Contribution to oral and maxillary surgery and surgical technique of osteo-odontokeratoprosthesis in Japan.

Osteo-odontokeratoprosthesis (OOKP) is a technique invented by Strampelli in 1963, in which the patient's own tooth root is used to support an optical cylinder. It uses an autologous tooth-bone-periodontal complex to mount an optical cylinder, which is stabilised by overlying autologous buccal mucosa. OOKP involves two, staged procedures done by ophthalmologists and oral surgeons, and the main contribution from the oral surgeon is during the first stage. To date we have done nine first-stage, and completed eight second-stage, OOKP operations in Japan with a mean follow-up of eight years and 11 months by modifying the original method of the oral surgery. All OOKP procedures were unilateral, and canines were selected as the donor teeth. Patients developed ocular blindness as a result of Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and chemical and thermal burns to the cornea and ocular surface. All eight patients who completed the second stage have been stable, and there have been no major perioperative or postoperative oral complications. The patients' visual acuities were stable with no serious complications. Here we report the technical details of the oral contribution to OOKP.

Anesthesia Considerations in Modified Osteo-odonto-keratoprosthesis.

PURPOSE: To elucidate anesthesia-related challenges in patients who underwent modified osteo-odonto-keratoprosthesis (MOOKP). DESIGN: Retrospective cohort study. METHODS: Medical records of consecutive patients who underwent MOOKP surgery between January 2007 and January 2015 were reviewed. Data including demographic details, systemic comorbidities, indications for MOOKP, and anesthesia techniques at various stages of MOOKP were collected and analyzed. RESULTS: A total of 74 patients (47 men, 27 women) were included in this study. The mean age of the patients was 29.7 ± 9.1 years. The most common indication for MOOKP was Stevens-Johnson syndrome (53%), followed by chemical burn (38%). In all stages of the MOOKP procedure, 94.6% of patients were American Society of Anesthesiologists (ASA) grade II, whereas 5.4% were ASA grade III. Mallampati score 1 was found in 79.7% of patients in stage 1A, 82.4% of patients in stage 1B + 1C, and 81.1% of patients in stage 2. Recovery grade of 10 was noted in all patients at all stages of the MOOKP procedure. Intubation in the second attempt was carried out in 8 patients and oral intubation in stage 1B + 1C was performed in 4 patients. Difficulty in intubation was noted in 3 patients in stage 1A, 4 patients in stage 1B + 1C, and 1 patient in stage 2. CONCLUSIONS: In patients undergoing MOOKP, a good preoperative anesthetic evaluation and intraoperative anesthesia plan before each stage could help in successful administration of anesthesia in these patients.

Osteo-Odonto-Keratoprosthesis in Severe Thermal and Chemical Injuries.

PURPOSE: To report the results of osteo-odonto-keratoprosthesis (OOKP) surgery in patients who sustained severe chemical and thermal injuries. METHODS: This is a noncomparative retrospective case series of 14 patients who underwent OOKP surgery between 2001 and 2016 at the Sussex Eye Hospital, Brighton, UK, because of severe chemical and thermal injuries RESULTS:: OOKP surgery was performed in 14 eyes of 14 patients. Eight patients (57%) sustained thermal injuries and 6 patients (43%) chemical injuries. Every eye had previously undergone adnexal or ocular surgery, including 2 cases that underwent synthetic keratoprosthesis implantation. One case had choroidal hemorrhage during stage 2. Laminar retention was observed in 11 cases (85%) at the end of the study. The Kaplan-Meier curve showed a probability of 81% of laminar retention at 5 years and a decrease at 15 years to 61%. Functional visual success was observed in only 7 patients (50%) because of end-stage glaucomatous optic neuropathy in 4 cases and macular scar in 1 case. Two cases developed endophthalmitis. Two cases required removal of laminae, one because of endophthalmitis, bone resorption and aqueous leak and the other because of development of a retroprosthetic membrane. Glaucoma was the most frequent complication (79%) and required surgical intervention with tube shunts in 5 cases. Six cases (43%) required buccal mucosal repair, which included two cases that developed endophthalmitis. CONCLUSIONS: Anatomic success was achieved in 11 of 13 cases in this series of OOKP surgery after severe chemical and thermal trauma; 8 of these cases had at least 5 years of follow-up and thus qualified as long-term.

Canine and Premolar Root Dimensions in Chinese. A Reference for Osteoodontokeratoprosthesis Surgery.

PURPOSE: Osteoodontokeratoprosthesis (OOKP) surgery is used to restore vision in end-stage corneal disorders, where an autogenous tooth supporting an optical cylinder is implanted through the cornea under a buccal mucosal graft. The ideal tooth for OOKP is a healthy single-rooted permanent tooth with sufficient buccolingual/palatal root diameter to accommodate an optical cylinder. The aim of this study was to determine the buccolingual/palatal diameters of canine and premolar roots in Chinese, for selection of teeth for OOKP surgery. DESIGN: This was an anatomical study on root dimensions of extracted intact teeth. METHODS: Extracted canine and premolar teeth (excluding maxillary first premolars) were collected and the buccolingual/palatal and mesiodistal diameters of the root at the cervical line and at 2-mm intervals below the cervical line were measured with Vernier calipers. Other measurements included total tooth length, crown buccolingual/palatal diameter, and root length. Mean and minimum buccolingual/palatal root diameters were compiled for each 2-mm interval. RESULTS: A total of 415 extracted teeth (198 male, 217 female) were collected and measured. Recorded dimensions of keratoprostheses in 55 previous OOKP surgeries were used to establish acceptable lamina dimensions to ascertain root size adequacy. Premolars in Chinese female patients were undersized in a small minority. Minimal dimensions of teeth were insufficient if at 6 mm root level, the buccolingual/palatal width was less than 5 mm, or the mesiodistal width was less than 3 mm. This was noted in female mandibular first premolars (5.6%), maxillary second premolars (4.5%), and mandibular second premolars (1.5%). CONCLUSIONS: Canines have adequate dimensions for OOKP surgery. However, premolars in Chinese females may be undersized in a small minority.

Vitreoretinal Complications and Outcomes in 92 Eyes Undergoing Surgery for Modified Osteo-Odonto-Keratoprosthesis: A 10-Year Review.

PURPOSE: To analyze vitreoretinal (VR) complications and treatment outcomes in eyes undergoing modified osteo-odonto-keratoprosthesis (OOKP) surgery. DESIGN: Retrospective case series. PARTICIPANTS: All patients who underwent modified OOKP (mOOKP) surgery at a tertiary eye-care center from March 2003 to February 2013 were included. METHODS: Medical records were reviewed for relevant medical history, best-corrected visual acuity (BCVA), slit-lamp examination, ultrasound scan, oral examination findings, and VR complications. MAIN OUTCOME MEASURES: The BCVA at the last visit. Optimal anatomic outcome was attached retina with a normal intraocular pressure at the last visit. RESULTS: A total of 92 eyes of 90 patients were included. Indications for OOKP included Stevens-Johnson syndrome (n = 53), chemical injury (n = 36), and ocular cicatricial pemphigoid (n = 3). A total of 41 eyes of 39 patients developed VR complications, including vitritis (n = 21), retinal detachment (RD) (n = 12; primary RD = 5), retroprosthetic membrane (RPM) (n = 10; primary RPM = 2), endophthalmitis (n = 8), vitreous hemorrhage (VH) (n = 5; primary VH = 1), serous choroidal detachment (n = 5), hemorrhagic choroidal detachment (n = 2), and leak-related hypotony (n = 1). Mean interval from mOOKP surgery to occurrence of VR complication(s) was 43.8 months (median, 41.9 months; range, 0.2-95.5 months). After treatment of VR complication, visual improvement was seen in 17 eyes (42%) (mean improvement = 1.2 logarithm of the minimum angle of resolution [logMAR]; median, 0.8 logMAR; range, 0.1-2.5 logMAR), visual decline in 7 eyes (14%) (mean decline in BCVA = 0.6 logMAR; median, 0.4 logMAR; range, 0.3-1.8 logMAR), and no change in BCVA in 17 eyes (42%). However, BCVA ≥6/60 was retained in 19 eyes and ≥6/18 was retained in 9 eyes after final VR treatment. CONCLUSIONS: Vitreoretinal complications constitute a significant cause of visual morbidity in eyes undergoing mOOKP surgery and pose a challenging situation to manage. However, appropriate and timely intervention can achieve encouraging results.

The osteo-odonto-keratoprosthesis.

PURPOSE OF REVIEW: To describe the practice of and recent developments in the osteo-odonto-keratoprosthesis. RECENT FINDINGS: Formal psychological assessment and support have been described. A sub-aqua system for fashioning the osteo-odonto-keratoprosthesis lamina; adoption of thicker laminae; use of bisphosphonate drugs; advances in laminar imaging; and use of bone augmentation and bone morphogenetic protein have been described for prevention, detection, and management of laminar resorption. Two systems of optical cylinders available commercially. A stepladder approach to buccal mucous membrane overgrowth onto the optical cylinder has been described, including use of mitomycin-C. Orbital decompression has been used for cosmetic improvement. Detection of glaucoma may be aided by an intraocular pressure sensor, whereas surgical treatment is mainly by way of glaucoma drainage devices, as endolaser ciliary ablation and recti muscle disinsertion and reinsertion not having prolonged and significant long-term beneficial effect. Sublingual timolol has been described. The use of endoscopy has been proposed for preoperative evaluation of the posterior segment, ciliary ablation and for vitreoretinal surgery although wide-angle viewing systems remains standard practice. SUMMARY: The osteo-odonto-keratoprosthesis is the procedure of choice for rehabilitation of corneal blindness for end-stage ocular surface disease, serving a completely different patient group to the Boston Type 1 KPro.

Enhanced regeneration potential of mobilized dental pulp stem cells from immature teeth.

OBJECTIVES: We have previously demonstrated that dental pulp stem cells (DPSCs) isolated from mature teeth by granulocyte colony-stimulating factor (G-CSF)-induced mobilization method can enhance angiogenesis/vasculogenesis and improve pulp regeneration when compared with colony-derived DPSCs. However, the efficacy of this method in immature teeth with root-formative stage has never been investigated. Therefore, the aim of this study was to examine the stemness, biological characteristics, and regeneration potential in mobilized DPSCs compared with colony-derived DPSCs from immature teeth. MATERIALS AND METHODS: Mobilized DPSCs isolated from immature teeth were compared to colony-derived DPSCs using methods including flow cytometry, migration assays, mRNA expression of angiogenic/neurotrophic factor, and induced differentiation assays. They were also compared in trophic effects of the secretome. Regeneration potential was further compared in an ectopic tooth transplantation model. RESULTS: Mobilized DPSCs had higher migration ability and expressed more angiogenic/neurotrophic factors than DPSCs. The mobilized DPSC secretome produced a higher stimulatory effect on migration, immunomodulation, anti-apoptosis, endothelial differentiation, and neurite extension. In addition, vascularization and pulp regeneration potential were higher in mobilized DPSCs than in DPSCs. CONCLUSIONS: G-CSF-induced mobilization method enhances regeneration potential of colony-derived DPSCs from immature teeth.

Prognostic Factors for Clinical Outcomes in Autotransplantation of Teeth with Complete Root Formation: Survival Analysis for up to 12 Years.

INTRODUCTION: Tooth autotransplantation is a treatment option that has the potential to restore masticatory function and esthetics to edentulous spaces resulting from extracted teeth. The purpose of this study was to investigate the prognostic factors and clinical outcomes for autotransplanted teeth with complete root formation. METHODS: Patients who had received tooth autotransplantation in the Department of Conservative Dentistry, Yonsei University Dental Hospital, Seoul, Korea, from July 2001 to August 2010 were electronically searched, and a total of 105 cases of autotransplanted teeth met the inclusion criteria. Tooth survival, inflammatory root resorption (IRR), ankylosis, and related prognostic factors were assessed by using the survival analysis that was based on clinical and radiographic examination. RESULTS: The cumulative tooth survival rate was 68.2% at 12 years after the tooth autotransplantation. According to the Cox proportional hazard regression analysis, patient age, donor position, and extraoral time were significantly associated with tooth survival (P < .05). Donor extraction type was significantly associated with IRR (P < .05), and transplantation timing and initial stability were significantly associated with ankylosis (P < .05) CONCLUSIONS: Patients less than 45 years of age, maxillary donor teeth, and an extraoral time of less than 15 minutes were associated with significantly higher tooth survival. Surgical extraction of the donor tooth was associated with a significantly higher incidence of IRR. Immediate transplantation after the extraction of the recipient site's tooth and low initial stability were associated with a significantly lower incidence of ankylosis.

Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

PURPOSE: To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. METHODS: Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. RESULTS: Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. CONCLUSIONS: Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

Bone augmentation of the osteo-odonto alveolar lamina in MOOKP--will it delay laminar resorption?

PURPOSE: We aimed to describe a new technique and analyse the early outcomes of augmenting the canine tooth using a mandibular bone graft in an attempt to delay or retard the process of laminar resorption following the modified osteo odonto keratoprosthesis (MOOKP) procedure. DESIGN: This was a retrospective case series. PATIENTS AND METHODS: Eyes that underwent the bone augmentation procedure between December 2012 and February 2014 were retrospectively analysed. The procedure, performed by the oromaxillofacial surgeon, involved securing a mandibular bone graft beneath the periosteum on the labial aspect of the canine tooth chosen to be harvested for the MOOKP procedure. This procedure was performed simultaneously with the Stage 1 A of the MOOKP. Three months later, the tooth was harvested and fashioned into the osteo-odonto alveolar lamina similar to the method described in the Rome-Vienna Protocol. RESULTS: The bone augmentation procedure was performed in 11 eyes (five SJS/ six chemical injuries). The mean follow-up after Stage 2 of MOOKP procedure in these eyes was 7.45 months (2 to 20 months). Complications noted were peripheral laminar exposure (three eyes-SJS) and bone graft exposure and necrosis in the mouth (nine-SJS). No evidence of clinical laminar resorption was noted in any of the eyes. CONCLUSION: Laminar resorption in MOOKP can lead to vision and globe threatening complications due to the consequent cylinder instability and chances of extrusion. Augmenting the bone on the labial aspect of the canine tooth might have a role to play in delaying or preventing laminar resorption.

Vitreoretinal aspects of permanent keratoprosthesis.

Permanent keratoprosthesis (KPro) is a treatment option in patients with severe corneal disease not amenable to traditional penetrating keratoplasty. There are several types of permanent keratoprostheses available for use worldwide, including the Boston KPro, osteo-odonto KPro, and AlphaCor, among others. A multidisciplinary team of cornea, glaucoma, and vitreoretinal specialists is necessary to ensure proper patient selection, preoperative planning, keratoprosthesis placement, postoperative monitoring and management of complications. We provide a comprehensive review of the vitreoretinal aspects of permanent keratoprostheses.

Cone-beam computed tomography for planning and assessing surgical outcomes of osteo-odonto-keratoprosthesis.

PURPOSE: The aim of this study was to investigate the feasibility and effectiveness of cone-beam computed tomography (CBCT) in the planning, assessment, and follow-up for osteo-odonto-keratoprosthesis (OOKP). METHODS: Six OOKP patients received a CBCT scan. CBCT scans were performed before and/or between ∼5 and 504 months after the primary OOKP intervention. Preoperative and postoperative results of the CBCT were assessed, regarding the available teeth and to assess the loss of bone in 1 patient, respectively. Resorption of the osteo-odonto-lamina was measured and graded. Five different measurements (I-V) were performed in the coronal and transversal views of CBCT. RESULTS: Four CBCT scans were performed preoperatively and 4 postoperatively. The follow-up time of the patients is between ∼1 to 528 months. Visualization of the potential donor teeth resulted in accurate 3-dimensional visualization of the tooth-lamina-bone complex. CBCT was found to help in the preoperative decision-making process (diameter of optical implant) and in enabling accurate postoperative evaluation of the bone volume and resorption zones of the OOKP. Loss of bone could be measured in a precise range and showed in the completed cases an average loss of 20.2%. CONCLUSIONS: The use of CBCT simplifies the preoperative decision making and ordering process. It also helps in determining the postoperative structure and resorption of the prosthesis.

Glaucoma in modified osteo-odonto-keratoprosthesis eyes: role of additional stage 1A and Ahmed glaucoma drainage device-technique and timing.

PURPOSE: To report the technique, timing, and outcomes of the Ahmed glaucoma drainage device in eyes with the modified osteo-odonto-keratoprosthesis (MOOKP) and the role of an additional stage 1A to the Rome-Vienna protocol. DESIGN: Retrospective interventional case series. METHODS: Case records of 22 eyes of 20 patients with high intraocular pressure at various stages of the MOOKP procedure performed in 85 eyes of 82 patients were studied. Stage 1A, which includes total iridodialysis, intracapsular cataract extraction, and anterior vitrectomy, was done in all eyes as the primary stage. RESULTS: Seventeen Ahmed glaucoma drainage devices were implanted in 15 eyes of 14 patients (chemical injury in 9 [10 eyes] and Stevens-Johnson syndrome in 5 patients). Implantation was performed during and after stage 1A in 2 and 7 eyes, respectively, after stage 1B+1C in 1 eye, and after stage 2 in 6 eyes. Eleven of 15 eyes (73.3%) remained stable with adequate control of intraocular pressure over a mean follow-up period of 33.68 months (1-90 months). Complications related to the drainage device were hypotony in 1 eye and vitreous block of the tube in 1 eye. CONCLUSION: It is ideal to place the Ahmed glaucoma drainage device prior to the mucosal graft when the anatomy of the ocular surface is least altered with best outcomes. The technique of placement of the drainage device during the various stages of the MOOKP procedure has been described. The intraocular pressure stabilized in three quarters of the eyes with pre-existing glaucoma.

A brief review of Boston type-1 and osteo-odonto keratoprostheses.

Globally there are ≈4.9 million bilaterally corneal blind and 23 million unilaterally corneal blind. Majority of this blindness exists in the developing countries, where resources for corneal banking and transplant surgery are less than adequate. Survival of corneal grafts gradually declines over the long term. Corneal transplantation has poor prognosis in vascularised corneal beds, ocular surface disease and viral keratitis. Keratoprosthesis (KPro) remains as a final option for end-stage ocular surface disease, multiple corneal transplant failures and high-risk corneal grafts. Boston type-1 KPro and osteo-odonto-keratoprosthesis are the two devices proven useful in recent years. Choice of a keratoprosthetic device is patient specific based on the underlying diagnosis, ocular morbidity and patient suitability. KPro surgery demands a high level of clinical and surgical expertise, lifelong commitment and extensive resources. Improvements in techniques and biomaterials may in the future provide retainable KPros that do not need regular follow-up of patients, have low complications but high retention rates and may be produced at a low cost on a mass scale to be available as 'off the shelf' devices. Because KPros have the potential to effectively address the burden of surgically treatable corneal blindness and may also eliminate the problems of corneal transplantation, more research is required to develop KPros as substitutes for corneal transplantation even in low-risk cases. In those countries where corneal blindness is a major liability, we need a two pronged approach: one to develop eye donation, eye banking and corneal transplantation and the second to establish centres for keratoprostheses, which are affordable and technically not challenging, in a population where default on follow-up visits are high. Until the latter is achieved, KPros should be viewed as a temporary means for visual restoration and be offered in national and supraregional specialised centres only.

Endoscopic cyclophotocoagulation in refractory glaucoma after osteo-odonto-keratoprosthesis in Stevens-Johnson syndrome: a case report.

PURPOSE: To report successful treatment of refractive glaucoma in a patient submitted to osteo-odonto-keratoprosthesis surgery for Stevens-Johnson syndrome. METHODS: An interventional case report. RESULTS: The patient is a 62-year-old Indian man with known Stevens-Johnson syndrome since 1972 secondary to tetracycline therapy, with bilateral dry eye and corneal blindness. He underwent symblepharon release surgery with mucous membrane graft in both eyes. Osteo-odonto-keratoprosthesis surgery was later performed on the left eye. He was submitted to 2 Ahmed valve implants to control secondary glaucoma but visual fields continued to worsen; hence, he underwent endoscopic 140° cyclophotocoagulation with a good control of IOP. CONCLUSION: Endoscopic cyclophotocoagulation as alternative treatment provides good results in refractory glaucoma after osteo-odonto-keratoprosthesis surgery.

Optical functional performance of the osteo-odonto-keratoprosthesis.

PURPOSE: The aim of this study was to evaluate optical and visual functional performance of the osteo-odonto-keratoprosthesis (OOKP). METHODS: Optical design and analysis was performed with customized optical design software. Nine patients with implanted OOKP devices and 9 age-matched control patients were assessed. Contrast sensitivity was assessed and glare effect was measured with a brightness acuity test. All OOKP patients underwent kinetic Goldmann perimetry and wavefront aberrometry and completed the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). RESULTS: Optical analysis showed that the optical cylinder is near diffraction-limited. A reduction in median visual acuity (VA) with increasing glare settings was observed from 0.04 logMAR (without glare) to 0.20 logMAR (with glare at "high" setting) and significantly reduced statistically when compared with the control group at all levels of glare (P < 0.05). Contrast sensitivity was significantly reduced when compared with age-matched controls at medium and high spatial frequencies (P < 0.05). Median Goldmann perimetry was 65 degrees (interquartile range, 64-74 degrees; V-4e isopters) and 69 degrees excluding 2 glaucomatous subjects. Several vision-related NEI VFQ-25 subscales correlated significantly with VA at various brightness acuity test levels and contrast sensitivity at medium spatial frequencies, including dependency, general vision, near activities and distance activities. CONCLUSIONS: The OOKP optical cylinder provides patients with a good level of VA that is significantly reduced by glare. We have shown in vivo that updates to the optical cylinder design have improved the patient's field of view. Reduction of glare and refinement of cylinder alignment methods may further improve visual function and patient satisfaction.

Investigation of dental pulp stem cells isolated from discarded human teeth extracted due to aggressive periodontitis.

Recently, human dental pulp stem cells (DPSCs) isolated from inflamed dental pulp tissue have been demonstrated to retain some of their pluripotency and regenerative potential. However, the effects of periodontal inflammation due to periodontitis and its progression on the properties of DPSCs within periodontally compromised teeth remain unknown. In this study, DPSCs were isolated from discarded human teeth that were extracted due to aggressive periodontitis (AgP) and divided into three experimental groups (Groups A, B and C) based on the degree of inflammation-induced bone resorption approaching the apex of the tooth root before tooth extraction. DPSCs derived from impacted or non-functional third molars of matched patients were used as a control. Mesenchymal stem cell (MSC)-like characteristics, including colony-forming ability, proliferation, cell cycle, cell surface antigens, multi-lineage differentiation capability and in vivo tissue regeneration potential, were all evaluated in a patient-matched comparison. It was found that STRO-1- and CD146-positive DPSCs can be isolated from human teeth, even in very severe cases of AgP. Periodontal inflammation and its progression had an obvious impact on the characteristics of DPSCs isolated from periodontally affected teeth. Although all the isolated DPSCs in Groups A, B and C showed decreased colony-forming ability and proliferation rate (P < 0.05), the decreases were not consistent with the degree of periodontitis. Furthermore, the cells did not necessarily show significantly diminished in vitro multi-differentiation potential. Only DPSCs from Group A and the Control group formed dentin-like matrix in vivo when cell-seeded biomaterials were transplanted directly into an ectopic transplantation model. However, when cell-seeded scaffolds were placed in the root fragments of human teeth, all the cells formed significant dentin- and pulp-like tissues. The ability of DPSCs to generate dental tissues decreased when the cells were isolated from periodontally compromised teeth (P < 0.05). Again, increased periodontal destruction was not necessarily followed by a decrease in the amount of dentin- and pulp-like tissue formed. These findings provide preliminary evidence that periodontally compromised teeth might contain putative stem cells with certain MSC properties, as long as the vitality of the pulp has not been totally damaged. Whether these cells can serve as a source of autologous multipotent MSCs for clinical regenerative therapies warrants further investigation with larger sample sizes and various types of periodontitis.

Mitomycin-C for mucous membrane overgrowth in OOKP eyes.

PURPOSE: The aim of this study was to report the use of mitomycin-C (MMC) in the treatment of mucous membrane overgrowth in eyes with osteo-odonto-keratoprosthesis (OOKP). METHODS: Records of 4 cases with mucous membrane overgrowth after stage 2 OOKP surgery were reviewed. RESULTS: All the patients had undergone a mucous membrane trimming procedure followed by MMC application. None of the patients had any episode of recurrence of the mucous membrane overgrowth after a single application of MMC in the follow-up period that ranged from 1 to 11 years. CONCLUSIONS: MMC can successfully arrest mucous membrane overgrowth in OOKP-implanted eyes including refractory cases.