Avaliação tomográfica das dimensões verticais dos tecidos periodontais supracrestais em dentes anteriores da maxila / Tomographic evaluation of the vertical dimensions of periodontal supracrestal tissues in maxillary anterior teeth

O objetivo do presente estudo foi avaliar em tomografias computadorizadas as dimensões dos tecidos periodontais supracrestais (TPSC). Cem pacientes, 600 dentes anteriores da maxila (200 incisivos centrais, 200 incisivos laterais e 200 caninos), foram avaliados. A distância média da margem gengival até a crista óssea alveolar (COA) foi de 3.25mm (95% IC: 3.20-3.30), enquanto que da junção cemento-esmalte até a COA foi de 1.77mm (95% IC: 1.72-182mm). As medidas foram significativamente diferentes entre os grupos de dentes (ANOVA, p < 0.001). A tomografia, pode representar uma importante ferramenta para a avaliação das dimensões dos TPSC.

The aim of this study was to evaluate the dimensions of the supracrestal periodontal tissues (SPT) on tomographic scans. One hundred patients, 600 maxillary anterior teeth (200 central incisors, 200 lateral incisors and 200 canines), were evaluated. The average distance from the gingival margin to the alveolar bone crest (ABC) was 3.25mm (95% CI: 3.20-3.30), while the distance from the cemento-enamel junction to ABC was 1.77mm (95% CI: 1.72-182mm). The measurements were significantly different between the tooth groups (ANOVA, p < 0.001). When properly indicated, tomography can be an important tool for assessing the dimensions of TPSCs on a case-by-case basis.

Positions of the Mandibular Foramen and Canal in Different Skeletal Classes and Implications for Bilateral Sagittal Split Osteotomy.

Objectives: To evaluate the positions of the mandibular foramen (MF) and mandibular canal (MC) between different skeletal classes to highlight the implications for bilateral sagittal split osteotomy (BSSO). Methods: A cross-sectional study was performed using cone-beam computed tomography on 90 patients classified into classes I, II and III. Linear measurements were performed on multiplanar reconstructions as follows: from the MF to the edge of the mandibular ramus (1), to the mandibular notch (2), to the ramus width (3) and to the occlusal plane (4); and from the MC to the alveolar crest (A), to the lower border of the mandible (B) and to the mandibular buccal cortical bone (C). Mandibular thickness (D), width (E) and height (F) of the MC were measured. Intra-class correlation coefficient (ICC) checked the reliability. Two-way ANOVA and Tukey's test were used to compare measurements and classes. Results: Linear measurements 2 presented a statistically significant difference between classes I and II. There was no statistically significant difference between the classes and measurements B, C, D, E and F. Linear measurements A were shorter in class III than in class II. Conclusions: Although most measurements suggest that the BSSO technique does not need to be modified for each skeletal class, measurements from the MF to the mandibular notch in class II and from the MC to the alveolar crest on distal of the second molars in class III could help surgeons to recognize critical regions.

Analysis of palatal marginal alveolar exostosis and palatal torus using cone-beam computed tomography.

The aim of the present study was to analyze palatal marginal alveolar exostosis (PMAE) and palatal torus (PT). Cone-beam computed tomography (CBCT) of the maxilla in multiplanar sections and volumetric renderings were used to assess this. PT and PMAE were classified according to location and morphology. Height, width, length, and thickness of the overlying mucosa were determined. The prevalence of PT and PMAE was assessed according to sex and age group. The correlation between the occurrence of PMAE and PT was also evaluated. A total of 385 CBCT scans were examined. PT was found in 38.70% of the sample and located more frequently in the middle third of the maxilla (52.35%) with a flat shape (42.95%). PMAE was found in 54.80% of the sample, bilaterally in 56.40% of the cases, and located more frequently in the molar region (62.42%) in the form of small nodules (36.97%). The mucosa covering PMAE was generally thicker than that over PT. The use of CBCT for the identification of PT and PMAE in vivo showed high frequencies of both conditions. The occurrence of PMAE was independent of the presence of PT.

Morphology of Roots and Canals of Maxillary First Premolars: A CBCT Study in a Peruvian Sample.

Introduction: It is important to take into account variations in structures related to dental pulp for planning the most adequate endodontic treatment management. The objective of this study was to determine the morphology of roots and canals of maxillary first premolars (MFPs) using cone-beam computed tomography (CBCT). Materials and Methods: This retrospective study included a sample of 392 CBCTs of Peruvian adults proportionally selected by sex, age, and quadrant. One MFP per individual was selected for evaluation by a calibrated evaluator based on the number of roots and canal configuration according to the Vertucci classification (VC; Cohen's κ ≥ 0.834). Pearson's χ 2 and Kruskal-Wallis tests were used with a significance level of P < 0.05. Results: Most MFP presented double roots (59.9%) and were VC type IV (52%). Morphology showed a nonsignificant difference by quadrants (P=0.994). A significant positive association was found between the presence of double roots and type IV in men and with older age, while single roots and type I and II were associated with women and younger age (P < 0.05). Double roots were associated with VC type IV (86%) and single roots with types III (34%), II (32%), and I (26%; P < 0.001). Conclusions: MFPs in a Peruvian sample presented a higher frequency of double roots with two separate canals. The morphology of root and canals was associated with age and sex.

Repeatability and Reproducibility of a Modified Lekholm and Zarb Bone Quality Classification Based on Cone Beam Computed Tomography: An Observatsion Study.

Aim: We propose a modified Lekholm and Zarb classification that considers all possible combinations of cortical and cancellous bone to provide parameters that favor greater repeatability and reproducibility. Materials and Methods: This observational and analytical study consisted of a sample of 50 cone beam computed tomography (CBCT) scans. Two new types (V and VI), three subtypes to type II (II-A, II-B, and II-C), and two subtypes to type III (III-A and III-B) were added to the original bone quality classification. The new types refer to regenerated bone (type V) and bone with some pathology (type VI). The subtypes are described as type II-A: thick cortical surrounding the abundant cancellous bone with sharp trabeculae throughout the image and presence of small and visible medullary spaces; type II-B: thick cortical surrounding the abundant cancellous bone with predominance of diffuse trabeculae in the basal bone and predominant presence of wide and visible medullary spaces; type II-C: thick cortical surrounding the abundant cancellous bone with predominance of very thick and sharp trabeculae in the basal third as well as presence of small and visible medullary spaces; type III-A: thin cortical surrounding the abundant cancellous bone with sharp trabeculae throughout the image and presence of small and visible medullary spaces; type III-B: thin cortical surrounding the abundant cancellous bone with predominance of diffuse trabeculae and presence of diffuse medullary spaces. Five dental specialists were trained in the use of the modified classification and were provided with CBCT-sectioned images of edentulous jaws for classification. Each specialist classified the images twice at a 7-day interval. The strength of intra-examiner and inter-examiner agreement was measured with Cohen's and Fleiss' kappa index, respectively. In addition, the agreement between both classifications was analyzed. All data were analyzed at a 95% confidence level, considering a P-value <0.05. Results: According to the modified Lekholm and Zarb classification, an almost perfect intra-examiner agreement was significant (P < 0.05) in all five specialists, with the kappa index [k] ranging from 0.91 [95% confidence interval (CI): 0.82-0.99) to 0.95 (95% CI: 0.89-1.00). Furthermore, substantial inter-examiner concordance (k=0.76; 95% CI: 0.73-0.79) was significant (P < 0.05). Conclusion: The high repeatability and reproducibility of the modified Lekholm and Zarb classification on CBCT suggest its applicability to distinguish between the various combinations of cortical and cancellous bone and help to define treatment appropriately to optimize results.

Effective doses of scout projections in maxillofacial cone beam computed tomography.

OBJECTIVES: To assess the effective and organ/tissue equivalent radiation doses of different scout projection protocols in four CBCT units. METHODS: Optically stimulated luminescence dosimeters (OSLD) were placed in reference anatomical locations in the head and neck segments of an anthropomorphic phantom representing an average adult male. Ten repeated exposures were obtained from each of the twelve scout projections studied, acquired from four maxillofacial cone beam computed tomography (CBCT) units (Midmark EIOS, 3D Accuitomo F170, Veraviewepocs 3D R100, and Veraview X800). The effective and organ/tissue equivalent doses were calculated for each protocol. RESULTS: Effective doses ranged from 0.7 µSv (Accuitomo F170 60 × 60 mm-anterior maxilla) to 6.9 µSv (Midmark 50 × 50 mm-anterior maxilla). The highest organ/tissue equivalent doses were recorded for the oral mucosa and salivary glands; however, the thyroid was the highest contributor to the effective dose, followed by the salivary glands. CONCLUSIONS: Despite some variability among CBCT machines and protocols, the acquisition of scout projections is a low-dose procedure. The use of scout projections to ensure an adequate position of the region of interest within the field of view is highly desirable as they contribute minimally to overall CBCT patient dose.

Combination of metal artifact reduction and sharpening filter application for horizontal root fracture diagnosis in teeth adjacent to a zirconia implant.

Purpose: This study examined the influence of metal artifact reduction (MAR), the application of sharpening filters, and their combination on the diagnosis of horizontal root fracture (HRF) in teeth adjacent to a zirconia implant on cone-beam computed tomography (CBCT) examinations. Materials and Methods: Nineteen single-rooted teeth (9 with HRF and 10 without) were individually positioned in the right central incisor socket of a dry human maxilla. A zirconia implant was placed adjacent to each tooth. Imaging was performed using an OP300 Maxio CBCT (Instrumentarium, Tuusula, Finland) unit with the following settings: a current of 8 mA, both MAR modes (enabled and disabled), a 5×5 cm field of view, a voxel size of 0.085 mm, and a peak kilovoltage of 90 kVp. Four oral and maxillofacial radiologists independently evaluated the CBCT scans under both MAR conditions and across 3 levels of sharpening filter application (none, Sharpen 1×, and Sharpen 2×). Diagnostic metrics were calculated and compared using 2-way analysis of variance (α=5%). The weighted kappa test was used to assess intra- and inter-examiner reliability in the diagnosis of HRF. Results: MAR tool activation, sharpening filter use, and their combination did not significantly impact the area under the receiver operating characteristic curve, sensitivity, or specificity of HRF diagnosis (P>0.05). Intra- and inter-examiner agreement ranged from fair to substantial. Conclusion: The diagnosis of HRF in a tooth adjacent to a zirconia implant is not affected by the activation of MAR, the application of a sharpening filter, or the combination of these tools.

Investigation of nasal cavity alterations in individuals with neurofibromatosis type 1 using CBCT.

OBJECTIVES: This study aimed to investigate nasal septum deviation (NSD), nasal bone length (NBL), and the morphology of the middle nasal conchae (MNC) and inferior nasal conchae (INC), as well as their correlations. MATERIALS AND METHODS: The sample included 56 cone-beam computed tomography scans divided into two groups: a study group (SG; individuals with NF1; n = 28) and a control group (CG; individuals without NF1; n = 28). NSD, NBL, MNC, and INC classifications were assessed. MNC images were classified as normal, bullous, paradoxical, secondary, and accessory. INC images were classified as normal, lamellar, compact, combined, and bullous. Intra- and interobserver reliability were evaluated. RESULTS: SG had a mean NSD of 11.6° (±4.5°) compared with 9.6° (±3.2°) for the CG, showing moderate deviations with no significant difference between groups. SG had a mean NBL of 22.4 mm (±3.4 mm) compared with 22.1 mm (±3.2 mm) for the CG, with a statistically significant difference. Both groups exhibited normal, bullosa, and accessory MNC classifications. SG INC were normal, lamellar, and combined, whereas CG INC were normal and lamellar. There was a weak correlation between NSD and NBL across groups. CONCLUSION: Individuals with NF1 showed longer NBL. The weak correlation between NSD and NBL suggested multifactorial influences on these variations. These findings advance our understanding of craniofacial development in NF1 and highlight the need for further research into nasal cavity involvement in this complex genetic disorder.

Prevalence of radix accesoria dentis in a northern Peruvian population evaluated by cone-beam tomography.

Radix accessoria dentis are anatomical variations of the mandibular molars and identifying them radiographically can be challenging for the clinician, especially in specific areas such as endodontics. The objective this study was to determine the prevalence of radix accessoria dentis evaluated in cone-beam computed tomography in a northern Peruvian population. The study design was descriptive and cross-sectional. The sample consisted of 2640 permanent mandibular first and second molar teeth evaluated by cone beam tomography. Non-probabilistic convenience sampling was used. For the analysis of radix accesoria dentis, the axial and coronal views of the tomography were evaluated. Prevalence was evaluated according to sex and according to type of tooth and average length. The statistical analyses used were the chi-square test and Kruskal-Wallis H test to find the correlation of the variables. A prevalence of 2.5 % of radix accesoria dentis was determined. According to sex, radix accesoria dentis was present in 1.36 % in females and 1.14 % in males (p > 0.05). The tooth 4.6 obtained the highest prevalence with 1.33 % (p > 0.05) and the average length of radix accesoria dentis found was 9.27 mm (p > 0.05). The prevalence of the radix accesoria dentis evaluated in cone beam tomography in a northern Peruvian population is low. Sex does not influence its presentation. Mandibular first molars are the ones that present the greatest amount of this anatomical variation and the average length of the radix accesoria dentis is less than 10 mm.

Procedural errors detected by cone beam tomography in cases with indication for retreatment: in vivo cross-sectional study.

Objectives: This study aimed to investigate the frequency and type of endodontic procedural errors in cases indicated for retreatment through cone-beam computed tomography (CBCT) analysis. Materials and Methods: The sample consisted of 96 CBCT scans, encompassing 122 permanent teeth with fully formed roots. Errors included perforation, instrument fracture, canal transportation, missed canals, and inadequate apical limit of filling. Additionally, potential risk factors were analyzed and subjected to statistical modeling. Results: The most frequent procedural error observed was the inadequate apical limit of filling, followed by canal transportation, perforation, missed canal, and instrument fracture. Statistically significant associations were identified between various procedural errors and specific factors. These include canal transportation and root canal wall, with the buccal wall being the most commonly affected; missed canal and tooth type, particularly the palatine and second mesiobuccal canal canals; inadequate apical limit of filling and root curvature, showing a higher deviation to the mesial direction in severely curved canals; inadequate apical limit of filling and the presence of calcifications, with underfilling being the most frequent; canal transportation and periapical lesion, notably with deviation to the buccal direction; and the direction of perforation and periapical lesion, most frequently occurring to buccal direction. Conclusions: CBCT emerges as a valuable tool in identifying procedural errors and associated factors, crucial for their prevention and management.

Incidental Findings Following Dental Implant Procedures in the Mandible: A New Post-Processing CBCT Software Analysis.

Background/Objectives: The aim of this study was to evaluate incidental findings in the mandible after the placement of dental implants using a new cone-beam computed tomography (CBCT) software. Methods: The initial sample consisted of 2872 CBCT scans of patients of both sexes. The parameters evaluated in this study were the location of the implants in the mandible, implant length, anatomical relationship of the implant with the mandibular canal, presence or absence of damage to the adjacent teeth, presence or absence of implant fractures, and presence or absence of bone support. Fisher's exact test was performed to compare the variables. The significance level was set at p = 0.05. Results: Out of 2872 CBCT scans, 214 images of patients with an average age of 44.5 years were included. The most frequent location of the implants was the posterior region (93.5%), with 54% of the implants having a length between 9 and 14 mm. It was found that 92% of the implants were positioned above the mandibular canal. Damage to adjacent teeth was observed, with no correlation with the implant positioning (p = 1.000). In 100% of cases of implants in the anterior region, there was bone support. Fracture was observed in 1.7% of implants with a length between 9 and 14 mm. Conclusions: The installation of implants in the mandible occurs more frequently in the posterior region, with a high presence of bone support and a low incidence of damage to adjacent teeth, anatomical structures, and fractures.

Metal artifact reduction tool and mA levels impact on the diagnosis of fracture extension in endodontically treated teeth using cone-beam CT.

AIM: To evaluate the influence of different levels of metal artifact reduction (MAR) tool and milliamperage (mA) on the diagnosis of fracture extension in endodontically treated teeth using cone beam CT (CBCT). MATERIALS AND METHODS: Ten maxillary premolars were endodontically treated and positioned in the empty sockets of a human maxilla covered with wax. CBCT acquisitions were performed using the Eagle Edge device (Dabi Atlante, Brazil) adjusted to 120 kVp, FOV of 4 × 6 cm, exposure time of 24 s and voxel size of 0.2 mm in 8 different conditions with different MAR (1, 2 and 3) and mA (3.2 and 6.3) levels. Crown-root fractures were simulated in the universal testing machine, and CBCT images were acquired again. Five radiologists evaluated the presence and extension of fractures with a 5-point scale. Statistical analysis was performed by analysis of variance, Tukey and Kappa test (α = 0.05). RESULTS: Although different mA levels did not significantly (p > 0.05) affect the diagnosis values for fracture presence and extension, when evaluated the different levels of MAR, AUC and sensitivity showed significantly higher values (p < 0.05) for MAR 0 using 6.3 mA and kappa agreement showed significantly higher values (p < 0.05) for MAR 0 and 2 using 6.3 mA. CONCLUSIONS: Although mA levels do not have a diagnostic effect when isolating the MAR level; in 6.3 mA, MAR 0 and 2 can positively influence the diagnosis of fracture extension in endodontically treated teeth using CBCT. CLINICAL RELEVANCE: The isolate evaluation of dental fracture presence can overlook diagnostics error of its extension.

Tomographic Evaluation of the Odontogenic Maxillary Myxoma. Case Report and Literature Review / Evaluación tomográfica del mixoma odontogénico en maxilar superior. Reporte de caso y revisión de la literatura

Odontogenic myxoma (OM) is a slow-growing, painless, aggressive and non-metastatic central jaw tumor of mesenchymal origin. Radiographically, it can vary from a unilocular radiolucent lesion to a multilocular lesion with well-defined or diffuse margins. The aim of this paper is to recognize the radiographic and tomographic characteristics of OM in a patient who attended the Dental Clinic of the Faculty of Dentistry of the Universidad Nacional Mayor de San Marcos in Lima-Peru. Case presentation: 86 year old male patient, who in the panoramic radiography indicated for his oral rehabilitation, a unilocular radiolucent image was found in the anterosuperior area with partially defined limits, corticalized edges and oval shape. In the volumetric tomography there was evidence of thinning and erosion of both bone tables, thinning of the floor of the nasal cavity. The radiolucent image seems to havean extension close to the alveolar ridge.In adition, there was an effacement of the cortices of the nasopalatine duct. The lesion was enucleated and an anatomopathological examination was performed. Diagnosis was odontogenic myxoma. The patient was evaluated at one year and six months with satisfactory results. The wide variety of radiographic characteristics of odontogenic myxoma leads us to think of a large number of differential diagnoses, being the histological evaluation together with the imaging analysis the ones that provide a definitive diagnosis. Although the anterosuperior area is the least common for its presentation, radiolucent images in this area should be considered as possible odontogenic myxomas, since this condition is more frequent in latín race.

El mixoma odontogénico (MO) es un tumor mandibular central de origen mesenquimal, de crecimiento lento, indoloro, agresivo y no metastásico. Radiográficamente, puede variar desde una lesión unilocular radiolúcida a una lesión multilocular con márgenes bien definidos o difusos. El objetivo de este trabajo es reconocer las características radiográficas y tomográficas del MO en un paciente que acudió a la Clínica Odontológica de la Facultad de Odontología de la Universidad Nacional Mayor de San Marcos en Lima-Perú. Presentación del caso: Paciente masculino de 86 años, en la radiografía panorámica indicada para rehabilitación oral, se encontró una imagen radiolúcida unilocular en la zona anterosuperior con límites parcialmente definidos, bordes corticalizados y forma ovalada. En la tomografía volumétrica se evidenció adelgazamiento y erosión de ambas tablas óseas, adelgazamiento del piso de la cavidad nasal, la imagen radiolúcida parece tener una extensión cercana a la cresta alveolar. Además, había un adelzamiento de las corticales del conducto nasopalatino. La lesión fue enucleada y se realizó un examen anatomopatológico. El diagnóstico fue mixoma odontogénico. La paciente fue evaluada al año y a los seis meses con resultados satisfactorios. La gran variedad de características radiográficas del mixoma odontogénico nos lleva a pensar en un gran número de diagnósticos diferenciales, siendo la evaluación histológica junto con el análisis de imagen los que proporcionan un diagnóstico definitivo. Aunque el área anterosuperior es la menos común para su presentación, las imágenes radiolúcidas en esta área deben ser consideradas como posibles mixomas odontogénicos, ya que esta condición es más frecuente en la raza latina.

Impact of CBCT acquisition protocols and artifact reduction filters on diagnosing vertical root fractures.

AIM: To evaluate the impact of acquisition protocols and artifact reduction filters in cone beam computed tomography on diagnosing vertical root fractures in endodontically treated teeth with and without intraradicular posts. MATERIALS AND METHODS: We analyzed 480 tomographic images acquired from two J. Morita scanners (0.125- and 0.08-mm voxel sizes protocols), with application of a blooming artifact reduction filter. Three evaluators assessed these images for root fractures using a 5-point Likert scale. Diagnostic accuracy between filters and protocols was determined using generalized linear models with binomial distribution for the outcome, considering protocol, filter, and dental status. Sensitivity, specificity, positive predictive value, and negative predictive value were also estimated for the filters and protocols. RESULTS: The 0.08-mm voxel size protocol demonstrated a significantly higher percentage of accurate diagnosis compared to the 0.125-mm protocol (p = .001). No statistically significant differences (p ≥ .087) were observed for filter application, interaction between protocol and filter, or dental status. Accuracy, sensitivity, and specificity values were respectively: .93, .87, 1.00 (protocol 1); .99, .99, .99 (protocol 2); .98, .96, .99 (no filter); .95, .90, 1.00 (with filter). CONCLUSION: The new findings found for the two J Morita scanners used in our study were that images acquired using the voxel size of 0.08 mm showed an improvement in the diagnosis of root fractures and the filters in these devices have no relevance significant for the diagnosis.

Nonsurgical Endodontic Treatment of Type II Dens Invaginatus in A Maxillary Lateral Incisor: A Case Report.

Dens invaginatus (DI) is one of the developmental dental anomalies that results in an invagination of the enamel organ into the dental papila during odontogenesis. The purpose of this study is to report a case of nonsurgical endodontic treatment of an Oehlers type II DI in a right maxillary lateral incisor with an extensive periapical damage, along with the two-year clinical and tomographic follow-up. A 30-year-old patient was referred for endodontic treatment of tooth #12. On clinical examination, a change in the shape and color of the crown was observed. The tooth responded negative to pulp sensibility, percussion, palpation and mobility tests. After tomographic evaluation, an Oehlers type II DI was visualized, in addition to an extensive periradicular lesion. The diagnosis was asymptomatic apical periodontitis. The treatment was carried out in two sessions, through intense enhancement of the auxiliary chemical substance with passive ultrasonic irrigation, XP-Endo Finisher and the use of hydroxide-based intracanal medication. Appropriate treatment in cases with anatomic variations requires an accurate and early diagnosis based on clinical examination and radiographic images. A two-year follow-up of the present case showed that the correct diagnosis associated with appropriate instrumentation techniques, supplementary disinfection, and adequate three-dimensional sealing of the canal with filling material, resulted in regression of the periradicular lesion and bone repair.

Guided Endodontic Treatment of Mandibular Incisor with Pulp Canal Obliteration following Dental Trauma: A Case Report.

Root canal obliteration is caused by hard tissue apposition and is often associated with teeth with a history of trauma, orthodontic movement, caries reaction, restorative procedures near the pulp chamber, and teeth of elderly patients. Preoperative planning of root canal treatment should be thorough and include an assessment of the patient's signs and symptoms in addition to the evaluation of complementary examinations. In a 27-year-old patient with dyschromia of the lower central incisor, a history of dental trauma, and a positive response to vertical percussion, an initial periapical radiograph was obtained that showed calcification of the canal and presence of a periapical lesion. The patient presented with pain on chewing, a positive response to palpation and a vertical percussion test. The diagnosis was symptomatic apical periodontitis. A cone-beam computed tomography scan was requested and a surface scan was performed to establish a static guide. The root canal was accessed in the middle third of the root and the canal was located using a minimally invasive approach. The root canal was treated conventionally. Results obtained showed the success of the treatment after a 3-year clinical and radiographic follow-up. Therefore, the use of an endodontic guide in cases of calcified canals significantly reduces the clinician's working time and offers a more predictable approach to the treatment of these pathologies.

Periodontal evaluation after maxillary expansion with a tooth-bone-borne expander in growing patients : A randomized clinical trial.

PURPOSE: This two-arm parallel randomized controlled trial aimed to evaluate and compare periodontal changes due to rapid maxillary expansion (RME) using tooth-bone-borne and tooth-borne devices in growing patients via clinical examinations and cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Forty-two eligible patients (aged 11-14 years; transverse maxillary deficiency, posterior crossbite) were screened and divided into two groups based on the treatment received (randomization was performed using computer-generated numeric sequences): hybrid hyrax tooth-bone-borne group (TBB) and hyrax tooth-borne group (TB). The primary outcome was the change in cortical bone thickness (by CBCT). In addition, the clinical attachment level (CAL), gingival recession, and bleeding were assessed. Both examinations were performed before and 3 months after the activation phase. Intergroup comparisons were performed using analysis of covariance (ANCOVA; P < 0.05). RESULTS: Twenty-one patients (12 girls and 9 boys; mean initial age, 13.3 years) were included in the TBB group and 21 (5 girls and 16 boys; mean initial age, 13.2 years) were included in the TB group. The TB group exhibited a decrease in buccal bone thickness in the first premolars and first molars at all three evaluated levels. Specifically, tooth 14 at 3 mm from the enamel-cement junction showed a significant width reduction (0.7 mm; p < 0.001), accompanied by a notable increase in palatal cortical thickness at 6 mm of enamel-cement junction (1.13 mm; p < 0.001). CONCLUSIONS: RME resulted in buccal bone thickness reduction at the first premolar with hyrax treatment. In the molar region, both devices resulted in cortical bone alterations that were less pronounced in the TBB group.

Variations in head tilt during the acquisition of CBCT scans and their effects on effective radiation dose.

OBJECTIVES: This study evaluated the impact of variations in anteroposterior and lateral tilts of patients' head on radiation-weighted doses to organs/tissues and effective doses using three different cone beam computed tomography machines. METHODS: An anthropomorphic phantom was used to estimate radiation doses in three CBCT machines (OP300, Eagle X 3D, and Eagle Edge). Thermoluminescent dosimeters were placed in regions corresponding to pre-stablished organ/tissues. CBCT examinations from the posterior mandible and anterior maxilla regions were acquired, with three different anteroposterior angulations (0°, 30°, and 45°), and from the posterior mandible in three different lateral angulations (0°, 20° to the left, and 20° to the right side). Radiation-weighted doses for each organ/tissue and effective doses were calculated for each machine and angulation. RESULTS: For the posterior mandible acquisitions, anteroposterior angulations of the head at 30° and 45° yielded a reduction in effective doses in all three devices. A 20° tilt to the right side resulted in lower doses than to the left (same side as the FOV). For the anterior maxilla, increased anteroposterior angulation was associated with reduction in effective dose in two devices. CONCLUSION: Effective doses are lower when small FOV CBCT exams of the posterior mandible and anterior maxilla are acquired with increased anteroposterior head angulation at 30° and 45°. For FOV in the posterior mandible, a 20° lateral tilt towards the side opposite to the FOV also yields lower effective doses. The main contribution to these dose reductions is the decrease in dose to salivary glands.

Localización Morfológica del Foramen Mental con Tomografía Computarizada Cone-Beam en San Luis Potosí, México / Morphological Location of the Mental Foramen with Cone-Beam Computed Tomography in San Luis Potosí, Mexico

El foramen mental, una abertura en la parte inferior de la mandíbula, es la salida de un ramo del nervio alveolar inferior, proporcionando sensibilidad a la mandíbula y la piel del mentón. Su variabilidad anatómica es importante en procedimientos dentales y quirúrgicos. Nuestro estudio en San Luis Potosí, México, examinó la posición y características morfológicas del foramen mental en una muestra de tomografías computarizadas de la mandíbula. En mujeres, la zona entre el primer y segundo premolar fue la más común, mientras que en hombres, fue la misma zona pero con mayor prevalencia en el lado izquierdo. Se observaron diferencias en la dirección del foramen mental entre sexos y lados de la mandíbula, con la dirección posterior predominante en ambos sexos. Estos hallazgos concuerdan con estudios previos en diferentes poblaciones, aunque se identifican variaciones significativas en la prevalencia y ubicación específica del foramen. La comparación con otros estudios resalta la importancia de considerar factores étnicos y geográficos en la interpretación de los resultados. Las diferencias anatómicas observadas tienen implicaciones clínicas importantes para procedimientos dentales y quirúrgicos, subrayando la necesidad de enfoques adaptados a la población específica para mejorar la precisión y seguridad de las intervenciones en el área del mentón.

SUMMARY: The mental foramen, an opening at the bottom of the jaw, is the exit of the inferior alveolar nerve branch, providing sensation to the jawbone and skin of the chin. Its anatomical variability is important in dental and surgical procedures. Our study was carried out in San Luis Potosí, Mexico and examined the position and morphological characteristics of the mental foramen in a sample of lower jaw CT scans. In women, the area between the first and second premolar was the most common, while in men, it was the same area but with a greater prevalence on the left side. Differences in the direction of the mental foramen were observed between sexes and sides of the mandible, with the posterior direction predominating in both sexes. These findings are consistent with previous studies in different populations, although significant variations in the prevalence and specific location of the foramen are identified. The comparison with other studies highlights the importance of considering ethnic and geographic factors in the interpretation of results. The anatomical differences observed have important clinical implications for dental and surgical procedures, underscoring the need for approaches tailored to the specific population to improve precision and safety of interventions in the mental foramen area.

Mandibular advancement device in obstructive sleep apnea treatment: what happens to the condyle position and patient response?

BACKGROUND: This study aims primarily to assess the mandibular condyles and patient response to MAD therapy using cone-beam computed tomography (CBCT). Also, the study proposes to analyze whether variations in condylar position, OSA severity and mandibular protrusion influence patient response. METHODS: 23 patients diagnosed with mild/moderate OSA and treated with MAD comprised the sample. Clinical, CBCT, and PSG assessments were conducted at baseline and with MAD in therapeutic protrusion (4-6 months of MAD use). The condyle position was vertically and horizontally evaluated at baseline and at the therapeutic protrusion. RESULTS: The condyle position significantly changed with MAD, showing anterior (7.3 ± 2.8 mm; p < 0.001) and inferior (3.5 ± 1 mm; p < 0.001) displacement. Patients with mild OSA required more protrusion (p = 0.02) for improvement. Responders exhibited a significantly prominent (p = 0.04) anterior baseline condyle position. A negative modest correlation was found between treatment response and baseline condyle anterior position (p = 0.03; r=-0.4), as well as between OSA severity and the percentage of maximum protrusion needed for therapeutic protrusion (p = 0.02; r=-0.4). The patient protrusion amount did not predict condylar positional changes. Neither condyle position, OSA severity, nor therapeutic protrusion were predictors of MAD treatment response. CONCLUSION: MAD resulted in anterior and inferior condylar displacement, and the amount of protrusion did not predict condylar positional changes. Responders showed a more anterior baseline condyle position. OSA severity and mandibular protrusion did not predict treatment response.