Reading a Case from the Front Teeth Backward

In a recent TikTok, Dr. Lucas Shapiro of Wall Street Orthodontics walked through his initial thinking on a case involving proclined lower incisors, meaning the lower front teeth are tipped further forward than they should be. Working from what was visible, he laid out a likely three-part treatment strategy: lower premolar extraction combined with mandibular advancement surgery, MARPE on the upper arch, and a probable explanation for why the upper midline appeared off.

Watch the original TikTok here: https://www.tiktok.com/@drshap/video/7665865736581139726

As with any case reviewed from limited visual information, Dr. Shapiro frames this as his most likely read rather than a final diagnosis, an important distinction we've discussed before when it comes to why complete records matter before finalizing any treatment plan. But the reasoning behind each part of this proposed plan is worth breaking down, because it shows how multiple treatment decisions connect to one another in a more involved case.

Why Proclined Lower Incisors Often Point to a Deeper Issue

When the lower front teeth are proclined, it's often not just a dental alignment issue, it's frequently a sign that the teeth are compensating for an underlying skeletal discrepancy, commonly a mandible (lower jaw) that sits further back than ideal. The teeth tip forward to help the front teeth meet the upper arch, even though the jawbone underneath isn't actually in the ideal position.

This is a similar concept to what we discussed in our post on bimaxillary protrusion, where dental compensation can mask, rather than correct, an underlying jaw discrepancy. In cases like this one, addressing only the teeth without addressing the jaw position tends to produce a less stable, less balanced result.

Lower Premolar Extraction and Mandibular Advancement

Dr. Shapiro's proposed approach addresses both sides of that equation. Extracting lower premolars creates the space needed to upright the proclined lower incisors, moving them out of their compensated, forward-tipped position and into a healthier position relative to the lower jawbone. On its own, though, uprighting the teeth doesn't fix the actual jaw position.

That's where mandibular advancement comes in. This orthognathic surgery procedure physically repositions the lower jaw forward, correcting the underlying skeletal deficiency directly rather than asking the teeth to keep compensating for it. Combining extraction-based uprighting with mandibular advancement allows both the teeth and the jawbone to end up in their correct, coordinated positions, rather than treating one and leaving the other uncorrected. Learn more about how these procedures are approached on our Surgical Orthodontics page.

Why MARPE on the Upper Jaw Makes Sense Here

The second part of the proposed plan involves the upper arch: using MARPE (Miniscrew-Assisted Rapid Palatal Expansion) to widen the maxilla. At first glance, this might seem unrelated to a lower jaw and incisor problem, but arch coordination is a critical part of planning any case involving mandibular advancement.

When the lower jaw is surgically moved forward, the width relationship between the upper and lower arches needs to line up correctly at the new, more forward position. If the upper arch is too narrow relative to where the advanced mandible will sit, the bite may not seat properly, or a posterior crossbite could develop. Widening the upper jaw first, using an adult expansion technique like MARPE, gives the surgical team the transverse room needed for the advanced mandible to fit properly against the upper arch.

We've covered MARPE and other adult expansion options in more detail in our post on expansion, jaw surgery, and diagnosis, and as with that case, MARPE offers many adult patients a way to achieve meaningful skeletal expansion without more invasive surgery to the upper jaw itself. As a side benefit, widening the maxilla can also support better nasal airway function, something we consider as part of a broader airway dentistry approach to treatment planning, even when the main goal of expansion is arch coordination for surgery.

The Midline Mystery: A Missing Premolar as a Likely Culprit

The third observation in this case is more of an educated guess pending further records: Dr. Shapiro suspects the upper midline may be off due to a missing premolar. When a tooth, especially a premolar, is missing from the arch (whether congenitally absent or previously extracted), neighboring teeth can gradually drift to fill that space over time. That drifting can shift the midline of the arch away from its ideal position relative to the face, even when nothing else about the bite has obviously changed.

Confirming this would require a full set of records, including detailed imaging, to see the actual arch and tooth positions clearly rather than relying on visual impression alone.

Why These Three Pieces Have to Work Together

This case is a good example of why more involved orthodontic-surgical treatment plans aren't a single decision, they're a coordinated sequence. Extraction and uprighting address the compensated lower incisors. Mandibular advancement addresses the underlying jaw position. MARPE addresses the width relationship needed to support that advancement. And identifying the cause of the midline shift ensures nothing gets missed along the way. Each piece supports the others, and skipping one could undermine the stability or success of the whole plan.