Two large Swiss studies from the same university clinic give a clear picture of how differently upper and lower wisdom teeth behave. After 1,199 lower wisdom teeth were removed, 4.2% of sockets developed dry socket. After 1,562 upper wisdom teeth were removed, the figure was 0.4%. The upper teeth had their own issue instead: a small opening into the sinus in 2.4% of cases.
Those numbers sum up the difference. Lower wisdom teeth tend to be harder to remove and harder to heal, with the nerve to the lip and chin as the main structure to protect. Upper wisdom teeth are often quicker, and the sinus above them is what the dentist plans around.
Lower wisdom teeth are more often impacted
A lower wisdom tooth develops at the back of a dense jaw, often with little room in front of it. It is common for it to be tilted forwards or sideways, partly covered by bone or wedged against the molar in front. Removing such a tooth usually means lifting a flap of gum, removing a little bone and dividing the tooth into sections so it can come out in pieces. This is routine surgery, but it takes longer than lifting out an erupted tooth and leaves a larger wound to heal.
Upper wisdom teeth more often come through fully or sit just under the gum, and many can be removed without cutting. That is not universal: an upper tooth can also be impacted, and its roots can be curved or close to the sinus.
The nerve below and the sinus above
Running through the lower jaw, close to the roots of the lower wisdom teeth, is the inferior alveolar nerve, which gives feeling to the lower lip, chin and teeth. A 2020 systematic review by Kang and colleagues in the Journal of Stomatology, Oral and Maxillofacial Surgery, covering more than 44,000 lower wisdom tooth removals, found temporary altered sensation in 1.2% and lasting altered sensation in 0.28%. The risk was higher with deeper impaction and when the tooth was in contact with the nerve canal.
The roots of upper wisdom teeth often sit just below the maxillary sinus. In the Swiss upper-jaw study by Pourmand and colleagues, the risk of an opening into the sinus could be assessed from how the root tips projected onto the sinus floor on the pre-operative X-ray. A very small opening may close on its own, while larger ones may need a procedure to close them. Your dentist will give specific instructions, such as avoiding blowing your nose hard, if the sinus is close.
Where a lower tooth's roots appear to touch the nerve, a coronectomy may be offered, removing the crown and leaving the roots in place. Lumi offers coronectomy for suitable cases, and our coronectomy article explains when it is considered.
Side by side
| Upper wisdom teeth | Lower wisdom teeth | |
|---|---|---|
| How often impacted | Less often | More often |
| Usual removal | Often without cutting the gum | Often surgical, with sectioning |
| Main nearby structure | Maxillary sinus | Nerve to the lip and chin |
| Dry socket in the Zurich studies | 0.4% | 4.2% |
What it means for recovery
If you have all four wisdom teeth out, the lower sites usually feel sorer and take longer to settle than the uppers. Aftercare matters for both, but it pays to be especially careful with the lower sockets in the first days: avoid straws, spitting and vigorous rinsing, as the Better Health Channel advises, and do not smoke for at least 48 hours. Our guides to eating after wisdom teeth removal and wisdom teeth stitches cover the practical side, and our cost guide explains why upper and lower teeth are often quoted differently.
Questions about upper and lower wisdom teeth
Can I have only the upper or only the lower teeth removed?
Sometimes. Each tooth is assessed on its own merits. If a lower tooth is removed, the dentist will consider whether the upper tooth opposite it may drift down without a tooth to bite against.
Does the lip numbness always go away?
In most cases altered sensation is temporary. In the review by Kang and colleagues, lasting altered sensation occurred in about 0.28% of lower wisdom tooth removals.
Should I worry about my sinus after an upper removal?
Follow the instructions you are given. Contact your dentist if fluid comes out of your nose when you drink, or if you notice air passing between your mouth and nose.
Sources
- Sigron GR, et al. The most common complications after wisdom-tooth removal: part 1, a retrospective study of 1,199 cases in the mandible. Swiss Dental Journal, 2014.
- Pourmand PP, et al. The most common complications after wisdom-tooth removal: part 2, a retrospective study of 1,562 cases in the maxilla. Swiss Dental Journal, 2014.
- Kang F, et al. Determining the risk relationship associated with inferior alveolar nerve injury following removal of mandibular third molar teeth: a systematic review. Journal of Stomatology, Oral and Maxillofacial Surgery, 2020.
- Better Health Channel (Victorian Government). Wisdom teeth.
A consultation and X-ray show what each of your wisdom teeth would involve. The team at Lumi Dental can assess them and explain your options. See our current offers or book a general dental appointment. If you are still deciding whether removal is needed, our article on wisdom teeth that do not hurt may help.
This article is general information only and is not a substitute for personalised dental advice. Please see a dentist for advice about your own situation.
