary advancement surgery were included in our study. Skeletal, dental and soft tissue measurements were performed by a single researcher using Dolphin Imaging software version 11.95 (Dolphin Imaging, Chatsworth, CA, USA). Paired t test was used for statistical evaluation and p < 0.05 was considered statistically significant. RESULTS: The amount of motion in soft tissues, respectively, are UL-E: 2.05 mm, ST.A: 0.65 mm, ST.B: - 5 mm, ST.Pog: - 5.73 mm, ST.Conv: - 3.95 mm, nasal prominence: - 1.58 mm, nasal height: 2.76 mm and upper lip length: 2.22 mm. The change of distance to horizontal and vertical reference planes are, respectively, Prn-HRL: 3.02 mm Prn-VRL: 1.76 mm Sn-HRL: 2.76 mm Sn-VRL: 2.94 mm ST. A-HRL: 3.74 mm ST. A-VRL: 3.81 mm UL-HL: 3.93 mm UL-VRL: 4.57 mm LL-HRL: 2.29 mm LL-VRL: 5.31 mm. CONCLUSIONS: It can be concluded that soft tissues related to maxilla moved anteriorly due to maxillary advancement.

Assessment of mandibular ramus for sex determination: Retrospective study.

BACKGROUND: The determination of sex is as a keystone in the identification. The skull is considered the second-best mark of gender determination. However in cases where a complete dry skull is not found, the mandible may play an important role in gender estimation as it is the most dimorphic, largest, and strongest bone of the skull. Studies showed cone beam computed tomography (CBCT) found better than traditional methods. The using of CBCT device can obtain undistorted and good-quality 3D images with a low radiation dose.In this study, it was purposed to measure the morphometric parameters of the 3D mandible models in the Central Anatolian Turkish population and to evaluate the effectiveness of measurements in gender determination. METHOD: The study was consisted of 70 individuals (35 males, 35 females; mean age 24,69 ± 2,85 years). Linear parameters were measured in mm using the mouse-driven method. The measurements were recorded from the both of right and left side. Acquired measurements between groups were evaluated with Student t-test. RESULTS: In the present study five different parameters of mandible were measured and mean values were determined. It was found that all variable of mandibular ramus on CBCT models showed a statistically significant difference among the sex (p < 0.05). CONCLUSIONS: Mandibular ramus measurements can be useful tool for sex determination. These results propose that the mandible describes sexual dimorphism in the modern adult Central Anatolian Turkish population. However further studies with larger populations are needed to reveal this relation.

Effect of body mass index percentile on skeletal maturation of cervical vertebrae and hand-wrist and dental maturation.

Objective: The aim of this study was to evaluate the relationship between age- and gender-specific body mass index (BMI) percentile and skeletal and dental maturation in Turkish adolescents.Materials and methods: A sample of 429 patients (171 males, 258 females aged between 7 and 17 years) was selected. Skeletal maturation was identified in the hand-wrist radiography by Björk, Grave and Brown (BGB), and the cervical vertebrae maturation (CVM) method defined by Hassel and Farman in lateral cephalometric radiography. Dental maturation was determined by the Demirjian method. BMI was calculated by reference curves used for Turkish children. A regression model was used for the relationship between BMI percentile and skeletal and dental maturation.Results: There was no significant correlation between BMI and skeletal maturation of cervical vertebrae and dental maturation. A one-percentile increase in BMI percentile accelerates the increase of period (likelihood of being post-pubertal period) to 1.016 times (p < .05). Skeletal maturation of hand-wrist and cervical vertebrae and dental maturation were more prominent in females compared to males (p < .05). Males and females were not statistically significantly different in BMI percentile (p = .52).Conclusions: BMI may be considered before deciding to estimate the skeletal and dental maturation in an individual by the relevant methods.

Effect of rapid maxillary expansion on halitosis.

INTRODUCTION: The objective of this study was to evaluate the effect of rapid maxillary expansion (RME) on halitosis. METHODS: Thirty children (11-15 years old) were randomly divided into RME and control groups. The RME group consisted of 15 children treated with hyrax appliances, and the control group included 15 children without treatment. Halitosis was evaluated with the halimeter and the organoleptic method. Plaque index and gingival index scores were recorded. Acoustic rhinometry was used to measure the nasal volume. Measurements were obtained at 2 times: before RME, and after retention at 4 months. The Wilcoxon signed rank test and the paired t test were used for intragroup comparisons, and the Mann-Whitney U test and the Student t test were used for intergroup comparisons. RESULTS: Halitosis (halimeter and organoleptic values) decreased significantly in the RME group (P <0.001). Insignificant changes of halitosis were observed in the control group. Intragroup and intergroup comparisons showed no statistically significant differences for the plaque index. Gingival index values were significantly decreased with RME (P ≤0.05). Nasal cavity volume increased significantly in the RME group (P <0.01). CONCLUSIONS: RME was shown to lower halitosis values. RME could be a treatment option for patients with maxillary transverse deficiency and halitosis.