多生牙，即出现额外的牙齿，是一种常见的口腔问题。这种情况通常发生在儿童时期，但也可能在成年人身上发生。尽管多生牙普遍不会引起疼痛或不适，但有时却会导致疼痛的症状。那么，为什么多生牙会痛呢？

首先，多生牙可能导致牙齿拥挤。正常情况下，一个人的口腔中应该只有一定数量的牙齿。然而，当额外的牙齿生长出来时，它们会与本来的牙齿争夺有限的空间。这种拥挤可能导致牙齿位移和错位，进而导致疼痛和不适。

In some cases, the extra teeth may not align properly with the existing teeth, leading to malocclusion. This misalignment can result in uneven distribution of biting forces and can put stress on surrounding teeth and the jaw joint, causing pain.

其次，多生牙可能引发牙齿感染。当额外的牙齿生长到一定程度时，它们会触及周围的牙龈组织。由于难以清洁到这些隐蔽的区域，残留的食物和细菌可能会在此处滋生。这可能导致牙龈炎、牙周炎和蛀牙等口腔感染，进而引起牙齿疼痛。

In addition, the eruption of extra teeth can cause irritation and inflammation of the surrounding gum tissue. This condition, known as pericoronitis, often occurs when a wisdom tooth or an extra tooth partially erupts through the gum tissue. The overlying gum flap can trap food debris and bacteria, leading to infection and subsequent pain.

Furthermore, the presence of extra teeth can disrupt the normal development and eruption of other teeth. The additional pressure exerted by these extra teeth can interfere with the proper alignment and growth of adjacent teeth, leading to discomfort and pain.

最后，多生牙可能引发颌骨囊肿。当多生牙没有足够的空间顺利生长时，它们可能被包裹在颌骨内，形成囊肿。这些囊肿可能会导致颌骨的膨胀和不适，也会在周围组织上施加压力，引起疼痛。

In summary, the pain associated with multiple teeth is primarily caused by crowding, misalignment, infections, disruption of normal development, and the formation of cysts in the jawbone. If you are experiencing pain or discomfort related to extra teeth, it is important to consult with a dental professional for a proper diagnosis and appropriate treatment.

总之，多生牙引起的疼痛主要是由拥挤、错位、感染、阻碍正常发育和颌骨囊肿形成所致。如果您因多生牙而感到疼痛或不适，重要的是咨询牙医以获取正确的诊断和适当的治疗。

Translation:

Multiple teeth, also known as supernumerary teeth, are a common oral issue. This condition typically occurs during childhood but can also affect adults. While supernumerary teeth generally do not cause pain or discomfort, they can sometimes lead to painful symptoms. So why do supernumerary teeth cause pain?

Firstly, supernumerary teeth can cause overcrowding of the teeth. Normally, a person's mouth should only have a certain number of teeth. However, when extra teeth grow in, they compete for limited space with the existing teeth. This crowding can result in tooth displacement and misalignment, leading to pain and discomfort.

In some cases, the extra teeth may not align properly with the existing teeth, leading to malocclusion. This misalignment can result in uneven distribution of biting forces and can put stress on surrounding teeth and the jaw joint, causing pain.

Secondly, supernumerary teeth can lead to tooth infections. When the extra teeth grow to a certain extent, they can impinge on the surrounding gum tissue. Due to the difficulty of cleaning these hidden areas, residual food and bacteria may accumulate here. This can lead to gum inflammation, periodontal disease, and tooth decay, resulting in toothache.

In addition, the eruption of extra teeth can cause irritation and inflammation of the surrounding gum tissue. This condition, known as pericoronitis, often occurs when a wisdom tooth or an extra tooth partially erupts through the gum tissue. The overlying gum flap can trap food debris and bacteria, leading to infection and subsequent pain.

Furthermore, the presence of extra teeth can disrupt the normal development and eruption of other teeth. The additional pressure exerted by these extra teeth can interfere with the proper alignment and growth of adjacent teeth, leading to discomfort and pain.

Lastly, supernumerary teeth can trigger jawbone cysts. When the extra teeth do not have enough space to grow properly, they may become encased within the jawbone, forming cysts. These cysts can cause expansion and discomfort in the jawbone, as well as exert pressure on surrounding tissues, resulting in pain.

In summary, the pain associated with multiple teeth is primarily caused by crowding, misalignment, infections, disruption of normal development, and the formation of cysts in the jawbone. If you are experiencing pain or discomfort related to extra teeth, it is important to consult with a dental professional for a proper diagnosis and appropriate treatment.