PMC4470929_01
Initial clinical examination of a frontal view, b right lateral view, c left lateral view, d maxillary occlusal view, and e mandibular occlusal view
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Fig1
Both maxillary and mandibular right second primary molars were present while all other primary teeth had exfoliated (Fig. 1). Cephalometric analysis showed a skeletal class I relationship and hyperdivergent skeletal pattern (Fig. 2b, Table 1). Cephalometric analysis showed that the mandibular incisors did not experience lingual movement as a result of molar protraction (Fig. 9b, Table 1).
a Panoramic radiograph showing congenitally missing right 2nd premolars. b Cephalometric radiograph at the start of treatment
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Fig2
Radiographic examination revealed congenitally missing right second premolars and all third molars (Fig. 2a). Cephalometric analysis showed a skeletal class I relationship and hyperdivergent skeletal pattern (Fig. 2b, Table 1).
Induced ankylosis technique a extraoral root canal treatment of the mesial root of the primary tooth, b hemisectomy of the primary tooth, and c replantation of the mesial part and splinting
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Fig3
The ankylosis technique included extraction of the primary molar under local anesthesia followed by root canal treatment of the mesial root, performed ex vivo using a zinc oxide and eugenol sealer (Fig. 3a). The crown was then restored with composite resin and a 2-mm apicoectomy and hemisectomy of the tooth was performed (Fig. 3b). To stabilize the tooth and assure ankylosis, a rigid splint was applied, extending from the right canine to the right first molar, using a 0.016'' x 0.022'' stainless steel (SS) rectangular wire (Fig. 3c).
Radiograph 10 weeks post replantation showing the absence of periodontal ligament and root ankylosis
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Fig4
Ankylosis of the mesial root of the primary mandibular right second molar was diagnosed after 10 weeks through clinical and radiographic examination, and the splint was removed (Fig. 4).
Initial orthodontic space closure using a T-loop to close the space between the primary molar segment and the permanent first molar
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Fig5
T-loop 0.017'' x 0.025'' TMA sectional wire was inserted between the permanent and primary molar, without any prior levelling, to move the permanent first molar mesially (Fig. 5). The T-loop was activated 9 times.
Radiograph 6 months post replantation showing almost total root resorption and complete space closure between the 1st permanent molar and 2nd primary molar
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Fig6
At 6 months, clinical and radiographic examination revealed almost total replacement resorption of the root of the primary tooth and complete closure of the space (Fig. 6).
Orthodontic space closure using a retraction elastic chain to close the space between the permanent first molar and the first premolar; a stop was added to the wire to maximize anchorage
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Fig7
Remaining space closure was performed, during the next year, using elastic chain on a 0.017'' x 0.025'' SS wire with tip-back (Fig. 7) and support from class II elastics.
Clinical examination after the completion of orthodontic treatment showing the 1st permanent molar in the position of the 2nd premolar a frontal view, b right lateral view, c left lateral view, d maxillary occlusal view, and e mandibular occlusal view
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Fig8
Final records show class I canine and molar relationship on both sides; full space closure of the agenesis sites, confirmed with the use of dental floss; and correction of overbite and overjet; however, a slight midline deviation remained (Figs. 8 and 9a).
a Panoramic radiograph at the end of orthodontic treatment showing the 1st permanent molar in the position of the 2nd premolar. b Final cephalometric radiograph
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Fig9
Final records show class I canine and molar relationship on both sides; full space closure of the agenesis sites, confirmed with the use of dental floss; and correction of overbite and overjet; however, a slight midline deviation remained (Figs. 8 and 9a). Cephalometric analysis showed that the mandibular incisors did not experience lingual movement as a result of molar protraction (Fig. 9b, Table 1).