Gigi bungsu itu menekan rahang saya.

Yes, gigi bungsu is a fixed expression meaning wisdom tooth.

Literally:

• gigi = tooth / teeth
• bungsu = youngest, youngest child, last-born

So the idea is something like the last tooth to come in, which matches the idea of a wisdom tooth.

In Indonesian, demonstratives like ini (this) and itu (that) usually come after the noun.

So:

• gigi bungsu itu = that wisdom tooth / the wisdom tooth

This is normal Indonesian word order:

• buku itu = that book
• rumah ini = this house

That is different from English, where this/that come before the noun.

It can feel like either one, depending on context.

gigi bungsu itu can mean:

• that wisdom tooth if you are pointing it out or contrasting it with another one
• the wisdom tooth if both speaker and listener already know which one is being talked about

In natural translation, English often uses the even when Indonesian uses itu.

So this sentence could be understood as:

• That wisdom tooth is pressing on my jaw or
• The wisdom tooth is pressing on my jaw

Menekan is the active verb form built from the root tekan (press).

• tekan = press / pressure / to press
• menekan = to press, to push against, to put pressure on

The prefix meN- often forms an active verb in Indonesian. With tekan, it becomes menekan.

So:

• Gigi bungsu itu menekan rahang saya = The wisdom tooth is pressing on my jaw

Using just tekan here would not sound right in a normal sentence like this.

Indonesian often does not use a verb equivalent to is/am/are in the way English does.

Also, Indonesian does not usually need a special form like is pressing to show present continuous action. Context often makes it clear.

So:

• menekan can mean presses, is pressing, or is putting pressure on

In this context, English naturally uses is pressing, but Indonesian does not need a separate word for is.

Rahang saya is the normal and natural way to say my jaw.

Pattern:

• noun + saya = my noun

Examples:

• rumah saya = my house
• tangan saya = my hand
• rahang saya = my jaw

You can say saya punya ... for possession, but it is less natural here and more like I have ... or a more emphatic possessive structure.

So:

• rahang saya = the standard choice

Because menekan can take a direct object in Indonesian.

So:

• menekan rahang saya = pressing my jaw / pressing on my jaw

English often prefers press on in this medical context, but Indonesian can simply use the object directly.

That means the structure is:

• subject: gigi bungsu itu
• verb: menekan
• object: rahang saya

Indonesian nouns do not automatically show singular vs. plural the way English nouns do.

So gigi can mean:

• tooth
• teeth

But in this sentence, gigi bungsu itu is understood as the/that wisdom tooth, singular, because of context.

If the speaker meant more than one, the context would usually make that clear. Indonesian does not have to mark plural unless needed.

Yes, and it means something slightly different:

• Gigi bungsu itu menekan rahang saya = that/the wisdom tooth is pressing on my jaw
• Gigi bungsu saya menekan rahang saya = my wisdom tooth is pressing on my jaw

So the difference is in what is being specified:

• itu points to a particular tooth already identified
• saya shows possession: my wisdom tooth

Both are grammatical.

Saya is more neutral and polite than aku.

• saya = standard, polite, widely usable
• aku = informal, more personal, common with friends/family

So:

• rahang saya sounds neutral and standard
• rahangku or rahang aku would be more informal, and rahang aku is less natural than rahangku

In a medical or general statement like this, saya is a very natural choice.

Yes, it is natural. Menekan means to press, to press against, or to put pressure on, which fits this kind of dental complaint well.

Depending on context, Indonesian speakers might also use other verbs or phrases, but menekan rahang saya is understandable and natural for saying that the wisdom tooth is exerting pressure on the jaw.

So for a learner, this is a good sentence to remember:

• menekan = pressing / putting pressure on

The basic order is:

Subject + Verb + Object

So:

• Gigi bungsu itu = subject
• menekan = verb
• rahang saya = object

That is the same basic order as English:

• That wisdom tooth
  • is pressing on
    • my jaw

So although some details are different, the overall sentence structure is quite familiar to an English speaker.