Wisdom Teeth: When They Need to Come Out and When They Do Not

Wisdom teeth are the third molars, the last teeth to develop. Most people have four of them, one in each corner of the mouth, and most people do not have enough room for them. They typically begin pushing toward the surface between ages 17 and 25 -- and whether that creates a problem depends entirely on how they are positioned, how much space exists, and whether they erupt cleanly.

This article covers how that decision is made: the anatomy of impaction, the criteria dentists use to recommend removal, and what questions to ask at your evaluation. Once you have decided to proceed, Wisdom Teeth Removal Recovery: Day-by-Day Timeline and What to Watch For covers what to expect after the procedure.

Here is how dentists evaluate wisdom teeth and what the decision actually involves.

Why wisdom teeth cause problems

Human jaws have become smaller over evolutionary time while the number of teeth has stayed the same. The result is that third molars frequently lack the space to erupt in a functional position. When a tooth cannot fully emerge, it is called impacted.

There are a few types of impaction:

Soft tissue impaction -- The tooth has partially erupted through the gum but a flap of gum tissue (called the operculum) covers part of the biting surface. That flap traps food and bacteria, creating a chronic low-grade infection called pericoronitis. Symptoms: pain and swelling in the back of the jaw, bad taste, sometimes difficulty opening the mouth fully.

Partial bony impaction -- The tooth has come partway through the bone but cannot complete its eruption. It sits at an angle, often pressing against the second molar.

Full bony impaction -- The tooth is entirely enclosed in the jawbone, sometimes horizontal or at a sharp angle. These are usually asymptomatic but may cause pressure symptoms, resorption of the second molar root, or cyst formation around the crown.

When removal is recommended

The decision is not automatic. Dentists evaluate wisdom teeth on a case-by-case basis using X-rays, typically panoramic or cone-beam CT. Removal is generally recommended when:

• The tooth is causing active pain, infection, or swelling
• It is impacted against the second molar and creating a cleaning or structural problem
• It is only partially erupted and creating a chronic pericoronitis risk
• Decay is present in the wisdom tooth itself or in the second molar at the contact point
• A cyst or tumor has developed around an impacted tooth
• There are signs of resorption of adjacent teeth

Removal is generally not recommended when a fully erupted, correctly positioned wisdom tooth can be reached and cleaned effectively. Some patients in their 20s have all four wisdom teeth in excellent position and function. Monitoring with annual X-rays is appropriate for these cases.

When to think about removal preemptively

The strongest argument for early removal -- in the late teens or early 20s -- is that the procedure is simpler when roots are not fully formed and recovery is faster when bone is less dense. If panoramic X-rays show that a wisdom tooth is heading toward an impacted position, removing it before it causes symptoms generally results in less surgical complexity and a shorter recovery.

The American Association of Oral and Maxillofacial Surgeons recommends third molar evaluation by the late teens. Some dental organizations have taken a more conservative stance, recommending removal only when there is active disease or high risk of it. Your dentist and oral surgeon's assessment of your specific anatomy is more relevant than either blanket position.

What the procedure involves

Most wisdom tooth extractions are performed by an oral and maxillofacial surgeon, though simple erupted extractions can be done by a general dentist. Impacted extractions use local anesthesia, often combined with IV sedation if the patient prefers.

For an impacted tooth, the surgeon makes a small incision in the gum, removes any bone covering the tooth, sections the tooth if needed (breaking it into pieces makes removal easier), and cleans the socket before stitching the gum closed. The procedure takes 20 to 45 minutes per tooth.

Recovery follows a predictable arc: swelling peaks in 48 hours, soft foods for five days, most people back to normal within a week. The main risk is dry socket, which affects about 2 to 5% of extractions and is more common in lower wisdom teeth. It is treatable with medicated socket packing and resolves quickly once treated.

What to ask at your evaluation

Before agreeing to any extraction plan, it is reasonable to ask: why is this tooth recommended for removal right now? Is there active disease or immediate risk, or is this preventive? What are the risks specific to my anatomy, particularly regarding proximity to the inferior alveolar nerve for lower wisdom teeth? What type of anesthesia is recommended and what are the options?

An oral surgeon who explains the reasoning clearly and addresses your specific imaging is worth seeking out. The anatomy varies enough between patients that a conversation about your particular case matters more than any general rule.

sources

• Dodson TB. "The management of the asymptomatic, disease-free wisdom tooth: removal versus retention." Atlas of the Oral and Maxillofacial Surgery Clinics, 2012.
• American Association of Oral and Maxillofacial Surgeons. "White Paper on Third Molar Data." aaoms.org, 2023.
• Mettes TG et al. "Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults." Cochrane Database of Systematic Reviews, 2012.

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