The longer deer live, the more they wear down their teeth from chewing forage and browse. It used to be that hunters could only age extremely worn deer jaws as “5½-plus” or some variation of “very old.” Today, however, affordable services can dial in a lot closer to the actual age of rare old deer using a microscope to count cementum growth rings.
With my own growing collection of cementum-aged deer jawbones, and gathering a few from other contributors, I compiled a photo series to share with you. Several of these “5½-plus” jawbones were actually teenagers, ancient in deer years. The patterns of gradual tooth erosion will help you recognize the jaw of an extremely old deer when you see one.
Two Deer Aging Methods
First, it’s good to know about the two methods for estimating the ages of deer using their teeth. The tooth replacement and wear technique is a method you can learn and use in the field, and it’s free. The cementum annuli technique requires you to submit an incisor to a commercial laboratory for analysis, but it’s more accurate for older deer. All of the examples of older deer shown below were aged by a cementum lab.
Tooth Replacement and Wear
With this method, you can study the tooth replacement and wear patterns of the pre-molars and molars in a deer jawbone to estimate some ages. This method is 100% accurate for identifying fawns, yearlings (1½-year-olds), and 2½-year-olds, because tooth replacement patterns are clear. It is also the more accurate method for separating 2½-year-olds from 3½-year-olds. When using this method, the oldest age class you can identify is simply “5½-plus,” because increasing variation in wear patterns leads to higher error rates.
For example, deer are born with three temporary pre-molars. By 18 to 20 months of age, they gain three permanent molars and also replace their temporary pre-molars with permanent teeth. Thus, any deer jawbone with less than six teeth is under one year of age – a fawn. Above is an example of a fawn jawbone. There are three pre-molars (labeled 1 to 3), one emerged molar (4), and a second molar is only beginning to emerge (5). The third molar isn’t even visible yet. You can identify fawns with 100% accuracy simply by counting emerged teeth in the lower jaw.
Above is the jawbone of a yearling (1½ years old). All three pre-molars (labeled 1 to 3) and all three molars (4 to 6) are emerged, so the deer is older than 1 year. However, there are two clues it is not older than 2 years. First, the third pre-molar is still a temporary three-cusped tooth, a “baby tooth” (indicated by the dashed line). Second, in this deer you can actually see the permanent pre-molars emerging just below the baby teeth. This happens before 2½ years of age. You can identify yearlings with 100% accuracy by studying these tooth-replacement clues.
Above is the jawbone of a 2½-year-old. At this point, all three permanent pre-molars are fully emerged, and the “baby teeth” are gone. We know this because the third pre-molar is now a two-cusped tooth (indicated by the dashed line). Only the temporary third pre-molar has three cusps, and it is gone. However, these three teeth look fairly new, and there is not enough wear on the molars to begin exposing significant amounts of dentine, the dark interior of the molars.
In our Deer Steward 2 course, we dive into much more detail on identifying yearlings, 2½-year-olds and additional groups using the tooth wear and replacement technique.
Cementum Annuli Aging
Estimating age using toothwear patterns for deer 3½ and older is more error-prone. At 4½, cementum aging becomes the more accurate method. With cementum aging, a lab scans and enlarges a cross-section of the root of a deer incisor and counts cementum layers to estimate age. Hunters can pay for this service, and in fact NDA has an official deer aging kit you can use.
While not 100% accurate, this method is more accurate than studying tooth wear for all deer older than 3½ years. For older deer, we consider cementum aging to be as close as you can get to determining the true age of a deer. Studies showed cementum aging gets within one year of the actual age 93% of the time with deer 2½ and older.
Now, let’s look at the jawbones from several older deer that were aged using the cementum annuli method. Note the differences compared to the younger deer shown above.
4½ Years Old – buck taken by Lindsay Thomas Jr. in Georgia, 2024. Hunters familiar with the tooth replacement and wear method might call this deer 5½ based on wear, but remember that studies have shown this method is less accurate than cementum aging for deer older than 2½. A cementum aging lab said this buck was 4½.
5½ Years Old – buck taken by Kip Adams in North Dakota, 2021. Notice these teeth actually seem to have less wear than the 4½-year-old above. Could variations in forage quality between Georgia and North Dakota explain the difference? Or could the two cementum ages be off by a year in opposite directions? There is always some uncertainty in aging wild deer using their teeth.
6½ Years Old – buck taken by Lindsay Thomas Jr. in Georgia, 2018. Notice that the crevice separating the inside and outside of the fourth tooth is gone and the surface of the tooth has now been worn down to a single smooth dish. As you scroll down into older ages, more of the teeth look like this.
8½ Years Old – buck taken by Kip Adams in Pennsylvania, 2024. Below is a trail-camera photo of this buck taken a few days before Kip tagged him.
9½ Years Old – doe taken by Lindsay Thomas Jr. in Georgia, 2023. Below is a trail-camera image of this doe taken just two weeks before I harvested her. I know this is her in the photo because of the deep notch in her right ear.
11½ Years Old – buck taken by George Douglas in South Carolina, 2023.
12½ Years Old – Kyle Sutton killed this doe on public hunting land in Georgia, Tuckahoe WMA, in 2021. This is getting very old for any wild deer, but especially on public hunting land! We are now getting into ages where the teeth are worn down to the gum line.
13½ Years Old – doe taken by Katie Adams in Pennsylvania, 2019. Almost every tooth is scooped out and worn smooth.
14½ Years Old – doe take by Bo Adams in Pennsylvania. 2020. This old doe was suffering from some dental decay and likely infection. Your dentist would call this “gum disease.” This led to bone loss, gaps between the teeth, and unusual wear patterns likely due to pain from chewing. Still, you can tell this is an extremely old deer at a glance. Below is Bo Adams and his dad, Kip, with this 14½-year-old doe, a very rare deer for any hunter!
15½ Years old – Charles Hendrix of Georgia took this buck after several years of getting him on trail cameras. Like the other older deer in these images, the crests of the molars are almost completely worn away and flattened into a single smooth dish on each tooth. The buck even appears to have sheared off parts of the last molar.
Up to 16½ Years Old – This jawbone from a Georgia doe shows catastrophic wear. Some of these nubs are actually exposed tooth roots and would have been below the gum line. Even the incisor teeth were extremely degraded, so the quality of the sample earned a lower “confidence grade” from the cementum lab. For this reason, they gave an age range: 14 to 16 years.
Note that the wear is significantly more extreme than in the 15½-year-old deer before it. Variation among individual deer, habitat quality (and thus food quality), injuries and diseases can all explain why some old deer wear down their teeth faster than others. However, research shows soil properties are not a factor, as a study in Texas showed varying levels of sand in soil made no significant differences in wear patterns.
The Oldest Deer?
Even without losing their teeth, deer rarely reach their late teens in the wild. Hunter harvest, predators, extreme weather, disease, infections, injuries, vehicle collisions and other factors represent a gauntlet that eventually claims almost every deer. The only deer we know of that lived beyond 22 years lived in captivity.
Next time you harvest a deer, take a closer at its teeth. You might find you’ve taken a rare, old deer. Consider sending an incisor tooth for closer analysis!
Editor’s Note: If you have a deer jawbone in your collection that is matched with a cementum age we are missing from the set shown here, let us know! We’d love to add a photo of your deer jawbone to this article. Click here to contact the author.