Maxillofacial CT Research Articles

Effects of clear aligners combined with maxillary protractor on mixed dentition patient with skeletal class Ⅲ malocclusion: a finite element study

Objective: To compare the effects of expansion screw with maxillary protractor and clear aligners combined with maxillary protractor on the maxilla and maxillary dentition of mixed dentition patients with class Ⅲ skeletal malocclusion using finite element analysis, further providing clinical guidance for clear aligner treatment. Methods: A finite element model was established based on maxillofacial cone-beam CT data of a 10-year-old boy with mixed dentition, class Ⅲ skeletal malocclusion, who visited Department of Orthodontics, School of Stomatology, The Fourth Military Medical University in January, 2024. The expander with protractor group (group A) and the clear aligners with protractor group (group B) were divided. The arch was extended by 0.25 mm in both groups, and the forward pull force was 2.94 N (working condition 1) and 4.90 N (working condition 2), respectively. The initial displacement trend of maxilla and maxillary dentition in two groups under two working conditions were evaluated. Results: Under two working conditions, the maxilla of both groups showed clockwise rotation and labial inclination. The labial inclination of maxilla was more significant in clear aligners with protractor group, about 2.2-3.0 times that of expander with protractor group under the same working condition. Maxillary dentition showed mesial and buccal displacement, with anterior teeth extrusion and posterior teeth intrusion in two groups under two working conditions. Under the working condition 1 and 2, the labial displacement of central incisor of clear aligners with protractor group (-0.065, -0.089 mm) were greater than that in expander with protractor group (-0.024, -0.024 mm). Under two working conditions, the posterior teeth of expander with protractor group moved close to the buccal bodily direction, while those of clear aligners with protractor group moved tilted towards the buccal direction in the horizontal direction. The forward displacement trend of maxilla and maxillary dentition in clear aligners with protractor group was more obvious than expander with protractor group with the increase of the forward pull force. Under two working conditions, the anterior teeth' s hydrostatic stress of periodontal membrane and the equivalent stress of alveolar bone in clear aligners with protractor group were higher than those in expander with protractor group, mainly concentrated on the labial cervical region of the incisor. Conclusions: Clear aligners combined with maxillary protractor can produce forward force on the maxilla, but labial inclination occurs in the anterior teeth. It can be an effective orthopedic treatment strategy for mixed dentition patients with class Ⅲ skeletal malocclusion.

Soft tissue inflammation around upper third molar cause limited mouth opening: common but overlooked.

The aim of this study was to explore inflammation of soft tissue around the upper third molar as a prevalent cause of limited mouth opening, identify the clinical and radiographic features, and summarize the therapeutic effectiveness of tooth extraction. A retrospective analysis of data from 264 patients with limited mouth opening over the last five years was performed. Among the 264 patients, 24 (9.1%) had inflammation of the soft tissue around the upper third molar, which was the second most common cause of limited mouth opening. Twenty-one of the twenty-four affected patients, with an average mouth opening of 19.1 ± 7.6mm, underwent upper third molar extraction. Gingival tenderness around the upper third molar or maxillary tuberosity mucosa was a characteristic clinical manifestation (p < 0.05). The characteristic features on maxillofacial CT included soft tissue swelling around the upper third molar and gap narrowing between the maxillary nodules and the mandibular ascending branch. Post extraction, the average mouth opening increased to 31.4 ± 4.9mm (p < 0.05), and follow-up CT demonstrated regression of the inflammatory soft tissue around the upper third molar. Inflammation of soft tissue around the upper third molar is a common cause of limited mouth opening. Symptoms of pain associated with the upper third molar and distinctive findings on enhanced maxillofacial CT scans are crucial for diagnosis. Upper third molar extraction yields favorable therapeutic outcomes. Inflammation of the soft tissue around the maxillary third molar commonly causes limited mouth opening, but this phenomenon has long been overlooked. Clarifying this etiology can reduce the number of misdiagnosed patients with restricted mouth opening and enable more efficient treatment for patients.

Application of mixed reality technology in free fibular flap transplantation for repairing mandibular defects

To explore the feasibility and effectiveness of mixed reality technology for localizing perforator vessels in the repair of mandibular defects using free fibular flap. Between June 2020 and June 2023, 12 patients with mandibular defects were repaired with free fibular flap. There were 8 males and 4 females, with an average age of 61 years (range, 35-78 years). There were 9 cases of ameloblastomas and 3 cases of squamous cell carcinomas involving the mandible. The disease duration ranged from 15 days to 2 years (median, 14.2 months). The length of mandibular defects ranged from 5 to 14 cm (mean, 8.5 cm). The area of soft tissue defects ranged from 5 cm×4 cm to 8 cm×6 cm. Preoperative enhanced CT scans of the maxillofacial region and CT angiography of the lower limbs were performed, and the data was used to create three-dimensional models of the mandible and lower limb perforator vessels. During operation, the mixed reality technology was used to overlay the three-dimensional model of perforator vessels onto the body surface for harvesting the free fibular flap. The length of the fibula harvested ranged from 6 to 15 cm, with a mean of 9.5 cm; the size of the flap ranged from 6 cm×5 cm to 10 cm×8 cm. The donor sites were sutured directly in 7 cases and repaired with free skin grafting in 5 cases. Thirty perforator vessels were located by mixed reality technology before operation, with an average of 2.5 vessels per case; the distance between the exit point of the perforator vessels located before operation and the actual exit point ranged from 1 to 4 mm, with a mean of 2.8 mm. All fibular flaps survived; 1 case had necrosis at the distal end of flap, which healed after dressing changes. One donor site had infection, which healed after anti-inflammatory dressing changes; the remaining incisions healed by first intention, and the grafts survived smoothly. All patients were followed up 8-36 months (median, 21 months). The repaired facial appearance was satisfactory, with no flap swelling. Among the patients underwent postoperative radiotherapy, 2 patients had normal bone healing and 1 had delayed healing at 6 months. In free fibular flap reconstruction of mandibular defects, the use of mixed reality technology for perforator vessel localization can achieve three-dimensional visualization, simplify surgical procedures, and reduce errors.

FRI357 A Rare Case Of Paraneoplastic Syndrome Of Inappropriate Secretion Of Antidiuretic Hormone In Oropharyngeal Squamous Cell Carcinoma

Abstract Disclosure: N. Torres: None. H. Rios: None. G. Rios: None. Y. Medina: None. L. Valerio: None. S. Rosa: None. A. Ortiz: None. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by hyponatremia that results from water retention attributable to persistent arginine vasopressin release. SIADH is considered the most common cause of euvolemic hyponatremia. Head and neck cancers are linked with 1.5% of SIADH cases. Cases reported in the literature about this association with oropharyngeal squamous cell carcinoma (SCC) were few, and no incidence data is currently available. We present a rare case of a patient with SIADH secondary to well-differentiated oropharyngeal squamous cell carcinoma. A case of 63 y/o male with Oropharyngeal SCC, previous gastrostomy, and tracheostomy due to malignancy. The patient initially presented with general malaise and weakness. Maxillofacial and neck CT scans were remarkable for a mass at the left lateral floor of the mouth, measuring approximately 5.7 cm AP x 2.5 cm transverse x 3.7 cm CC. Physical examination was remarkable for cachexia, but normal skin turgor and moist oral mucosa. An incidental finding of severe hyponatremia of 114 mEq was found. Confirmation of hypotonic euvolemic hyponatremia was performed with a urine osmolality of &amp;gt;100 mOsm per kg and high urine sodium (&amp;gt;40 mEq). These findings presented a strong case for our differential diagnosis of SIADH. Other differential diagnoses were hypothyroidism or adrenal insufficiency. The patient’s thyroid stimulating hormone was within normal levels, and adrenal insufficiency workup was negative, making paraneoplastic SIADH the more likely diagnosis due to SCC. Initial treatment was started with a 3% hypertonic solution drip running at 15 ml/hr. The chemistry panel was monitored every six hours to achieve a 6 mEq change, at a slow rate to avoid osmotic demyelination syndrome, a goal of 122 mEq. Sodium was corrected in 24 hours; 3% saline solution drip was discontinued. Once this level was reached, we continued the fluid restriction (&amp;lt;1L daily), and salt packets with meals. After consultation, Nephrology and Endocrinology services agreed with our diagnosis of hypotonic euvolemic hyponatremia due to ectopic production of paraneoplastic SIADH due to the oropharyngeal SCC. The patient’s hypotonic euvolemic hyponatremia was corrected, symptoms improved, and he was discharged with close follow-up with Hematology/Oncology, Nephrology, and Endocrinology services. Paraneoplastic SIADH due to squamous cell carcinoma is rarely observed in the hospital setting. It is important to consider paraneoplastic SIADH from SCC in the differential diagnosis of hypotonic euvolemic hyponatremia since early diagnosis and treatment can decrease long-term complications. We could have also considered pharmacological therapy for SIADH including the use of demeclocycline, vaptans, and furosemide if the patient had not responded to our interventions. We followed guideline therapy with intravenous hypertonic saline at the start, then transitioned to only using oral salt tablets and fluid restrictions. The patient's hyponatremia steadily improved with our interventions and was able to be discharged with close outpatient follow-up. Presentation: Friday, June 16, 2023

THU446 A Case Of Isolated Osteonecrosis Of Torus Palatinus In A Patient On Alendronate

Abstract Disclosure: A.A. Noor: None. A. Zia: None. B. Hoard: None. K. Romo: None. S. Bhamre: None. M. Gabriel: None. S. Shu: None. R. Ozolins: None. T. Pulisetty: None. G.I. Uwaifo: None. Introduction: Osteonecrosis of the jaw (OJN) is a rare complication of bisphosphonate and RANKL inhibitor use. Most cases have been described in cancer or immunocompromised patients using high dose parenteral therapy, but have even more rarely been described with oral bisphosphonate (OBP) use. The estimated risk is 1 in 10,000 to 1 in 100,000 patient-years in patients taking OBP for osteoporosis. We describe a case isolated osteonecrosis of torus palatinus (OTP) in a patient with long-term use of OBP (alendronate) for postmenopausal osteoporosis. Case Report: 75-year-old female with a history of torus palatinus (TP), osteoporosis, fibromyalgia, echondromas of humerus, degenerative disc disease, and spinal stenosis initially presented at a primary care clinic with three weeks of inflamed, painful, red, and swollen oral ulcer; associated with exudative tonsillitis. She finished an antimicrobial course which improved tonsillitis, but the oral ulcer persisted. She was on alendronate 70 mg weekly for ∼ three years prior to symptom onset. Examination showed a nearly 1 cm shallow ulcer on the left aspect of her large TP with associated erythema and tenderness to palpation. The rest of the oral cavity was normal. She was given triamcinolone paste for two weeks. Follow-up 1 month later showed progression of ulcer down to bone underlying the TP. The mucosa of the TP was erythematous, thickened, and tender. Given the lack of resolution after antimicrobials and topical steroids, a biopsy was done which showed squamous mucosa with reactive changes, hyperkeratosis, and chronic inflammation, but negative for dysplasia or malignancy. Maxillofacial CT showed, “a lobulated bony mass in the roof of the mouth consistent with TP with left-central heterogeneous density and cortical bone thinning without soft tissue mass or extension. Due to suspicion for osteomyelitis and possible underlying malignancy, lesion excision, and debridement was done. Alendronate was stopped at this point. Excisional biopsy showed necrotic bone consistent with OTP with associated acute and chronic osteomyelitis. She was treated with four weeks of metronidazole and two weeks of fluconazole. The postoperative course was uneventful, with appropriate healing. Conclusion: While OJN is uncommon in setting of OBP use, among patients with TP and other bone overgrowth states high index of suspicion is needed for bony lesions developing in such patients. The possibility of OTP development should be considered with appropriate oral complaints among OBP users with TP. Further retrospective analyses to ascertain how prevalent this uncommon condition is would provide much needed clinical information. Presentation: Thursday, June 15, 2023

Three-dimensional finite element study on the effects of maxillary anterior two-step retraction and en-masse retraction with clear aligners

Objective: To investigate the effects of two-step retraction and en-masse retraction on tooth movement pattern of anterior teeth and posterior anchorage with clear aligners using three-dimensional finite element analysis. Methods: A finite element model of maxillary first premolar extraction case undergoing clear aligner treatment was established based on maxillofacial cone-beam CT data of a 24-year-old adult male with individual normal occlusion, who visited Department of Oral Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine for impacted mandibular third molar in June, 2022. The initial tooth displacement of five anterior retraction protocols (two-step with canine retraction, two-step with incisor bodily retraction, two-step with incisor retraction-overtreatment, en-masse bodily retraction, and en-masse retraction-overtreatment) were evaluated. Results: Two step with canine retraction caused distal tipping of the canine and labial tipping of the incisors (0.18° for central incisor and 0.13° for lateral incisor). Two step with incisor retraction caused mesial tipping of the canine. In two step with bodily retraction protocol, uncontrolled lingual tipping was found in central incisor (0.29°) and lateral incisor (0.32°). In two-step with incisor retraction-overtreatment protocol, the movement pattern of the incisors didn't change, but the inclinations reduced to 0.21° and 0.18°. En-masse retraction caused distal tipping of the canine. In en-masse bodily retraction protocol, uncontrolled lingual tipping was also found in central incisor (0.19°) and lateral incisor (0.27°). In en-masse retraction-overtreatment protocol, the central incisor showed controlled lingual tipping (0.02°) and the lateral incisor showed palatal root movement (0.03° labial inclination). Posterior teeth exhibited mesial tipping in all five protocols. Conclusion: En-masse retraction with incisor overtreatment was beneficial to incisor torque control in clear aligner treatment.

Motion Correction for Separate Mandibular and Cranial Movements in Cone Beam CT Reconstructions.

Patient motions are a repeatedly reported phenomenon in oral and maxillofacial cone beam CT scans, leading to reconstructions of limited usability. In certain cases, independent movements of the mandible induce unpredictable motion patterns. Previous motion correction methods are not able to handle such complex cases of patient movements. Our goal was to design a combined motion estimation and motion correction approach for separate cranial and mandibular motions, solely based on the 2D projection images from a single scan. Our iterative three-step motion correction algorithm models the two articulated motions as independent rigid motions. First of all, we segment cranium and mandible in the projection images using a deep neural network. Next, we compute a 3D reconstruction with the poses of the object's trajectories fixed. Third, we improve all poses by minimizing the projection error while keeping the reconstruction fixed. Step two and three are repeated alternately. We find that our marker-free approach delivers reconstructions of up to 85% higher quality, with respect to the projection error, and can improve on already existing techniques, which model only a single rigid motion. We show results of both synthetic and real data created in different scenarios. The reconstruction of motion parameters in a real environment was evaluated on acquisitions of a skull mounted on a hexapod, creating a realistic, easily reproducible motion profile. The proposed algorithm consistently enhances the visual quality of motion impaired CBCT scans, thus eliminating the need for a re-scan in certain cases, considerably lowering radiation dosage for the patient. It can flexibly be used with differently sized regions of interest and is even applicable to localtomography. This article is protected by copyright. All rights reserved.

Treatment of mild hemifacial microsomia in children by autologous nano-fat mixed granule fat transplantation

To investigate the effectiveness of autologous nano-fat mixed granule fat transplantation in the treatment of facial soft tissue dysplasia in children with mild hemifacial microsomia (HFM). A total of 24 children with Pruzansky-Kaban type Ⅰ HFM were admitted between July 2016 and December 2020. Among them, 12 children were treated with autologous nano-fat mixed granule fat (1∶1) transplantation as study group and 12 with autologous granule fat transplantation as control group. There was no significant difference in gender, age, and affected side between groups ( P>0.05). The child's face was divided into region Ⅰ(mental point-mandibular angle-oral angle), region Ⅱ (mandibular angle-earlobe-lateral border of the nasal alar-oral angle), region Ⅲ (earlobe-lateral border of the nasal alar-inner canthus-foot of ear wheel). Based on the preoperative maxillofacial CT scan+three-dimensional reconstruction data, the differences of soft tissue volume between the healthy and affected sides in the 3 regions were calculated by Mimics software to determine the amount of autologous fat extraction or grafting. The distances between mandibular angle and oral angle (mandibular angle-oral angle), between mandibular angle and outer canthus (mandibular angle-outer canthus), and between earlobe and lateral border of the nasal alar (earlobe-lateral border of the nasal alar), and the soft tissue volumes in regions Ⅰ, Ⅱ, and Ⅲ of healthy and affected sides were measured at 1 day before operation and 1 year after operation. The differences between healthy and affected sides of the above indicators were calculated as the evaluation indexes for statistical analysis. At 1 year after operation, the parents, the surgeons, and the nurses in the operation group made a self-assessment of satisfaction according to the frontal photos of the children before and after operation. The study group and the control group were injected with (28.61±8.59) and (29.33±8.08) mL of fat respectively, with no significant difference ( t=0.204, P=0.840). After injection, 1 child in the control group had a little subcutaneous induration, and no related complications occurred in the others. All children in both groups were followed up 1 year to 1 year and 6 months, with an average of 1 year and 4 months in the study group and 1 year and 3 months in the control group. At 1 year after operation, the asymmetry of the healthy and affected sides improved in both groups; the satisfactions of parents, surgeons, and nurses in the study group were all 100% (12/12), while those of the control group were 100% (12/12), 83% (10/12), and 92% (11/12), respectively. The differences between healthy and affected sides in mandibular angle-oral angle, mandibular angle-outer canthus, earlobe-lateral border of the nasal alar, and the soft tissue volume in 3 regions of the two groups after operation were significantly smaller than those before operation ( P<0.05). There was no significant difference in the above indexes between the two groups before operation ( P>0.05). After operation, all indexes were significantly lower in study group than in control group ( P<0.05). Autologous nano-fat mixed granule fat transplantation and autologous granule fat transplantation can both improve the facial soft tissue dysplasia in children with mild HFM, and the former is better than the latter.

Study on static parameters of internal nasal valve in 3-dimensional model of nasal cavity space

Objective: To identify the internal nasal valve (INV) and to evaluate its key parameters in the established 3D models of nasal cavity space via Mimics from CT images, in order to provide evidence for quantitative diagnosis of nasal valve compromise. Methods: A total of 32 Han adults without nasal diseases who underwent maxillofacial CT test in Shanghai Ninth People's Hospital from January 2015 to December 2018 were retrospectively recruited, including 16 males and 16 females, with the age ranged from 20 to 80 years (50% age<50 years old). Maxillofacial CT images were used to create 3D model of nasal cavity space. The INV was identified and the following parameters were measured: the angle between the INV and the nasal bone (θINV-B), unilateral cross-sectional area of the INV (AINV-R, AINV-L), total cross-sectional area of the INV (AINV), unilateral height of the INV (HINV-R, HINV-L), unilateral nasal valve angle (αINV-R, αINV-L), and the sum of nasal valve angle (αINV). The AINV in our study was compared with the results of the previously adopted planes (PlaneC, perpendicular to the hard palate and PlaneB, plane perpendicular to the nasal bone). The parameters above were compared among genders, age and race groups. SPSS 26 and GraphPad Prism 9 software were used for statistical analysis and mapping of data. Results: The AINV in our study was (214.87±52.94) mm², which was significantly less than that of PlaneC (254.97±47.80) mm² and PlaneB (226.07±57.36) mm². The measured parameters were as follows: θINV-B was (82.07±7.06)°; AINV-R was (112.66±31.39) mm²; AINV-L was (102.21±27.14) mm²; AINV was (214.87±52.94) mm²; HINV-R was (24.87±4.62) mm; HINV-L was (24.35±4.86) mm; αINV-R was (20.48±2.99)°; αINV-L was (19.65±3.82)°; αINV was (40.13±6.24)°. The AINV-R was larger than AINV-L (t=2.33, P<0.05); The HINV, AINV-R, AINV-L and AINV of males were more than those of females (t value was 5.77, 3.21, 2.91 and 3.52, respectively, all P<0.01). The AINV of the young group (<50 years) was larger than that of the old group (t=2.83, P<0.01); The θINV-B was different between the Han people and the Caucasian (t=2.92,P<0.01). The αINV of the Han people was larger than that of Caucasians (Z=-6.92, P<0.01), but the HINV was smaller (Z=-3.89, P<0.01). Conclusion: The AINV carried out in 3D models of nasal cavity space is significantly smaller than that obtained by the previous methods of CT evaluation. INV static parameters differ among genders, age and race groups.

Az MRI története, dinamikus szájüregi és maxillofaciális alkalmazása

The incredible evolution of medicine in the 20th century was made possible by the appearance and rapid innovation of diagnostic procedures. The discovery of the medical application of X-rays gave the opportunity to image the human body without disrupting tissue structure. The use of X-rays spread around the world at an incredible speed and almost all medical fields, including dentistry, began to use them. In the second half of the 20th century, exponential improvement of computing technology replace the summation scans with a new three-dimensional technique, Computer Tomography. Cone Bean CT scanners (CBCT), which use a non-traditional cone-shaped beam as a radiation source, have made three-dimensional imaging widely available in dentistry. However, the harmful side effects of X-rays soon came to the attention of the public, and further research led to the development of a previously unknown technique, magnetic resonance imaging (MRI). This device was the result of the collaborative work of many scientists, mainly physicists. From the experiment by Isiodor I. Rabi, who proved that the atomic spin of nuclei can be changed in a magnetic field, to the scientists involved in the development of nuclear magnetic resonance spectroscopy, to the experiment of Paul C. Lautenburg, who was the first to create an image using this method. Raymond Damadien demonstrated that the NMR signal of tumour tissue differs from that of healthy tissue, thus providing the basis for the medical application of the method. Sir Peter Mansfield's new method greatly reduced the scanning time, allowing fast-moving organs such as the heart to be imaged. The measurement of contrast medium, and soon afterwards of blood oxygenation, made it possible to perform functional MRI examinations. The use of positron emission tomography combined with three-dimensional imaging techniques gives accurate diagnostic results, can be preferable in certain clinical situations and provides similar results at lower radiation levels. In terms of maxillofacial applications, CT and MRI scans are mainly used in cases of oral cavity tumour abnormalities. In dentistry, the imaging technique used in everyday practice is the CBCT, a non-traditional cone beam technique, which allows better quality images to be obtained in a shorter exposure time and using a lower dose of radiation.

Leontiasis Ossea about a Case Treated at Chu Owendo

Introduction: Leontiasis ossea is the most severe bone complication of the maxillae of chronic renal failure. The objective of this work is to determine the clinical, paraclinical and therapeutic aspects of this condition. Observation: A 42-year-old patient with chronic anuric terminal renal failure dialysis for 12 years had consulted for multiple maxillo-mandibular swelling evolving for 2 years deforming the face with discomfort to chewing. The biological assessment was: PTH: 5252 pg/mL, Ca2+: 2.86 mmol/L, free T3: 4.16 pmol/L, free T4: 6.55 pmol/L, TSH: 3.13 U/mL, serum protein: 61 g/L, Creatinine: 835 μmol/L. The maxillofacial CT noted heterogeneous diffuse thickening of the cranial vault and bones of the facial massif evoking leontiasis ossea with right mandibular brown tumor. The biopsy diagnosed fibrous gingival epulis. The patient had undergone modeling surgery, under general anesthesia after dialysis, of the right mandibular tumor whose histological result was Leontiasis ossea. Conclusion: Treatment is modeling surgery under hemostatic control.

RF05 | PSUN364 A Rare Case of Bilateral Parathyroid Carcinoma in the Setting of Multiple Endocrine Neoplasia Type 1

Abstract Background Multiple Endocrine Neoplasia type 1 (MEN1) is an autosomal dominant disorder classically characterized by parathyroid gland tumors, anterior pituitary adenomas, and tumors of the gastro-entero-pancreatic tract. The majority of MEN1 cases involving lesions of the parathyroid gland causing hyperparathyroidism are almost always benign. It is extremely rare for hyperparathyroidism to be caused by parathyroid carcinomas. We report a very rare case of parathyroid carcinoma presenting in MEN1 syndrome. Case Report We present the case of a 45 year old male with a history of untreated hypertension, nephrolithiasis, and CKD, who became suddenly unresponsive, was intubated, and found to have a severe acute intraparenchymal hemorrhage secondary to severe hypertension on Head CT. Secondary causes of hypertension were ruled out, with renin activity, aldosterone levels, and urine metanephrines unremarkable; abdominal ultrasound with doppler was also negative for renal artery stenosis. Stroke protocol was initiated, with CTA Head negative for any acute findings. However, CTA Neck showed bilateral large nodules posterior to the thyroid lobes measuring 4.0×3.2 cm on the right and 3.9×2.5 cm on the left, with mass effect on the thyroid and adjacent carotids. Routine labs showed hypercalcemia of 13.3 (8.4-10.2 mg/dL) in the setting of elevated PTH levels of 1085 (15-65 pg/mL), with repeat PTH level of 1106 confirming primary hyperparathyroidism. Other causes of hypercalcemia were investigated, with levels of Calcitonin and Calcitriol/1,25 vitamin D within normal limits, but a decreased level of 25 hydroxy vitamin D of &amp;lt;12.8 (30-100 pg/mL). Maxillofacial CT was negative for any ossifying fibromas, ruling out jaw tumor syndrome. CT Abdomen showed hyperdense nodular areas in the pancreas, and MRI Brain was negative for any discrete pituitary gland lesions. Thyroid US was performed and revealed mixed cystic and solid masses posterior to both lobes of the thyroid; as a result, FNA of the thyroid and posterior mass was done, confirming hypercellular parathyroid tissue and benign thyroid tissue. Due to high suspicion for parathyroid carcinoma, the patient underwent a parathyroidectomy, with pathology confirming bilateral parathyroid carcinoma. Genetic testing was positive for MEN1, with a frameshift variant mutation of c.1299_1312del (p.Val434Leufs*10). Conclusion This is a very rare case of bilateral parathyroid carcinoma presenting in MEN1. To the best of our knowledge, this genetic mutation has not been reported in online databases or published literature. The clinical presentation of parathyroid lesions and pancreatic nodules in the setting of hypercalcemia should prompt further evaluation of genetic disorders such as MEN1. In this context, it is essential that MEN1 patients be managed with a multidisciplinary approach given the disorder's complexity of diagnosis and treatment. Presentation: Saturday, June 11, 2022 1:18 p.m. - 1:23 p.m., Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

A novel dual-energy cone beam computed tomography device for assessment of jaw bone density

<h3>Objective</h3> To evaluate a novel dual-energy cone beam computed tomography (DE-CBCT) device for jaw bone density assessment. <h3>Study Design</h3> An ongoing clinical trial has enrolled 19 subjects with a target enrollment of 24 subjects. All subjects were 21 years and older and required a maxillofacial CT scan for standard-of-care diagnosis. Each subject received 2 examinations: one with a 64-slice multi-detector CT (MDCT) scanner and the second with the experimental DE-CBCT device (RCT720, Ray Co. Seoul, Korea). Asynchronous scanning of a custom hydroxyapatite phantom (concentrations of 0.8, 1.0 and 1.2 g/cc) provided calibration for bone density measurement. DICOM data from both CT examinations were imported into a custom version of OnDemand software<i>.</i> Calibration curves were generated from the MDCT and DE-CBCT scans of the hydroxyapatite phantoms. The MDCT and DE-CBCT scans of study subjects were superimposed and custom tools allowed calculation of bone density within a specified region of interest (ROI). Concordance between the MDCT- and DE-CBCT-derived bone densities was examined. <h3>Results</h3> In our preliminary assessments of data from current subjects, the mean calculated bone density in all the ROIs measured was 0.51 ± 0.27 g/cc for MDCT imaging and 0.50 ± 0.32 for DE-CBCT imaging. The range of the calculated bone densities was 0.06 to 1.1 g/cc for MDCT and 0.04 to 1.3 g/cc for DE-CBCT. Overall, there was strong correlation between bone densities calculated from MDCT scans with those calculated from DE-CBCT scans (r = 0.96, p <0.0001). Bland-Altman analysis identified a bias of 0.01 ± 0.1, and 95% limits of agreement range was -0.19 to 0.21. <h3>Conclusion</h3> The RCT720, a newly-developed DE-CBCT device, produced measurement of bone density equivalent to MDCT and overcomes the inaccuracies of bone density assessment using conventional CBCT scans. <b>Statement of Ethical Review</b> Human/Animal subjects were used and this study was approved by an institutional ethics panel

Algorithms used in medical image segmentation for 3D printing and how to understand and quantify their performance

Background3D printing (3DP) has enabled medical professionals to create patient-specific medical devices to assist in surgical planning. Anatomical models can be generated from patient scans using a wide array of software, but there are limited studies on the geometric variance that is introduced during the digital conversion of images to models. The final accuracy of the 3D printed model is a function of manufacturing hardware quality control and the variability introduced during the multiple digital steps that convert patient scans to a printable format. This study provides a brief summary of common algorithms used for segmentation and refinement. Parameters for each that can introduce geometric variability are also identified. Several metrics for measuring variability between models and validating processes are explored and assessed.MethodsUsing a clinical maxillofacial CT scan of a patient with a tumor of the mandible, four segmentation and refinement workflows were processed using four software packages. Differences in segmentation were calculated using several techniques including volumetric, surface, linear, global, and local measurements.ResultsVisual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Volumetric intersections and heatmaps provided useful local metrics of mismatch or variance between models made by different workflows. They also allowed calculations of aggregate percentage agreement and disagreement which provided a global benchmark metric. For the relevant regions of interest (ROIs), statistically significant differences were found in the volume and surface area comparisons for the final mandible and tumor models, as well as between measurements of the nerve central path. As with all clinical use cases, statistically significant results must be weighed against the clinical significance of any deviations found.ConclusionsStatistically significant geometric variations from differences in segmentation and refinement algorithms can be introduced into patient-specific models. No single metric was able to capture the true accuracy of the final models. However, a combination of global and local measurements provided an understanding of important geometric variations. The clinical implications of each geometric variation is different for each anatomical location and should be evaluated on a case-by-case basis by clinicians familiar with the process. Understanding the basic segmentation and refinement functions of software is essential for sites to create a baseline from which to evaluate their standard workflows, user training, and inter-user variability when using patient-specific models for clinical interventions or decisions.

Three-dimensional finite element analysis of the effect of alveolar cleft bone graft on the maxillofacial biomechanical stabilities of unilateral complete cleft lip and palate

BackgroundThe objective is to clarify the effect of alveolar cleft bone graft on maxillofacial biomechanical stabilities, the key areas when bone grafting and in which should be supplemented with bone graft once bone resorption occurred in UCCLP (unilateral complete cleft lip and palate).MethodsMaxillofacial CAD (computer aided design) models of non-bone graft and full maxilla cleft, full alveolar cleft bone graft, bone graft in other sites of the alveolar cleft were acquired by processing the UCCLP maxillofacial CT data in three-dimensional modeling software. The maxillofacial bone EQV (equivalent) stresses and bone suture EQV strains under occlusal states were obtained in the finite element analysis software.ResultsUnder corresponding occlusal states, the EQV stresses of maxilla, pterygoid process of sphenoid bone on the corresponding side and anterior alveolar arch on the non-cleft side were higher than other maxillofacial bones, the EQV strains of nasomaxillary, zygomaticomaxillary and pterygomaxillary suture on the corresponding side were higher than other maxillofacial bone sutures. The mean EQV strains of nasal raphe, the maximum EQV stresses of posterior alveolar arch on the non-cleft side, the mean and maximum EQV strains of nasomaxillary suture on the non-cleft side in full alveolar cleft bone graft model were all significantly lower than those in non-bone graft model. The mean EQV stresses of bilateral anterior alveolar arches, the maximum EQV stresses of maxilla and its alveolar arch on the cleft side in the model with bone graft in lower 1/3 of the alveolar cleft were significantly higher than those in full alveolar cleft bone graft model.ConclusionsFor UCCLP, bilateral maxillae, pterygoid processes of sphenoid bones and bilateral nasomaxillary, zygomaticomaxillary, pterygomaxillary sutures, anterior alveolar arch on the non-cleft side are the main occlusal load-bearing structures before and after alveolar cleft bone graft. Alveolar cleft bone graft mainly affects biomechanical stabilities of nasal raphe and posterior alveolar arch, nasomaxillary suture on the non-cleft side. The areas near nasal floor and in the middle of the alveolar cleft are the key sites when bone grafting, and should be supplemented with bone graft when the bone resorbed in these areas.

Septic shock induced by latent odontogenic orbital infection: a case report

A 65-year-old patient was admitted to the hospital due to proptosis of the left eye accompanied with ophthalmodynia and toothache for two months. Ophthalmic examination revealed a palpable mass around the lateral orbit and temporal fossa, and maxillofacial CT suggested a malignant tumor invading the left orbital floor wall. One week later, the patient was diagnosed with left orbital cellulitis and septic shock due to peri-orbit redness, eyelid edema, chest tightness, nausea, vomiting, hypotension, and a marked increase in peripheral blood neutrophil count. The infection was well controlled after remission of shock, anti-infective therapy and surgical drainage. At 2 months after surgery, the surgical incision of the upper eyelid skin recovered well and the best corrected visual acuity of the left eye was 1.0.

Clinical and radiographic predictors of the need for facial CT in pediatric blunt trauma: a multi-institutional study

BackgroundFacial injuries are common in children with blunt trauma. Most are soft tissue lacerations and dental injuries readily apparent on clinical examination. Fractures requiring operative intervention are rare. Guidelines for...

EP455: Fetal ultrasound presentation and neonatal diagnosis of Freeman-Sheldon syndrome in son of previously undiagnosed adult male

eP455: Fetal ultrasound presentation and neonatal diagnosis of Freeman-Sheldon syndrome in son of previously undiagnosed adult male

Neuroradiology in Transgender Care: Facial Feminization, Laryngeal Surgery, and Beyond.

Transgender individuals experience incongruence between their gender identity and the sex assigned to them at birth. This incongruence can cause many transgender individuals to experience distressing physical and mental discord, a diagnosis known as gender dysphoria. Craniofacial structures have distinct anthropometric characteristics that affect perceived masculinity and femininity. The face, neck, and voice are highly exposed anatomic areas that have recognizable gender-specific characteristics that may hinder a transgender individual's successful social integration and public acceptance. Reconstructive facial and laryngeal procedures are among the surgical options transgender persons may elect to undergo to better align their physical appearance with their gender identity. These include feminization surgeries such as facial feminization and reduction chondrolaryngoplasty, as well as masculinizing facial and laryngeal surgeries. Maxillofacial CT is frequently used in the preoperative evaluation of patients before facial feminization surgery (FFS). Several CT measurements guide surgeons to the optimal correction required in FFS to achieve appropriate aesthetic planes. Mapping important craniofacial landmarks to avoid untoward surgical complications is crucial. Transgender patients may encounter other neurologic complications that require neuroimaging evaluation. For example, gender-affirming hormone therapy (eg, estrogen and testosterone) may increase the risk of stroke or may influence growth of various hormone-sensitive tumors such as pituitary adenomas. Radiologists may interpret imaging examinations in transgender patients for routine care or for evaluation before and after facial and laryngeal surgeries and must be aware of the role of neuroimaging in the care of this population. An invited commentary by Callen is available online. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2022.

Atypical metastasis localization, buccal mucosa,in a patient with invasive lobular breast cancer: a case report

Background: Buccal mucosa metastasis is rare in breast cancer patients. Case Presentation: A 50-year-old female breast cancer patient with invasive lobular carcinoma (ILC) in his eight years follow-up period presented with a swelling in the right eye. Head and neck MRI was showed soft tissue formation with dimensions of 59x31 mm was detected in the axial plane, extending from the level of the right infratemporal fossa to the right buccinator muscle and right maxillary sinus in front of the alveolar process. In the right periorbital region, there was a thickness increase of up to 1 cm in the thickest part of the globe, which was evident in the anterolateral. In addition, there was no bone destruction in the right infratemporal region in maxillofacial CT, and no additional organ metastasis was detected in PET-CT performed for systemic scanning. In the histopathological examination of the tissue, carcinoma infiltration was detected. Radiotherapy was applied to the right buccal and orbital region of the patient as 30 Gy in 12 fractions (2.5 Gy per fraction) with volumetric modulated arc therapy technique and then 15 Gy in 6 fractions (2.5 Gy per fraction) boost radiotherapy with the adaptive technique were applied. At the follow-up 2 months later, clinical response was observed in the patient, and significant regression of the lesion was observed in facial and orbital MRI. At the 15th month follow-up of the patient, clinical and radiological remission continues. All clinical complaints regressed. Conclusion: ILC is a subtype of breast cancer that is characterized by unusual metastasis. Therefore, during the follow-up of these patients, it is necessary to monitor both laboratory values and clinical complaints very carefully.