A 10-mm overjet, two episodes of incisor trauma, and a mother who wants to wait
An 11-year-old girl attends with her mother. She has a Class II division 1 malocclusion with a 10-mm overjet, a 6-mm overbite with palatal impingement, incompetent lips and a lower lip trap; the lower lip rests behind the upper incisors. She has had two episodes of trauma to the upper incisors during play, with no fracture but one episode of transient mobility. She is in the late mixed dentition: all permanent teeth except the second and third molars are erupted, and 13 and 23 are palpable buccally but not fully erupted. She is self-conscious and has been teased at school. The clinic has fixed appliances and a visiting orthodontist once a month; removable appliances can be made locally within two weeks; functional appliances must be ordered and will take about three months to arrive. The girl is cooperative but says she dislikes removable appliances. Her mother wants to wait "until she is bigger, next year".
1. What are the immediate and medium-term risks of leaving this untreated, and how would you explain them to the mother?
Read the worked answer
Risks of doing nothing.
- Trauma to the upper incisors. A 10-mm overjet places the incisors outside the protection of the lower lip, and the two previous episodes are the warning. Each episode can fracture, luxate or avulse a permanent incisor; at 11 the apices of 11 and 21 may still be open, so a severe injury can arrest root development. This is the strongest argument for early treatment.
- Soft tissue damage. The 6-mm overbite with palatal impingement traumatizes the palatal gingiva, and the lip trap strips the labial gingiva of the lower incisors while pushing the uppers further forward and the lowers lingually, so the overjet maintains and worsens itself.
- Function and psychosocial effects. She is being teased; this is a legitimate indication, not a cosmetic afterthought.
- Loss of the growth window. She is near the pubertal growth spurt. A Class II skeletal pattern with a still-growing mandible can be improved with growth modification now and will not improve once growth has finished.
What to tell the mother: this is not only about straight teeth. The front teeth are at real risk of being knocked out, and the window in which growth can be guided is open now and will close. Waiting "until she is bigger" is precisely when the growth advantage is lost - that is exactly the point to make, calmly, with the trauma history in front of her.
2. Compare the treatment options available at this clinic and justify the sequence you would choose.
Read the worked answer
Option A - growth modification now (functional appliance, e.g. twin block), then fixed appliances in the permanent dentition. Best biological fit: she is at or near the pubertal spurt, the overjet has a skeletal as well as a dental component, and a functional appliance can hold the mandible forward, reduce the overjet and correct the lip trap. Downside: compliance is essential and she dislikes removable appliances, and the appliance takes three months to arrive, eating into the growth window.
Option B - single-phase fixed treatment later, with or without upper premolar extraction. Predictable alignment, independent of compliance, but it treats the problem dentally after growth has finished, may require extractions, and leaves the incisors at trauma risk for another two to three years.
Option C - an early, locally made appliance now. An upper removable appliance with an anterior bite plane and labial bow can start reducing the deep bite and overjet - and the deep bite is itself a trauma risk, since it puts the upper incisors where the lower ones can strike them - while the functional appliance is ordered. Pragmatic bridging if she will wear it.
My choice: Option A with Option C as a bridge. Start the locally made bite-plane appliance within two weeks to address the deep bite and trauma risk, order the functional appliance now, and place fixed appliances once the remaining permanent teeth have erupted. Do not promise or refuse extractions today; that is a decision for the fixed phase, taken on a cephalometric assessment at the right time.
3. How would you handle the mother's wish to wait, and what would you do in the next three months while the appliance is on order?
Read the worked answer
Handling the request.
- Acknowledge her position rather than dismissing it: cost, travel, school and the belief that treatment is easier later are all legitimate concerns.
- Be specific about the cost of waiting for this child: the two trauma episodes, the 10-mm overjet, the deep bite and the approaching growth spurt. Braces later can straighten teeth but cannot recover a lost incisor, and the growth-guidance window will not stay open indefinitely.
- Offer a staged, affordable compromise: a written plan with an earliest start date, a locally made appliance to begin in the meantime, and a fixed review date.
- Agree red flags that trigger urgent review: another blow to the teeth, pain, mobility, a fractured incisor, or a new ulcer from the lower incisor against the palate.
- Document what was explained, what was accepted or declined, and the review date. This protects the patient and protects you.
Next three months. (1) Take baseline records - photographs, study models, panoramic radiograph, cephalometric radiograph if available. (2) Fit the bite-plane appliance to reduce the deep bite and protect the palate. (3) Provide a well-fitting mouthguard for sport and insist on it, since she is active and has already had two injuries. (4) Order the functional appliance and confirm the delivery date in writing. (5) Bring her back monthly with the visiting orthodontist so the growth spurt is not missed, and review the plan with the mother at each visit. Do not simply agree to "review in a year".