Treatment of overjet by retraction of frontal teeth to temporary anchorage devices (TADs)

Extra-oral examination: mesocephalic, round symmetric face, pupils equally round, pupillary line horizontal, incompetent lips with average tonicity, profound mentolabial groove.

Smile analysis: asymmetric, gummy smile not present, display of half of the crowns of upper incisors, incisal edges don’t copy the lip line.

Examination of TMJ: Maximum mouth opening - 42mm, no displacement or deviation on closure, without pain, pathological sounds and path of closure.

Intra-oral examination: Average oral hygiene, average cariosity, pink gingiva, oral mucous membrane with no pathological signs, good periodontal condition, upper labial frenulum inserts to the incisive papilla.

Cast analysis: Permanent dentition, AII/1, overjet=10mm, overbite=-1mm, midline shift, crowding in the lower dental arch, space discrepancy in maxilla -1mm, in mandible -7mm, anterior Bolton ratio - 78.3%, overall Bolton ratio - 91.6%, Tonn‘s index - 77%, McNamara analysis - 35mm.

Cephalometric analysis before therapy: SNA: 79°, SNB: 73°, SNPo: 75°, ANB: 6°, Wits: 9mm, NS-ML: 35°, S-Go:N-Me: 63%, Mx 1-NS: 110°, Mx 1-NPo: 12mm, Interincisal: 118°, Mn 1-ML: 97°, Mn 1-Apo: -1mm, Beta: 21°.

AII/1; Overjet: 10mm; Overbite: -1mm; Class II skeletal base; Average growth pattern; Crowding of lower frontal teeth; Proclination of upper frontal teeth; Upper labial frenulum inserts to the incisive papilla; Lingual dystopic 32; Lingually inclined 35; Mesially rotated 41 and 42

Treatment objectives:
1. Extraction of 14, 24
2. Level and align upper and lower dental arch
3. Apply TADs and by bodily movement retract upper frontal segment
4. Relevelling
5. Frenectomy
6. Retention (ESSIX)

Treatment plan and appliances:
Preadjusted edgewise appliance – slot .022, prescription Roth, ceramic brackets Clarity Advanced
Orthodontic bands 16, 26, orthodontic tubes 36, 46
Orthodontic brackets 15-25, 35-45
TAD inbetween 16-15, 26-25 (6mm, 3M UNITEK)
Plan of occlusion - AII

Maxilla:
1. Levelling and aligning (NiTi .016)
2. .017x.025 NiTi
3. .017x.025 SS in the range of 13-23 with crimpable hooks, TAD inbetween 16-15 a 26-25, closed coil springs from the hooks to TADs
4. .020x.020 NiTi to relevel
5. Retention (ESSIX)

Mandible:
1. .014 NiTi
2. .016 SS, distalizing open coil spring 31-33 to enlarge the space for 32 – align with overlay .014 NiTi
3. .020x.020 NiTi
4. Interproximal reduction of approximal surfaces of lower frontal teeth
5. Retention (fixed retainer 33-43 + ESSIX)

Success of the treatment of proclined incisors with Angle class II of the whole unit consists in correct setting of anchorage forces. When there is a need for absolute anchorage, TAD’s are placed into the bone. The movement of the distal teeth forward is thereby eliminated. Nickel-Titanium closed coil springs are adapted inbetween the hooks cramped on the stainless steel archwire and TAD’s and they exert low but continuous forces. In correctly set system, the retraction of upper frontal segment is continuous without the need of activating this system. The patient left abroad after adapting and activating whole retraction unit. The evidence of self-sufficiency of this system are photographs she sent just after removal of the appliance. Tooth 32 was left mildly lingually inclined, which will be corrected with adjusted thermoformed plastic retainer.