Orthodontic questions.
The questions practices ask most often about orthodontic laboratory work.
How soon after debond should the record be taken?
Immediately. Teeth begin moving as soon as the appliances come off, and a retainer made from a record taken days later may not seat.
Where a bonded retainer is being placed at the same appointment, place it first and then take the record, so the removable appliance accommodates it.
Hawley or clear?
It depends on what was corrected. Difficult rotations favour a clear retainer, because full coverage holds them more rigidly. Cases where posterior settling is wanted favour a Hawley, because the occlusal surfaces are not covered.
Durability favours the Hawley; appearance and patient acceptance favour the clear. The appliance a patient will actually wear outperforms the theoretically better one they will not.
Many patients end up with a fixed lower and a removable upper, which is a reasonable default.
Can a retainer be remade from the original model?
If the teeth have not moved, yes — and keeping the records makes replacement straightforward.
If the patient has been without the appliance for a period, or reports that the teeth feel different, take a new record. Remaking to an old model reproduces a position the teeth no longer occupy, and the appliance either will not seat or will apply unintended force.
Can you make a retainer over a bonded retainer?
Yes, provided the bonded retainer is captured in the record or its position is noted. The removable appliance has to accommodate it without rocking on it.
If the bonded retainer is placed after the record was taken, the removable appliance will not seat properly.
What thickness should a clear retainer be?
Heavier material is more rigid, more durable and slightly less comfortable. It suits patients who are hard on appliances, cases with a high retention demand, and anyone showing evidence of parafunction.
Lighter material is more comfortable and has a shorter life. State a preference if you have one; otherwise we apply our standard.
The patient grinds through clear retainers. What now?
A thermoformed retainer in a bruxer has a short life, and replacing it repeatedly is treating the symptom.
The options are heavier material, a Hawley design, or a separate night guard worn alongside a retention protocol. Which is appropriate depends on how severe the parafunction is and what is being retained.
See night guards.
Do you make appliances for patients in fixed treatment?
Sport guards designed around fixed appliances, yes — with relief over the brackets and enough space to accommodate continued tooth movement.
Tell us how long remains in treatment. A guard for a patient with six months left is specified differently from one with two years, and both should be expected to need remaking as teeth move.
How long should a patient wear retainers?
Indefinitely, in practical terms. Teeth continue to change through life, and late lower incisor crowding occurs in people who were never treated.
Most protocols move from full-time to night-time wear over the first year or two and then continue night-time indefinitely, but the specific regime is a clinical decision.
What matters from the laboratory side is that patients understand replacement is expected over the years and is not a failure of the treatment.
Can a broken appliance be repaired?
Usually, if all fragments are present and the appliance still fits. Send everything including small pieces, and do not attempt a temporary repair with adhesive — it contaminates the surfaces and frequently forces a remake.
Where an appliance has broken repeatedly in the same place, the cause needs addressing rather than the breakage. Tell us the history.
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