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.

Alveolar graft in the cleft lip and palate patient: review of 104 cases

INTRODUCTION

Alveolar bone grafting is a vital part of the rehabilitation of cleft patients. The factors that have been most frequently associated with the success of the graft are the age at grafting and the pre-grafting orthodontic treatment.

OBJECTIVES

1) Describe the cases of alveolar bone grafts performed at the Maxilofacial Unit of Hospital Sant Joan de Déu, Barcelona (HSJD); and 2) Analyze the success/failure of alveolar grafts and related variables.

MATERIAL AND METHODS

Descriptive retrospective study using a sample of 104 patients who underwent a secondary alveolar graft at the Craniofacial Unit of HSJD between 1998 and 2012. The graft was done by the same surgeon in all patients using bone from the iliac crest.

RESULTS

70% of the patients underwent the procedure before the age of 15 (median 14.45 years); 70% of the graft patients underwent pre-graft maxillary expansion. A total of 100 cases were recorded as successful (median age of 14.58 years, 68 underwent pre-graft expansion) and only 4 were recorded as failures (median age of 17.62 years, 3 underwent pre-graft expansion). We did not find statistically significant differences in age at the time of grafting or pre-surgical expansion when comparing the success and failure groups. We found the success rate of the graft to be 96.2%.

CONCLUSIONS

The number of failures was too small to establish a statistically significant conclusion in our sample regarding the age at grafting and pre-grafting expansion. The use of alveolar bone grafting from the iliac crest has a very high success rate with a very low incidence of complications. Existing controversies regarding secondary bone grafting and the wide range of success rates found in the literature suggest that it is necessary to establish a specific treatment protocol that ensures the success of this procedure.

Laminar resorption in modified osteo-odonto-keratoprosthesis procedure: a cause for concern

PURPOSE

To analyze the cases of lamina resorption following the modified osteo-odonto-keratoprosthesis (MOOKP) procedure.

DESIGN

Retrospective case series.

PATIENTS AND METHODS

Case records of 18 eyes (20 laminae) of 17 patients who showed evidence of lamina resorption out of the 85 eyes (87 laminae) of 82 patients that underwent MOOKP procedure between March 2003 and March 2013 were analyzed.

RESULTS

Of the 17 patients (20 laminae), 1 underwent MOOKP procedure following multiple graft failures, 6 (7 laminae) belonged to the chemical injury group, and 10 (12 laminae) to the Stevens-Johnson syndrome (SJS) group. Resorption was noted in 20 out of 87 laminae (22.98%). The need for removal of lamina/extrusion was noted in 3 out of the 7 laminae in the chemical injury group and 8 out of the 12 laminae in the SJS group. The mean duration to the first sign suggestive of resorption among patients of SJS was 36.7 months and among patients of chemical injury was 43 months. Vitritis was the presenting feature (7 of 20 laminae, 35%) indicative of early resorption, and the occurrence of the same in eyes with lamina resorption was noted to be statistically significant in comparison to controls (P<.001). Sixteen out of 20 laminae showed evidence of resorption superiorly.

CONCLUSION

Vitritis was the most common presenting feature of lamina resorption and could be an indicator of lamina resorption. Resorption of the laminae was noted to occur along the aspect with thinner bone support in all eyes. Incidence of severe resorption with extrusion of cylinder/requiring lamina removal was noted to be higher among patients with SJS.

Vitreoretinal complications and vitreoretinal surgery in osteo-odonto-keratoprosthesis surgery

PURPOSE

To describe the indications for and approaches to vitreoretinal surgery in patients with osteo-odonto-keratoprosthesis (OOKP).

DESIGN

Retrospective case series.

METHODS

This was a retrospective review of all patients who had undergone OOKP surgery between 2003 and 2012 at our center. OOKP procedures were performed for severe ocular surface disease according to the indications and techniques described in the patient demographics of the Rome-Vienna Protocol. Indications for retinal surgery, surgical outcomes, and intraoperative and postoperative complications were documented. Operative techniques were reviewed from the surgical records, and any subsequent surgeries were also recorded.

RESULTS

Thirty-six patients underwent OOKP, and retinal surgery was indicated in 13 (36%). The indications for and approaches to surgery were retinal detachment repair using an Eckardt temporary keratoprosthesis; assessment of retina and optic nerve health prior to OOKP surgery, using either a temporary keratoprosthesis or an endoscope; endoscopic cyclophotocoagulation for intractable glaucoma; endoscopic trimming of a retroprosthetic membrane; or vitrectomy for endophthalmitis with visualization through the OOKP optic using the binocular indirect viewing system. In all cases, retinal surgical aims were achieved with a single procedure. Postoperative vitreous hemorrhage occurred in 16 patients (44%), but all resolved spontaneously.

CONCLUSIONS

OOKPs represent the last hope for restoration of vision in severe ocular surface disease, and the retinal surgeon is frequently called upon in the assessment and management of these patients. Temporary keratoprostheses and endoscopic vitrectomies are valuable surgical tools in these challenging cases, improving functional outcomes without compromising OOKP success.

Revision rates of alveolar bone grafting in unilateral cleft lip and palate patients with and without orthodontic preparation

The main purpose of the present study was to compare the revision rates of alveolar bone grafting in cleft lip and palate (CLP) patients with and without orthodontic preparation. The dental record of 101 patients with unilateral cleft lip and palate were examined. Details were recorded of general characteristic, the need for revision, intraoral condition prior to surgery, surgical procedure and the cause of revision. The revision rates were 11.9% and 20.6% in orthodontic preparation and non-orthodontic preparation groups, respectively. The Fisher's exact test showed that there was no difference in the revision rate between both groups. Intraoral conditions prior to grafting and different surgical procedures did not affect the success of alveolar bone grafting.

Comparison of a clinical method with two radiographic methods for assessing quality of alveolar bone grafts

The aim of the present study was to test the agreement between a new developed clinical examination method and two commonly used radiographic scales (Bergland and Chelsea) for assessing alveolar bone graft outcomes in the cleft lip and palate patients. This new clinical method consisted of: (1) Probing depth for the teeth adjacent to the cleft and (2) Residual defects at the bone graft site. Two trained examiners examined the subjects in the present study. The inter- and intra-reliability tests of the two clinical criteria and the two radiographic scales produced the excellent agreement level of Kappa values (0.85-1.00). Comparison of the "acceptable-unacceptable" proportions between clinical and radiographic examination methods using McNemar's Chi-square showed non-significant differences (p-values 0.317-1.00), and good level Kappa values (0.68-0.77). It is suggested that the new clinical examination method could be used as an alternative screening tool for alveolar bone graft assessment.

Osteo-odonto-keratoprosthesis for end-stage cornea blindness

We report the first case of Osteo-odonto-keratoprosthesis (OOKP) who successfully underwent surgery in Malaysia following a grade 4 (severe) chemical injury in both eyes in 2006. The patient's left eye was eviscerated and his right eye underwent penetrating keratoplasty. However, the corneal graft failed and became opaque. His right eye could only perceive light. The OOKP was offered to him hoping to recover some functional vision. He underwent a 2-stage surgery to implant the OOKP into his right eye. However, 2 months post-operation, he developed vitreous haemorrhage. A successful pars plana vitrectomy (PPV) was performed via the limited view through the lens. He attained a final visual acuity of 6/60 (N36). He was able to mobilize more independently, feed, dress himself and read large print.

Osteo-Odonto-Keratoprosthesis: A Human Model of Autotransplant

We evaluated the microscopical changes that occurred when bone and dental tissue were exposed to such a foreign environment as the ocular surface and anterior chamber in 17 osteo-odonto-keratoprostheses removed from the recipient's eye after 1 to 20 years. Histochemical methods were performed to demonstrate elastic and precursor fibers, while immunohistochemical procedures were used to study the distribution of collagen types I to VI. Islands of heterotopic, newly formed bone were observed in the dentin and the periodontal space, leading to focal dentoalveolar ankylosis. Remodelling and disappearance of the periodontal ligament was never diffuse.

[Effect of crestal rotated flap on esthetics of peri-implant soft tissues in anterior maxilla]

OBJECTIVE

To investigate the height of interdental papillae around single-tooth implants in the anterior maxillae after exposure of implant using crestal rotated flap.

METHODS

The study comprised 34 implants in the anterior maxillae from 32 patients. All implants were uncovered by use of crestal rotated flap technique. Impressions were taken before and after stage 2 surgery, and stone models were used to evaluate the change of papillae height. The gingival papillae index around single-tooth implants was compared before and after the surgery.

RESULTS

The average increase in papillae height was (0.77 +/- 0.25) mm, which was statistically significant with analysis of a paired t test (P < 0.05). The change of gingival papillae index showed no significant difference using statistical analysis of rank sum test (P > 0.05). The lower the gingival papillae index was before the surgery, the less the papillae height increased after the surgery.

CONCLUSIONS

The main advantages of the crestal rotated flap technique are simplicity and predictability, and it consistently provides high papillae for the maxillary implants.

Osteo-odonto-keratoprosthesis surgery: a combined ocular–oral procedure for ocular blindness

The aim of this retrospective study was to describe the oral procedures used in osteo-odonto-keratoprosthesis (OOKP) surgery, and the demographics and oral findings of candidate patients in Singapore. The OOKP procedure utilizes an autologous tooth-bone complex to mount a poly-methylmethacrylate optical cylinder, as an artificial cornea, stabilized by an overlying autologous buccal mucosal graft. Consecutive patients referred over 3 years for dental evaluation prior to OOKP surgery were included. A total of 21 patients underwent oral clinical and radiographic evaluation. The aetiology of blindness included Stevens-Johnson's syndrome (11 cases), chemical burns (9 cases) and multiple failed corneal grafts (1 case). Evaluation revealed that 12 patients were suitable for OOKP surgery, 8 were at risk of complication or failure and 1 had no usable teeth. Fourteen patients have undergone unilateral OOKP Stage 1 surgery successfully. Complications included fracture of a tooth from its lingual bone necessitating the harvesting of a second tooth (1 case), oronasal perforation (1 case), exposure of adjacent roots (5 teeth), lower lip paresthesia (2 cases) and submucosal scar band formation in the buccal mucosal graft donor site (10 cases). Thirteen patients have completed Stage 2 surgery, with attainment of their best possible visual potential following OOKP surgery.

Replantation and transplantation following avulsion of two maxillary incisors

Here we describe replantation and transplantation as a treatment conducted in a 16-year-old patient following a bicycle accident. An avulsed left central incisor in maxilla was replanted after extra-oral root canal treatment, and the lost right central incisor of the maxilla was replaced by a left lateral incisor of the mandible in the region of the fracture fissure. Follow-up examination at 34 months showed validity of treatment, although slight evidence of replacement resorption in the transplanted and replanted teeth was revealed.

Tissue engineering of a periodontal ligament-alveolar bone graft construct

PURPOSE

This paper reports on a 2-phase study of a novel membrane-scaffold graft construct, its ability to support periodontal ligament fibroblast (PDLF) and alveolar osteoblast (AO) growth in vitro, and its use for tissue engineering a PDL-AO interface in vivo.

MATERIALS AND METHODS

Human PDLFs were seeded onto perforated poly(epsilon-caprolactone) membranes (n=30) at 78,000 cells/cm2; human AOs were seeded on poly(epsilon-caprolactone) scaffolds (n=30) with fibrin glue at 625,000 cells/cm3. Cell attachment, morphology, viability, and metabolic activity were monitored for 3 weeks in vitro. Subsequently, cell-seeded membrane-scaffold constructs (experimental group, n=9) and nonseeded constructs (control group, n=4) assembled with fibrin glue were implanted subcutaneously into 7 athymic mice for 4 weeks.

RESULTS

PDLFs formed confluent layers on membranes, whereas AOs produced mineralized matrices within scaffolds upon osteoinduction in vitro. Well-vascularized tissue formation was observed after implantation. Integration at the membrane-scaffold interface was enhanced in the experimental group. Type I collagen, type III collagen, fibronectin, and vitronectin were found adjacent to membranes and within constructs. Bone sialoprotein expression and bone formation were undetectable.

DISCUSSION

Membrane perforation and scaffold porosity facilitated tissue integration and vascularization at the construct-recipient site. However, the interaction between PDLF and AO could have interfered with osteogenesis at the interface of soft and mineralizing tissues.

CONCLUSIONS

Both matrices supported PDLF and AO attachment and proliferation in vitro. The membrane-scaffold construct facilitated tissue growth and vascularization while providing strength and form in vivo.

Effect of proliferating tissue on transplanted teeth in dogs

OBJECTIVE

The objective of this study was to investigate the effect of transplanted proliferating tissue on the regeneration of periodontal ligaments (PDL) in tooth transplantation.

STUDY DESIGN

Two weeks after removing the alveolar bone, proliferating tissues were excised and examined for expression of basic fibroblast growth factor (bFGF) and alkaline phosphatase (ALP) using a LightCycler. Next, the teeth to be transplanted (first premolars) were extracted and PDLs were removed by scaling. After that, the first premolar teeth and proliferating tissues for the experimental group were transplanted into bone cavities created at the sites of the third and fourth premolars, while the control sites received teeth only. Finally, 1, 2, and 4 weeks later, the animals were sacrificed and specimens were collected and processed for histopathologic examination.

RESULTS

bFGF and ALPmRNA showed a significant increase in the transplanted proliferating tissue. Transplantation of the proliferating tissues positively affected the formation of new cementum and PDL. Moreover, application of the transplanted proliferating tissues decreased the occurrence and extent of ankylosis and root resorption at the root surface.

CONCLUSION

These results indicate that transplanted proliferating tissue may promote the regeneration of periodontal tissue and prevent ankylosis and root resorption following the transplantation of teeth.

Correction of the nose in patients with unilateral cleft lip with composite grafts

We used composite conchal cartilage graft for columellar lengthening in eight patients with unilateral cleft lip and a nasal deformity. In 16 patients we used a buccal mucosal graft to line the nasal vestibule. We also used corrective procedures such as alveolar bone grafting for closure of palatal fistulas, septoplasty, malar augmentation, nasal osteotomy, and Le Fort I osteotomy to deal with associated deformities. Grafts took well with no loss and no donor site morbidity. In the follow up of 8 months-3 years, corrections were found to be stable and satisfying to all the patients. Only by replacing deficient tissues with similar tissues and putting them in the proper anatomical position can long term consistent and reliable results be achieved in the correction of nasal deformities associated with unilateral cleft lip.

Progressive replacement of oral mucosa by conjunctiva in osteo-odonto-keratoprosthesis: preliminary observations

PURPOSE

In a Strampelli osteo-odonto-keratoprosthesis, a patch of oral mucosa is frequently used to cover the ocular surface after implantation of an osteodental lamina into the eye. In many cases, gross modifications in the eye covering become apparent a few years later. The aim of this study was to investigate the histologic findings in the clinically modified ocular surface.

METHOD

Biopsies were performed in 7 patients at the junction between the osteodental acrylic lamina and surrounding modified oral mucosa, during surgery for local plastic reconstruction or positioning of antiglaucoma silicone tubes. Specimens were examined by light microscopy.

RESULTS

Six of the 7 clinically modified specimens corresponded microscopically to conjunctiva. Typical oral mucosa could still be observed overlying the osteodental acrylic lamina.

CONCLUSIONS

The production of local regulatory factors is a possible explanation for the survival of oral mucosa over the osteodental acrylic lamina, whereas their absence in distant areas may have induced the oral mucosa to transdifferentiate into a conjunctival-type lining. Alternatively, conjunctival regrowth from forniceal stem cells should be taken into consideration.

Standards for Modified Osteoodontokeratoprosthesis (OOKP) Surgery According to Strampelli and Falcinelli

PURPOSE

To establish a time-proven "gold standard" in modified osteoodontokeratoprosthesis (OOKP) surgery.

METHODS

The OOKP is the procedure of choice for restoring sight in patients with corneal blindness caused by end-stage ocular surface disease not amenable to penetrating keratoplasty. Members of the OOKP Study Group met in Rome, Italy in 2001 and Vienna, Austria in 2002 to discuss indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of OOKP surgery according to Strampelli and modified by Falcinelli.

RESULTS

Falcinelli's modification of Strampelli's technique of OOKP surgery remains the gold standard as far as visual and keratoprosthesis-retention results are concerned. The agreement on indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of this technique of OOKP surgery is summarized in the text of this manuscript.

CONCLUSION

This standard technique of modified OOKP surgery, where adequately performed, is capable of providing excellent anatomic and functional results even in the long term. In patients with corneal blindness untreatable by other approaches, we strongly recommend this technique for visual rehabilitation. Students of OOKP surgery should become familiar with the protocol described in this paper before subjecting the technique to further modifications.

Modified Osteo-odonto-keratoprosthesis for Treatment of Corneal Blindness

OBJECTIVE

To evaluate long-term anatomical and functional outcomes of a modified osteo-odonto-keratoprosthesis (OOKP) technique for treatment of corneal blindness from various etiologies.

METHODS

Two-hundred three patients (224 eyes) underwent modified OOKP surgery between 1973 and 1999. Of the original cohort, 181 patients (98 men and 83 women; mean [SD], age 54.3 [15] years) in whom a standardized 2-step surgical procedure was performed were included in the study. Preoperative diagnoses were dry eye (n = 70) due to ocular pemphigoid (n = 39), Sjögren syndrome (n = 11), trachoma (n = 8), Lyell syndrome (n = 6), Stevens-Johnson syndrome (n = 4), and graft-vs-host disease (n = 1) and congenital lid coloboma (n = 1), severe corneal burns (n = 68), bullous keratopathy (n = 13), keratitis sequelae (n = 15), and bullous keratopathy secondary to antiglaucoma surgery (n = 15). Several innovations were made to the original Strampelli technique. Median follow-up duration was 12 years (range, 1-25 years).

RESULTS

Anatomical complications leading to OOKP loss were found in 11 (6.07%) of 181 patients. Survival analysis estimated that 18 years after surgery, the probability of retaining an intact OOKP was 85% (95% confidence interval, 79.3%-90.7%). Pooling patient groups, mean (SD) best postoperative visual acuity was 0.76 (0.34). Mean (SD) final acuity at the end of follow-up declined slightly (0.69 [0.39]) but significantly (P<.01). In individual diagnostic groups, mean acuity decline reached statistical significance (P<.05) only in the pemphigoid (1 line), trachoma (1 line), and bullous keratopathy secondary to antiglaucoma surgery (2 lines) groups. Survival analysis estimated that 18 years after surgery, the probability of retaining best postoperative visual acuity (within 2 lines) was mean (SD) 55.5% (12.9%).

CONCLUSION

Modified OOKP surgery for corneal blindness of different etiologies may provide, in the long-term, anatomically stable corneal prosthesis as well as an effective, rehabilitating recovery in visual acuity.

The osteo-odonto-keratoprosthesis (OOKP)

The osteo-odonto-keratoprosthesis (OOKP), although described over 40 years ago, remains the keratoprosthesis of choice for end-stage corneal blindness not amenable to penetrating keratoplasty. It is particularly resilient to a hostile environment such as the dry keratinized eye resulting from severe Stevens-Johnson syndrome, ocular cicatricial pemphigoid, trachoma, and chemical injury. Its rigid optical cylinder gives excellent image resolution and quality. The desirable properties of the theoretical ideal keratoprosthesis is described. The indications, contraindications, and patient assessment (eye, tooth, buccal mucosa, psychology) for OOKP surgery are described. The surgical and anaesthetic techniques are described. Follow-up is life-long in order to detect and treat complications, which include oral, oculoplastic, glaucoma, vitreo-retinal complications and extrusion of the device. Resorption of the osteo-odonto-lamina is responsible for extrusion, and this is more pronounced in tooth allografts. Regular imaging with spiral-CT or electron beam tomography can help detect bone and dentine loss. The optical cylinder design is discussed. Preliminary work towards the development of a synthetic OOKP analogue is described. Finally, we describe how to set up an OOKP national referral center.

Reconstruction of maxillectomy defect by transport distraction osteogenesis

The study aimed to explore the feasibility of posterior maxillectomy reconstruction by transport distraction in a primate model. In each of 14 male adult rhesus monkeys, posterior partial maxillectomy was performed on one side of maxilla to create a posterior maxillary deflect. Immediately after the maxillectomy, a dentoalveolar segment anterior to the defect was osteotomized as transport segment and a custom-made transport distractor was fixed on the residual maxilla. After a latency period of 5 days, the distractor was activated 1 mm daily to move the transport segment backward to the defect. This process lasted about 2 weeks. The transport segment was allowed to consolidate and the animals were sacrificed at different defined intervals. Transport distraction was successful in six animals. Three other cases were completed with minor wound dehiscence and one had a small oro-antral fistula with subsequent maxillary sinusitis. New bone bridging the distraction gap was confirmed by radiography and histology in the animals completing distraction. Reconstruction of posterior maxillectomy defect is proven feasible by transport distraction osteogenesis.

Early bone grafting in Tessier number 4 cleft: a case report

Rare craniofacial clefts have an incidence of at least 1 per 100,000 live births. A Tessier number 4 cleft is one of the most rare craniofacial clefts, with less than 50 cases being reported in the literature. Both soft and bony tissue abnormalities take place in the cleft morphology, so not only clinical examination of the maxillofacial region but a detailed radiological workup is needed to assess clearly the nature of the clefts. A patient with a Tessier number 4 cleft is presented, whose bony defect was obliterated with autogenous iliac bone graft chips and soft tissue reconstruction was performed with multiple Z-plasty flaps. Postoperative clinical and radiological results demonstrate fine healing and good cosmesis. Although controversy still exists about the treatment of facial clefts with early bone grafts, advantages of performing both bony and soft tissue reconstructions in a single session make this treatment a good alternative with satisfactory clinical and radiological results.

Secondary alveolar bone grafting in cleft lip and palate patients

The case records of 72 patients in Northern Ireland who had secondary bone grafting of 94 alveolar clefts between 1987 and 1997 were examined. Details were recorded of age, sex, laterality of cleft, preoperative orthodontic treatment, whether grafting was combined with soft tissue revision, method of harvesting the graft, complications, eruption of canines, and the success of grafting as established by bone levels around the erupted canine. Bone levels were assessed on a four-point scale. Of 64 canines fully erupted in 94 clefts, 91% achieved bone levels of Type I or II and only two grafts failed. The outcome was more favourable when the canine was unerupted preoperatively.

A retrospective study of bilateral alveolar bone grafting

OBJECTIVE

To evaluate the treatment results of bilateral alveolar bone grafting (BABG) in patients with bilateral complete clefts of lip and palate.

METHODS

A retrospective study was performed in 66 bilateral complete cleft lip and palate patients who received the procedure of BABG, among them 15 were primary BABG and 51 were secondary BABG. The patients were further divided into three groups according to age and eruption stage of the canine at the time of surgery. The result of BABG was evaluated on the radiographs.

RESULTS

(1) The overall success rate of BABG was 75.0%, with 83.3% and 72.5% for primary and secondary BABG respectively; (2) The marginal bone level was found to be significantly higher in the youngest age group than in the other groups both for primary and secondary BABG; (3) For both primary and secondary BABG, Group C (patients' age more than 16 years) had the least optimal success rate, with 66.7% and 65.1% respectively.

CONCLUSION

Simultaneous primary palate repair and BABG is safe and feasible procedure for treating unoperated bilateral complete cleft lip and cleft palate patients. For both primary and secondary BABG, significantly better results can be achieved if the operation is performed before eruption of the canine.

Horizontal osteotomy for reconstruction of the narrow edentulous mandible

The aim of this retrospective study was to evaluate the applicability of a horizontal osteotomy procedure for reconstruction of a narrow edentulous mandible in order to enable insertion of implants. In 7 edentulous patients a narrow inferior alveolar ridge was reconstructed with autogenous bone grafts harvested by a horizontal osteotomy procedure (mean width of the top of the alveolar crest before grafting 1.3 +/- 0.3 mm, after grafting 5.6 +/- 0.6 mm). Insertion of endosseous implants (10 Brånemark implants, 8 ITI Bonefit implants) was performed 3 months after the grafting procedure. Implant supported overdentures were fabricated 3 months after implantation. At regular time intervals a standardized clinical and a radiographic evaluation was performed. All grafted sites showed sufficient bone volume for insertion of the implants at the moment of implantation. At time of evaluation (mean 37 +/- 14.6 months, range 14-68 months) all implants and overdentures functioned well. None of the patients showed a disturbed sensitivity of the lip or chin region. It is concluded that reconstruction of a narrow edentulous mandible with autogenous bone grafts harvested by an intraoral horizontal osteotomy was shown to be a reliable preimplantology procedure with potential applicability in this group of patients.

[An experimental study on transplantation of frozen autogenous tooth-mandible compound]

OBJECTIVE

To study the feasibility of reserving the teeth in the transplantation of frozen autogenous mandible.

METHODS

Forty adult Wistar rats were used for these operations of transplantation of frozen autogenous tooth-mandible compound (ATMC) and fresh ATMC. Then the healing process after transplantation of frozen ATMC and fresh ATMC was compared by clinical, radiographical, histological and microangiographical observation.

RESULTS

There were no significant differences between the healing process of frozen ATMC and that of fresh ATMC, and the fibres of regenerated periodontal membrane which maintained the dental root in normal position could be imbedded in the newly formed cementum.

CONCLUSION

It is feasible to transplant the frozen ATMC for reconstructing the mandible and improving its function in clinic.

[A retrospective analysis of autogenous alveolar bone grafting in clefts of the lip and palate]

OBJECTIVE

To analyse factors which are able to influence the result of alveolar bone grafting (AABG).

METHODS

A retrospective analysis was performed in a group of 54 alveolar cleft patients (30 males and 13 females, total 66 sides) who received AABG. The age range of the patients was 8-44 years. The cleft area was restored with autogenous cancerous bone from iliac crest. All the patients have been followed up for at least three months postoperatively. The result of the bone grafting was evaluated on the radoigraphs.

RESULTS

1. The overall survival rate of AABG was 94%, and clinical successful rate of AABG was 89%; 2. The successful rate of AABG was correlated with the age of the patients. The successful rate of AABG in group of patients above 18-year-old was significantly lower than other groups; 3. With the exception of cleft palate fistula operation, when the AABG was done simulatneously with other cleft lip and palate operations, the successful rate of AABG was not significantly different from that of the sole AABG operation; 4. The successful rate of AABG in patients with cleft lip or incomplete cleft palate was superior to patients with complete cleft palate.

CONCLUSION

Forming of excelent bone grafting bed and closely surturing is the key to the success of AABG.

[The study of presurgical and postsurgical orthodontic treatment of alveolar bone grafting on patients with complete cleft lip and palate]

OBJECTIVE

To investigate the patients who need the orthodontic treatment before and after alveolar bone grafting; the selection of the indications and so on.

METHODS

To select 20 patients with cleft lip and palate, each of them is treated by edgewise appliance, light-wire appliance or removable appliance half to one year before the operation.

RESULTS

After orthodontic treatment, the patients' maxillary teeth are drawn up in order; the distorted teeth have the right positions; the shape of the arch is normal and the teeth beside the cleft are no longer oblique. All of these give a good space to the grafted bone.

CONCLUSION

The orthodontic treatment before and after alveolar bone grafting is an important composition of serial treatment of cleft lip and palate. It not only gives a promise to the successful operation, but also makes patient a better shape and function of the occlusion.

Effect of alveolar bone grafting on maxillary growth in unilateral cleft lip and palate patients

This cephalometric study reports the extent to which maxillary growth may be impaired by grafting of alveolar bone during the period of mixed dentition. The analysis is confined to subjects with unilateral cleft lip and palate (UCLP). The craniofacial dimensions of a group of 28 children who underwent grafting before the age of 12 years were compared by t-test to those of a nongrafted group (N = 30) at 9 and 16 years of age. In addition, two multiple-regression analyses were performed, the second on a group of 70 subjects with UCLP who received a bone graft between the ages of 8 and 15 years. The principal finding was that bone grafting, even when performed on those as young as 8 or 9 years, had no adverse effect on anteroposterior or vertical maxillary growth. This may be attributable to postponement of grafting until most anteroposterior and transverse growth of the anterior maxilla had ceased and to the grafted tissue's ability to participate in the vertical development of the alveolar process.

Changes in periodontal fibre organization in mature bone/tooth isografts in mice

Mature mouse mandibular third molars together with their periodontal ligaments and alveolar bone were isografted to two heterotopic sites: the renal subcapsular site and the tibial shaft medulla. The pulps and periodontal ligaments of the grafts underwent cellular degeneration after transplantation but demonstrated signs of revascularization and cellular repopulation 7 days after transplantation. Grafts obtained at 28, 60 and 100 days after transplantation demonstrated a significant decrease in the width of the periodontal ligament, a decrease in the number and organization of mature periodontal fibre bundles, the appearance of fibers arranged parallel with the root surface and a decrease in the thickness of surrounding alveolar bone. These regressive changes in the periodontal ligament were considered to be due primarily to the nonfunctional status of the teeth at the two heterotopic sites.

Fixation of onlay bone grafts with lag screws

A method is described of fastening bone segments to the mandible and maxilla by means of lag screws. The indications are discussed, as are the possible advantages of the procedure compared with fixation of bone grafts by wiring or by osteosynthesis plates. Indications include: 1. Fixation of bone segments at the lower border of the mandible when, after maximal displacement of the segments, the surface of contact between the mandible and the bone segment becomes too small. 2. Filling-in defects in the alveolar process, e.g. stabilising bone grafts for augmentation of the height of the alveolar ridge. 3. Fixation of fragments serving to bridge over mandibular defects. Within the stated range of indications lag screws appear to have the following advantages compared with wire fixation: a) more stable immobilisation of the grafts b) closer contact between graft and recipient surface through compression between the two; c) the possibility of easier removal of the screws compared with removal of wires. Within the range of indications lag screws appear to have the following advantages compared with bone graft fixation by means of osteosynthesis plates: a) The plate acts as a separating medium between graft and the soft tissue bed. b) The more tedious removal of plates is avoided with screws.

The healing extraction site: a donor area for periodontal grafting material

In cases of advanced periodontal disease, it is likely that vertical osseous defects will be present and that selected teeth will require extraction. The healing extraction site provides a source of vital osseous grafting material for the treatment of these infrabony defects. The preparation and grafting of the recipient site, as well as the management of the donor area, are described in detail. Three cases are presented which illustrate the efficacy of this type of therapy.

[Strampelli's osteoodontokeratoprosthesis--indications, personal surgical methods and clinical experiences]

Keratoprosthetics, twenty years ago, was regarded as technically without solution. Today, merely biological questions remain. Although clinical experience does not allow us to give a final judgement, it seems more than probable that osteoodontokeratoprosthesis will obtain its indication as last resort for otherwise hopeless cases.

A histologic examination of a free osseous autograft. Case report

Twenty-eight months following free osseous autograft therapy, a block section was taken for histologic examination. (2) Microscopically, the periodontal structures were reconstructed with new alveolar bone, periodontal ligament, and cementum. (3) A 'separation artifact' was present between new and old cementum. This defect is probably an artifact of histologic processing.