Radiological, histological and clinical side effects of incisor trimming in rabbits.

INTRODUCTION: Incisor malocclusion in rabbits (Oryctolagus cuniculus) is a common clinical problem seen in general practice. Given that the growth rate is about 2 mm per week, a lack of wear quickly leads to feeding difficulties and soft tissue injuries. Therefore, pathologically elongated incisors must be shortened every three to six weeks. The goal of this study was to assess the potential adverse effects on dental and periodontal tissues associated with the three most commonly used trimming methods: nail cutter, diamond-coated cutting disc and diamond burr. The left mandibular incisor of 28 healthy New Zealand rabbits was subjected to four trimmings with one of the three cutting methods. After the fattening period, the mandibles were collected and both mandibular incisors were investigated on dental radiographs, micro-computed tomography scans and histological sections. Dental and periodontal tissue changes were evaluated. This study allowed a more accurate statement of the potential short-term adverse effects of the three trimming methods. At the clinical level, the nail cutter caused the formation of an irregular occlusal surface with sharp edges. Both engine-drive methods allowed the attainment of a smooth surface but the disc was less accurate. Histological evaluation revealed that the primary modifications, including coronal fractures, periodontal ligament widening and inflammation, reparative osteodentine, paracementosis and biofilm accumulation, were found in the nail cutter group.

INTRODUCTION: La malocclusion des incisives chez le lapin (Oryctolagus cuniculus) est un problème clinique courant en médecine générale. Étant donné que le taux de croissance est d'environ 2 mm par semaine, un manque d'usure entraîne rapidement des difficultés d'alimentation et des lésions des tissus mous. Par conséquent, les incisives pathologiquement trop longues doivent être raccourcies toutes les trois à six semaines. L'objectif de cette étude était d'évaluer les effets négatifs potentiels sur les tissus dentaires et parodontaux associés aux trois méthodes de taille les plus couramment utilisées: le coupeongles, le disque de coupe diamanté et la fraise diamantée. L'incisive mandibulaire gauche de 28 lapins néo-zélandais en bonne santé a été soumise à quatre tailles avec l'une des trois méthodes de coupe. Après la période d'engraissement, les mandibules ont été prélevées et les deux incisives mandibulaires ont été examinées sur des radiographies dentaires, des examens micro-tomodensitométriques et des coupes histologiques. Les modifications des tissus dentaires et parodontaux ont été évaluées. Cette étude a permis de mieux cerner les effets indésirables potentiels à court terme des trois méthodes de coupe. Au niveau clinique, le coupe-ongles a entraîné la formation d'une surface occlusale irrégulière avec des bords tranchants. Les deux autres méthodes de taille permettent d'obtenir une surface lisse, mais le disque est moins précis. L'évaluation histologique a révélé que les modifications primaires, y compris les fractures coronaires, l'élargissement et l'inflammation du ligament parodontal, l'ostéodentine réparatrice, la paracémentose et l'accumulation de biofilm, ont été trouvées dans le groupe coupe-ongles.

Change in taste sensation after orthognathic surgery.

OBJECTIVE: The objective of this study was to evaluate the effect of orthognathic surgery on taste sensation. MATERIALS AND METHODS: Thirty-five patients scheduled to undergo Le Fort I osteotomy (LFIO), sagittal split ramus osteotomy (SSRO), and bimaxillary surgery (BMS) were evaluated by administering localized and whole-mouth taste tests preoperatively and postoperatively at months 1, 3, and 6. The patients were asked to identify the quality of four basic tastes applied to six locations on the palate and tongue and to rate the taste intensities they perceived. Taste recognition thresholds and taste intesity scores were evaluted according to operation groups and follow-ups. RESULTS: There were significant decreases in the quinine HCl recognition thresholds at the postoperative follow-ups compared to the preoperative in LFIO patients (p = 0.043). There were significant decreases in sucrose taste intensity scores in the right posterolateral part of the tongue at months 3 and 6 compared to preoperative in SSRO patients (p = 0.046), and significant increases in quinine HCL taste intensity scores in the right and left anterior parts of the tongue at month 6 compared to preoperative in LFIO patients (p < 0.05). CONCLUSION: Taste perception is affected due to potential damage to the chemosensory nerves during orthognathic surgical procedures. Generally, non-significant alterations have been observed in taste perception after orthognathic surgery, except for significant alterations in bitter and sweet taste perceptions. CLINICAL RELEVANCE: Maxillofacial surgeons should be aware of taste perception change after orthognathic surgery procedures and patients should be informed accordingly. THE TRIAL REGISTRATION NUMBER (TRN): NCT06103422/Date of registration: 10.17.2023 (retrospectively registered).

[Evaluation of the 5-year clinical restoration effect of implants retained complete overdentures with Locator attachments in 48 patients].

PURPOSE: To observe the long-term clinical effect of implants retained complete overdentures with Locator attachments. METHODS: A total of 48 patients with edentulous jaws treated with implants retained complete overdentures with Locator attachments were selected from the Outpatient Department of Peking University School and Hospital of Stomatology from 2016 to 2017. Among them, 21 patients underwent double-maxillary complete overdentures restoration and 27 patients underwent single-maxillary restoration. A total of 230 implants were implanted. The clinical observation indicators included the implant survival rate, peri-implant mucosal bleeding on probing(BOP), the change in the vertical height of alveolar bone absorption around the implants, overdenture base fracture rate, artificial tooth fall off and fracture rate and other complications. The change of the locator attachment retention force of the implant-supported overdentures was evaluated. SPSS 13.0 software package was used for data analysis. RESULTS: During the five-years clinical observation period, 5 implants fell off, 1 narrow dimeter implant in the anterior zone was broken, and 12 implants were lost to follow-up. The implant survival rate was 97.25%. One year after the restoration therapy finished, peri-implant mucosal bleeding on probing (BOP+) was detected in 48 (21.4%) implants. The average BI was 0.21±0.42, which was higher in the anterior zone than that in the posterior zone. The vertical alveolar bone absorption height around the implants was (0.21±0.35) mm, 2 implants-supported complete overdenture bases were broken. After 5 years of restoration, 163(76.89%) implants had peri-implant mucosal bleeding on probing(BOP+). The average BI was 1.00±0.70, and the vertical alveolar bone absorption height around the implants was (0.58±0.85) mm. There was no significant difference between males and females. There was no significant difference in the peri-implant mucosal bleeding index and the alveolar bone vertical absorption height between the anterior zone and the posterior zone(P＞0.05). The mean BI of peri-implant mucosa and the vertical absorption height of peri-implant alveolar bone were significantly different between the 1-year observation period and the 5-year observation period respectively(P＜0.01). There were 17(26.15%) cases with overdenture bases fracture, and the fracture rate of artificial teeth was 16.92%. Most of them occurred in the midline area of the anterior zone and the location of the overdenture base on the locator attachments. The average first replacement time of the locator attachment nylon retainer washer was 34.2±10.3 months. CONCLUSIONS: Implants retained complete overdentures with Locator attachments are effective in long term clinical observation. Complications are mainly found in peri-implant mucosal bleeding on probing and vertical alveolar bone absorption, and tended to increase gradually over time. The fracture of the implant retains complete overdenture bases and the fall off or fracture of the artificial teeth are the second serious complications. Overdenture base with metal frame at the location of the Locator abutment and the midline of the anterior area should be strengthened, and narrow diameter implants should be avoided as far as possible in the anterior zone.

Endoscopically-assisted extraction of broken roots or fragments within the mandibular canal: a retrospective case series study.

PURPOSE: To assess the impact of endoscope-assisted fractured roots or fragments extraction within the mandibular canal, along with quantitative sensory testing (QST) alterations in the inferior alveolar nerve (IAN). METHODS: Six patients with lower lip numbness following mandibular third molar extraction were selected. All patients had broken roots or fragments within the mandibular canal that were extracted under real-time endoscopic assistance. Follow-up assessments were conducted on postoperative days 1, 7, and 35, including a standardized QST of the lower lip skin. RESULTS: The average surgical duration was 32.5 min, with the IAN exposed in all cases. Two of the patient exhibited complete recovery of lower lip numbness, three experienced symptom improvement, and one patient remained unaffected 35 days after the surgery. Preoperative QST results showed that the mechanical detection and pain thresholds on the affected side were significantly higher than those on the healthy side, but improved significantly by postoperative day 7 in five patients, and returned to baseline in two patients on day 35. There were no significant differences in the remaining QST parameters. CONCLUSIONS: All endoscopic surgical procedures were successfully completed without any additional postoperative complications. There were no cases of deterioration of IAN injury, and lower lip numbness recovered in the majority of cases. Endoscopy allowed direct visualization and examination of the affected nerve, facilitating a comprehensive analysis of the IAN.

Comparison of condylar position after free fibular flap mandibular reconstruction using computer-assisted and traditional techniques.

OBJECTIVES: To compare the changes in condylar position after mandibular reconstruction with free fibular flap(FFF) and the differences between computer-assisted techniques and traditional methods on CT images. METHODS: Thirty-four patients who underwent mandibular reconstruction with free fibular flap were selected according to the inclusion and exclusion criteria. In the 3D group, virtual surgical planning (VSP) with osteotomy cutting plate and placement guiding plate were used, while the traditional group underwent freehand reconstruction. The CT data of 68 temporomandibular joints (TMJs) were recorded before and immediately after surgery. The condylar position was evaluated by measuring the anterior space (AS), posterior space (PS) and superior space (SS), and the ln (PS/AS) was calculated according to the method proposed by Pullinger and Hollender. RESULTS: In the patients included in the 3D group, the condyle on the ipsilateral side moved slightly backward; however, in the patients in the traditional group, the ipsilateral side moved considerably anteroinferior. No obvious changes on the contralateral side were noted. In the 3D group, 33% of ipsilateral condyles were in the posterior position postoperatively when compared with the preoperative position (13%). In the traditional group, the number of ipsilateral condyles in the anterior position increased from 4 to 10, accounting for 53% postoperatively. Contrary to the traditional group, the 3D group presented less condylar displacement on the ipsilateral side postoperatively. CONCLUSIONS: This study showed a decreased percentage of change in condylar position postoperatively when VSP was used. Virtual surgical planning improved the accuracy of FFF mandibular reconstruction and made the condylar position more stable.

3D printing vs traditional workflow for the fabrication of mandibular implant overdentures: study protocol for a mixed-methods cross-over RCT.

BACKGROUND: Complete tooth loss is a significant global oral health issue, particularly impacting older individuals with lower socioeconomic status. Computer-assisted technologies enhance oral healthcare access by the elderly. Despite promising in vitro reports on digital denture materials, evidence from randomized clinical trials (RCTs) is lacking to verify their performance. This cross-over RCT will investigate whether 3D-printed implant-retained mandibular overdentures (IMO) are more satisfactory for edentulous seniors than those made through traditional methods. METHODS/DESIGN: We will recruit 26 completely edentulous participants (any sex/gender) based on the following eligibility criteria: age ≥ 60 years, no tooth extraction in the past 12 months, two implants in the lower jaw, and need for new dentures in both jaws. Each participant will receive two denture pairs, either manufactured by 3D printing or traditionally, to be worn in a random order. A timeline of 3 months with each denture pair will be considered for outcome assessment (total: 6 months). Patient satisfaction with dentures will be measured by the McGill Denture Satisfaction Questionnaire. We will evaluate other patient-reported outcomes (including oral health-related quality of life) as well as clinician-assessed quality and cost. At the end of the trial, participants will choose which denture pair they wish to keep and interviewed about their experiences with the 3D-printed IMO. The quantitative and qualitative data will be incorporated through an explanatory mixed-methods strategy. A final quantitative assessment will happen after 12 months with the preferred IMO to assess the long-term performance and maintenance needs. DISCUSSION: This mixed-methods RCT will explore patient experiences with 3D-printed IMOs, aiming to assess the potential for altering clinical practice and dental public health policies. Our results will inform policies by showing whether 3D printing offers comparable outcomes at lower costs, facilitating greater access to oral care for the elderly. TRIAL REGISTRATION: ClinicalTrials.gov, NCT06155630, Registered on 04 December 2023. https://classic. CLINICALTRIALS: gov/ct2/show/NCT06155630.

[Clinical observation of minimally invasive extraction of lower third molar by retaining the buccal bone plate].

PURPOSE: To explore the effect of extracting the completely impacted teeth by minimally invasive surgery with preserving the buccal bone plate. METHODS: Eighty-six cases were selected and randomly divided into 2 groups. In the experimental group, a fenestration was made with a ball drill to expose the buccal and lingual margin of crown, and the buccal bone plate was preserved. T-shaped crown cuttings were performed, minimally invasive extraction was conducted.In the control group, the distal and buccal bone plates were removed with a ball drill, the distal and buccal crowns were exposed, and T-shaped crown was cut. The other procedures were the same. The degree of swelling, restricted mouth opening and VAS pain score after operation were observed, the levels of C-reactive protein and anti-hemolytic streptoglobulin were detected by laboratory tests, and the periodontal probing depth(PD), bleeding index (BI), and clinical attachment loss(CAL) of the adjacent second molar were examined 1 month after surgery. SPSS 25.0 software package was used for data analysis. RESULTS: The swelling degree of the two groups was significantly relieved in the experimental group than in the control group (P＜0.05), and there was no significant difference in the degree of mouth opening limitation and pain (P＞0.05). The level of C-reactive protein in the control group was significantly higher than that in the observation group (P＜0.05). There was no significantly difference in the level of anti-hemolytic streptococcus between the 2 groups (P＞0.05). One month after operation, the PD and CAL in the control group were significantly higher than those in the experimental group(P＜0.05). There was no significant difference between the 2 groups in BI(P＞0.05). CONCLUSIONS: The patients who preserve the buccal bone plate by minimally invasive extraction of impacted mandibular teeth have less reaction and better wound healing.

Ramus Frame Dental Implant Functional Survival and Safety in Severely Atrophic Edentulous Human Mandibles.

Ramus frame dental implants were retrospectively studied in 360 adults with severely atrophic edentulous mandibles. Patient records up to 12 years post-treatment were independently reviewed after a single clinician surgically placed titanium long-arm ("Tatum") ramus frame implants and immediately loaded them with a mandibular overdenture. A total of 11 ramus frames were removed at 19 to 109 months post-treatment, mostly due to supramucosal bar fracture (N = 6) or mobility (N = 3). Kaplan-Meier product-limit analysis revealed the post-treatment survival probability for functional ramus frame implants to be 99.3% at 2 years (266 patients), 98.9% at 3 years (223 patients), 97.9% at 4 years (198 patients), 96.9% at 5 years (160 patients), 96.9% at 6 years (123 patients), 95.0% at 7 years (86 patients), 95.0% at 8 years (67 patients), 93.3% at 9 years (43 patients), and 91.1% at 10 years (25 patients). No statistically significant differences in functional ramus frame implant survival were found relative to patient gender, smoking, presence of natural maxillary teeth, or compliance with semi-annual maintenance care. Fracture of endosseous anterior feet/posterior arms was the most frequent implant-related complication on 29 implants, which were left in place, repaired, or replaced in situ without implant removal. At 5 years, the ramus frame implant functional survival probability without any implant-related biological or mechanical complication was 88.9%. Ramus frame dental implants, immediately loaded with a fully implant-borne mandibular overdenture, exhibited a high degree of long-term functional survival and safety in severely atrophic edentulous human mandibles.

Evaluation of masticatory efficiency and OHRQoL in implant-retained overdenture with different numbers of implant in the edentulous mandible: a one-year follow-up prospective study.

PURPOSE: The aim of this article is to evaluate to the masticatory function performance and Oral Health-related Quality of Life (OHRQoL) in implant-retained overdenture compared with different implant number placements in the edentulous mandible. METHODS: From 2013 to 2015, each patients received 3 implants (iSy-Implant, Camlog, Wimsheim, Germany) in intraforaminal mandible (34, 41/31, 44). After operation, inserted implants were gradually loaded and incorporated into an overdenture with a self-aligning attachment system (Locator abutments) in 3 + 3 + 3 months. Five checked points were performed chewing cycle test with multicolored chewing gum and OHIP-G14 questionnaire and a sum score questionnaire as following: pre-operation, one implant load (41/31), two implants loaded (33,43), three implants loaded and 1-year follow up. RESULT: A total of 10 patients with 30 implants were placed, the survival rate of the implants was 100% within 1-year follow-up. Regarding the masticatory function analysis, for the higher number of chewing cycles, the higher mixing rate was observed. After 1 year, the inter-mixing rate without significant changes was found compared to the time after three implants were loaded with attachment system. The mean value of OHIP-G14 was 30.4 preoperatively, 21.1 after loading the first locator, 10.7 after loading two locator abutments, and 3.2 after loading all three locator abutments. After 1 year, OHIP-G14 was 2.6 without significantly changed. The mean of the sum score was 15.5 preoperatively, 27.8 after activation of the first locator, 39.4 after activation of two locators, 46.2 after activation of all three locators, and 47.3 after 1 year. An increase of 0.7 sum score units per time point was observed. No significance was detectable, analogous to OHIP-G14, compared to the time of activation of all three locator setups (p-value = 0.22). CONCLUSIONS: A significant improvement in masticatory function performance and OHRQoL was evaluated with the increasing number of implants with locator attachment in edentulous mandible. With the investigation of the OHIP-G14 and sum score, the results of patient report outcome might be associated with the increase in the number of implants.

Immediate implant placement in the anterior mandible: a cone beam computed tomography study.

BACKGROUND: The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. PURPOSE: This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. MATERIALS AND METHODS: CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. RESULTS: Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). CONCLUSION: The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning with CBCT is a great tool for minimizing the risk of implant unsafe placement with regards to the anatomical conditions in the mandible.

Minimally invasive surgical removal of bilateral impacted mandibular supernumerary teeth using 3D surgical guide template: a case report.

Impacted supernumerary teeth are defined as the presence of one or more teeth in a patient's upper and lower jaws in addition to the normal number of teeth in the dental arch. It has an incidence rate of approximately 1%-14% and more frequently occurs in males than females, may be single or multiple, unilateral or bilateral, erupted or impacted. In this article, we describe the case of a patient with two supernumerary teeth between the roots of the mandibular second premolar and the first molar, which influenced the effectiveness of the first orthodontic treatment. The special anatomical position of the complex supernumerary teeth made tooth extraction challenging. Given the higher risk status of surgery, we implemented a novel tooth extracting technique for this patient. Thus, in this study, we describe a case of minimally invasive extraction of bilateral mandibular impacted supernumerary teeth using a digital 3D positioning guide plate.

Curettage combined with decompression for the treatment of ameloblastoma in children: report of two cases.

BACKGROUND: Ameloblastoma (AM) is the most common benign odontogenic tumor, which is more often detected in the mandible than maxilla, especially the mandibular body and mandibular angle. Pediatric AM is a rare disease, especially in patients aged 10 and younger. Compared with the mainstream osteotomy and reconstructive surgery for adult ameloblastoma, there is more room for discussion in the treatment of pediatric ameloblastoma. The postoperative functional and psychological influence can not be ignored. Especially for children in the period of growth and development, an osteotomy is often challenging to be accepted by their parents. We report two patients with ameloblastoma under 10 years old who are treated with curettage and fenestration, which is a beneficial method for children with ameloblastoma. CASE PRESENTATION: We present two cases of classic ameloblastoma in children. We describe in detail the patients' characteristics, treatment processes, and follow-up result. The bone formation and reconstruction in the lesion area after fenestration decompression and curettage are recorded at every clinic review. The surgical details and principles of curettage and decompression are also described and discussed. The two patients have good bone shape recovery and no recurrence. CONCLUSIONS: Children are in the growth and development period and possess an extremely strong ability of bone formation and reconstruction. Based on the principles of minimally invasive and functional preservation, we believe that curettage combined with decompression can be the first choice for treating AM in children, especially for mandibular lesions.

Evaluating risk factors and complications in mandibular ramus block grafting: a retrospective cohort study.

OBJECTIVES: This retrospective cohort study aimed to identify the complications and risk factors associated with alveolar grafting using autologous mandibular ramus grafts, guided by the research question: What are the complications encountered in patients undergoing alveolar bone grafting using autologous mandibular ramus block and what are the risk factors associated with the development of these complications? MATERIALS AND METHODS: The study included 70 patients who underwent alveolar crest augmentation with autologous mandibular ramus block grafting. Intraoperative, early postoperative, and late postoperative complications were analyzed, as were various risk factors. RESULTS: The results showed that the majority of patients had successful outcomes with minimal complications. Sex was found to significantly influence the visibility of the inferior alveolar nerve (IAN). Early postoperative complications were associated with IAN visibility and the use of a single screw for graft fixation. Late postoperative complications were significantly associated with the presence of infection. CONCLUSION: The findings emphasize the importance of careful surgical techniques, infection prevention, and patient selection in minimizing complications. CLINICAL RELEVANCE: This article may contribute to clinicians' and so patients' understanding of potential risk factors associated with over all ramus block grafting procedure. Based on this information, clinicians can also improve their ability to manage risk factors and associated complications and compare ramus block grafting with other alternatives to determine the best treatment approach for that particular patient.

[Analysis of surgical approaches and mandibular treatment strategies for different types of tumors involving parapharyngeal space].

In view of the surgical complexity of parapharyngeal space tumors involved, this paper summarized the disease data of patients with parapharyngeal space tumors involved in the Department of Oral and Maxillofacial Surgery, the First Hospital of Shanxi Medical University from January 2015 to January 2021. It also summarized the surgical approach and mandibular management, so as to explore surgical strategies for different characteristics of parapharyngeal space tumors involved. A total of 49 patients, including 28 males and 21 females, median age 52 years (range 24-72 years). They were treated with four surgical approaches for tumor resection, 25 cervical approach, 5 cheek and neck approach, 3 transoral approach, and 16 cervical-maxillary approach. Among the patients treated with cervical-maxillary approach, 3 patients were treated with mandible square resection, and 6 patients were treated with temporary mandible dissection. Seven cases were treated with tumor resection and partial mandibular resection. There are various surgical approaches and mandibular management methods involving tumors in the parapharyngeal space, and clinical decisions should be made based on tumor diameter, location, boundary, blood supply and pathological types.

Functional and esthetic outcomes of virtual surgical planning versus the conventional technique in mandibular reconstruction with a free fibula flap: A retrospective study of 24 cases.

This study aimed to compare the functional and esthetic results in patients following mandibular reconstruction with a free fibula flap (FFF) by virtual surgical planning (VSP) versus the conventional technique. Patients who had undergone mandibular reconstruction with a FFF by VSP or the conventional technique were retrospectively assessed. The two groups were compared regarding functional and esthetic variables with appropriate scales preoperatively, intraoperatively, and postoperatively. Twenty-four patients were evaluated in two groups: conventional (n = 8) and VSP (n = 16). The mean amount of mandibular asymmetry was 2.62 mm (SD = 1.59) in the conventional group and 1.19 mm (SD = 1.32) in the VSP group. Of the patients who underwent conventional surgery, 12.5% had mandibular asymmetry of <2 mm and 87.5% had asymmetry of 2-5 mm. Of the VSP patients, 61.5% had mandibular asymmetry of <2 mm and 38.5% had mandibular asymmetry of 2-5 mm (p = 0.03). The mean difference in size of mandibular angle on the surgical and control sides was not significantly different between the two groups (p = 0.62). The difference in mean length of the mandibular body on the surgical side relative to the control side was not significant between the two groups (p = 0.75). Differences in functional variables between the two groups were not significant. Within the limitation of the study, it seems that the VSP technique resulted in better facial symmetry and superior esthetic outcomes compared with the conventional technique.

Streamlining complex mandibular fracture treatment: Integration of virtual surgical planning and short-segment drilling guides.

This study aimed to evaluate the feasibility and accuracy of a combined virtual surgical planning (VPS) and short-segment drilling guides (SSDGs) workflow for the treatment of complex mandibular fractures. Consecutive patients with complex mandibular fractures underwent treatment using the VPS and SSDGs workflow from August 2020 to April 2022. Various mandibular landmarks were compared between the preoperative virtual surgical plan and postoperative data, including condylar distance (CoD), mandibular angle width (GoL-GoR), GoMeGo angle (∠GoL-Me-GoR), the difference in mandibular angles between the left and right sides (Δ∠Co-Go-Me), and the difference in length between the left and right mandibular body (ΔGo-Me). Additionally, preoperative preparation time and surgical duration were retrospectively analyzed and compared to conventional surgery. All 14 consecutive patients with complex mandibular fractures achieved successful reduction using the VPS and SSDGs workflow. Three-dimensional comparison revealed a mean deviation distance of 0.91 ± 0.50 mm and a root-mean-square deviation of 1.75 ± 0.47 mm between the preoperative designed mandible model and the postoperative mandible model. The percentage of points with deviation distances less than 2 mm, 1 mm, and 0.5 mm between preoperative and postoperative models were 78.47 ± 8.87 %, 60.02 ± 14.28 %, and 38.64 ± 15.48 %, respectively. There were no significant differences observed in CoD, GoL-GoR, ∠GoL-Me-GoR, Δ∠Co-Go-Me, and ΔGo-Me between preoperative virtual surgical planning and postoperative measurements. Furthermore, no significant differences were found in the injury-to-surgery interval, admission-to-surgery interval, and surgical duration between the workflow and conventional surgery. The combined VPS and SSDGs workflow proved to be an accurate and feasible method for treating complex mandibular fractures. It offers advantages such as minimal preoperative preparation time and the ability to precise transfer screw positions of the pre-bent reconstruction plate during surgery. This approach is particularly suitable for managing complex mandibular fractures.

An in vitro study in separating tensile loads during maxillo-mandibular fixation using wire and/or elastics.

Intermaxillary fixation (IMF) or maxillo-mandibular fixation (MMF) is a fundamental process in stabilizing the maxilla and mandible through dental maximum intercuspation (MIP) during the management of trauma, orthognathic surgery, and reconstruction. Despite the availability of several techniques in achieving adequate maxillo-mandibular fixation, concerns have been raised regarding the sufficiency of using only latex elastics to counter displacing forces during reduction and fixation. To address this, an in vitro study was conducted to compare the efficacy of three maxillo-mandibular fixation methods: wire, elastics, and a combination of both. Custom-made models simulating dental arches were used, and a vertical separation of up to 1 mm was applied at a loading rate of 1 mm/minute using an Instron 5566 Universal Testing Machine. Tensile loads were recorded at 0.5 and 1 mm vertical separation, with each process repeated 10 times in each sample group. The average peak tensile load was then calculated. Statistical analysis using one-way ANOVA at a significance level of p<0.05 revealed significant differences between all three subject groups. The outcomes of this in vitro study suggest that the combination technique (using both wire and elastics) outperformed the individual methods in achieving robust maxillo-mandibular fixation. This positions the combination technique as the most effective among the evaluated fixation methods.

Clinical efficiency and stability of surface-modified implants: acid modification versus photoactivation.

OBJECTIVE: . Aim: To study the stability of surface-modified dental implants, with the usage of sandblasting/acid modification vs. photoactivation. PATIENTS AND METHODS: Materials and Methods: In the observation were included 164 patients with dental defects. All patients had digital impressions taken by scanning the oral cavity with an intraoral scanner 3Shape TRIOSR. Group A (80 subjects) included implants whose surface was modified with a combination of sandblasting and acid. Group B (84 subjects) - implants after modification with photoactivation. The implant stability quotient was recorded using an Osstell MentorTM device. RESULTS: Results: The reliable effectiveness of the photoactivation method in complex treatment of the surface of dental implants in improving the stability of fixed dentures in the short and long-term periods of observation was proven. When assessing immediate clinical outcomes, there was no significant difference in the frequency of hyperemia, algesia, hyperthermia, soft tissue edema, regional lymphadenitis, depending on the classical method of treating the implant surface and the complex method with photoactivation. Of the long-term clinical outcomes with classical surface treatment, the absolute risk of implant failure was 1.2%, relative risk - 0,99 [CI%0,96-1,0]. The average value of the implant stability coefficient (ISQ) and the data of the Periotest study at the time of surgery probably did not differ in the observation groups, after 3 months, a higher index was proven in the treatment of the surface by the method of photoactivation and greater stability of the mandibular implants. At the time of implantation, there were no statistically significant differences in implant fixation between the groups, however, during prospective observation in group A, secondary stability indicators based on periotestometry results were significantly lower. CONCLUSION: Conclusions: It was proved the reliable effectiveness of the photoactivation-method for surface modification in the short and long-term periods of observation for improving the results of orthodontically treatment.

Reparative osteogenesis in mandible in cases of filling a bone defect with hydroxyapatite-containing osteotropic material and injecting the surrounding soft tissues with thymalin: experimental and morphological study.

OBJECTIVE: Aim of the study was to identify the morphological features of reparative osteogenesis in the lower jaw bone of rats in cases of filling a bone defect with hydroxyapatite-containing osteotropic material (bone graft "Biomin GT") and injecting the surrounding soft tissues with thymalin. PATIENTS AND METHODS: Materials and Methods: An experiment was conducted on 48 mature rats of the WAG population weighing 160-180 grams which were divided into four groups. Group 1 included 12 rats with a simulated holey defect in the lower jaw. Group 2 included 12 rats with a simulated holey defect in the lower jaw followed by its closure with hydroxyapatite-containing osteotropic material (bone graft "Biomin GT"). Group 3 included 12 rats with a simulated holey defect in the lower jaw with injecting the surrounding soft tissues with thymalin. Group 4 included 12 rats with a simulated holey defect in the lower jaw followed by its closure with hydroxyapatite-containing osteotropic material (bone graft "Biomin GT") and injecting the surrounding soft tissues with thymalin. The material for the morphological study was a fragment of the lower jaw from the area of the simulated holey defect. Histological, morphometric and statistical research methods were used. RESULTS: Results: In this study, it was shown by the authors an activation of reparative osteogenesis in the lower jaw under conditions of simultaneous filling the bone defect with hydroxyapatite-containing osteotropic material (bone graft "Biomin GT") and injection the surrounding bone defect soft tissue with thymalin. Stimulation of reparative osteogenesis in the lower jaw of rats occurred due to rapid cleaning of the bone defect cavity from necrotic tissues and hematoma fragments; a decrease in the number of neutrophil leukocytes, an increase in the number and morphofunctional state of monocytes, macrophages, lymphocytes, cells of fibroblastic differon; balanced change (increase or decrease) in the number and morphofunctional state of bone forming osteoblasts and bone resorbing osteoclasts depending on the stage of reparative osteogenesis; activation of hematopoietic processes in lamellar bone tissue from the regenerate; activation of bone tissue mineralization processes. CONCLUSION: Conclusions: Thymalin injection in the soft tissues surrounding the bone defect in the lower jaw, filled with hydroxyapatite-containing osteotropic material (bone graft "Biomin GT"), significantly stimulates the process of reparative osteogenesis, which makes it possible to recommend this technique in dentistry for treatment the patients with mandible bone tissue defects.

Lateralization of the Inferior Alveolar Nerve in the Rehabilitation of Mandibular Atrophy: Case Report.

The lateralization of the inferior alveolar nerve, or LIAN procedure, may be a surgical consideration for implant-prosthetic rehabilitation in the edentulous mandibular posterior region. This technique can be advantageous in that it does not require a donor site and allows for the immediate placement of an implant, potentially leading to reduced morbidity, healing time, and costs. Although such risks as altered sensory nerve function and weakening of the mandibular body are associated with the LIAN procedure, it is a viable alternative to various regenerative techniques to rehabilitate a patient with an implant-supported fixed prosthesis.