Evaluation of Spontaneous Bone Regeneration after Enucleation of Large Cysts of the Jaws using Radiographic Computed Software.

INTRODUCTION: Spontaneous regeneration of bone is commonly seen in the small surgical defects caused by enucleation of cysts. However, in case of large surgical defects caused by the enucleation, spontaneous regeneration of bone is a rare phenomenon and it depends on factors, such as age of the patient, intact periosteum, and proper stabilization. MATERIALS AND METHODS: The study included 16 patients, who reported to the department of oral and maxillofacial surgery with the complaint of pain and swelling in the jaws diagnosed as cyst. The sample included equal numbers of male and female subjects aged between 15 and 40 years. Panoramic radiographs were taken pre- and postoperatively on day 2 of the enucleation. The dimensions of the cyst were evaluated on the radiograph according to the proforma. Subsequent radiographs were taken at regular intervals of 1.5, 3, and 6 months using standard parameters and were analyzed using MCID™ analysis software of imaging research. RESULTS: Mean reduction was seen in up to 39 and 60% in the cystic cavity size and increase in the mean density up to 59 and 90.2% at 3 and 6 months intervals respectively. CONCLUSION: Spontaneous bone regeneration was seen even after primary closure of the large cystic defect without the need for placement of foreign substances or grafts and it also eliminated the complications resulting from placement of foreign substance. Further studies are required in a larger sample with longer follow-up durations to confirm the outcome of the present work for the benefit of patients. CLINICAL SIGNIFICANCE: The present study depicted that spontaneous bone regeneration can occur with accepted results after simple enucleation of jaw cyst without the aid of any graft material. Hence, simple enucleation may be considered as a first line of treatment modality for cystic lesion of the jaws. This simplifies the surgical procedure, decreases the economic and biologic costs, and reduces the risk of postoperative complications. Follow-up is necessary along with patient's compliance for the success of treatment.

Stress Distribution of the Zygomatic Implants in Post-mucormycosis Case: A Finite Element Analysis.

Aim: The aim of this study was to assess the stress distribution of the zygomatic implants in maxillectomy cases and to understand the long-term prognosis of this rehabilitation option using finite element analysis. Materials and Methods: A three-dimensional finite element model was designed using computed tomography of a patient who underwent maxillectomy post-mucormycosis. Zygomatic implants and abutments were designed based on the manufacturer's design. Quad zygomatic implants were placed in the canine and premolar region into the zygomatic bone bilaterally. A prosthesis with an entire complement of teeth extending from the first molar teeth bilaterally was designed and attached to the multiunit abutments and zygomatic implants. Forces were applied to the zygomatic implants at six different locations bilaterally on the prosthesis which included occlusal and laterally directed forces on the central incisor region, canine region, and molar region using von Mises criteria. A three-dimensional finite element analysis was run, and maximum stress distribution was recorded at various loads. Statistical Package for Social Sciences for Windows version 22.0 Released 2013. Armonk, NY: IBM Corp., was used to perform statistical analyses. Kruskal-Wallis test was used to compare the mean stress values. Multiple comparisons of mean difference in stress values between force applications in implant were done using Dunn's post hoc test. Results: The maximum stress was observed at the distal head of the implant in the models. Minimum stress was observed at the apex of the implant in the models. The mean stress values based on force application in the bone and fixed prosthesis showed less significance when compared to the zygomatic implants which was statistically significant at p = 0.03.