[Isolation and characterization of normal mandibular periosteal stem cells from human and macaca mulatta and cross-species single-cell analysis].

Objective: To investigate the presence of a distinct stem cell populations different from mesenchymal stem cells in the mandibular periosteum of both human and non-human primates (macaca mulatta), to explore its properties during intramembranous osteogenesis and to establish standard protocols for the isolation, culturing and expanding of mandibular periosteal stem cells (PSC) distinguished from other PSCs in other anatomical regions. Methods: Periosteum was harvested from the bone surface during flap bone removal in patients aged 18-24 years undergoing third molar extraction and from the buccal side of the mandibular premolar region of 6-year-old macaca mulatta respectively, and then subjected to single-cell sequencing using the Illumina platform Novaseq 6000 sequencer. Cross-species single-cell transcriptome sequencing results were compared using homologous gene matching. PSC were isolated from primary tissues using two digestion methods with body temperature and low temperature, and their surface markers (CD200, CD31, CD45 and CD90) were identified by cell flow cytometry. The ability of cell proliferation and three-lineage differentiation of PSC expanded to the third generation in vitro in different species were evaluated. Finally, the similarities and differences in osteogenic properties of PSC and bone marrow mesenchymal stem cells (BMSC) were compared. Results: The single-cell sequencing results indicated that 18 clusters of cell populations were identified after homologous gene matching for dimensionality reduction, and manual cellular annotation was conducted for each cluster based on cell marker databases. The comparison of different digestion protocols proved that the low-temperature overnight digestion protocol can stably isolate PSC from the human and m. mulatta mandibular periosteum and the cells exhibited a fibroblast-like morphology. This research confirmed that PSC of human and m. mulatta had similar proliferation capabilities through the cell counting kit-8 assay. Flow cytometry analysis was then used to identify the cells isolated from the periosteum expressed CD200(+), CD31(-), CD45(-), CD90(-). Then, human and m. mulatta PSC were induced into osteogenesis, adipogenesis, and chondrogenesis to demonstrate their corresponding multi-lineage differentiation capabilities. Finally, comparison with BMSC further clarified the oesteogenesis characteristics of PSC. The above experiments proved that the cells isolated from the periosteum were peiosteal cells with characteristics of stem cells evidenced by their cell morphology, proliferation ability, surface markers, and differentiation ability, and that this group of PSC possessed characteristics different from traditional mesenchymal stem cells. Conclusions: In this study, normal mandibular PSC from humans and m. mulatta were stably isolated and identified for the first time, providing a cellular foundation for investigating the mechanism of mandibular intramembranous osteogenesis, exploring ideal non-human primate models and establishing innovative strategies for clinically mandibular injury repair.

[Effects of cortical bone thickness and jaw bone density on pain during implant surgery].

PURPOSE: To investigate the effects of different cortical bone thickness and jaw bone density at implant sites on intraoperative pain during implant surgery. METHODS: One hundred and eighty-seven patients(263 implant sites) who underwent implant placement surgery at the Fourth Affiliated Hospital of Nanchang University from August 2021 to August 2022 were selected to investigate the effects of different cortical bone thickness and jaw bone density HU values at implant sites on the anesthetic effect under local infiltration anesthesia with epinephrine in articaine. SPSS 26.0 software package was used for data analysis. RESULTS: The mean cortical bone thickness at the painful sites[(3.90±1.36) mm] was significantly greater than that at the non-painful sites [(2.24±0.66) mm], and the difference was statistically significant(P＜0.05). The differences in cortical bone thickness in the mandibular anterior, premolar, and molar regions were statistically significant in the comparison of pain and non-pain sites. The mean HU value of bone density was (764.46±239.75) for the painful sites and (612.23±235.31) for the non-painful sites, with significant difference(P＜0.05). The difference was not significant(P＞0.05) when comparing the HU values of painful sites with non-painful sites in the mandibular anterior teeth and anterior molar region, while the difference was significant(P＜0.05) when comparing the HU values of painful sites with non-painful sites in the mandibular molar region. CONCLUSIONS: Sites with large cortical bone thickness have a greater effect on blocking infiltrative anesthetic penetration and are more prone to intraoperative pain during implantation. In the mandibular anterior and premolar regions, the HU value of the implant sites had less effect on infiltrative anesthetic penetration, and the effect was greater in the mandibular molar region, and the implant sites with high HU values in the mandibular molar region were more likely to have intraoperative pain. When the cortical bone thickness in the planned implant site is greater than 3.9 mm and the mean bone density in the mandibular molar region is greater than 665 HU. If there is sufficient safe distance for hole operation, it is recommended to apply mandibular nerve block anesthesia combined with articaine infiltration anesthesia to avoid intraoperative pain and bad surgical experience for the patients.

Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study.

AIM: To assess the implant stability and amount of marginal bone loss in immediate implant placement (IIP) in mandibular molars by using pre-extractive interradicular implant bed preparation vs conventional post-extractive interradicular implant bed preparation. MATERIALS AND METHODS: This randomized clinical trial was conducted on fourteen patients who had an immediate dental implant at the mandibular molar area by two different techniques. All patients were divided randomly into two equal groups: Group I (control) was treated with conventional post-extractive interradicular implant bed preparation, and group II (test) was treated by pre-extractive interradicular implant bed preparation All surgeries were performed by the same surgeon. All patients were followed up clinically at immediate post-surgery (T0), 7 days (T1), 3 weeks (T2), 90 days (T3), and 3 months after loading (T6) for healing and to evaluate the marginal bone loss radiographically at T0, T3 and T6. Descriptive and bivariate statistics were computed using the SPSS version (SPSS, IBM Inc., Chicago, IL), and p ≤ 0.05 was considered an indicator of statistical significance. RESULTS: A total of 7 female and 7 male patients with a mean age of 32.07 ± 5.87 years. Radiographically, there is no significant statistical difference in comparing between two groups for the marginal bone loss. However, there was a highly significant statistical difference (p < 0.001) in each group between different interval periods (T0, T3, T6) with mean start 5.27 ± 0.53, and 5.19 ± 0.72 at (T0) reaching 7.60 ± 0.89 and 7.09 ± 0.96 at (T3) and slightly decrease of 7.52 ± 0.79 and 7.02 ± 0.79 in (T6) with radiographic evaluation, and it represented clinically in each group with mean 3.57 ± 0.313 and 4.0 ± 0.58 at (T0) increase to 6.55 ± 0.395 and 6.52 ± 0.45 at (T6) for both group respectively. There is no statistically significant difference in soft tissue healing with an average mean of 4.57 ± 0.24 and 3.57 ± 0.509 (p = 0.001) when comparing between both groups respectively. CONCLUSION: Both techniques seem useful for dental implant placement in badly decayed mandibular molars. However, pre-extracted interradicular implant bed preparation for IIP might offer advantages in terms of primary implant stability and bone preservation. However, further studies are needed to confirm these findings. CLINICAL SIGNIFICANCE: Both techniques are alternative methods for the treatment of badly decayed mandibular molars by immediate dental implant except for minor complications that do not interfere with dental implant placement. How to cite this article: Alzaibak LMA, Abdel-Monem TM, Elgohary NM, et al. Immediate Implant Placement with Different Interradicular Osteotomies in the Mandible: A Randomized Clinical Study. J Contemp Dent Pract 2024;25(4):303-312.

Rare mandibular condition presenting as trismus: an exploration of IgG4-related disease.

A woman in her 30s presented with a 12-month history of reduced mouth opening and swelling on the right side of her mandible. The swelling was non-tender and firm on palpation. The swelling began to increase in size after the extraction of her carious wisdom tooth. Histopathological and serological examinations confirmed the diagnosis of IgG4-related disease, manifested as a mass in the mandible. The patient was prescribed oral corticosteroids at a tapering dosage over 8 weeks. After 3 months, there was an improvement in the patient's mouth opening and a reduction in the size of the swelling. The patient remains in follow-up care. Including IgG4-related disease in the list of potential diagnoses for oral soft tissue masses is crucial, given their positive response to medical treatment, highlighting the significance of an accurate diagnosis to prevent unnecessary surgery, with oral lesions potentially serving as early indicators before multiorgan complications arise.

A three-dimensional quantitative assessment on bony growth and symmetrical recovery of mandible after decompression for unicystic ameloblastoma.

Unicystic ameloblastoma (UAM) of the jaw can be effectively reduced in volume through decompression, which promotes bone regeneration and restores jaw symmetry. This study quantitatively evaluated changes in mandible volume and symmetry following decompression of mandibular UAM. This study included 17 patients who underwent surgical decompression followed by second-stage curettage for mandibular UAM. Preoperative and postoperative three-dimensional computed tomography (CT) images were collected. Bone volume and the area of cortical perforation were measured to assess bone growth during decompression. Mandibular volumetric symmetry was analyzed by calculating the volumetric ratio of the two sides of the mandible. Twelve pairs of landmarks were identified on the surface of the lesion regions, and their coordinates were used to calculate the mean asymmetry index (AI) of the mandible. Paired t-tests and the Mann-Whitney U test were used for statistical analysis, with p < 0.05 considered indicative of statistical significance. The mean duration of decompression was 9.41 ± 3.28 months. The mean bone volume increased by 8.07 ± 2.41%, and cortical perforation recovery was 71.97 ± 14.99%. The volumetric symmetry of the mandible improved significantly (p < 0.05), and a statistically significant decrease in AI was observed (p < 0.05). In conclusion, UAM decompression enhances bone growth and symmetry recovery of the mandible. The present evaluation technique is clinically useful for quantitatively assessing mandibular asymmetry.

[Harvesting of autologous bone graft for the mandible: from the hip or the jaw?] / Oogsten van autologe botgraft voor de mandibula: uit heup of kaak?

A 61-year-old edentulous patient presented with dental problems. Examination revealed a very narrow alveolar process in the symphysis area of the chin, with moderate vertical resorption. The decision was made for bone augmentation by means of harvesting an autologous bone graft from the alveolar process. This method can be carried out in an outpatient or day surgery unit and is much more cost effective and less invasive than harvesting an autologous bone graft from the hip area.

Does mandibular advancement ortho-surgical procedure cause condyle changes? A case-series analysis.

INTRODUCTION: Mandibular advancement surgery corrects bone bases while establishing patients' functional and aesthetic rehabilitation. However, little is known about the results of this procedure in the structures that make up the stomatognathic system, as the condyles. OBJECTIVE: This study aimed to evaluate the structural and positional changes of mandibular condyles in ortho-surgical patients who underwent mandibular advancement surgery. MATERIAL AND METHODS: A prospective investigation was conducted with cone-beam computed tomography images. Using Dolphin Imaging® software, seven ortho-surgical patients with Angle Class II malocclusion and mandibular deficiency were evaluated. The images assessed were obtained at pre-surgical phase and after, at least, 1 year of the procedure. To study the structural and positional changes of condyles, linear and angular measurements were obtained, and the right and left sides of patients were compared. Descriptive statistical analysis was performed and, in order to verify possible significant differences, normality tests (Kolmogorov-Smirnov) were applied, followed by a paired t-test to define significance. RESULTS: For all measures evaluated in this study, no statistically significant differences were found. CONCLUSION: The ortho-surgical procedure performed did not change the structure and position of the condyles of patients who underwent surgical mandibular advancement. Right and left mandibular condyles behaved similarly, suggesting stability and condylar adaptation after surgery.

Schizodontic Molarization of Mandibular Premolars: A Case Report of Gemination.

Background: Tooth gemination is a single enlarged or joined tooth with a normal tooth count when the anomalous tooth is counted as one. Mandibular second premolars show an elevated variability of crown morphology. Only nine cases of isolated second premolar macrodontia have been reported in the literature. Case Description: This case report presents the clinical and radiographic findings and conservative treatment of an atypical and rare case of localized bilateral molarization of mandibular second premolars. Conclusion: Dental professionals should acquire deeper knowledge about anomalies and plan treatment carefully to avoid unexpected complications during dental procedures caused by morphological ignorance.

Cyanoacrylate versus suture as flap closure methods in mandibular third molar surgery: a split-mouth randomized controlled clinical study.

BACKGROUND: Sutures have been the standard flap closure method of choice following mandibular third molar surgery but can lead to some complications. Tissue adhesives, including cyanoacrylate, have emerged as alternative flap closure method in this surgery to overcome such drawbacks. However, limited clinical trials can be found. Therefore, the aim of this clinical study was to compare two methods of flap closure in mandibular third molar surgery, cyanoacrylate and 4/0 silk sutures, by assessing post-operative outcome measures (pain, swelling, trismus, and healing) and patient-reported outcome measures (PROMs). MATERIAL AND METHODS: A randomized split-mouth clinical trial was designed, in which mandibular third molar (M3M) extractions were performed, where the control side flap was closed with 4/0 silk sutures and the test side flap with cyanoacrylate. Swelling, pain, trismus, healing, and PROMs were recorded post-operatively. These variables were analyzed by means of the nonparametric Mann-Whitney U test, using SPSS statistical software version 28.0.0 (IBM® SPSS®, Chicago, IL, USA). For all results, a 95% confidence interval was recorded (significance level p < 0.05, two-tailed). RESULTS: A total of 17 patients were recruited and 34 mandibular third molar extractions were performed. No statistically significant differences were found in terms of swelling, pain, trismus, healing, and PROMs between both groups (p<0.05). CONCLUSIONS: No statistically significant differences were found between flap closure with 4/0 silk sutures and cyanoacrylate, in terms of surgical post-operative outcomes and PROMs. However, further studies with larger sample sizes are required to be able to affirm it with greater certainty.

Evaluation of the resection plane three-dimensional positional accuracy using a resection guide directional guidance slot; a randomized clinical trial.

AIM: The study was performed to compare the mandibular resection guide with a directional guidance slot with the conventional guide regarding three-dimensional positional accuracy. MATERIALS AND METHODS: Twenty-six patients with lateral segmental mandibular defects were selected, and randomly allocated into two groups. All defects were managed with preoperative virtual surgical planning. Resection in the test group was conducted using a resection guide with a directional guidance slot, while a conventional resection guide design was utilized in the control group. The linear and angular deviation of the osteotomy planes was analyzed for both groups, along with the accuracy of the insertion of the reconstruction bone block in the resected defect. Data were documented, absolute deviation was calculated, statistical analysis was performed and significance was set at the 5% level. RESULTS: The cases conducted with a directional guidance templet reported a statistically significant difference when compared to the conventional edge-cutting guide regarding the linear and angular spatial osteotomy plane position (P < 0.001). The defect span analysis reported excellent levels of agreement in both groups (ICC = 1.00, ICC = 0.995), however, the difference between the groups was statistically significant (P < 0.001). CONCLUSION: The study demonstrated the enhanced positional accuracy of the resection plane and reconstruction block placement when a directional slot is incorporated in the computer-generated resection guide.

Combined Periodontal-Orthodontic Treatment with Periodontal Corticotomy Regenerative Surgery in an Adult Patient Suffering from Periodontitis and Skeletal Class II Malocclusion: A Case Report with 5-Year Longitudinal Observation.

A thick periodontal phenotype with thick gingiva and alveolar bone volume is required for safe orthodontic tooth movement and long-term stability. A high incidence of dehiscence and fenestration in the labial aspect of mandibular anterior teeth may limit the correction of deformity and orthodontic treatment, especially when the lower anterior teeth are needed to have a large range of movement. This study reports a combination of periodontal therapy and orthodontic therapy with periodontal corticotomy regenerative surgery (PCRS) in a 25-year-old patient suffering from skeletal Class II malocclusion and periodontitis. The patient received periodontal therapy 5 years ago and commenced orthodontic treatment 4.5 years ago. During the 4 years of follow-up for PCRS, the clinical and radiographic evaluations revealed significant improvements in the periodontal phenotype of the mandibular anterior region. The periodontal phenotypes in the mandibular incisors region were all modified from thin to thick. Supplementing orthodontic treatment with labial PCRS could be a promising treatment strategy to maintain long-term periodontal health in adult patients with alveolar deficiency and thin gingiva tissue.

Chronic Diffuse Sclerosing Osteomyelitis of the Mandible: The Use of Bisphosphonates as a Treatment for a Rare and Challenging Condition.

Chronic diffuse sclerosing osteomyelitis is a very rare condition, described as a non-suppurative, inflammatory disease of the bone and characterized by a proliferative endosteal reaction, which clinically reveals itself with cyclic pain of the jaw and swelling. We reported two clinical cases, where patients suffered recurrent swelling and pain at the mandible irradiating to the preauricular area, denying any previous trauma or significant medical history. Odontogenic causes were excluded. An initial treatment with antibiotics and NSAIDs temporarily relieved the symptoms without complete resolution, prompting further investigations. After a comprehensive array of diagnostic tools (X-rays, CT scans, scintigraphy, bone biopsy, serum markers), both patients were diagnosed with chronic diffuse sclerosing osteomyelitis of the mandible. Bisphosphonates (clodronate and zolendronate) with different treatment schemes were used to treat the condition, until a full recovery from symptoms was reported. Bisphosphonates could therefore represent an effective option in managing this rare but impactful condition. Further research is warranted to better understand the underlying mechanisms of the disease and to optimize treatment strategies.

Fibula Grafting for Oromandibular Reconstruction and its Effect on Patient Quality of Life - A Scoping Review.

Fibula osteoseptocutaneous flap has been widely used for oncologic bony reconstruction of both the mandible and maxilla. Early and late morbidities of the donor side such as leg weakness, ankle instability, limited ankle mobility, tibial stress fractures or incision area pain are well documented; however, there is a lack of information about the effects of fibula grafting on patient quality of life. To address this issue, a scoping literature search in the PubMed electronic database was performed to identify all relevant studies and reviews in the period between 2010 and 2022. The potential discomforts after free fibula grafting and their impact on different domains of everyday living were identified and evaluated. The present literature review indicates that donor site morbidity can negatively impact patients' quality of life, albeit generally classified as minor. However, the functional and aesthetic benefits of oromandibular reconstruction clearly outweigh the associated sequelae. Nevertheless, the authors of this review highlight the importance of a comprehensive clinical evaluation of the donor site besides the recipient site during follow-up examinations. This would help to subjectively evaluate the functional and esthetical limitations of a patient's site and promptly detect morbidities that could lead to long-term complications.

Mandibular distraction osteogenesis in children with Pierre Robin sequence: long-term analysis of teeth and jaw growth.

Treatment of children with Pierre Robin sequence (PRS) having a hypoplastic mandible and upper airway distress after birth may consist of external distraction devices. Shape anomalies of the permanent molars and positional changes due to surgery have been documented. The aim of this study is to compare the long-term effects (>5 years) on the growth pattern of PRS-patients treated with an external mandibular distraction device with no-surgery cases and to investigate the dental development or damage. A retrospective cohort study was performed. PRS-patients with and without surgery were included. A digital cephalometric analysis was made to evaluate the growth pattern of the mandible between groups as well as with normal values. Nine of 19 patients underwent an external mandibular distraction. All children were extubated after 4-5 days with no signs of respiratory distress. Screw and device loosening presented in one patient. The articular and sellar angles were significantly larger and smaller, respectively, in the Surgery group. Mandibular distraction surgery might result in a 'growth boost' compared to the No-surgery group. No significant difference in dental development was found. Mandibular distraction osteogenesis is an effective way of relieving severe upper airway obstruction.

Risk factors for distal caries of second molars adjacent to mesioangular or horizontal partially erupted mandibular third molars: a cross-sectional study.

Introduction Impacted mandibular third molars can be asymptomatic or cause some pathologies, such as distal caries and odontogenic cysts and tumours. This study investigates the prevalence of distal caries of the mandibular second molar adjacent to the mesioangular or horizontally partially erupted mandibular third molar and its relationship regarding decayed, missing and filled teeth (DMFT) risk group, age, side (left-right) and sex.Methods The study included patients who had an appointment for mesioangular or horizontally positioned and partially erupted mandibular third molar surgery. Before the surgery, the DMFT score, age, sex and side were recorded. After extraction, the second molar was clinically examined for distal caries. The prevalence of distal caries and the correlation between the DMFT risk group, age, sex and side were determined.Results The study was conducted on 514 patients and involved 639 teeth. Men and patients in the moderate- or high-risk group are significantly prone to developing distal caries of the second molar. No statistically significant relationship exists regarding age group, side and position.Conclusion Sex and DMFT risk groups affect the prevalence of distal caries in second molars adjacent to the mesioangular or horizontally partially erupted third molars. The prophylactic extraction should be considered in men and patients in the moderate- or high-risk group.

Systematic review and meta-analysis of surgical approaches for improving airway stability in infants with Robin sequence: evaluating complications and outcomes.

The purpose of this systematic review and meta-analysis was to determine the most effective and least morbid surgical technique for relieving retroglossal airway obstruction in infants with Robin sequence (RS). The study adhered to PRISMA guidelines and included 25 studies (24 cohorts and one case series) that investigated interventions for airway improvement, including conservative measures, tongue-lip adhesion (TLA), mandibular distraction osteogenesis (MDO), and tracheostomy. The primary outcome variable was complication rate, while predictor variable was the use of interventions for airway improvement. Results showed that conservative measures were the preferred initial management strategy in most studies, while TLA was recommended for infants with mild obstruction, and MDO or tracheostomy was reserved for severe cases. Only complications could be analysed via meta-analysis due to data heterogeneity, revealing that tracheostomy had a summary odds ratio of 5.39 in favour of TLA, while MDO had a ratio of 2.8 over TLA, and the complication rates were similar between MDO and tracheostomy. If conservative measures fail, the study recommends mandibular distraction as the preferable technique for stable airway improvement. If the infant is unsuitable for distraction, tongue-lip adhesion may serve as an alternative, while tracheostomy should be reserved for cases of severe multi-level obstruction. The authors propose that large-scale, multicentre trials comparing long-term outcomes are required to establish definitive guidelines.

[The use of magnetic therapy in the treatment of children with lower micrognathia using compression-distraction osteosynthesis]. / Primenenie magnitoterapii pri lechenii detei s nizhnei mikrognatiei metodom kompressionno-distraktsionnogo osteosinteza.

PURPOSE: To study the effect of magnetic therapy on the formation of distraction regenerate of the lower jaw in patients with lower micrognathia. MATERIALS AND METHODS: The study comprised 159 patients with inferior micrognathia of congenital and acquired etiology. The patients were divided into 2 groups. The main group consisted of 112 patients who received magnetic therapy: 55 patients with congenital micrognathia and 57 patients with acquired micrognathia. The control group included 47 patients who did not undergo magnetic therapy: 20 patients with congenital micrognathia and 27 patients with acquired micrognathia. Magnetic therapy was performed daily starting from day 1 or 2 after surgery. Ultrasound monitoring began on the 7th day of distraction and was carried out every 3-4 days, which made it possible to assess the dynamics of the formation of the distraction regenerate. RESULTS: Ultrasound examination on the 7th day of distraction revealed that in the main group the number of distraction regenerates of the normotrophic type was 36.5%, hypotrophic type 18%, hypertrophic type 54.5%. In the control group, the corresponding rates were 53%, 31% and 22%. CONCLUSION: Magnetic therapy induces osteogenesis and accelerates the maturation of the distraction regenerate. This makes it possible to accelerate the pace of distraction without reducing the quality of the regenerate.