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Updated fields: d4, d9, g3, g6, h2, h3, h4, h6, h11.The mayfield modified skull clamp (a1059) was returned for evaluation: device history record (dhr) - the dhr was reviewed and shows no abnormalities related to the reported failure.Failure analysis - the investigation of the returned handpiece (hp) shows that the flow rate of cooling water is decreasing due to the narrowing of the flow path due to the aging and twisting of the cable.The coil foam has also deteriorated over time, there is metal deterioration, and there is a high possibility that it will break in the future.Asa result, the cable and coil foam will be replaced as a set.In addition, it was confirmed that the shaft misalignment occurred due to overtorque of the hp during insertion and detachment.The inside of the housing (resin part of the handle) is scraped and damaged due to shaft misalignment, so the housing needs to be replaced.Root cause - the root cause is confirmed as "incorrect assembly and disassembly of the handpiece by the customer when using the torque wrench resulting in torque wrench misaligning the dot on the hp and the handpiece connector.Additionally, during servicing, it was confirmed that the cooling water flow rate had decreased due to narrowing of the flow path, attributed to cable aging, twisting, and general wear over time.The restricted cooling water flow resulted in overheating of the handpiece.A review of the service history indicated that this was the first service performed in 13 years, suggesting that preventive maintenance is overdue.Regular maintenance is essential to prevent handpiece related issues and to ensure consistent, reliable performance.Furthermore, the coilform exhibited signs of deterioration consistent with wear and tear after 13 years in operation.A corrective and preventative action (capa) has been raised to investigate this issue and is pending corrective action.At present, we consider this complaint to be closed.
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