Volumetric analysis of spontaneous bone healing after jaw cyst enucleation

Volumetric Analysis and Healing Ratio: Refining Prognostic Assessment in Maxillofacial Cysts Using Cone-Beam Computed Tomography

Introduction

Volumetric analysis with imaging techniques provides clinicians with the capability to visualize the spatial extent of the lesions. CBCT offers images with minimal radiation, facilitating a detailed assessment of cystic dimension's relationships. This crucial information helps in formulating appropriate strategies, including excision, enucleation, or nonsurgical approaches. The "Healing ratio" emerges as a valuable technique for prognostic evaluation.

Materials and Methods

This retrospective study focused on outpatient cases with, clinic-radiologically diagnosed cases of odontogenic keratocyst or radicular cysts. Preoperative CBCT was utilized for volumetric analysis through MIMIC Software. Subsequent analyses were performed at 24 and 48 weeks postoperatively. The healing ratio was calculated for further correlation.

Results

A total of 21 cases were included in the study, with a mean age of 36.67 years with predominance of males (72.6%, n = 16). Healing ratio estimation revealed minimal or no association with age, gender, and location on point-biserial analysis. Noteworthy implications were observed concerning total cyst volume and the specific diagnosis of the cyst. Results suggested more favorable healing outcomes in smaller cysts and those diagnosed as radicular cysts.

Discussion

Proficiency in deciphering three-dimensional CBCT images accurately demands specialized training. The crux of our study lies in the application of volumetric analysis, particularly the "Healing Ratio," as a robust means of evaluating prognoses in management. The Healing Ratio, derived from three-dimensional imaging techniques, offers a comprehensive insight into the spatial dynamics of cystic lesions. Our findings underscore its significance as the optimal technique for prognostic assessment in the context of cyst management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12663-024-02168-7.

Trends in American Plastic Surgery Procedures (2005-2019): Observing the Growth Rate of Maxillofacial Surgery and Cosmetic Minimally Invasive Procedures in ASPS Data

BACKGROUND

This study explores the dynamic changes in plastic surgery practices, focusing on the growth rates across different subcategories, particularly highlighting the trends in the United States.

OBJECTIVES

To analyze evolving trends in plastic surgery using statistical methods, providing insights into the changes and growth patterns in various segments over time.

MATERIALS AND METHODS

Utilizing data from 2005 to 2019 from the American Society of Plastic Surgeons, the authors, conducted a comprehensive statistical analysis using the SPSS program to investigate trends in plastic surgery procedures.

RESULTS

Our analysis revealed no significant differences in year-on-year growth rates between cosmetic and reconstructive surgery. However, in reconstructive surgery subcategories, maxillofacial surgery showed the highest mean growth rate at 11.61%, though this was not statistically significant. In cosmetic minimally invasive procedures, soft tissue filler injections and botulinum toxin A injections experienced notably higher growth trends compared with microdermabrasion.

CONCLUSION

The findings suggest that practitioners considering a career in plastic surgery should not focus solely on choosing between reconstructive and cosmetic surgery. Recognizing substantial growth in cosmetic minimally invasive procedures, especially botulinum toxin A injections and fillers, is vital for making informed career decisions.

Computer-Assisted Evaluation Confirms Spontaneous Healing of Donor Site One Year following Bone Block Harvesting from Mandibular Retromolar Region-A Cohort Study

Bone augmentation prior to dental implant placement is a common scenario in the dental implantology field. Among the important intraoral harvesting sites to obtain bone blocks is the ramus/retromolar region that has a high success rate and long-lasting alveolar ridge augmentation. Preserving the bone volume and quality at the donor site is crucial for preventing further complications or to serve as a site for re-harvesting. Healing of the intraoral donor sites has been described in the maxillofacial field. This study aimed to evaluate the spontaneous healing of the mandibular retromolar donor site utilizing computer-assisted quantification 6 and 12 months after bone harvesting.

MATERIALS AND METHODS

The study was conducted on patients who underwent an alveolar ridge augmentation using an intraoral retromolar bone graft. Three CBCT scans were performed-intraoperative, and at six months and one year after the surgical procedure. By using the Materialise Mimics Innovation Suite software 26.0 features segmentation by thresholding, Hounsfield unit averaging, and superimposition of the tomographies, we could precisely quantify the healing process utilizing spatial and characteristic measures.

RESULTS

In all cases, the computer-aided quantification showed that six months following surgery, the donor site had recovered up to 64.5% ± 4.24 of its initial volume, and this recovery increased to 89.2% ± 2.6 after one year. Moreover, the Hounsfield unit averaging confirmed dynamic bone quality healing, starting at 690.3 ± 81 HU for the bone block, decreasing to 102 ± 27.8 HU at six months postoperatively, and improving to 453.9 ± 91.4 HU at the donor site after a year.

CONCLUSIONS

This study demonstrates that there is no need for additional replanting at the donor site following retromolar bone block harvesting, whether autogenous or allograft, since spontaneous healing occurs 12 months following the surgery.

A case of concentrated growth factor gel to fill the defect after large jaw cyst enucleation

Management of large jaw cyst is challenging since high risks including pathologic fracture, limited opening, and insufficient bone healing occur after enucleation. The current case of concentrated growth factor (CGF) gel to fill defect after enucleation of large jaw cyst is rare. A 12-year-old boy with pain and swelling for 4 months in the left mandible region made a medical consultation at our hospital. Computerized tomography scan indicated that cystic lesion was found in the left mandible region. In this case, we present a patient with large jaw cyst (31 mm × 44 mm × 53 mm) who received enucleation followed by CGF gel filling the defect. The patient was discharged after 13 days without discomfort symptoms. The lesion size was reduced significantly at 1-month re-examination. No abnormality was detected in maxillofacial region at 1-year re-examination. Application of CGF gel is one of the possible options for filling defect after jaw cyst enucleation.

Rat Calvaria Model Mimicking the Intraoral Lesion of Medication-Related Osteonecrosis in the Jaw: A Preliminary Test

Numerous preclinical intraoral models have been proposed to study medication-related osteonecrosis of the jaws (MRONJ). However, an extraoral animal model is necessary to investigate the effects of interventions such as grafts or direct therapeutics. This study aimed to establish a MRONJ rat model on the calvaria. Seven rats were allocated to either the control or MRONJ group. The MRONJ group received injections of zoledronic acid and dexamethasone to induce osteonecrosis over 4 weeks. Two weeks after these injections, the maxillary first molar was extracted, and two calvaria defects were created using a 4 mm trephine burr. One defect was left untreated, while the other was filled with harvested calvaria bone. A histological examination of all calvaria in the MRONJ group revealed avascular necrosis and the destruction of cortical bone. An independent t-test and Pearson's correlation coefficient were used for statistical analysis and the evaluation of alveolar and calvaria defects. The total alveolar and calvaria defect volume in the control group was significantly smaller than that in the MRONJ group. A statistically significant correlation was observed between alveolar and calvaria defects (Pearson correlation = 0.6, p = 0.023). The autogenous grafts showed poor results in the MRONJ group since they failed to revascularize and exhibited necrosis. The calvaria in this study successfully mimicked MRONJ lesions with avascular necrosis. This preclinical model could be used to develop treatments that are applicable to MRONJ.

Volumetric reduction in large cystic jaw lesions postoperative enucleation: a longitudinal clinical study

BACKGROUND

Enucleation, a surgical procedure, is commonly used to treat large jaw cysts, unicystic ameloblastomas and keratocysts. However, it remains unclear to what extent the jaw bone regenerates after enucleation. We aimed to evaluate the percentage and the survival analysis of jaw bone regeneration, in terms of cavity volume residual (CVR), in patients who underwent enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts.

METHODS

We collected data longitudinally from 75 patients who underwent jaw cystic lesions enucleation at the Stomatological Hospital of Xi'an Jiaotong University, between January 2015 and June 2021. All patients had both preoperative and postoperative cone-beam computed tomography (CBCT) imaging data. CBCT images were analyzed using Image J. Changes in the CVR were assessed at various follow-up time points, and the Kaplan-Meier method was utilized to evaluate the CVR over time.

RESULTS

The patients had a mean age of 31.7 years (range: 5.5-72 years) with 58.66% of them being male. The postoperative CVR was 32.20% at three months, 21.10% at six months, 15.90% at 12 months, and 5.60% at 24 months. The percentage of CVR during follow-up periods for the initial size Quartile (Q)1 (212.54-1569.60 mm3) was substantially lower than those of Q2 and Q3 at and after seven months of follow-up and became statistically significant at the 12-month mark.

CONCLUSION

This study demonstrates that spontaneous bone regeneration can occur after enucleation of large jaw cysts, unicystic ameloblastomas and keratocysts, even without the use of filler materials. The initial size of the lesion had a significant impact on the outcome of cystic lesion enucleation over time. To minimize the risks associated with radiation exposure and expenses, we recommend reducing the frequency of CT imaging follow-ups for patients with small initial cavity sizes (ranging from 212.54 to 1569.60 mm3).

Incorporating Moldable Demineralized Dentin Matrix into Treatment for a Jaw Cyst

The enucleation procedure is a standard treatment for jaw cysts; however, it often results in post-operative bony defects. These defects can lead to serious complications such as the risk of pathologic fracture and delayed wound healing, especially in the case of large cysts where there may be soft tissue dehiscence. Even in the case of smaller cysts, most cystic defects remain visible on postoperative radiographs and can be mistaken for cyst recurrence during follow-up periods. To avoid such complications, the use of bone graft materials should be considered. While autogenous bone is the most ideal graft material as it can be regenerated into functional bone, it has limitations due to the inevitable harvesting surgery. Many tissue engineering studies have been conducted to develop substitutes for autogenous bone. One such material is moldable-demineralized dentin matrix (M-DDM), which can aid in regeneration in cases of cystic defects. This case report highlights a patient who demonstrated the efficacy of M-DDM in bone healing for filling the cystic defect.

Pseudocysts of the jaw: a retrospective study of 41 cases from a single institution

OBJECTIVE

The purpose of this retrospective study was to investigate and compare the clinical, radiographic, pathological, pathogenesis, and therapeutic features of simple bone cysts (SBCs) and aneurysmal bone cysts (ABCs) of the jaw.

METHODS

35 patients with SBCs and 6 patients with ABCs who received treatment at the Department of Oral and Maxillofacial Surgery, Zhejiang University School of Medicine from 2017 to 2022 were followed up and reviewed retrospectively.

RESULTS

The study included 41 patients, accounting for 2.14% of all jaw pathologies, with 35 patients having SBCs and 6 patients having ABCs; their average ages were 26.63 ± 13.62 years and 17.83 ± 7.88 years, respectively. The prevalence of SBC and ABC did not differ significantly by sex. The mandible was the most vulnerable area to be involved. Only 5.71% (2/35) of patients with SBCs and 16.7% (1/6) of patients with ABCs reported histories of previous trauma in the same region of the pseudocysts. A total of 42.86% (15/35) of SBC cases and 66.67% (4/6) of ABC cases had malocclusions. The radiographic features of pseudocysts varied in shape, were associated with the root, and unilocular or multilocular. All patients had curettage with or without bone graft or substitute implantation, and recurrences did not occur in 94.29% (33/35) of SBC patients and 100% (6/6) of ABC patients after a mean follow-up time of 26.23 ± 15.47 months and 21.67 ± 19.75 months, respectively.

CONCLUSIONS

Pseudocysts, including SBCs and ABCs, are benign osteolytic lesions without an epithelial lining that occur occasionally in the jaw, mostly in adolescents and young adults, and their incidence did not significantly differ by sex. The most vulnerable site of involvement is the mandible, and they are generally not overtly aggressive. Trauma has a less significant role in pseudocysts, but minor trauma, such as malocclusion, has the potential to influence pseudocyst development. The clinical presentation of pseudocysts lacks specificity, and most patients are asymptomatic and found incidentally during radiographs. Dental panoramic radiographs and CBCT cannot accurately distinguish between SBC and ABC, and the final diagnosis depends on pathological diagnosis. Curettage combined with bone grafting is currently the best treatment for both, with a 5.71% (2/35) recurrence rate for SBC and no recurrence found for ABC.

Impact of Autogenous Demineralized Dentin Matrix on Mandibular Second Molar after Third Molar Extraction: Retrospective Study

The purpose of this retrospective study was to evaluate bone healing after autogenous demineralized dentin matrix (DDM) grafts, focusing on the distal root of the mandibular second molar after the extraction of the third. We included retrospective data from 20 patients who had undergone molar extractions (15 male, 41.9 ± 12.0 years) between January 2020 and September 2022 and had DDM grafts implanted on the extraction socket, immediately ("immediate graft") or 6 weeks ("delayed graft") after the first surgery without primary closure. Patients who underwent grafting on only one side were used as the control group (n = 4). Bone defects at the mandibular second molar were measured preoperatively and 4 months after the graft surgery using cone-beam computed tomography (CBCT). Improvement of bone defect (i.e., the change in the bony defect pre- vs. postoperatively) was compared between the control and graft groups using the Wilcoxon Signed Rank test, and the difference between immediate and delayed grafts was analyzed with the Mann-Whitney U test. Complications such as infections or graft failure did not occur. Although pre-operative defects were smaller in the control than in the graft group (2.98 ± 1.77 and 10.02 ± 3.22 mm, p = 0.001), post-operative defects were similar in both (2.12 ± 0.59 and 2.29 ± 1.67 mm, respectively). The improvement ratio was not statistically significant in the control group (22.68 ± 15.36%) but a difference was observed in the graft group (76.70 ± 15.36%, p = 0.001). The amount of improvement of bone defect was not affected by graft timing or patient sex. In conclusion, DDM can improve bone defect at the distal aspect of the mandibular second molar after third molar extraction.