• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.155-167
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• 2023

The aim of this study was to investigate the effects of slow maxillary expansion (SME) on the dentoalveolar, skeletal, upper airway, and maxillary sinus using cone-beam computed tomography (CBCT). Twenty-three orthodontic patients (mean age 8.93 ± 1.61 years) who were treated with maxillary expansion using banded hyrax in the Department of Pediatric Dentistry at Jeonbuk National University Dental Hospital were included. According to the expansion speed applied, they were divided into two groups: SME (12 subjects, mean age 8.92 ± 1.45 years) and rapid maxillary expansion (RME, 11 subjects, mean age 8.94 ± 1.84 years). CBCT were obtained before (T0) and after (T1) the treatment and were analyzed with InVivo5 software (Anatomage, San Jose, CA, USA). Descriptive statistics showed no significant differences between the two groups in age, sex, or skeletal maturity. There were significant increases in maxillary width at the dentoalveolar and skeletal levels for both groups. Upper airway volume revealed a significant increase of 38.59% in the SME group and 28.72% in the RME group. However, there was no significant difference between SME group and RME group in all measurements. This study suggested the efficacy of SME in growing patients. SME was effective in increasing not only dentoalveolar and skeletal measurements but also airway volume. Therefore, pediatric dentists should select an appropriate expansion method considering the physiological aspects of periodontal tissues and discomfort in growing children.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.243-248
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• 2009

Purpose: Rehabilitation of the edentulous posterior maxilla with dental implants often poses difficulty because of insufficient bone volume caused by pneumatization of the maxillary sinus and by crestal bone resorption. Sinus grafting technique was developed to increase the vertical height to overcome this problem. The present study was designed to evaluate the sinus floor augmentation with anorganic bovine bone (Bio-$cera^{TM}$) using histomorphometric and clinical measures. Patients and methods: Thirteen patients were involved in this study and underwent total 14 sinus lift procedures. Residual bone height was ${\geq}2mm$ and ${\leq}6mm$. Lateral window approach was used, with grafting using Bio-$cera^{TM}$ only(n=1) or mixed with autogenous bone from ramus and/or maxillary tuberosity(n=13). After 6 months of healing, implant sites were created with 3mm diameter trephine and biopsies taken for histomorphometric analysis. The parameters assessed were area fraction of new bone, graft material and connective tissue. Immediate and 6 months after grafting surgery, and 6 months after implantation, computed tomography (CT) was taken and the sinus graft was evaluated morphometric analysis. After implant installation at the grafted area, the clinical outcome was checked. Results: Histomorphometry was done in ten patients.Bio-$cera^{TM}$ particles were surrounded by newly formed bone. The graft particles and newly formed bone were surrounded by connective tissue including small capillaries in some fields. Imaging processing revealed $24.86{\pm}7.59%$ of new bone, $38.20{\pm}13.19%$ connective tissue, and $36.92{\pm}14.51%$ of remaining Bio-$cera^{TM}$ particles. All grafted sites received an implant, and in all cases sufficient bone height was achieved to install implants. The increase in ridge height was about $15.9{\pm}1.8mm$ immediately after operation (from 13mm to 19mm). After 6 months operation, ridge height was reduced about $11.5{\pm}13.5%$. After implant installation, average marginal bone loss after 6 months was $0.3{\pm}0.15mm$. Conclusion: Bio-$cera^{TM}$ showed new bone formation similar with Bio-$Oss^{(R)}$ histomorphometrically and appeared to be an effective bone substitute in maxillary sinus augmentation procedure with the residual bone height from 2 to 6mm.

• Journal of Periodontal and Implant Science
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• v.45 no.6
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• pp.238-246
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• 2015

Purpose: The purpose of this study was to evaluate bone formation around recombinant human bone morphogenetic protein (rhBMP-2)-coated implants placed with or without absorbable collagen sponge (ACS) in rabbit maxillary sinuses. Methods: The Schneiderian membrane was elevated and an implant was placed in 24 sinuses in 12 rabbits. The space created beneath the elevated membrane was filled with either blood (n=6) or ACS (n=6). In the rabbits in which this space was filled with blood, rhBMP-2-coated and non-coated implants were alternately placed on different sides. The resulting groups were referred to as the BC and BN groups, respectively. The AC and AN groups were produced in ACS-grafted rabbits in the same manner. Radiographic and histomorphometric analyses were performed after eight weeks of healing. Results: In micro-computed tomography analysis, the total augmented volume and new bone volume were significantly greater in the ACS-grafted sinuses than in the blood-filled sinuses (P<0.05). The histometric analysis showed that the areas of new bone and bone-to-implant contact were significantly larger in the AC group than in the AN group (P<0.05). In contrast, none of the parameters differed significantly between the BC and BN groups. Conclusions: The results of this pilot study indicate that the insertion of ACS after elevating the Schneiderian membrane, simultaneously with implant placement, can significantly increase the volume of the augmentation. However, in the present study, the rhBMP-2 coating exhibited limited effectiveness in enhancing the quantity and quality of regenerated bone.

• Archives of Craniofacial Surgery
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• v.24 no.2
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• pp.59-65
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• 2023

Background: Fibrous dysplasia (FD) is a localized bone disorder in which fibro-osseous tissue replaces the normal bone structure. Patients with craniofacial FD often present with gradual swelling, deformity, and compromised vision or hearing. We previously introduced "the core extirpation method," a novel surgical technique that is minimally invasive like traditional bone shaving but has longer-lasting effects. This study presents the long-term outcomes of our core extirpation method. Methods: We conducted a retrospective analysis of patients who underwent core extirpation for FD of the zygomaticomaxillary region from 2012 through 2021. Computed tomography (CT) scans were performed 6 to 12 months before the operation, immediately before and after the operation, and during follow-up visits. We performed all operations using the upper gingivobuccal approach, and we extirpated the core of the lesion while preserving the cortical structures of the zygoma and the maxilla to maintain symmetrical facial contour. Results: In 12 patients with lesions in the growth phase, anteroposterior/mediolateral (AP/ML) length discrepancies and the volume increased between preoperative and immediate postoperative CT scans. All patients' immediate postoperative AP/ML discrepancies were stable up to 12-17 months postoperatively. Postoperative volume showed continuous lesion growth; the median volume growth rate was 0.61 cc per month. Conclusion: In this article, we present our experiences managing FD using the minimally invasive core extirpation technique, which entails small expected blood loss and can be performed as day surgery. It provides similar cosmetic outcomes as traditional bone shaving but with longer-lasting results. Although there are some limitations with the study's retrospective nature and small sample size, our 4-year follow-up results show promising results of the core extirpation method in well-indicated patients.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.347-353
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• 2019

Most orbital surgeons believe that it's difficult to restore the primary orbital wall to its previous position and that the orbital wall is so thin that cannot be firmly its primary position. Therefore, orbital wall fractures generally have been reconstructed by replacing the bony defect with a synthetic implant. Although synthetic implants have sufficient strength to maintain their shape and position in the orbital cavity, replacement surgery has some drawbacks due to the residual permanent implants. In previous studies, the author has reported an orbital wall restoring technique in which the primary orbital wall fragment was restored to its prior position through a combination of the transorbital and transantral approaches. Simple straight and curved elevators were introduced transnasally to restore the orbital wall and to maintain temporary extraorbital support in the maxillary and ethmoid sinus. A transconjunctival approach provided sufficient space for implant insertion, while the transnasal approach enabled restoration of the herniated soft tissue back into the orbit. Fracture defect was reduced by restoring the primary orbital wall fragment to its primary position, making it possible to use relatively small size implant, furthermore, extraorbital support from both sinuses decreased the incidence of implant displacement. The author could recreate a natural shape of the orbit with the patient's own orbital bone fragments with this dual approach and effectively restored the orbital volume and shape. This procedure has the advantages for retrieving the orbital contents and restoring the primary orbital wall to its prior position.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.1
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• pp.86-91
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• 2009

The success of implants essentially depends on a sufficient volume of healthy bone at the recipient site during implant placement. In patients who have the severe alveolar bone resorption or pneumatized maxillary sinus, it should be performed that bone regeneration procedure before implant placement. Development of barrier membrane makes it possible that predictable result of alveolar bone reconstruction. Many kind of materials used for barrier membrane technique are introduced, non-absorbable or absorbable membranes. But, when operation site was ruptured with membrane exposure, bacterias can be grow up at the bone graft site. Then morphology and migration of fibroblast will be changed. It works as a negative factor on healing process of bone graft site. In oral and maxillofacial department of Chonbuk national university dental hospital, we use variable suture technique like as subgingival suture, vertical mattress suture, simple interrupted suture, if need, tenting suture after GBR or block bone graft. Within these suture technique, wound healing was excellent without complication, so now we take a report of suture technique in reconstruction of alveolar bone surgery.

• Archives of Craniofacial Surgery
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• v.19 no.4
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• pp.264-269
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• 2018

Background: Orbital resorbable mesh plates are adequate to use for isolated floor and medial wall fractures with an intact bony buttress, but are not recommended to use for large orbital wall fractures that need load bearing support. The author previously reported an orbital wall restoring surgery that restored the orbital floor to its prior position through the transnasal approach and maintained temporary extraorbital support with a balloon in the maxillary sinus. Extraorbital support could reduce the load applied on the orbital implants in orbital wall restoring surgery and the use of resorbable implants was considered appropriate for the author's orbital wall restoring technique. Methods: A retrospective review was conducted of 31 patients with pure unilateral orbital floor fractures between May 2014 and May 2018. The patients underwent transnasal restoration of the orbital floor through insertion of a resorbable mesh plate and maintenance of temporary balloon support. The surgical results were evaluated by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values. Results: The OVR decreased significantly, by an average of 6.01% (p<0.05) and the preoperative and postoperative Hertel scale measurements decreased by an average of 0.34 mm with statistical significance (p<0.05). No complications such as buckling or sagging of the implant occurred among the 31 patients. Conclusion: The use of resorbable mesh plate in orbital floor restoration surgery is an effective and safe technique that can reduce implant deformation or complications deriving from the residual permanent implant.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.156-163
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• 1998

Background & Objectives: Frameless fractionated stereotactic radiotherapy(FFSRT) is a modification of stereotactic radiosurgery(SRS) with radiobiologic advantage of fractionation without losing mechanical accuracy of SRS. Local recurrence of head and neck cancer at or near skull base benefit from reirradiation. Main barrier to successful palliation is dose limitation secondary to normal tissue tolerance. We try to evaluate the efficacy and safety of FFSRT as a new modality of reirradaton in these challenging patients. Materials & Methods: Seven patients with recurrent head & neck cancer involving at or near skull base received FFSRT from September 1995 to November 1997. Six patients with nasopharyngeal cancer had received induction chemotherapy and curative radiation therapy. One patient with maxillary sinus cancer had received total maxillectomy and postoperative radiation therapy as a initial treatment. Follow-up ranged from 11 to 32 months with median of 24 months. Three of 7 patients received hyperfractionated radiation therapy(1.1-1.2Gy/fraction, bid, total 19.8-24Gy) just before FFSRT. All patients received FFSRT(3-5Gy/fraction, total 15-30Gy/5-10fractions). Chemotherapy(cis-platin $100mg/m^2$) were given concurrently with FFSRT in four patients. Second course of FFSRT were given in 4 patients with progression or recurrence after initial FFSRT. Because IF(irregularity factor; ratio of surface area of target to the surface area of sphere with same volume as a target) is too big to use conventional stereotactic RT using multiple arc method for protection of radiation damage to critical normal tissue, all patients received FFSRT with conformal method using irregular static ports. Results: Five of 7 patients showed complete remission in follow-up CT &/or MRI. Three of these five patients who developed marginal, in-field, and out-field recurrences, respectively. Another one of complete responders has been dead of G-I bleeding without evidence of local recurrence. One partial responder who showed progressive disease 15 months after initial FFSRT has received additional FFSRT, and then he is well-being with symptomatic improvement. One minmal responder who showed progression of locoregional disease 9 months after $1^{st}$ FFSRT has received 2nd FFSRT, and then he is alive with stable disease. Five of 7 case had showed direct invasion to skull base and had complaint headache and various symptoms of cranial nerve involvement. Four of these five case showed improvement of neurologic symptoms after FFSRT. No significant neurologic complicaltion related to FFSRT was observed during follow-up periods. Tumor volumes were ranged from 3.9 to 50.7 cc and surface area ranged from 16.1 to $114.9cm^2$. IF ranged from 1.21 to 1.74. The average ratio of volume of prescription isodose shell to target volume was 1.02 that indicated the improvement of target coverage and dose distribution with FFSRT with conformal method compared to target coverage with FFSRT with multiple arc method. Conclusion: Our initial experience suggests that FFSRT with conformal method was relatively effective and safe modality in the treatment of recurrent head and neck cancer involving at or near skull base. Treatment benefit included good palliation of symptoms and reasonable radiographic response. However, more experience and additional follow-up are needed to better assess its ultimate role in treating these challenging patients.