Clinicians manage three-dimensional (3D) data in routine practice in the era of digital dentistry. Fundamental knowledge of digital data beyond the user’s manual provided by the companies needs to understand and handle the 3D data in clinics. 3D data used in the clinic is acquired by scanners and processed step-by-step procedure. A point cloud is an initial form of raw data. After that, it is filtered, and a triangle mesh is generated. The meshes could be exported in various file formats. This fundamental knowledge would be helpful for clinicians in daily practice.

Implants in maxilla can cause various complications. Implant fixture mount design has not been considered in any case as a posible cause of complications. This report presents a case of a man, 69 years old, who visits the dentist in September 2020 for oral rehabilitation due to the absence of teeth in the maxilla. A Galimplant IPX 4×8 implant was placed in position 17. Primary stability was achieved, close to the sinus but without invasion of it. When the fixture mount was removed from the implant, it was not released. A lateral movement was made to release it and the implant lost its stability. The fixture mount could be removed, but the implant was already displaced into the maxillary sinus. The difficulty of separating the fixture mount from the implant was the determining factor that caused the complication. In this circunstance, the dentist had to make lateral strength to separate it and this caused the loss of stability of the implant. I point out as a possible cause of the described complication the conical design of the fixture mount of Galimplant implants, since its excessive adjustment makes it difficult to separate it from the implant once it is inserted in the bone. This reduces the possibilities of using this type of implants in areas with low bone density.

Various considerations must be made when planning implant treatments using digital technology. These considerations include integrated total data, implant surgical guide CAD design, and understanding of 3D printing technology. In this paper, we summarize and analyze these considerations to confirm more accurate and predictable digital technology.

Patients who visit the dental clinic for molar implant therapy often present with extruded opposing teeth or inclined adjacent teeth. In such cases, if implant therapy is performed with limited orthodontic treatment, natural tooth structure can be preserved as much as possible. These treatment methods are frequently conducted, but most related studies have been confined to case reports. This study is considered meaningful as it is the first report to review and analyze the prognosis of dental implants with limited orthodontics. From 2010 to 2017, among patients who underwent implant therapy at Seoul National University Bundang Hospital, those who also underwent limited orthodontic treatment were investigated. A total of 11 implants placed in 11 patients was retrospectively analyzed. To evaluate improvement of horizontal or vertical occlusal relationship through limited orthodontics, 3D modeling software with scanned diagnostic models were used. The prognosis for the tooth undergoing orthodontic treatment was also evaluated. The average age of the 11 patients (4 males and 7 females) was 46.7 years, ranging from 26 to 63 years. All 11 implants placed in the posterior region survived without complications for an average of 36.7 months after functioning. Nine of 10 implants met the success criteria. An average of 11.4 months was required to upright the inclined posterior teeth, and an average of 3.2 mm of space was gained. Extruded molars were intruded by an average of 2.1 mm over an average of 13.5 months. One of the teeth that had undergone molar uprighting was extracted due to increased mobility after 27.0 months of orthodontic treatment completion, and none of the remaining 10 teeth exhibited significant findings. Dental implant therapy accompanied by limited orthodontic treatment could be considered a good treatment method that produced a satisfactory prognosis.

There is a lack of clear evidence on the use of auto-polymerizing and temperature activated softliners as attachments for implant overdentures for the elderly patients. This study was conducted to comparatively evaluate the initial and reduced retention force of two different soft liners over ball abutments for mandibular implant overdentures. Two implants corresponding to 33 and 43 (mandibular left and right canine, FDI notation) placed in a mandibular edentulous heat cure master model with ball abutmIents of 3mm diameter and 0.5 mm collar height. Overdentures processed in the heat activated denture base resin and divided into three groups of group A (n=15), group B (n=15), and group C (n=15). Group A-lined with Ufi-gel P followed with group B lined with Molloplast B and group C polymerized with plastic caps. Each of 45 denture bases subjected to initial retention force and reduced retention force testing after 3,348 cycles using a servohydraulic testing machine. The dual recess areas and the soft liner bonded to the denture base observed with a stereomicroscope both before and after 3,348 cycles. Statistical analysis performed using ANOVA Kruskal Wallis test and Wilcoxon signed-rank test. There were insignificant differences (P>0.05) in the mean rank values of all the three groups for reduced retention force after 3,348 cycles and percentage reduction in force. There were significant differences in all the three groups between initial retention force and reduced retention force after 3,348 cycles (P<0.05). Both the liners could be used as attachments for mandibular implant overdentures over the three year simulation period.

Purpose: Thyroidectomy is often required in the management of benign thyroid disorders. Conventional open thyroidectomy remains the standard of care for various benign and malignant thyroid disorders. We aim to present our experience in performing a transoral endoscopic thyroidectomy vestibular approach (TOETVA) for benign disease of the thyroid gland that is safe, and feasible when compared with open thyroidectomy. Methods: Sixty-six patients who underwent an open thyroidectomy or TOETVA between 2014 and 2019 for a benign thyroid condition were identified and retrospectively studied. Outcomes between the 2 groups, including postoperative complications, operative time, estimated blood loss (EBL), and length of stay, were compared. Patients were followed from 2 weeks up to 2 years postoperatively. Results: Sixty-six patients whose age ranges between 22 and 82 were stratified into an open thyroidectomy group and a TOETVA group with 33 patients in each group. In the TOETVA group, twenty-four (72.2%) patients underwent a total thyroidectomy while the rest underwent a lobectomy. One case of TOETVA was converted to open. There were no significant differences in the EBL, recurrent laryngeal nerve injury, hematoma formation, or hypocalcemia postoperatively between the 2 groups (P>0.05). Conclusion: We conclude that when thyroidectomy, either total or partial, is pursued for the management of benign thyroid disorders, TOETVA in patients with favorable features is a viable alternative to open thyroidectomy with regards to postoperative outcomes and provides superior cosmetic results leaving the patient with no cutaneous scars.

Hyperthyroid states can negatively impact cardiac function and exacerbate cardiac failure. In cases refractory to medical management, thyroidectomy may be indicated. However, the myocardial depressive effects of inhaled anesthetics in addition to hemodynamic lability of induction, complicate operative planning. While other institutions have published their experience utilizing local anesthesia and sedation during thyroidectomy, this requires agreement with the patient to employ that strategy. We report a case of a patient with refractory hyperthyroidism and exacerbated cardiac failure who underwent thyroidectomy after intra-aortic balloon pump placement given his reluctance to proceed utilizing local anesthesia and monitored anesthesia care.

Delayed manifestation of surgical emphysema as cervical pneumatocele post thyroid surgery is rare and unexpected that which needs to be managed appropriately. Herein we report three cases of delayed tracheal injury presenting with persistent subcutaneous emphysema, without acute respiratory distress. All three cases were managed surgically. Possible risk factors were discussed alongside hypotheses on the mechanisms of delayed tracheal injury and recommendations to prevent such complications. The management algorithm was summarized after the literature review. While surgical management is definitive, the non-surgical approach can also be a reasonable option, but requires a longer hospital stay.

Purpose: Quantitative analysis of forearm muscle movements during actual surgery has not yet been performed. The aim of this study was to evaluate forearm muscle activity patterns during open thyroid lobectomy using 8-channel surface electromyography, specifically Myo gesture-control arm bands. Methods: We developed a raw-signal recording program based on output from a Myo device. Eight Myo electrodes were allocated to the following adjacent forearm muscles: pronator teres (PT), brachioradialis (BR), extensor carpi radialis & brevis (ECR), extensor digitorum (ED), extensor carpi ulnaris (ECU), flexor carpi ulnaris (FCU), palmaris longus (PL), and flexor carpi radialis (FCR). EMG signals were measured from the time of skin incision to the end of thyroid lobectomy. Root mean square (RMS) value was used to indicate muscle activity during surgery. Results: Total of 10 thyroid lobectomies (5 right and 5 left lobectomies) were performed with Myo devices. The right arm muscles had higher RMS values than the left arm muscles (mean RMS 632.427 versus 367.170, P<0.001). In the right arm, PT, BR, ECR, FCU, PL and FCR showed higher mean RMS values, which means that the right arm made a greater variety of movements than the left arm. Only ED and ECU showed higher mean RMS values in the left arm, which means that the left arm muscles acted to counteract the motion of the right arm. Conclusion: We are the first to quantitatively evaluate forearm muscle activity patterns during thyroid lobectomy. More detailed research will be needed to apply our results in other surgical fields.

Purposes: We report a single surgeon s experiences and surgical outcomes of 100 recent transoral robotic thyroidectomy (TORT) cases. Methods: A sample of 100 patients who underwent TORT from December 2019 to December 2020, were included and analyzed in this study. All patients were diagnosed with papillary thyroid cancer (PTC). Eighty-five patients underwent a 3-ports TORT without axillary incision. Central lymph node dissections were performed in all cases diagnosed with PTC. Results: The mean operative time was 122.4±33.8 minutes. The number of retrieved lymph nodes was 4.5±3.3 and the serum thyroglobulin off thyroid hormone in total thyroidectomy was 0.1 ng/mL in one patient. Postoperative complications including transient hypocalcemia (n=1, 9.1%) in 11 cases of total thyroidectomy and transient recurrent laryngeal nerve palsy (n=1, 1.0%) were rarely observed. Focal transient numbness in lip area was observed only in six patients without severe mental nerve palsy and all patients recovered fully after surgery. Conclusion: Transoral robotic thyroidectomy is an effective and safe treatment option for patients who do not want to have visible scars on their neck area post-thyroidectomy.

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine cutaneous malignancy. The thyroid gland is an exceptionally rare site of metastasis for MCC. Thus, metastasis to the thyroid gland may entail diagnostic difficulties. An 82-year-old man presented with a palpable neck tumor in the right anterior neck. Computed tomography scan revealed a 3.4 cm, enhancing tumor in the right thyroid gland. The patient underwent fine needle aspiration, and cytologic and immunohistochemical findings revealed metastasis of MCC to thyroid gland. We decided to perform surgical excision of the right thyroid gland. The patient was discharged 2 days after surgery without any complications. Various immunohistochemical studies were performed with the surgical specimen. The tumor cells were positive for CK 20 and CD 56, but negative for thyroid transcription factor-1. Finally, the histopathologic diagnosis confirmed as metastasis of MCC to the thyroid gland. Here, we present an exceedingly rare metastasis of MCC to the thyroid gland and discuss its diagnosis and treatment. In patients with a known history of a primary malignancy, the differential diagnosis of any abnormal findings in the thyroid gland should always include possibility of potential metastasis.

This case report presents a case of immediate loading with guided surgery in a patient who had complete edentulous jaws. The patient experienced discomfort in the upper and lower removable complete dentures, and wanted to change it fixed complete prosthesis. The full-mouth rehabilitation was planned using 16 implant fixtures, eight each for maxilla and mandible. For guided surgery, surgical templates were fabricated by implant planning system, and provisional prostheses and customized abutments for immediate loading were fabricated by computer aided design and computer aided manufacturing technology. 28 months after the surgery, clinical and radiologic complications were not observed, and the patient’s masticatory function and esthetics were well-maintained.

Artificial intelligence (AI) can be used for broad field and have also applied in dental field. Although there have not been many studies on AI related to dental implants, research to identify implant systems in radiographic images using AI is being tried actively. The purpose of this study is to review articles related to application of AI for identification of dental implants system. A systematic review was conducted using Pubmed and Scopus databases to identify articles about AI and dental implants system in English literature. Factors such as Implant system, Data modality, Sample Size, Training time, Validation method, AI method, Accuracy, Sensitivity, Specificity, and Area under the receiver operating characteristic curve (AUC) were extracted from 4 articles. In the literatures, all of the research adopted to pretrained convolutional neural networks as AI method. AI accuracy to find correct implant system was ranged from 51 to 99.5 percent.

The management of medication-related osteonecrosis of the jaw (MRONJ) around a dental implant is difficult. Conservative treatment is recommended; however, patients do not exhibit improvement. Thus, several adjunctive therapies have been introduced. Herein, we describe a case of MRONJ around a dental implant in a 68-year-old man. Owing to the patient’s history of multiple myeloma, treatment with teriparatide was contraindicated. We achieved successful results with hyperbaric oxygen therapy and surgical intervention. Clinicians treating patients with MRONJ should conduct a thorough examination before selecting the modalities of adjuvant therapy, thereby establishing a solid treatment strategy.

Purpose Post-thyroidectomy bleeding (PTB) is rare but may be a life-threatening complication. This study investigated the incidence of and risk factors for postoperative bleeding after thyroid surgery. Methods The medical records of all patients who underwent thyroidectomy at Samsung Medical Center between November 1994 and July 2018 were reviewed retrospectively to identify any risk factors for PTB. Clinicopathological factors related to post-thyroidectomy bleeding were included in our analysis, and the association of potential risk factors with outcomes was tested by logistic regression analysis. Results Of 19,657 patients, PTB occurred in 132 (0.67%). In addition, 130 cases of PTB had emerged within 24 hours, while only 2 patients required re-operation after discharge. One patient expired due to hypoxic brain damage. A univariate analysis revealed that male sex (odds ratio [OR]=2.28, P<0.0001), chronic kidney disease (OR=5.26, P=0.02), the use of anti-hemorrhagic agents (OR=0.57, P=0.0017), and surgeon-specific factors (OR=3.4, P<0.0001) were significantly associated with PTB. However, upon multivariate analysis, only male sex (OR=2.34, P<0.0001) and surgeon-specific factors (OR=3.10, P<0.0001) were significant risk factors for PTB. Conclusion Male sex and surgeon-related factors significantly increased the risk of PTB. Since our study showed a tendency for PTB to increase within 24 hours of surgery, surgeons should look through whole surgical process or surgical techniques to minimize bleeding during the operation and conduct a close observation of all patients immediately after surgery.

Purpose Breast and thyroid cancers are the two most commonly diagnosed cancers in women. Many studies have described an increased risk of thyroid cancer in breast cancer patients. This may be related to hormonal exposure, genetic susceptibility, detection bias, and cancer treatment. We thus performed a retrospective descriptive study which aimed to assess the incidence and prevalence of thyroid cancer in breast cancer patients. Methods We reviewed electronic medical records of breast cancer patients who had undergone surgery between January 2013 and December 2017 in a single tertiary hospital. Patients with recurrent breast cancer, distant metastases, or previous history of thyroidectomy were excluded. A total of 966 patients were enrolled. Results A total of 37 (3.8%) patients were diagnosed with both breast and thyroid cancers during 46 months of median follow up. There were 28 (75.7%) synchronous cases diagnosed within 1 year, and 9 (24.3%) metachronous cases diagnosed after 1 year. The median age was 49 years (range, 30-65 years); 34 (91.9%) had thyroid microcarcinoma of less than 1 cm. The incidence and prevalence of thyroid cancer were 2.05 (95% confidence interval [CI], 0.93-3.61) times and 1.41 (95% CI, 0.93-1.98) times higher than those of general population, respectively. Conclusions The high incidence and prevalence of thyroid cancer among breast cancer patients are mostly attributable to the widespread screening with ultrasonography. Treatment strategies can be individualized with respect to the tumor characteristics, the patient s preference, and surgical resources.

Purpose Post-thyroidectomy hemorrhage has been conducted on re-operated reactive hemorrhage usually occurred within 24 hours. We investigated all hemorrhages including reoperated or not and also secondary hemorrhages occurred after discharge. Methods We retrospectively reviewed 16,701 patients from 1999 to 2019 and investigated the risk factors and time patterns of post-thyroidectomy hemorrhagic events. Results The annual incidence of hemorrhage decreased from 1.7% to 0.1%. The risk factors included age ≥55 years, male sex, body weight ≥60 kg, larger thyroid specimens, and advanced stage (stage III or IV). The type of surgery and body mass index showed no significant associations with the hemorrhagic events. Ligation methods were associated with a greater incidence of hemorrhagic events than energy devices (0.6% vs. 0.3%), but they were not independent predictive factors (odds ratio [OR]=1.5; P=0.157). The OR was high for surgeons experience <3.5 years (OR=1.8), age ≥55 years (OR=1.8), weight ≥60 kg (OR=1.9), and aggressive tumor stage (OR=4.8). The highest OR was observed for Surgeon X s procedures (OR=9.6). Extremely severe airway obstruction was observed in 17% of the patients and one patient did not survive. Most of the hemorrhagic events occurred during hospitalization, but 13% of the events occurred at home after discharge, or in the dialysis chamber of another hospital. Conclusion Post-thyroidectomy hemorrhagic events are life-threatening complications that can occur at unexpected times and places. Delicate hemostasis and careful monitoring even after normal discharge constitute the best approach to prevent these events. Moreover, we do not recommend routine outpatient-based thyroidectomy.

Purpose Clinicians still debate how to manage 2-4 cm papillary thyroid carcinoma (PTC). To understand the characteristics and prognosis of these tumors, we compared clinicopathological prognostic factors and prognosis among 1-2 cm, 2-4 cm, and >4 cm PTC. Methods We retrospectively reviewed the medical records of 2,079 patients with primary PTC >1 cm who were diagnosed between 2002 and 2017. Results The patients mean age was 47.9±12.5 years, and 83.2% were women. The follow-up period was 81.1±41.8 months. The tumor recurred in 138 patients (6.6%), and thyroid cancer-related death developed in 3 cases (0.1%). As tumor size increased, so did the proportion of male patients, lymphovascular invasion, resection margin positivity, lymph node (LN) metastasis, metastasis in >5 LNs, T4, N stage, and M stage. Recurrence increased linearly according to tumor size, as did distant metastasis as first recurrence and progression to distant metastasis. Tumor size, N stage, metastasis in >5 LNs, and LN metastasis were significant independent risk factors for PTC recurrence. The recurrence rate of 2-4 cm PTC was 13.4%, while the risk of recurrence was 3 times higher than in 1-2 cm PTC. The 5-year recurrence free survival (RFS) rates of 1-2 cm, 2-4 cm, and >4 cm PTC were 97.0%, 88.0%, and 74.0%, respectively, while the 10-year RFS rates were 95.0%, 84.0%, and 71.0%. Conclusion The 2-4 cm PTC may be pathologically distinct from 1-2 cm PTC and should be treated differently.

Purpose The bilateral axillary breast approach (BABA) is frequently utilized for remote access thyroid surgery. The first step in this surgical approach is to make a subcutaneous flap from the axilla to the neck, usually using a Harmonic ACE. Our institution has utilized LigaSure to create these flaps. This study reports comparative results with these 2 energy devices. Methods Medical data and video clips from 73 patients who underwent robotic BABA thyroid surgery were retrospectively reviewed. Flaps for BABA were created by first and second year endocrine fellows under the guidance of an experienced endocrine surgeon. There were no criteria for allocation to energy devices. Results Of the 73 patients, 31 and 42 underwent flap creation with the Harmonic ACE and LigaSure devices, respectively. Demographic characteristics were similar in the 2 groups. Mean time for flap creation was significantly shorter (33.46±8.33 vs. 38.27±7.14 min, P=0.012), and mean number of camera cleanings significantly lower (4.21±2.53 vs. 10.45±4.95, P<0.001), in the LigaSure group. Surgical site pain on day 2 was significantly lower in the LigaSure group. Postoperative bleeding and skin burn occurred only in patients in the Harmonic group. Conclusion LigaSure showed better performance than the Harmonic ACE device for BABA flap creation, as shown by time for flap creation, postoperative pain scores, and complications. Because this study was a small sized retrospective comparison, large randomized controlled trials are needed to confirm these results.