There really isn't any "normal" dot -- it's there only as a calibration point to check the gauge during manufacture. And it was also used as the "set point" for the temperature compensation board. The fact that your gauge may used to be "stuck" to it is a result of this TCB (which ought to be removed and jumpered, so that the gauge works properly) -- and if it's now showing a little above (and you still have the TCB), that may mean that the TCB is beginning to fail.

The only way to really know how hot your engine is running, because you have the TCB that lies notoriously, is to measure the temperature directly -- you can use a hand-held IR thermometer to scan the thermostat housing.

But, in fact, a little above that dot (i.e., about 9:30 or 10:00 as an hour hand on a clock), if the TCB has been removed, is actually a more efficient temperature for your engine. As another has already explained, you want the engine to run a little warm, to ensure that the water is "boiled off" out of your crankcase. Such temperature also helps in thermal efficiency, and that means better gas mileage. In fact, for your B230 engine, the proper thermostat is the hottest of the three available for the red blocks: 92 deg C. (as opposed to 89 or 87), and this would bring your gauge (assuming no TCB) to that 9:30-10:00 position I mentioned before.

Finally, the thermostat is a design that's called a diverter thermostat -- it has a broad plate on the bottom, and you need that if you're ever caught in a traffic jam to prevent overheating. Yes, the thermostat not only ensures that your engine stays up at proper temperature, but also prevents overheating. You see, when the engine is cold, the thermostat is closed and water is blocked from going to the radiator -- everyone knows that. And usually, at normal operating temperature, the thermostat is only part open.
But did you also know that when the engine is running too warm, the thermostat fully opens and that round disk at the bottom moves down and blocks a passage that would otherwise return coolant to the engine, reheating it and contributing to the overheating -- in other words, that disk on the bottom of the thermostat ensures, when running too hot, that all coolant is diverted to the radiator, ensuring better cooling. If you don't have a thermostat, some coolant will not flow through the radiator and will return to the engine instead -- you'll overheat.

Hope this saved your car.