Upper airway morphology in adults with positional obstructive sleep apnea.

PURPOSE: To compare the anatomical balance and shape of the upper airway in the supine position between adults with positional obstructive sleep apnea (POSA) and adults with non-positional OSA (NPOSA). METHODS: Adults diagnosed with OSA (apnea-hypopnea index (AHI) > 10 events/h) were assessed for eligibility. POSA was defined as the supine AHI more than twice the AHI in non-supine positions; otherwise, patients were classified as NPOSA. Cone beam computed tomography (CBCT) imaging was performed for every participant while awake in the supine position. The anatomical balance was calculated as the ratio of the tongue size to the maxillomandibular enclosure size. The upper airway shape was calculated as the ratio of the anteroposterior dimension to the lateral dimension at the location of the minimal cross-sectional area of the upper airway (CSAmin-shape). RESULTS: Of 47 participants (28 males, median age [interquartile range] 56 [46 to 63] years, median AHI 27.8 [15.0 to 33.8]), 34 participants were classified as having POSA (72%). The POSA group tended to have a higher proportion of males and a lower AHI than the NPOSA group (P = 0.07 and 0.07, respectively). After controlling for both sex and AHI, the anatomical balance and CSAmin-shape were not significantly different between both groups (P = 0.18 and 0.73, respectively). CONCLUSION: Adults with POSA and adults with NPOSA have similar anatomical balance and shape of their upper airway in the supine position. TRIAL REGISTRATION: This study was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR Trial ACTRN12611000409976).

Effects of mandibular advancement devices on upper airway dimensions in obstructive sleep apnea: responders versus non-responders.

STUDY OBJECTIVES: To compare the effects of mandibular advancement device (MAD) therapy on upper airway dimensions between responders and non-responders with mild to moderate obstructive sleep apnea (OSA). METHODS: Thirty-one participants (21 men and 10 women) with a mean ± SD apnea-hypopnea index (AHI) of 16.6 ± 6.7 events/h, and aged 48.5 ± 13.9 years, were included in this study. Polysomnographic recordings and cone beam computed tomography (CBCT) scans in supine position were performed for every participant at baseline and at 3-month follow-up with their MAD in situ. Responders were defined as having ≥ 50% reduction in baseline AHI with a residual AHI < 10 events/h. The primary outcome variable was the minimal cross-sectional area of the upper airway (CSAmin). RESULTS: No significant differences were found between responders (n = 15) and non-responders (n = 16) in age, gender distribution, body mass index, and neck circumference (P = 0.06-0.93), nor in AHI and CSAmin (P = 0.40 and 0.65, respectively) at baseline. The changes of the CSAmin with MAD in situ in the responder group were not significantly different compared to those in the non-responder group (P = 0.06). CONCLUSION: Within the limitations of this study, we conclude that the changes of the upper airway dimensions induced by MADs are not significantly different between responders and non-responders with mild to moderate OSA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.

Comparison of the upper airway morphology between Dutch and Chinese adults with obstructive sleep apnea.

PURPOSE: The pathogenesis of obstructive sleep apnea (OSA) is complex and may vary between different races. It has been suggested that the anatomical balance between skeletal tissues and soft tissues around the upper airway is a key pathophysiologic factor of OSA. Therefore, the aim of this study was to compare the anatomical balance of the upper airway between Dutch and Chinese patients with OSA based on cone beam computed tomography (CBCT) images. METHODS: This was a cross-sectional study performed in two centers and included Dutch and Chinese adults with OSA. CBCT scans in the supine position were obtained for both Dutch and Chinese OSA groups. The primary outcome variable was the anatomical balance of the upper airway, defined as the ratio of the tongue area and the maxillomandibular enclosure area. RESULTS: A total of 28 Dutch adults (mean age ± SD of 46.6 ± 14.1 years, body mass index [BMI] of 26.8 ± 3.5 kg/m2, and apnea-hypopnea index [AHI] of 15.7 ± 7.1 events/h) and 24 Chinese adults (age 41.0 ± 12.4 years, BMI 26.5 ± 3.3 kg/m2, and AHI 16.5 ± 7.8 events/h). There were no significant differences in AHI, age, BMI, and sex between the two groups (P = 0.14-0.76). The Dutch group had a significantly larger tongue area and tongue length compared to the Chinese group (P = 0.01 and P < 0.01). On the other hand, the Chinese group had a smaller maxilla length compared to the Dutch group (P < 0.01). However, the anatomical balance of the upper airway of both groups was not significantly different (P = 0.16). CONCLUSION: Within the limitations of this study, no significant difference was found in the anatomical balance of the upper airway between Dutch and Chinese patients with mild to moderate OSA. TRIAL REGISTRATION: The present study was registered at the ClinicalTrials.gov identifier NCT03463785.

Comparisons of the effects of two types of titratable mandibular advancement devices on respiratory parameters and upper airway dimensions in patients with obstructive sleep apnea: a randomized controlled trial.

OBJECTIVES: To compare the effects of two types of titratable mandibular advancement devices (MADs), namely MAD-H (allowing limited vertical opening) and MAD-S (allowing free vertical opening), on respiratory parameters and upper airway dimensions in patients with mild to moderate obstructive sleep apnea (OSA). MATERIALS AND METHODS: Patients with mild to moderate OSA (5 ≤ apnea-hypopnea index (AHI) < 30 /h) were randomly assigned to two parallel MAD groups. All MADs were subjectively titrated according to a standardized protocol during a 3-month follow-up. Every patient underwent two polysomnographic recordings, and two cone beam computed tomography scans in supine position: one at baseline and another one after 3 months with the MAD in situ. The primary outcome variables were the AHI in supine position (AHI-supine) and the minimal cross-sectional area of the upper airway in supine position (CSAmin-supine). RESULTS: A total of 49 patients were recruited, and 31 patients (21 men and 10 women) with a mean (± SD) age of 48.5 (± 13.9) years and a mean AHI of 16.6 (± 6.7) /h completed the study. In the per-protocol analysis, there was no significant difference between MAD-H (n = 16) and MAD-S (n = 15) in their effects on AHI-supine (P = 0.14) and CSAmin-supine (P = 0.59). Similar results were found in the intention-to-treat analysis (P = 0.47 and 0.57, respectively). CONCLUSIONS: Within the limitations of this study, we conclude that there is no significant difference in the effects of an MAD allowing limited vertical opening and an MAD allowing free vertical opening on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA. CLINICAL RELEVANCE: MADs allowing limited vertical opening and allowing free vertical opening have similar effects on respiratory parameters and upper airway dimensions in patients with mild to moderate OSA. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02724865. https://clinicaltrials.gov/ct2/show/NCT02724865.

Anaesthesia and Caries Treatment by Dental Hygienists: A Worldwide Review.

OBJECTIVES: This study aimed to summarise the competencies and legal position of the dental hygienist (DH) regarding local anaesthesia and caries treatment through a worldwide review. METHODS: A structured and peer-reviewed online questionnaire consisting of 27 questions was developed and emailed to all DH associations that are members of the International Federation of Dental Hygienists or European Dental Hygienists Federation. After obtaining the data, all responding associations were contacted to confirm that the data were summarised in the correct order and were asked to provide further clarification of answers if necessary. A descriptive analysis was performed to summarise the data. RESULTS: Thirty-one countries were approached and 26 responded, resulting in a response rate of 84%. In 62% of the countries, the DH can administer local anaesthesia via infiltration and/or block anaesthesia. In 23% of the countries, the DH can indicate the placement of a caries restoration. In 15% of the countries, the DH can place caries restorations. In 81% of the countries, the DH can apply sealants. CONCLUSIONS: Considerable variation exists amongst countries regarding the extended scope of DH practice. Overall, independently administering local anaesthesia appears to be more accepted as being within the scope of DH practice than caries removal and the placement of restorations.

Virtual reality and haptics in dental education: Implementation progress and lessons learned after a decade.

INTRODUCTION: The search for alternative training environments in dentistry responded mainly to scarcity and lack of standardisation of training material and non-availability of specific clinical procedures. The development of haptic virtual reality (VR) dental trainers provides a platform where irreversible procedures can be safely and unlimitedly practised. The aim of this study was to assess the educational implementation of these devices and evaluate schools' satisfaction. METHODS: Dental schools that were using haptic VR dental trainers, were approached. The Dental Trainer User Inventory (DTUI), addressing the educational implementation and users' satisfaction, was developed and distributed. RESULTS: Twenty-seven schools completed the DTUI. The total number of VR dental trainers available varied from one to 42 devices with a mean of 7 devices. The dental trainer was mostly made available from the first year (63.0%) of the undergraduate program, but it was mostly integrated into the curriculum by the third year (70.4%). Curricular integration was reported by 18 schools (66.7%), while nine schools (33.3%) indicated that they had not yet achieved integration. Twenty-one schools (69.4%) were 'satisfied' or 'very satisfied' with the devices, while two schools (7.4%) were dissatisfied and six schools (22.2%) were neither satisfied nor dissatisfied. CONCLUSION: VR haptic dental trainers are implemented in multiple dental programs and are also being used for educational research and clinical training. Even though curricular changes and teachers' acceptance remain a challenge, most schools are satisfied with VR haptic dental trainers and would recommend the device to other schools.

Worldwide Review of Dental Hygienists' Extended Scope of Practice in Radiology.

OBJECTIVES: This study aimed to summarise the competencies and legal position of the dental hygienist (DH) regarding oral radiology through a worldwide review. METHODS: A structured and peer-reviewed online questionnaire of 27 questions was developed. This was emailed to all DH associations that are members of the International Federation of Dental Hygienists (IFDH) or European Dental Hygienists Federation (EDHF). After obtaining the data, all responding associations were contacted to confirm that the data were summarised in the correct order and were asked to provide further clarification of answers if necessary. A descriptive analysis was performed to summarise the data. RESULTS: The response rate was 84%, as 26 out of 31 countries completed the questionnaire. In 78% of the countries, the DH can legally take intraoral radiographs, but in 42% of the countries, the dentist first needs to provide a referral or indication for a radiograph. In 46% of the countries, the DH may not formulate a diagnosis based on a radiograph. In only 27% of the countries, the DH can independently own radiographic equipment. CONCLUSIONS: The required qualifications, skills, and scope of practice of the DH regarding oral radiology vary by country and, within some countries, even vary by state or province.

Effects of miniscrew-assisted orthodontic treatment with premolar extractions on upper airway dimensions in adult patients with Class II high-angle malocclusion.

INTRODUCTION: The primary aim of this study was to investigate the change in upper airway dimensions and in mandibular position after miniscrew-assisted treatment with premolar extractions in adult patients with Class II high-angle malocclusion. The secondary aim was to determine the correlation between changes in upper airway dimensions and changes in mandibular position in these patients. METHODS: Eighteen adult patients with Class II high-angle malocclusion (mean ± standard deviation age = 21.2 ± 2.9 years) were selected retrospectively. All patients underwent 4 premolar extractions, and 2 miniscrews were implanted in the maxilla to intrude molar height. Cone beam computed tomography images were taken pretreatment and posttreatment for every patient. The primary outcome variable for the upper airway was the minimal cross-sectional area of the upper airway (CSAmin), and the primary outcome variables for the mandible were mandibular rotation (Mp-SN angle), mandibular horizontal position (SNB angle), and mandibular vertical position (ANS-Me distance). RESULTS: The CSAmin significantly increased by 47.2 mm2 (t = -2.26, P = 0.04) after orthodontic treatment. The mandible significantly rotated counterclockwise by 0.9° (t = 2.20, P = 0.04) after treatment, which consisted of forward movement of 1.2° (t = -4.30, P = 0.00) and upward movement of 1.3 mm (Z = -1.98, P = 0.05). Furthermore, the change of the CSAmin showed a significant correlation with the change of the ANS-Me (P = 0.01). CONCLUSIONS: By using miniscrews to intrude maxillary molars, orthodontic premolar extraction treatment results in mandibular counterclockwise rotation, and upper airway dimensions increase in Class II high-angle young adult patients. The increase of the upper airway dimensions significantly correlates to the upward movement of the mandible.

Ambient dose during intraoral radiography with current techniques: part 3: effect of tube voltage.

OBJECTIVES: This study was conducted to assess the impact of tube voltage on ambient dose during intraoral radiography, specifically remnant-beam transmission and scattered radiation. METHODS AND MATERIALS: Remnant-beam and scattered radiation doses were recorded using a phantom at tube voltages of 60, 63, 66 and 70 kV. Mathematical equations depicting their relations were then formulated, and reference values were calculated at the various voltages tested. Total ambient doses per exposure at 60 kV and at 70 kV were compared. RESULTS: Both remnant-beam transmission and scattered radiation increased ~40% by increasing tube voltage from 60 kV to 70 kV, and the relation was linear. A remnant beam transmission reference value of 7.5% was established at 70 kV, as well as a conversion factor of 0.035 µSv/mAs at 1 m for scattered radiation at 60 kV. Given longer exposure times at 60 kV, total ambient dose proved higher at 60 kV than at 70 kV. CONCLUSION: Higher tube voltage results in higher remnant-beam transmission and more scattered radiation per workload. The relation is linear in the range between 60kV and 70 kV. Remnant-beam transmission at 70 kV is safely assessed at 7.5%. A conversion factor at 60 kV of 0.035 µSv/mAs at 1 m for the scattered radiation dose can be proposed. Total ambient dose per exposure was higher at 60kV than at 70 kV.

Cone-Beam CT Compared to Multi-Slice CT for the Diagnostic Analysis of Conductive Hearing Loss: A Feasibility Study.

OBJECTIVES: Multislice computed tomography (MSCT) is commonly used as a diagnostic tool for patients with a conductive hearing loss. Recent studies indicate that cone-beam computed tomography (CBCT) may be used as a low-radiation dose alternative for temporal bone imaging. This study compares image quality and radiation dose between CBCT and MSCT when assessing anatomical landmarks related to conductive hearing loss. MATERIALS AND METHODS: Five human cadaver heads (10 ears) were imaged on the NewTom 5G CBCT and the Discovery CT750 HD MSCT. Visibility of 16 anatomical landmarks of the middle and inner ear was assessed by two observers on a 4-point Likert scale. Furthermore, effective radiation dose was compared, and contrast-to-noise ratio and spatial resolution were measured with a phantom head. RESULTS: Image quality of CBCT was assessed as superior to MSCT. Effective radiation dose of the high-resolution CBCT protocol was 30.5% of the clinical MSCT dose. High-resolution CBCT was reported as having a higher spatial resolution and superior contrast-to-noise perception in comparison with MSCT. CONCLUSION: High-resolution CBCT was evaluated as superior to MSCT in the assessment of structures related to conductive hearing loss. Furthermore, CBCT imaging resulted in a considerably lower effective radiation dose.

Schneiderian membrane thickness variation following endodontic procedures: a retrospective cone beam computed tomography study.

BACKGROUND: To assess the change of the Schneider membrane thickness measured by CBCT before and after root canal treatment, retreatment and pulp capping procedures. METHODS: This retrospective study was conducted on CBCT scans of a patient population of Guy's Hospital NHS Foundation Trust, London. Three groups of patients were studied: Group 1 consisted of patients referred for primary endodontic treatment; Group 2 for endodontic retreatment; Group 3 for indirect pulp capping procedures (serving as a control group). Follow up scans were carried out 1 year after treatment. Measurements were carried out on CBCT scans and data were analysed statistically by Wilcoxon Signed Rank Test. Linear regression was used to assess predictive parameters for membrane thickness. RESULTS: A statistically significant reduction of the Schneider membrane thickness was observed one year after endodontic treatment and retreatment (P < 0.05) but no significant reduction was observed after pulp capping procedures. Linear regression showed that age and gender were significant predictors influencing the Schneider membrane thickness. CONCLUSIONS: Within the limitations of this retrospective study, following root canal treatment and re-treatment a Schneiderian membrane thickness reduction occurred at 1-year follow-up. The removal of odontogenic infection following endodontic treatment may help reducing the thickness of the Schneider membrane.

An overview of radiological manifestations of acquired dental developmental disturbances in paediatric head and neck cancer survivors.

OBJECTIVES: In paediatric cancer survivors treated with chemotherapy and radiotherapy therapy, late effects on dental development are quite common. Oral radiologists are not familiar with the radiographic images of these specific dental consequences of chemotherapy and radiotherapy. With the goal of educating colleagues, to raise awareness of the needs of survivors, and to identify directions for future research, we present dental radiographs of survivors treated for head and neck rhabdomyosarcoma with chemotherapy and radiotherapy. Also, based on the survivors reviewed, a radiographic inventory of commonly found late dental developmental effects seen in conjunction with treatment is presented. METHODS: Panoramic radiographic findings of five illustrative cases are presented, from a group of 42 survivors of head and neck rhabdomyosarcoma treated at the Academic Medical Center Amsterdam, The Netherlands over the past 25 years. RESULTS: Five cases showing dental developmental disorders are presented. These cases show an association of the location of the radiation field and the developmental stage of the teeth with the severity of the effect on dental development. We also report an inventory of severe and moderate effects of chemotherapy and radiotherapy on the development of molars and anterior teeth. CONCLUSIONS: This paper presents five cases and a radiographic inventory to illustrate disturbances of dental development associated with chemotherapy and radiotherapy in children. Medical and dental professionals involved in the treatment of cancer survivors are relatively unaware of the dental consequences of radiation therapy and the age dependency of specific regional effects. These effects can be severe, with great impact on quality of life. Further research in this area could help improve planning of radiation therapy for children, potentially preventing or limiting dental or maxillofacial sequelae.

Cone beam CT imaging of the mandibular third molar: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology (EADMFR).

OBJECTIVES: Lack of evidence on the use of CBCT for management of mandibular third molars in Radiation Protection guideline no. 172 of the European Commission made the European Academy of DentoMaxilloFacial Radiology (EADMFR) decide to update the recommendations of the guideline. METHODS AND MATERIALS: A literature search was performed addressing the following questions: (1) does CBCT change the treatment of the patient?; (2) does CBCT reduce the number of post-operative sensory disturbances of the inferior alveolar nerve?; and (3) can CBCT predict the risk for a post-operative sensory disturbance of the inferior alveolar nerve? RESULTS:: Since the European Commission published the guideline in 2012 several high-evidence studies on the use of CBCT before removal of mandibular third molars have been conducted including five randomized controlled clinical trials and one meta-analysis. Present literature allows to propose recommendations with highest level of evidence. CONCLUSION: New and up-to-date evidence-based recommendations advocate that CBCT imaging of the mandibular third molar should not be applied as a routine method before removal of mandibular third molars and therefore, CBCT imaging should only be applied when the surgeon has a very specific clinical question in an individual patient case that cannot be answered by conventional (panoramic and/or intraoral) imaging.

Human jaw joint hypermobility: Diagnosis and biomechanical modelling.

Patients with hypermobility disorders of the jaw joint experience joint sounds and jerky movements of the jaw. In severe cases, a subluxation or luxation can occur. Clinically, hypermobility disorders should be differentiated from disc displacements. With biomechanical modelling, we previously identified the anterior slope angle of the eminence and the orientation of the jaw closers to potentially contribute to hypermobility disorders. Using cone-beam computed tomography (CBCT), we constructed patient-specific models of the masticatory system to incorporate these aspects. It is not known whether the clinical diagnosis of hypermobility disorders is associated with the prediction of hypermobility by a patient-specific biomechanical model. Fifteen patients and eleven controls, matched for gender and age, were enrolled in the study. Clinical diagnosis was performed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and additional testing to differentiate hypermobility from disc displacements. Forward simulations with patient-specific biomechanical models were performed for maximum opening and subsequent closing of the jaw. This predicted a hypermobility disorder (luxation) or a control (normal closing). We found no association between the clinical diagnosis and predictions of hypermobility disorders. The biomechanical models overestimated the number of patients, yielding a low specificity. The role of the collagenous structures remains unclear; therefore, the articular disc and the ligaments should be modelled in greater detail. This also holds for the fanned shape of the temporalis muscle. However, for the osseous structures, we determined post hoc that the anterior slope angle of the articular eminence is steeper in patients than in controls.

Predictive Value of Panoramic Radiography for Injury of Inferior Alveolar Nerve After Mandibular Third Molar Surgery.

PURPOSE: The purpose of the present systematic review was to assess the added value of panoramic radiography in predicting postoperative injury of the inferior alveolar nerve (IAN) in the decision-making before mandibular third molar (MM3) surgery. MATERIALS AND METHODS: MEDLINE and EMBASE were searched electronically to identify the diagnostic accuracy of studies that had assessed the predictive value of 7 panoramic radiographic signs, including root-related signs (darkening of the root, deflection of the root, narrowing of the root, and dark and bifid apex of the root) and canal-related signs (interruption of the white line of the canal, diversion of the canal, and narrowing of the canal) for IAN injury after MM3 surgery. RESULTS: A total of 8 studies qualified for the meta-analysis. The pooled sensitivity and specificity of the 7 signs ranged from 0.06 to 0.49 and 0.81 to 0.97, respectively. The area under the summary area under the receiver operating characteristic curve ranged from 0.42 to 0.89. The pooled positive predictive value (PPV) and negative predictive value (NPV) ranged from 7.5 to 26.6% and 95.9 to 97.7%, respectively. The added value of a positive sign for ruling in an IAN injury (PPV minus the prior probability) ranged from 3.4 to 22.2%. The added value of a negative sign for ruling out an IAN injury (NPV minus [1 minus the prior probability]) ranged from 0.1 to 2.2%. CONCLUSIONS: For all 7 signs, the added value of panoramic radiography is too low to consider it appropriate for ruling out postoperative IAN in the decision-making before MM3 surgery. The added value of panoramic radiography for determining the presence of diversion of the canal, interruption of the white line of the canal, and darkening of the root can be considered sufficient for ruling in the risk of postoperative IAN injury in the decision-making before MM3 surgery.

Severity and presence of atherosclerosis signs within the segments of internal carotid artery: CBCT's contribution.

OBJECTIVES: This study aims to assess with cone-beam computed tomography the distribution and interrelation of the presence of calcifications along the course of the internal carotid artery and to associate their severity with their allocation within the segments of internal carotid artery, gender, and age. STUDY DESIGN: Using a documented visual scale, 161 cone-beam computed tomography scans were evaluated on the allocation and severity of intracranial calcifications within the segments of the internal carotid artery. RESULTS: Calcifications were detected along the petrous (C2: 11.8%), lacerum (C3: 23.6%), cavernous (C4: 92.5%), and ophthalmic-clinoid (C5/C6: 65.8%) segments. The Friedman test showed significant differences in severity distribution among these segments; the highest degree was found in the C4 segment (P < .05). The Wilcoxon signed-rank test showed no significant differences between calcifications on the right or left side or between severities within the C1 (extracranial) and C5/C6 segments. The Chi-square test showed that the severity and allocation of calcifications are not influenced by gender; it also showed that their severity increases with age (P < .05). CONCLUSIONS: In the cohort studied, the incidence of calcifications increased throughout the C1, C5/C6, and C4 segments. More severe calcifications were found at the C4, C1, and C5/C6 segments in decreasing order but increased with age, regardless of gender.

The presence of calcifications along the course of internal carotid artery in Greek and Brazilian populations: a comparative and retrospective cone beam CT data analysis.

OBJECTIVES: We aimed to retrospectively compare the prevalence of soft tissue calcifications (STCs) depicted incidentally along the extra- and intracranial course of the internal carotid artery (ICA) on cone beam computed tomography examinations in 2 different populations (Greeks and Brazilians). METHODS: The cohort consisted of examinations of 232 Greeks and 174 Brazilians, for a total of 406 patients. The scans were evaluated for the presence of STCs along the course of the ICA, with data analyzed in each ethnic group according to gender and age criteria. RESULTS: In total, 355 STCs were recorded; 78 (22.0% of all STCs) and 58 (16.3%) were extracranials, and 128 (36.1%) and 91 (25.6%) were intracranials for Greeks and Brazilians, respectively. The χ(2) test indicated no statistical differences between Greeks and Brazilians in the occurrence of STCs; however, their prevalence differed between genders in those populations. The presence of lesions, both extra- and intracranially, was found to increase with age (P < .05). The odds ratios were estimated at 2.23 (95% CI, 1.81-2.74) and 3.26 (95% CI, 2.56-4.16) for extracranial and intracranial lesions, respectively, with increasing age. CONCLUSIONS: We found an equal distribution for both extra- and intracranial STCs among Greeks and Brazilians. The prevalence of lesions differed between genders within both populations. Aging was found to be a risk factor for STCs, as the odds ratio increased significantly.