Different Birmingham rhinplasty surgeons have different techniques. There are even some doctors who use different techniques for different patients. The two main techniques they use are open rhinoplasty and closed rhinplasty. A technique is better only when it addresses your special case. There is no general rule that open rhinoplasty or closed rhinoplasty is better. Each has to be used depending on the need.

Closed rhinoplasty makes incisions to the inner parts of the nose. The main advantage is that the scars are invisible. This technique is used for less complicated operations such as simple putting of a silicon implant for those who have flat nose. The nose should be straight when the surgeon uses this technique.
Open rhinoplasty is a technique where all of the network of cartilage and tissues underneath the skin on your nose are exposed to the plastic surgeon. The surgeon makes an additional incision to the columella or the column that divides our nostrils. From that incision, they pull the skin up and clip it up so that the structure of the nose is exposed while they are operating on you. This technique is used mainly for more complicated operations and if the nose is crooked or has hump and needs removal of bones.

The main disadvantage of open rhinoplasty over closed rhinoplasty is that the scar in the columella may be noticeable even after it healed. Since the nasal skin will be pulled, swelling and bruising will also last longer than in closed rhinoplasty.
The advantage of open rhinoplasty over closed Birmingham rhinoplasty is that the plastic surgeon can work on tissues, cartilages and and over-all structure of the nose better because they can see the whole nose.