The Scalloped Surgical Guide as an Alternative to Flat Bone Reduction Guide in Full-Arch Implant Restoration.

The goal of this clinical report was to present an alternative to traditional flat bone reduction guides, using a custom-designed 3-dimensional (3D)-printed guide according to the future gingival margin of the planned dentition. A 61-year-old woman with concerns regarding her smile appearance was presented. The initial examination revealed excessive gingival show accompanied by excessive overjet. The dentition was in a failing situation. The proposed treatment plan, relying on the sufficient amount of bone and keratinized tissue, consisted of recontouring of the alveolar ridge and gingiva and placement of 6 implants and an FP-1 prosthesis after extraction of all remaining maxillary teeth. Digital smile design was completed, and a fully digitally guided surgery was planned. This consisted of using 3 surgical guides, starting with the fixation pin guide, continuing with the scalloped hard- and soft-tissue reduction guide, and finally the implant placement template. Following the surgery, the patient received a temporary restoration, and on the 4-month follow-up, a new polymethyl meta-acrylate temporary prosthesis was delivered. The patient's 7-month follow-up is presented in the article. The report of this triple-template guided surgery indicated that digital 3D planning is a considerably predictable tool to properly establish and evaluate future occlusal plane, smile line, and lip support. Scalloped guides seem to be an excellent alternative to conventional bone reduction guides since they require less bone removal and improve patient comfort during surgery.

The Accuracy of Guided Implant Surgery With Different Fields of View of Cone-Beam Computerized Tomography.

Although a smaller size field of view (FOV) of cone-beam computerized tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on 8 identical scannable models (maxillae and mandibles) were randomly allocated to 2 FOV sizes: test (5 × 5 cm) and control (10 × 10 cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully guided s-CAIS protocol. IOS captured the implant positions with the scan body attached. Implant-planning software measured the angular deviation, 3-dimensional (3D) deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way analysis of variance was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (P > .198) on angular deviation, 3D deviation at the crest, or 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT.

Evaluation of the follicular space volume of lower third molars with different impaction positions and angulations: A cone-beam computed tomography and histopathological study.

Objective: To quantify the volume of the follicular spaces of impacted lower third molars (ILTMs) with different impaction positions and angulations using cone-beam computed tomography (CBCT) and to determine its association with the histopathological findings. Study design: This study included 103 ILTMs of 33 men and 70 women aged 18-46 years (mean age, 29.18 years). The follicular space volumes were measured on CBCT by manual segmentation and correlated with the histopathological diagnosis of each ILTM having different impaction positions and angulations. Statistical Product and Service Solutions, version 24, was used for statistical analyses by applying the t-test and binary logistic regression and multiple linear regression tests (p < 0.05). Results: Overall, 83 (80.6%) dental follicles presented a non-pathological diagnosis (mean follicular volume, 0.10 cm3), whereas 20 (19.4%) presented a pathological diagnosis (mean follicular volume, 0.32 cm3; p = 0.001). Similarly, the impaction depth in Position C cases was associated with a pathological diagnosis (p = 0.010). Conclusion: The follicular volume of the ILTMs varied significantly in teeth with a histopathological diagnosis of a follicular cyst and was associated with the impaction depth, mainly in Position C cases, and its relationship with the mandibular ramus. A mean follicular volume of 0.32 cm3 was associated with a greater probability of a pathological diagnosis.

Is There a Correlation Between Airway Volume and Maximum Constriction Area Location in Different Dentofacial Deformities?

PURPOSE: The purpose of the present study was to correlate the airway volume and maximum constriction area (MCA) with the type of dentofacial deformity in patients who required orthognathic surgery. MATERIALS AND METHODS: The present retrospective cohort study included orthognathic surgery patients selected from the private practice of one of us. The selected cases were stratified into 5 different groups according to the clinical and cephalometric diagnosis of their dentofacial deformity. The preoperative airway volume and anatomic location of the MCA were calculated using the airway tool of the Dolphin Imaging software module (Dolphin Imaging and Management Solutions, Chatsworth, CA) and correlated with the diagnosed dentofacial deformity. Differences in the pretreatment airway volumes and MCA location were compared among the deformities. RESULTS: The MCA location was more often the nasopharynx for maxillary deficiency and the oropharynx for mandibular deficiency deformities. The nasopharynx volume was significantly smaller statistically (P < .005) for maxillary deficiency plus mandibular excess compared with mandibular deficiency. The hypopharynx volume was significantly smaller statistically (P < .005) for vertical maxillary excess plus mandibular deficiency than for both maxillary deficiency and maxillary deficiency plus mandibular excess. No statistically significant difference was found among the different deformity groups in relation to the mean airway volume (P > .005). CONCLUSIONS: The location of the airway MCA seems to have a strong correlation with the horizontal position of the maxilla and mandible. The MCA in maxillary deficiencies (isolated or combined) was in the nasopharynx, and the MCA in mandibular deficiencies (isolated or combined) was in the oropharynx. Clinicians should consider these anatomic findings when planning the location and magnitude of orthognathic surgery movements to optimize the outcomes.

Validity of flexicurve for the assessment of spinal flexibility in asymptomatic individuals / Validade do flexicurva na avaliação da flexibilidade da coluna vertebral em indivíduos assintomáticos / Validez del flexicurve en la evaluación de la flexibilidad de la columna vertebral en individuos asimomáticos

Abstract Introduction: Spine problems are common, and assessment of spine flexibility provides relevant information; however, alternative evaluation methods need to be validated. Objective: To evaluate the concurrent validity of the Flexicurve using 3D videogrammetry as a reference value to assess spinal flexion and extension in the lumbar and thoracic regions. Method: The consecutive sample consisted of 39 individuals aged between 18 and 50 years. Two consecutive evaluations were performed by the same rater on the same day and at the same location: (1) Flexicurve and (2) 3D videogrammetry. The assessments were performed with the spine in the neutral position, followed by maximum flexion and extension. The range of motion (ROM) in the maximum flexion and extension positions was calculated in MATLAB® and defined as the difference between the maximum flexion or extension angle and that of the neutral position. Statistical analyses used were the Pearson Product-Moment Correlation coefficient, RMS error and Bland-Altman plot (α < 0.05). Results: The ROM between instruments was similar, with high correlations for thoracic flexion (r = 0.751), extension (r = 0.814) and lumbar flexion (r = 0.853), and RMS errors under 8°. The correlation for lumbar extension was moderate (r = 0.613) and the RMS error was more than 10°. The limits of agreement varied between ± 10º and ± 21º. Conclusion: The Flexicurve is valid for assessing maximum flexion and extension of the thoracic spine, and maximum flexion of the lumbar spine. We suggest caution in evaluating the maximum extension of the lumbar spine.

Resumo Introdução: Problemas na coluna vertebral são frequentes, sendo a avaliação da flexibilidade uma informação relevante a ser considerada pelo profissional. Métodos alternativos para realizar avaliação da flexibilidade da coluna carecem de validação. Objetivo: Avaliar a validade concorrente do Flexicurva utilizando a videogrametria 3D como medida de referência, para a avaliação da flexibilidade em flexão e extensão da coluna vertebral torácica e lombar. Método: A amostra consecutiva contou com 39 indivíduos com idades entre 18 e 50 anos. Duas avaliações consecutivas foram realizadas pelo mesmo avaliador no mesmo dia e local: (1) Flexicurva e (2) videogrametria 3D. As avaliações foram realizadas com a coluna na posição neutra, seguida das posições de flexão e extensão máximas. A ADM nas posições de flexão e extensão máximas foram calculadas no MATLAB®, sendo definida como a diferença entre os ângulos máximos de flexão ou extensão e a angulação da posição neutra. Na análise estatística utilizou-se: Teste de Correlação Produto-Momento de Pearson, Erro RMS e Análise de Bland-Altman. (α < 0,05). Resultados: Os valores de ADM entre os instrumentos foram similares, com correlações altas para a flexão torácica (r = 0,751), extensão torácica (r = 0,814) e para flexão lombar (r = 0,853), com erros RMS inferiores a 8°. Para a extensão lombar a correlação foi moderada (r = 0,613), com erro RMS superior a 10°. Limites de concordância variaram entre ± 10º e ± 21º. Conclusão: O Flexicurva mostrou-se válido para avaliar o movimento flexão máxima e extensão máxima da coluna torácica, e flexão máxima da coluna lombar. Sugerimos cautela na avaliação da extensão máxima da coluna lombar.

Resumen Introducción: Los problemas en la columna vertebral son frecuentes, siendo la evaluación de la flexibilidad de la columna vertebral una información relevante a ser considerada por el profesional. Los métodos alternativos para realizar la evaluación de la flexibilidad de la columna necesitan validación. Objetivo: Evaluar la validez concurrente del Flexicurva utilizando la videogrametría 3D como medida de referencia para evaluar la flexión y extensión de la columna en las regiones lumbar y torácica. Método: La muestra consecutiva consistió en 39 individuos de edades comprendidas entre 18 y 50 años. El mismo evaluador realizó dos evaluaciones consecutivas en el mismo día y local: (1) Flexicurve (2) Videogrametría 3D. Las evaluaciones se realizaron con la columna en posición neutral seguida de la máxima flexión y extensión. El RDM en la posición máxima de flexión y extensión se calculó en MATLAB®, la flexión máxima y la extensión se definieron como la diferencia entre el ángulo de la posición con respecto al punto neutro. Los análisis estadísticos consistieron en la prueba de correlación de producto-momento de Pearson, error de RMS y los análisis de Bland-Altman (α < 0,05). Resultados: Los valores de RDM entre instrumentos fueron similares, con altas correlaciones para flexión torácica (r = 0.751), extensión torácica (r = 0.814) y flexión lumbar (r = 0.853), y errores RMS por debajo de 8°. Para la extensión lumbar, se moderó la correlación (r = 0,613) y el error RMS fue superior a 10°. Los límites de concordancia variaron entre ± 10º y ± 21º. Conclusión: El Flexicurva se mostró válido para evaluar la flexión máxima y la extensión máxima de la columna torácica, y la flexión máxima de la columna lumbar. Sugerimos precaución al evaluar la extensión máxima de la columna lumbar.

In-House Digital Workflow for the Management of Acute Mandible Fractures.

Computer-aided design and additive manufacturing are revolutionizing oral and maxillofacial surgery. Current methods use virtual surgical planning sessions and custom plate milling via third-party vendors, which is costly and time-consuming, negating the effectiveness in acute facial trauma. This technical note describes a state-of-the-art in-house expedited digital workflow for computer-aided virtual fracture reduction, 3-dimensional printing, and preoperative reconstruction plate adaptation for the management of an acute mandible fracture. This process uses the computed tomographic scan a patient receives in the emergency department or clinic. The DICOM (Digital Imaging and Communications in Medicine) data are transferred into US Food and Drug Administration-approved software, in which the fracture is segmented and virtually reduced based on condylar position, midline symmetries, and occlusion if present. The reduced mandible is then printed, which serves as a template for preoperative reconstruction plate adaptation. This method facilitates a virtually reduced fractured mandible, 3-dimensionally printed model, and ideally adapted plates ready for sterilization before surgery within 2 hours after DICOM upload.

Transference of virtual planning and planning over biomedical prototypes for dental implant placement using guided surgery.

OBJECTIVES: This study evaluated the transference of virtual planning and planning over biomedical prototypes for dental implant placement using guided surgery. MATERIAL AND METHODS: This experiment was conducted with 11 identical replicas of a human edentulous mandible. For each mandible, models and surgical guides were manufactured using stereolithography. Simulated surgeries were performed on the prototypes. Following this, the implants were placed in the mandible replicas. Superposition of the tridimensional pre- and postoperative models was used for virtual evaluation. The real evaluation was conducted by linear measurements directly on the models. RESULTS: The variations in angles and distances between the coronal, central and apical regions of the 22 implants evaluated in this study had mean values <1.45 degrees and 0.41 mm. The correlations between the positions of implant beds in each mandible were fair to very good, according to the distance analyzed and the interpretation guidelines used. CONCLUSIONS: According to the results of this study, the variations found in the transference of dental implant positioning to the operative field, determined during virtual planning and obtained in surgeries simulated with biomedical prototypes, confirm the reliability of guided surgery techniques in implantology.

Measuring cortical thickness on panoramic radiographs: a validation study of the Mental Index.

OBJECTIVES: To validate the Mental Index assessment obtained from panoramic radiographs. STUDY DESIGN: Ten dried mandibles were selected, and standardized panoramic radiographs were obtained. The specimens were then perpendicularly sectioned at the mental foramen region, and the inferior mandibular cortical thickness was recorded using a digital caliper. Measurements of panoramic radiographs were compared with the dried mandibles. Four observers carried out twice the measurements for the panoramic radiographs. Two observers performed twice the measurements of the dried mandibles. Reliability was assessed by duplicate measurements. RESULTS: Agreement between the actual mandible measurements and the radiographic assessment was moderate for the noncorrected measurements. Agreement between anatomic and radiographic measurements improved remarkably after standard correction for magnification. CONCLUSIONS: Bone status reports based on measuring cortical thickness of the lower border of the mandible at the mental foramen based on panoramic radiographs, i.e., Mental Index, are accurate. Compensation for magnification, however, is necessary.

Mandibular morphological changes in low bone mass edentulous females: evaluation of panoramic radiographs.

OBJECTIVE: The objective of this study was to evaluate morphological changes of the mandible in osteopenic and osteoporotic edentulous females. STUDY DESIGN: Fifty-two female edentulous patients underwent panoramic radiography and dual-energy x-ray absorptiometry of the lumbar spine and femoral neck. Measurements of the gonial angle, antegonial angle, antegonial depth, antegonial index (AI), and mental index (MI) were performed. Patients were classified as normal (T-score > -1.0), osteopenic (T-score of -1.0 to 0 -2.5), or osteoporotic (T-score < -2.5). RESULTS: The gonial angle did not show differences among the three categories of skeletal bone status (P > .05). The antegonial angle was significantly smaller in individuals with low bone mass (P < .05). The antegonial depth was significantly greater in osteoporotic (P < .05) and osteopenic individuals (P < .05). The AI and MI were significantly smaller in individuals with low bone mass (P < .05); however, after age adjustment there were no differences among the groups (P > .05). CONCLUSIONS: Edentulous females with low bone mass have a deeper antegonial region. The thickness of the cortical mandibular bone is highly influenced by age.

Correlação entre a radiografia panorâmica e tomografia computadorizada na avaliação das alturas ósseas no planejamento em implantodontia / Correlation between panoramic radiograph and computed tomography measurements for the evalution of vertical bone height in oral implantology

O objetivo deste trabalho é avaliar a correlação entre a altura óssea medida em radiografias panorâmicas e tomografias computadorizadas para a avaliação pré-operatória de implantes osseointegrados. Cinqüenta sítios na região do forame mentual de pacientes que previamente realizaram tomografia computadorizada e radiografia panorâmica para planejamentode implantes osseointegrados nas regiões posteriores da mandíbula foram analisados. A comparação entre a TC e a radiografia panorâmica apresentou uma concordância moderada, sendo que a TC sistematicamente apresentou valores menores que as medições realizadas na radiografia panorâmica, sendo essa diferença (1,6 a 1,7mm) estatisticamente significante (p<0,0001). Os autores sugerem a utilização de uma margem de segurança de 2mm na região de forame mentual, após a compensação da magnificação da imagem, quando for utilizada a radiografia panorâmica

Radiomorphometric indices and their relation to gender, age, and dental status.

OBJECTIVES: To evaluate the antegonial index (AI) and the mental index (MI) in edentulous and dentate patients, in different age groups and between genders. STUDY DESIGN: We evaluated 312 panoramic radiographs and grouped them into 4 10-year age groups. Gender, dentition status and age were recorded. The measurements were performed by 2 researchers independently. RESULTS: The AI and MI were significantly smaller in older females, whereas they were greater for older males (P < 0.01). Edentulous individuals had a lower AI than dentate and partially dentate individuals (P < 0.01). CONCLUSIONS: There is a continuous remodelling in the mandibular cortex with age and this is influenced by dental status and gender. The difficulty of measuring the AI in a reproducible manner, its interaction with dental status and low correlation with MI in younger patients should discourage its use in detecting patients at risk of osteoporosis.

A utilização da ressonância magnética nuclear em Odontologia: revisão da literatura e relato de caso / The use of nuclear magnetic ressonance in Dentistry: review of the literature and case presentation

Os autores revisam a literatura sobre a utilização da ressonância magnética nuclear em Odontologia, seu estágio atual e suas perspectivas futuras, apresentando um caso clínico

Carcinoma do intestino grosso: análise de 93 caso / Large bowel carcinoma: a critical review of 93 cases

É apresentada a análise de 93 casos de carcinoma do intestino grosso. Os tumores foram divididos de acordo com a sua localizaçäo, havendo uma incidência maior dos mesmos no colón esquerdo. Dezessete casos eram de tumores inoperáveis. Entre os operáveis, 43 situavam-se no cólon, 27 no reto e junçäo retossigmoidiana e seis estavam no canal anal e regiäo perinatal. Cerca de 53 tumores do cólon e reto foram classificados no estágio C de Dukes. É feito um breve relato do método de preparo de cólon usado. A conduta cirúrgica nos tumores do intestino grosso é relatada, assim como o tratamento coadjuvante com quimioterapia. Em alguns pacientes foi realizada dosagem de antígeno cárcino-embrionário (CEA), para avaliar a evoluçäo