Clue 1: Orient yourself
Which feature existed before the ties?
Use the labels and the picture's left-to-right, near-to-far, or before-and-after order. Name only what you can point to.
The question
Why might a repaired face grow differently even when surgery went well?
Why it matters: Structure affects feeding, breathing, hearing, speech, teeth, and surgical planning. Care teams need to connect the exact structure to the function a child is using every day. Today you practice the professional reasoning behind that work: Cleft-related midface undergrowth can reflect both underlying anatomy and treatment history, so scar alone should not be treated as a proven single cause.
On your WebXam
Explaining the Class III pattern from poor forward growth of the repaired maxilla
For life
To find the cause, change one thing and watch what changes.
Principle: Same look, different cause
Five principles we return to
Having it is not using it
Same instructions, different switches
Same look, different cause
Change one thing and watch
Boss or doorman?
Decides the result or only allows it
Held down, not gone
Remove the brake and it returns
Many roads, one ending
One result can begin many ways
Try the everyday version first
A young tree's shape reflects both its starting form and the ties placed around it
A young tree grows from its original shape while wind, ties, and nearby supports guide it. Later form records both growth and outside forces.
Do not jump to the biology yet. Treat the picture as a small system. Track its parts, follow one change at a time, and keep more than one explanation open until the picture supplies a way to separate them.
Clue 2: Trace one change
How could the ties change later direction?
Follow one object, stage, or path. Point to the first place where the situation changes instead of jumping to the ending.
Clue 3: Keep the cause open
What comparison would separate the two influences?
List more than one explanation that still fits. Name the extra observation that would help you separate those possibilities.
Now inspect the illustration
Work from the visible evidence. A useful answer names the part of the picture that supports it and leaves unknown causes open.
- 1Which feature existed before the ties?
- 2How could the ties change later direction?
- 3What comparison would separate the two influences?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: Why might a repaired face grow differently even when surgery went well?
You can complete today's required check without opening the technical details below.
Ready for the real names? Optional tier 2
Technical rules and limits
Rule 1: Separate baseline anatomy from treatment exposure.
Rule 2: Measure growth over time.
Rule 3: Use cautious language when evidence cannot isolate one cause.
Where the analogy stops: Facial growth involves sutures, bone remodeling, muscles, teeth, and treatment, not plant growth.
Carry the previous idea forward
Alveolar graft timing follows dental development, usually before the adjacent permanent canine erupts, so living bone can support tooth movement.
Today's technical takeaway
Cleft-related midface undergrowth can reflect both underlying anatomy and treatment history, so scar alone should not be treated as a proven single cause.
Now map the same rules onto biology
Interpret Mateo's developing Class III relationship
Starting branch pattern
Intrinsic cleft-related growth pattern
Support ties
Surgical scar and treatment history
Serial photographs
Longitudinal cephalometric growth records
Educational illustration, not a clinical photograph, scan, or surgical plan. Use the labeled evidence cards and claim ceiling.
Mateo's case file: evidence supplied in this lesson
ANA15-E1
Mateo's serial records show the maxilla falling behind the mandible during growth.
Why it matters: The result is midface flattening and anterior crossbite.
ANA15-E2
Cleft anatomy and primary surgery both precede the later growth pattern.
Why it matters: More than one plausible contributor is present.
ANA15-E3
Systematic reviews find conflicting or limited evidence that one palate-repair technique determines facial growth.
Why it matters: Scar effects should be discussed without claiming one proven single pathway.
Make the clinical decision
You are presenting Mateo's growth conference.
A teammate says the palate scar alone definitely caused every millimeter of maxillary retrusion.
AReport the observed growth pattern and identify both intrinsic and treatment-related contributors.
BAssign all growth change to scar without comparison evidence.
CDeny that treatment could influence growth.
Choose the interpretation and cite longitudinal plus evidence-limit cards.
Evidence required
ANA15-E1 + ANA15-E2 Claim ceiling
You may describe association and plausible contributors. You may not assign a single cause from this composite record.Go deeper Optional tier 3
Everything required for today is above. Open these only if you want the explainer, source trail, or download files.
The everyday model and Tier 1 check are the complete required path for this lesson.
Use these checks to keep your place. They are not turned in through the portal.
Check off as you finish
- Worked through the everyday picture and answered its three questions.
- Completed the Tier 1 check in plain words.
Turn in: Anatomical lesson 15: Why the Repaired Midface Grows Backward
Go to Schoology to turn this in.
Submit one PDF. Put your first and last name in the document header. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Optional legacy technical materials Open only if you want the original notes, vocabulary, artifact, and CER work
Before this page, you should know
- An packs spongy , classically from the , into the cleaned-out bony gap so the arch becomes continuous.
- It is a secondary procedure done in the , timed to the canine that is about to erupt.
If not, review
Today's new idea is only
Two forces, the 's own poor forward growth plus the restraining scar, leave a flat midface and an underbite.
Goal: Explain how a repaired grows poorly forward, why scar adds a restraining effect, and how this produces a flat midface and a Class III (underbite) tendency.
Know by the end
- The is the upper jaw and the bone of the midface, the region under the eyes and around the upper lip.
- Two forces hold the midface back: an intrinsic tendency to grow poorly forward, plus a restraining scar from surgery.
- The result is a flat, set-back midface, called or .
- When the upper jaw is set back but the lower jaw grows normally, the lower teeth close in front of the upper teeth, a .
1
The two forces
Model start: The grows poorly forward for two reasons: an intrinsic growth tendency, plus the -surgery scar that tethers forward growth.
- The upper jaw and bone of the midface is the ____.
- The palatal ____ from surgery restrains forward growth, adding to the intrinsic tendency.
2
Surgery interacts with growth
- A pushback was associated with ____ (more) maxillary deficiency; a two-stage Sommerlad protocol had ____ (less) negative impact.
3
The bite result
- A set-back upper jaw with a normal lower jaw gives an underbite, called a ____ .
- Patients with this set-back pattern were also more likely to screen positive for ____ -disordered breathing.
Everything you need for today is on this page. These links are optional.
What to read
Read the short plain-language explanation written for this lesson. Plain-language explainer for this lesson
Why this source matters
This explanation gives you the background for today's idea without making you decode a research paper: Two forces, the 's own poor forward growth plus the restraining scar, leave a flat midface and an underbite.
Words to unlock first
maxillamaxillary hypoplasiamidface retrusionClass III malocclusionpalatal scar
Reading moves
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Stop point
Stop after the final 'Use it now' section. The research citations are available separately for advanced readers.
Your output
Write one claim-evidence sentence: state the main idea, then name the example or evidence that supports it.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Anatomical domain · Skeletal system and facial growth; how surgery and growth interact
WebXam domain
Molecular and Genetic Technology
Evidence to produce
Write one line in Mateo's growth chart at age 12, in three short sentences a parent could read: name what you are watching for in his midface and bite using today's terms, explain in plain words why his upper jaw tends to sit back (name the two forces), and note that this is something the team will plan to correct later, not a sign the earlier surgeries failed.
Lab / skill
Human Body Systems (HBS)
Everything required for today's decision is already in the case file and plain-language explainer. The links below are original papers and database records for teachers and advanced readers, not assigned student reading.
- American Cleft Palate Craniofacial Association. 2024 Parameters of Care.
- Dissaux et al. 2016, Evaluation of 5-Year-Old Children With Complete CLP, Part 2 (J Craniomaxillofac Surg)
- Fisher et al. 2024, Risk Assessment of Sleep-Disordered Breathing in Cleft Lip and/or Palate (Cleft Palate Craniofac J)
- Powell et al. 2022, Does Early Secondary ABG Influence Need for Maxillary Advancement (Cleft Palate Craniofac J)
- Claim: Mateo's repaired is likely to leave him with a flat midface and an underbite as he grows.
- Evidence: Cite the two forces holding the back, and one finding linking repair technique or the set-back midface to an outcome.
- Reasoning: Explain why a that grows too little forward causes the lower teeth to close in front of the upper teeth.
How this is graded (rubric)
For: Write one line in Mateo's growth chart at age 12, in three short sentences a parent could read: name what you are watching for in his midface and bite using today's terms, explain in plain words why his upper jaw tends to sit back (name the two forces), and note that this is something the team will plan to correct later, not a sign the earlier surgeries failed.
| Criterion | Proficient | Developing | Beginning |
|---|---|---|---|
| Complete | Every required part of the artifact is present and filled in. | Most parts are present, but one is missing or left blank. | Several parts are missing. |
| Accurate | The science and data are correct and match the evidence. | Mostly correct, with a small factual slip. | Key science or data is wrong. |
| Scientific reasoning (CER) | States a claim, backs it with specific evidence, and explains the reasoning. | Has a claim and evidence, but the reasoning is thin or missing. | Gives an answer with no evidence or reasoning. |
| Professional communication | Clear, organized, and labeled the way a clinician or scientist would write it. | Readable but disorganized or missing labels. | Hard to follow. |
| Submitted | Turned in through the route named under Submit here and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "Write one line in Mateo's growth chart at age 12, in three short sentences a parent could read: name what you are watching for in his midface and bite using today's terms, explain in plain words why his upper jaw tends to sit back (name the two forces), and note that this is something the team will plan to correct later, not a sign the earlier surgeries failed.".
- AccurateProficient: Every number and claim matches the case evidence.
- Scientific reasoning (CER)Proficient: It names a claim, cites the specific evidence, and explains the reasoning, not just the answer.
- Professional communicationProficient: It is organized and labeled like a real chart note.
- SubmittedProficient: It would be attached to your class form or handed in, and confirmed.
What's next: We found out why Mateo's midface grows backward and ends up flat, leaving an underbite as a teenager. We can name the problem, but we have not fixed it: the lip, , and gum graft are all done, yet his upper jaw still sits too far back. How do we correct the bite and midface later? We chase that next time.