RESUMO
BACKGROUND: Injury of the inferior alveolar nerve (IAN) sustained during surgical removal of an impacted lower third molar may cause paresthesia of the lower lip, chin, lower gingivae and anterior teeth. Lingual nerve (LN) injuries may result in ipsilateral paresthesia of the anterior two thirds of the tongue, mucosa of floor of mouth and lingual gingivae. A close anatomic relationship between the roots of the third molar and mandibular canal places the IAN at risk of damage. PURPOSE: The primary aim of this retrospective audit was to ascertain the incidence of IAN and LN damage after mandibular third molar surgery in National Dental Centre Singapore. A secondary aim was to identify the contributory factors for the risk of IAN and LN nerve injury on the basis of the data collected. METHODS: This retrospective audit included 1276 mandibular third molar surgical removals performed in the local anesthesia operating theatre (LAOT) at the National Dental Centre Singapore (NDCS) from April to December 2013. Data included patient details, clinical characteristics, and 1 week postoperative presence/absence of sensory alteration as reported by the patient. RESULTS: Summary of results- Out of 1276 third molar sites audited, 8 (0.62%) sites had altered sensation of the IAN and 1 (0.078%) had altered sensation of the LN at 1 week postoperative review. CONCLUSION: The incidence of IAN injury (0.62%) and lingual Nerve injury (0.08%) after one week from surgery in our audit was low compared to similar studies. This retrospective audit did not show any correlation of nerve injury to age, gender, race, site, angulation of tooth, grade of operator, removal of bone or tooth division. There was no single radiological sign associated with paresthesia, although the most common radiological signs were interruption of the canal line and darkening of the roots.
RESUMO
PURPOSE: To establish a multidisciplinary surgical program for osteo-odonto-keratoprosthesis (OOKP) surgery in Asia and to evaluate efficacy and preliminary safety of this keratoprosthesis in end-stage corneal and ocular surface disease. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Sixteen adults of Asian ethnic origin, bilaterally blind with end-stage corneal blindness from Stevens-Johnson syndrome, or severe chemical or thermal burns. METHODS: Osteo-odonto-keratoprosthesis surgery involves 2 procedures-in stage 1, an autologous canine tooth is removed, modified to receive an optical polymethyl methacrylate cylinder, and implanted into the cheek. The ocular surface is denuded and replaced with full-thickness buccal mucosa. Stage 2 surgery, performed 2 to 4 months later, involves retrieval of the tooth-cylinder complex and implanting it into the cornea, after reflection of the buccal mucosal flap, corneal trephination, iris and lens removal, and anterior vitrectomy. Concurrent glaucoma and vitreoretinal procedures are also performed at either stage, as required. MAIN OUTCOME MEASURES: Visual acuity (VA), field of vision, anatomical integrity and stability, and ocular and oral complications related or unrelated to the OOKP device. RESULTS: Osteo-odonto-keratoprosthesis surgery was performed on 15 patients, with a mean follow-up of 19.1 months (range, 5-31). Intraoperative complications included expulsive hemorrhage (keratoprosthesis device not implanted), tooth fracture (n = 1), oronasal fistula (n = 1), and mild inferior optic tilt (n = 1). Anatomical stability and keratoprosthesis retention has been maintained in all eyes, with no dislocation, extrusion, retroprosthetic membrane formation, or keratoprosthesis-related infection. Other complications not directly related to device insertion included retinal detachment (RD) related to silicone oil removal (n = 1) and endophthalmitis related to endoscopic cyclophotocoagulation performed 1 year after OOKP surgery (n = 1). Eleven patients (73.3%) attained a stable best spectacle-corrected VA of at least 20/40 or better, whereas 9 (60%) attained stable 20/20 vision. Four patients achieved their best visual potential, ranging from 20/100 to counting fingers vision, related to preexisting glaucomatous optic neuropathy or previous RD. CONCLUSIONS: Establishment of our OOKP program suggests that OOKP surgery has the potential to restore good vision to the most severe cases of corneal blindness in an Asian setting, with minimal device-related complications. Longer follow-up of these cases is currently underway.