Characteristics of Suture Materials Used in Oral Surgery: Systematic Review.

BACKGROUND: The aim of this review was to evaluate the most used suture materials with regards to their inflammatory response, their bacterial adhesion, and their physical properties when used to close oral wounds. METHODS: Four databases (PubMed, Scopus, Dentistry & Oral Sciences, and OVID) were searched to retrieve relevant studies from January 1, 2000, to January 31, 2020. RESULTS: Out of the 269 articles, only 13 studies were selected as they were relevant and met the systematic review's protocol. These studies showed that almost all suture materials studies (catgut, polyglycolic acid [PGA] sutures, nylon, expanded polytetrafluoroethylene, and silk sutures) caused bacterial adherence and tissue reaction. In nylon and chromic catgut, the number of bacteria accumulated was lowest. Silk and nylon were found to be more impacted than catgut and PGA in terms of physical characteristics such as tensile strength. PGA, on the other hand, was said to be the most susceptible to knot unwinding. CONCLUSIONS: Following an oral surgical operation, all sutures revealed varied degrees of irritation and microbial accumulation. Nonresorbable monofilament synthetic sutures, however, exhibited less tissue response and less microbial accumulation.

Comparison of the mechanical properties of biodegradable and titanium osteosynthesis systems used in oral and maxillofacial surgery.

To guide the selection of osteosynthesis systems, this study compared the mechanical properties of biodegradable and titanium osteosynthesis systems. SonicPins Rx and xG were subjected to pull-out tests. Additionally, 15 biodegradable (Inion CPS 2.0 and 2.5 mm; LactoSorb 2.0 mm; Macropore 2.0 mm; Polymax 2.0 mm; BioSorb FX 2.0 mm; ResorbX 2.1 mm; Osteotrans-MX 2.0 mm with plate thicknesses 1.0 and 1.4 mm; SonicWeld Rxplate/Rxpins, xGplate/Rxpins and xGplate/xGpins 2.1 mm without and with tapping the burr hole) and six titanium (CrossDrive (2006), CrossDrive (2018), MaxDrive; all 1.5 and 2.0 mm) straight, four-hole osteosynthesis systems were evaluated. All systems were subjected to tensile, bending and torsion tests. Pull-out loads of the SonicPins were comparable (P = 0.423). Titanium systems' tensile loads were higher than biodegradable systems (P < 0.001). CrossDrive (2018) and MaxDrive systems' tensile and torsional stiffness were lower, accompanied with higher ductility, than corresponding CrossDrive (2006) systems (P < 0.001). Bending stiffness of 1.5 mm titanium systems was comparable to, and of the 2.0 mm systems higher than, all biodegradable systems (P < 0.001). Regarding biodegradable systems, Inion CPS 2.5 mm had highest tensile load and torsional stiffness, SonicWeld 2.1 mm highest tensile stiffness, and BioSorbFX 2.0 mm highest bending stiffness (P < 0.001). On the basis of the results of this study, the CrossDrive (2018) and MaxDrive 1.5 mm titanium systems are recommended for midface fractures (e.g., zygomatic or maxillary fractures) and osteotomies (e.g., Le Fort I osteotomy), and the CrossDrive (2018) and MaxDrive 2.0 mm titanium systems for mandibular fractures and osteotomies when a titanium osteosynthesis system is used. When there is an indication for a biodegradable osteosynthesis system, the SonicWeld 2.1 mm or BioSorbFX 2.0 mm are recommended for midface fractures and osteotomies, and the Inion CPS 2.5 mm biodegradable system for mandibular osteotomies and non-load bearing mandibular fractures, especially when high torsional forces are expected (e.g., mandibular symphysis fractures).

Usefulness of fluorescence visualization-guided surgery for early-stage tongue squamous cell carcinoma compared to iodine vital staining.

BACKGROUND: In the most cases of oral squamous cell carcinoma (OSCC), oral epithelial dysplasia (OED) is found adjacent to the primary tumor. The delineation of surgical margins for OSCC is critical to minimize the risk for local recurrence. The aim of this study is to demonstrate that the fluorescence visualization (FV)- device can delineated the lesion visualizes OED of adjacent primary tumors by histopathologically comparison to conventional iodine vital staining. MATERIAL AND METHODS: The study involved 40 patients with superficial tongue squamous cell carcinoma treated from July 2016 to July 2018 at the Oral Cancer Center, Tokyo Dental College. RESULTS: Cytokeratin 13 (CK13) expression rate in the area of fluorescence visualization loss (FVL) was significantly lower than that in the area of fluorescence visualization retention (FVR). In addition, CK17, Ki-67, and p53 expression rates were significantly higher in FVL than FVR. There was no significant difference in the delineation rate or area between FVL and iodine-unstained area. High-grade dysplasia was observed most frequently at the FV and iodine-unstained boundary, but no significant pathological differences were found. CONCLUSION: We strongly suggest the FV-guided surgery is a useful method for accurate resection in early-stage tongue squamous cell carcinoma.

Evaluating the impact of smoking on disease-specific survival outcomes in patients with human papillomavirus-associated oropharyngeal cancer treated with transoral robotic surgery.

BACKGROUND: When treated nonsurgically with definitive chemoradiation, smokers with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) have a worse prognosis compared with their nonsmoking counterparts. To the authors' knowledge, the prognostic significance of smoking in surgically treated patients is unknown. METHODS: The current study is a retrospective case series of patients with HPV-positive OPSCC who underwent upfront transoral robotic surgery at a single institution from 2010 through 2017. Exclusion criteria were nonoropharyngeal primary tumors, histology other than SCC, HPV-negative tumors, previous history of head and neck cancer, and/or previous head and neck radiotherapy. Recurrence-free survival (RFS), overall survival, and disease-specific survival were compared using the Kaplan-Meier method and the log-rank test. Smoking history was categorized as never smokers (<1 pack-year), current smokers (smoking at the time of the cancer diagnosis), and former smokers. RESULTS: A total of 258 patients met the study criteria. The average age was 60 years, and approximately 87% of patients were male. A total of 148 patients (57.4%) were smokers whereas 110 (42.6%) reported never smoking. There were 44 active smokers (17.1%) and 104 former smokers (40.3%). The median follow-up was 3.23 years. There were 17 patients of disease recurrence. Smoking pack-year history was not found to be significant for RFS (hazard ratio, 1.01; 95% CI, 0.99-1.03 [P = .45]). There was no significant difference in RFS noted between never and ever smokers (92% vs 89.8%; P = .85) nor was there a difference observed between never, former, and current smokers (92% vs 91.5% vs 86.1%, respectively; P = .69). CONCLUSIONS: A smoking history is common in patients with HPV-positive OPSCC. In the current study, HPV-positive smokers were found to have excellent survival and locoregional control, similar to their nonsmoking counterparts. The results of the current study do not support the exclusion of smokers with early-stage, HPV-positive OPSCC from transoral robotic surgery-based deintensification trials.

Modeling and Clinical Application of Incision Space in Facial Contour Surgery.

Virtual simulation surgical system is a good way to develop surgical instruments, make surgical plan, and train surgeons. At present, due to the deformation of intraoperative soft tissue after retraction and the lack of effective data collection, the surgical simulation of facial contour surgery can only be conducted according to the preoperative computed tomography data. Due to the difficulty of obtaining real operative spatial data, it is difficult for the virtual surgery trajectory planning process to yield a good effect on surgeon training. In this study, an optical tracking device was used to record the actual posture of surgical instruments, patient position, and incision space in the surgical environment, so as to construct a more accurate actual surgical space. The clinical data obtained in this study can be used for virtual simulation of surgical instrument movement and osteotomy, as well as selection, planning, and teaching purposes of surgical programs.

The Importance of Dental Appliances for Oral Commissure Reconstruction in Trauma-Induced Microstomia: A Clinical Report.

Reconstruction of the oral commissure is necessary after trauma, pathological resection, or electrical, chemical, or thermal burns. Using dental appliances is strongly recommended to prevent microstomia in victims with oral commissure injury caused by burns. These appliances can be modified from dynamic to static for more patient comfort during the healing period and used in trauma patients to prevent rounding of the labial commissure. Preventing relapse of microstomia and forming acute angles at the corner of the mouth are 2 optimal goals when performing this surgery.

Transoral robotic tongue base reduction and supraglottoplasty combined with maxillomandibular advancement: a new option for selected sleep apnea patients? Preliminary report.

PURPOSE: Transoral robotic surgery (TORS) and maxillo-mandibular advancement (MMA) are effective options for obstructive sleep apnea patients. Identification of the correct candidate is by far the most important item in achieving a succesful outcome. As a consequence, not all patients can be managed successfully via one or the other procedure. To overcome the limits of any single procedure we have combined, in a very selected population of patients, TORS tongue base reduction and MMA. Preliminary data are encouraging, in terms of both AHI and ESS. METHODS: A retrospective cohort study was conducted on five patients treated with combined TORS-MMA surgery. Demographic and clinical data, pre-operative and post-operative PSG and ESS were collected. RESULTS: Three of five patients were recruited. All patients presented severe OSAHS. Mean AHI and ESS went respectively from 48 and 12 pre-operatively to 19 and 4 post-operatively. Minor bleeding occurred in two patients. No significant sequelae have been reported. CONCLUSIONS: Combined TORS and MMA is feasible and safe. Our very preliminary data are encouraging, in terms of both AHI and ESS. Long-term follow-up and a larger amount of subjects are needed to confirm this surgical approach as a valuable option for selected OSAHS patient.

Reparación multicapa de la fístula palatina con interposición de matriz de colágeno / Multilayer repair of palatal fistula with an interpositional collagen matrix

Objetivo. La fístula palatina tras la reparación del paladar fisurado aparece en un 7,7- 35% de pacientes. Presentamos dos casos de fístula palatina, detallando la técnica de reparación multicapa con injerto in-terposicional de colágeno. Material y métodos. Paciente 1: niña con fisura de paladar blando, operada mediante técnica de Furlow. Se programa reintervención por fístula secundaria tipo III de Pittsburgh. Paciente 2: varón con fisura de paladar blando, operado mediante técnica de Furlow. Se programa reintervención por fístula secundaria tipo V. Resultados. Reparación multicapa mediante flap rotacional y matriz de colágeno entre las capas nasal y oral. Refuerzo con adhesivo hemostático de fibrina. Ausencia de recidiva tras 2 años de seguimiento. Conclusiones. El cierre en tres capas es sencillo y efectivo a la hora de evitar refistulizaciones. Los injertos interposicionales de membrana reabsorbible de colágeno proporcionan un "andamio" para el crecimiento de los tejidos, revascularización y epitelialización de la mucosa

Objective. Palatal fistula after the repair of cleft palate appears in 7.7-35% of patients. We present two cases of palatal fistula, detailing a multi-layer repair with an interpositional collagen graft. Material and methods. Patient 1: girl with a cleft palate operated using a Furlow technique. A reintervention was performed due to a Pittsburgh type III fistula Patient 2: male with cleft palate operated using a Furlow technique. A reintervention was performed due to a type V fistula. Results. We used a multilayer repair with a local rotational flap and the interposition of a collagen matrix between the nasal and oral layers. The suture was reinforced with a fibrin hemostatic adhesive. No recurrence of the fistula after 2 years. Conclusions. The three-layer closure is simple, safe, effective and avoids refistulizations. Interpositional grafts of a resorbable collagen membrane provide a "scaffold" for tissue growth, revascularization and epithelialization of the mucosa

Machinability of enamel under grinding process using diamond dental burrs.

Enamel grinding is a critical dental surgery process. However, tooth damage during the process remains a significant problem. Grinding forces, burr wear, and surface quality were characterised in relation to grinding speed, enamel orientation, grinding depth, and burr grit grain size. Results indicated that enamel rod orientation, grinding depth, and grinding speed critically affected enamel grinding. Occlusal surface grinding resulted in significantly higher normal forces, surface roughness, and marginally greater tangential forces than axial surface grinding. Damage to enamel machined surfaces indicated the significant impact of diamond grit size and rod orientation. Burr wear was primarily diamond grit peeling off and breakage. Surface roughness of axial and occlusal sections was largely influenced by grinding speed and diamond grit size. Improving the surface quality of machined enamel surfaces could be realised using fine burrs, reducing the grinding speed and grinding depth, and adjusting the feed direction vertical to the rod orientation. Enamel surface quality and roughness could be improved by reducing brittle failure and circular runout during the grinding process, respectively.

Diode Laser as an Adjunct to Kirkland Flap Surgery-A Randomized Split-Mouth Clinical and Microbiological Study.

Background: Mechanical methods of periodontal therapy alone may fail to eliminate the tissue-invasive pathogenic flora; therefore, considerable attention has been given to adjunctive antimicrobial measures. Objective: The aim of this study was to investigate and compare the clinical and microbiological effects of diode laser (DL) as an adjunct to Kirkland flap surgery versus Kirkland flap surgery alone for the treatment of generalized chronic periodontitis. Materials and methods: A total of 20 patients with generalized chronic periodontitis with probing pocket depth ≥5 mm after phase I therapy were included in this split-mouth study. Two contralateral quadrants of each patient were randomly assigned to either test or control group. Control group was treated with Kirkland flap surgery alone, whereas test group was treated with DL as an adjunct to Kirkland flap surgery. Periodontal parameters were recorded, and subgingival plaque samples were collected from both the control and test groups at baseline and third and sixth month. The plaque samples were then analyzed for red complex organisms using quantitative real-time polymerase chain reaction. Results: Compared with baseline, both treatments showed an improvement in periodontal parameters at the third and sixth month. However, test group produced a significant improvement in plaque index (1.039 ± 0.069 vs. 1.392 ± 0.17, p < 0.001), bleeding on probing (16.512 ± 5.982 vs. 37.051 ± 7.459, p < 0.001), probing pocket depth (1.727 ± 0.39 vs. 3.016 ± 0.47, p < 0.001), and clinical attachment level (2.054 ± 0.524 vs. 3.354 ± 0.728, p < 0.001) at third and sixth month compared with the control group. Moreover, in the test group, levels of red complex bacteria were significantly reduced at third and sixth month compared with the control group. Conclusions: DL as an adjunct to Kirkland flap surgery has resulted in a greater reduction in clinical and microbiological parameters compared with Kirkland flap surgery alone, thereby offering additional benefit in treating generalized chronic periodontitis patients.

Comparative Evaluation of Diode Laser and Scalpel Surgery in the Treatment of Inflammatory Fibrous Hyperplasia: A Split-Mouth Study.

Objective: This study aimed to compare the efficacy of diode laser surgery and the scalpel surgery in the removal of inflammatory fibrous hyperplasia (IFH). Background data: Diode laser systems are proposed as an alternative to scalpel surgery on surgeries involving oral soft tissues. Some of the advantages of the laser systems are ease of application, adequate coagulation, reduced postoperative pain, and decreased scarring. In addition, there are increasing data on the antibacterial effects of the diode lasers in dentistry; however, the direct bactericidal role of the diode laser in oral soft tissue procedures has not yet been investigated. Materials and methods: A total of 22 patients were enrolled in this study. One side of IFH was randomly assigned for excision with scalpel blade or with diode laser. Perioperative bleeding, postoperative pain, wound healing, and bacterial counts were evaluated for both methods. Results: The bleeding on the side treated by diode laser was found significantly lower (p < 0.05). A notable reduction in total bacterial counts was observed in the laser group after the first postoperative day. However, this trend did not reach statistical significance. No significant differences were recorded regarding subjective postoperative pain between the groups (p = 0.065). The healing of the postoperative wounds was significantly faster in the conventional group at each time point. Conclusions: Diode laser has offered some advantages over conventional method in the management of IFH. However, large-cohort comparative studies are required to provide additional data regarding the wound healing capacity of the diode laser.

A histological evaluation of the surgical margins from human oral fibrous-epithelial lesions excised with CO2 laser, Diode laser, Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and cold scalpel.

BACKGROUND: We aim to evaluate the presence of histological artefacts in the surgical margins of human oral fibro-epithelial hyperplasias excised with lasers of different wavelengths, and also electrosurgical scalpel and cold scalpel. Moreover, we aim to determine if some of these instruments could impair the normal histological diagnosis of these lesions. MATERIAL AND METHODS: We included 130 consecutive surgical samples of 80 females and 50 males (mean age of 53.82±16.55) with a histological diagnosis of an oral benign fibrous-epithelial hyperplasias. The samples were categorized into 6 groups according to the type of instrument used: CO2 laser group, diode laser group, Er:YAG laser group, Nd:YAG laser group, electrosurgical scalpel group and cold scalpel group. Histological instrument-induced changes were microscopic evaluated and related with clinical and pathological variables. RESULTS: The instrument with highest tissue damage extension (TDE) was the electrosurgical scalpel (1002.2µm±434.92), followed by diode laser (913.73 µm±322.45), Nd:YAG (899.83µm±327.75), CO2 laser (538.37µm±170.50), Er:YAG laser (166.47µm±123.85), and at last with fewer alterations the cold scalpel group (2.36µm±7.27) (P < 0.001). The most regular incision was observed in CO2 laser group, followed by Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and diode laser group with the less regular incision using cold scalpel as comparison (P < 0.001). A correlation was found between the incision score and TDE (P < 0.001). Regarding histological diagnosis, no case showed any limitation of diagnosis related with the use of any instrument evaluated. CONCLUSIONS: Our results suggest that lasers can be used for the excision of oral benign fibrous-epithelial hyperplasias, without hispathological diagnosis limitations, as long as the physical properties of each laser are known and respected. Er:YAG laser have shown to be a laser with few tissue damage extension and with good incision regularity, been a possible instrument of choice for the surgical removal of these lesions.

Prevalence of obstructive sleep apnea in male patients with surgically treated maxillary and zygomatic fractures

Background: Midface fractures can cause airway obstruction and breathing disturbances. The purpose of the present study was to determine the prevalence of undiagnosed obstructive sleep apnea (OSA) among patients with surgically treated maxillary and zygomatic fractures. Methods: We retrospectively analyzed the medical records of 44 patients who had undergone surgical treatment of maxillary or zygomatic fractures between Jan. 1, 2003, and Dec. 31, 2013 at a single centre. All participants underwent polygraphy testing and were asked to complete the STOP (snoring, tiredness, observed apnea and high blood pressure) questionnaire, Nasal Obstruction Symptom Evaluation (NOSE) scale and Epworth Sleepiness Scale. Results: There were 27 participants (61%) with maxillary fracture and 17 (39%) with zygomatic fracture. Obstructive sleep apnea was diagnosed in 24 (54%) of the 44 participants, of whom 15 (62%) had maxillary fractures and 9 (38%) had zygomatic fractures. Participants with OSA had a mean Apnea­Hypopnea Index (AHI) of 15.5 (standard deviation [SD] 9.7) events/h, compared to 2.4 (SD 1.5) events/h for those without OSA (p < 0.001). Of the 30 participants with nose obstruction, 18 (60%) had an AHI of 5 or greater. Conclusion: The results suggest that the prevalence of OSA was higher in surgical patients with midface fractures, independent of the type of fracture, than in the general population. The NOSE scale results showed significant correlation with the presence of OSA.

Contexte: Les fractures affectant la portion médiane du visage peuvent provoquer une obstruction des voies respiratoires et gêner la respiration. La présente étude avait pour but de déterminer la prévalence de l'apnée obstructive du sommeil (AOS) non diagnostiquée chez des patients ayant été traités chirurgicalement pour des fractures du maxillaire et de l'os zygomatique. Méthodes: Nous avons analysé rétrospectivement les dossiers médicaux de 44 patients ayant subi un traitement chirurgical pour une fracture du maxillaire ou de l'os zygomatique entre le 1er janvier 2003 et le 31 décembre 2013 dans un seul établissement. Tous les participants ont subi un test polygraphique et ont été invités à répondre aux questionnaires STOP (snoring, tiredness, observed apnea et high blood pressure), NOSE (Nasal Obstruction Symptom Evaluation), de même qu'à l'échelle de somnolence d'Epworth. Résultats: Vingt-sept participants (61 %) avaient subi une fracture du maxillaire et 17 (39 %) de l'os zygomatique. L'AOS a été diagnostiquée chez 24 participants sur 44 (54 %), dont 15 (62 %) avaient subi une fracture du maxillaire et 9 (38 %) une fracture de l'os zygomatique. Les participants qui présentaient une AOS avaient un indice d'apnée-hypopnée (IAH) moyen de 15,5 (écart-type [É.-T.] 9,7) événements/h, contre 2,4 (É.-T. 1,5) événement/h pour les participants indemnes d'ASO (p < 0,001). Parmi les 30 participants qui avaient une obstruction nasale, 18 (60 %) avaient un IAH de 5 ou plus. Conclusion: Ces résultats donnent à penser que la prévalence de l'AOS était plus élevée chez les patients opérés pour une fracture affectant la portion médiane du visage (indépendamment du type de fracture) que dans la population générale. Les résultats au questionnaire NOSE ont montré une corrélation significative avec la présence d'AOS.

Nasopharyngeal Tube Effects on Breathing during Sedation for Dental Procedures: A Randomized Controlled Trial.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Dental procedures under sedation can cause hypoxic events and even death. However, the mechanism of such hypoxic events is not well understood. WHAT THIS ARTICLE TELLS US THAT IS NEW: Apnea and hypopnea occur frequently during dental procedures under sedation. The majority of the events are not detectable with pulse oximetry. Insertion of a nasal tube with small diameter does not reduce the incidence of apnea/hypopnea. BACKGROUND: Intravenous sedation is effective in patients undergoing dental procedures, but fatal hypoxemic events have been documented. It was hypothesized that abnormal breathing events occur frequently and are underdetected by pulse oximetry during sedation for dental procedures (primary hypothesis) and that insertion of a small-diameter nasopharyngeal tube reduces the frequency of the abnormal breathing events (secondary hypothesis). METHODS: In this nonblinded randomized control study, frequency of abnormal breathing episodes per hour (abnormal breathing index) of the patients under sedation for dental procedures was determined and used as a primary outcome to test the hypotheses. Abnormal breathing indexes were measured by a portable sleep monitor. Of the 46 participants, 43 were randomly allocated to the control group (n = 23, no nasopharyngeal tube) and the nasopharyngeal tube group (n = 20). RESULTS: In the control group, nondesaturated abnormal breathing index was higher than the desaturated abnormal breathing index (35.2 [20.6, 48.0] vs. 7.2 [4.1, 18.5] h, difference: 25.1 [95% CI, 13.8 to 36.4], P < 0.001). The obstructive abnormal breathing index was greater than central abnormal breathing index (P < 0.001), and half of abnormal breathing indexes were followed by irregular breathing. Despite the obstructive nature of abnormal breathing, the nasopharyngeal tube did not significantly reduce the abnormal breathing index (48.0 [33.8, 64.4] h vs. 50.5 [36.4, 63.9] h, difference: -2.0 [95% CI, -15.2 to 11.2], P = 0.846), not supporting the secondary hypothesis. CONCLUSIONS: Patients under sedation for dental procedure frequently encounter obstructive apnea/hypopnea events. The majority of the obstructive apnea/hypopnea events were not detectable by pulse oximetry. The effectiveness of a small-diameter nasopharyngeal tube to mitigate the events is limited.

Development of a Transoral Robotic Surgery Training Platform.

Transoral robotic surgery (TORS) presents unique challenges due to difficulty manipulating surgical instruments within the tight confines of the oral cavity. Collisions between the end effectors and anatomical structures can be visualized through the endoscope; however, instrument shaft collisions are outside of the field-of-view. Acquiring the requisite skill set to minimize these collisions is challenging due to the lack of an appropriate training platform. In this paper, we present a TORS training platform with an integrated collision sensing system and real-time haptic feedback. Preliminary testing involved the recruitment of 10 Otolaryngology residents assigned to `feedback' (N=5) and `no feedback' (N=5) groups. Each trainee performed three mock surgical procedures involving the resection of a tumor from the base of the tongue. Superior surgical performance was observed in the feedback group suggesting that haptic feedback will enhance the acquisition of surgical skills.

Robotic resection of lingual thyroglossal duct cyst in an infant.

Thyroglossal duct cysts (TDCs) are the most common congenital midline neck masses. Lingual TDC is a rare variant that emerges as an isolated cyst at the tongue base. Unlike conventional procedures aiming removal of cyst, duct, and hyoid bone via open surgical access, a transoral cystectomy is mostly sufficient in cases with lingual TDC. We present a case describing a 3-month-old infant patient with lingual TDC who was successfully treated with transoral robotic surgery. The cyst wall was completely excised with no complications or obvious bleeding occurred. The operating time was 10 min. He had an uneventful postoperative course. Six months postoperatively, he is free of symptoms with no evidence of recurrence. Surgical treatment of lingual TDC in an infant is possible with transoral robotic approach and minimal risk of complication. Further studies are strongly needed to confirm the safety of robotic surgery in pediatric population.

Recommended Drilling Parameters of Tungsten Carbide Round Drills for the Most Optimal Bone Removals in Oral Surgery.

BACKGROUND: High temperatures during drilling can cause thermal osteonecrosis and abnormal wound healing. According to our best knowledge, a widely accepted recommendation for optimal drilling parameters in routine oral surgery bone removals does not exist. PURPOSE: Our aim was to investigate the correlations of different drilling parameters, including axial load and revolution speed on drilling temperatures and preparation times. MATERIALS AND METHODS: Standard, 5 mm deep cavities were drilled in 20 PCF (lb/ft3) dens polyurethane blocks with 3 mm (50PCF) cortical layer using new and worn, 3.1mm in diameter tungsten carbide round drills. Worn drills were used in 50 impacted third molar operations before. Axial loads of 3N, 10N, and 25N and speeds of 4.000-8.000-16.000-40.000 revolutions per minute (rpm) were tested. Temperature differences of drilling parameters were calculated by 1-way ANOVA, followed by Tukey's HSD post hoc tests. Time differences and differences among "optimal" and "suboptimal" groups (with the cut-off value of 3°C and 3s) were estimated by Kruskal-Wallis test with pairwise comparisons. P<0.05 was considered significant. RESULTS: The highest mean temperatures with new and worn drills were 4.64±0.53°C and 6.89±1.16°C, while drilling times varied between 0.16±0.02s and 22.77±5.45s. A 3°C and 3s cut-off value classified drillings significantly to (1) optimal [3N and 8000-16000-40000 rpm or 10N and 4000-8000-16000-40000 rpm] or suboptimal due to (2) high temperatures or (3) long preparation times. Using worn drills, the following parameters should be avoided: 3N with 4.000-8.000 rpm, 10N with 40000 rpm, and 25N at any revolutions. DISCUSSION: The study extensively mapped the drilling temperatures and preparation times of tungsten carbide round drills. Temperatures did not exceed 10°C during drillings with maximal amount of cooling, as well as the drilling parameters, which kept temperatures and preparation times in the most optimal range which were clearly established.

Full in-Office Guided Surgery with Open Selective Tooth-Supported Templates: A Prospective Clinical Study on 20 Patients.

BACKGROUND: Guided implant surgery appears to have several benefits, such as the possibility of inserting flapless implants in a prosthetically driven manner, avoiding dangerous anatomical structures. However, to date, only a few surgeons routinely use guided surgery in partially edentulous patients. AIM: To present the results obtained with tooth-supported surgical templates characterized by an innovative open design with selective support, and manufactured via a full in-office procedure with a low-cost desktop 3D printer. METHODS: Over a two-year period (2016⁻2018), all partially edentulous patients with one to three missing teeth (in maxilla and/or mandible), referred to a private dental practice for restoration with dental implants, were considered for inclusion in this prospective clinical study. An intraoral scanner (CS 3600®, Carestream Dental) and cone beam computed tomography (CS 9300®, Carestream Dental) were used to acquire the 3D information on the patients. Guided surgery software (SMOP®, Swissmeda) was used to plan the surgeries and to design open, selective, tooth-supported templates that were fabricated with a stereolithographic (SLA) desktop 3D printer (XFAB2000®, DWS). Guided implant surgeries were performed and patients were followed for a period of one year. The study outcomes were fit and stability of surgical templates, duration (time) of surgery, intra and post-operative complications, and implant stability and survival. RESULTS: Twenty (20) partially edentulous patients (9 males, 11 females; mean age 54.4 ± 9.4 years) were included in the study; 28 open, selective, tooth-supported templates were designed with the aim of inserting 38 implants. Among the surgical templates, 24 had optimal fit and stability, three had optimal fit and sufficient stability, and only one had inadequate fit and unsatisfactory stability and was therefore not suitable for clinical use. The average time of the intervention was 15.7 ± 5.2 min per template. No intra-operative complications were reported, but one implant was not stable at placement and had to be removed. In total, 36 implants were restored with 10 two-unit fixed partial prostheses and 16 single crowns. All implants were successfully functioning at one year, even if, in two single crowns, minor prosthetic complications (abutment screw loosening) occurred. CONCLUSIONS: Full in-office guided surgery with open, selective, tooth-supported templates seem to represent a clinically predictable surgical procedure to restore partially edentulous patients. Further studies are needed to confirm these positive outcomes.