This is a 12Y11M female with both mesial tipped left and right mandibular second molars. She came to our hospital with her parents for orthodontic consultation due to crowding of teeth. She denied any major systemic disease and drug allergy. She had received dental care at local dental clinics, and she has good oral hygiene.
The findings of clinical examination are as followings: (1) extraoral findings: convex profile with facial symmetry, normal facial height proportion, no lip incompetence, no mentalis muscle strain, no occlusal canting, nasolabial angle 98°, upper incisor show is 50%; (2) intraoral findings: Class I molar relationship on both side, lower midline shift to left 2.5 mm, overjet 2.5 mm, overbite 2 mm, crowding of upper and lower anterior teeth, 13, 23 blocked out and 47, 37 are mesial tipped impaction. Figure 1
presents the initial models of this patient.
The panoramic film showed 47, 37 impaction with mesial tipping. The cephalometric analysis demonstrated that the SNA=86°, SNB=83°, ANB=3°, U1-SN=115°, L1-MP= 105°, U1-L1=111°, upper lip to E-line was 1.5 mm, lower lip to E-line 4 mm (Figure 4a, Table 1)
. Space analysis demonstrated space discrepancy of 3 mm in the upper arch, and -4 mm in the lower arch. Diagnosis and treatment
The diagnosis was dental and skeletal Class I malocclusion with bimaxillary protrusion, upper and lower anterior crowding and 37, 47 are mesial tipped impaction. The treatment goal is to upright the mesial tipped and impacted 37, 47, to relieve crowding of upper and lower anterior teeth, to retract proclined upper and lower incisors. The treatment plan was four 1st premolars extraction due to crowding of both arches, and using the uprighting spring to correct mesial tipped and impacted 37, 47.
The orthodontic treatment started with full mouth 0.022x0.028 slot pre-adjusted OPA-K bracket system. After 7 months of preliminary alignment and leveling, 16x22 stainless steel wire was inserted in lower arch. In the same time 17x25 TMA wire-bended lever arm was applied on 47, and a prefabricated Memory Titanol®
upright spring was applied on 37. The memory Titanol upright spring consist of a 16x22 Ni-Ti wire on the posterior part that is connected by means of a climbable tube to a 17x22 stainless steel wire on the anterior part (Figure 2a)
. After placing the auxiliary uprighting springs on both side for 4 months, 37 and 47 were uprighted. Figure 2b
presented the progress of treatment. We can also see the result of 37, 47 well uprighted in the panoramic film (Figure 3b)
The patient is still undergoing the final detailing stage of orthodontic treatment. The extraction space of 14,24,34,44 have been closed, Class I molar relationship is still maintained; proper overjet, overbite and interdigitation is almost achieved. The mandibular dental midline coincided with maxillary and facial midline (Figure 2c)
. Figure 3c
, Figure 4a
, right demonstrated the panoramic film and cephalometric film after molar uprighting. Compared to the initial cephalometric film (Figure. 4a
, left), the mandibular second molars were uprighted. The following are initial and progressive cephalometric analysis (Table 1). The progressive cephalometric analysis demonstrated SNA=85°, SNB=84°, ANB=1.5°, U1-SN=110°, L1-MP= 95°, U1-L1=128°, upper lip to E-line was 0 mm, lower lip to E-line 2mm. Figure 4b
showed superimposition of the Initial (blue line) and progressive (red line) cephalometric tracing.
The patient is still in growth, overall superimposition showed vertical skeletal and soft tissue growth. Maxillary superimposition presented the upper incisor crown lingually tipped 8°, and extruded 1 mm. The upper first molar mesially moved 4.5 mm. The lower incisor crown tipped lingually by 6°, retracted 3 mm and intruded 1 mm. The lower first molar extruded 2 mm, mesially moved 2.5 mm. The lower second molar uprighted distally by 48°.
Cephalometric analysis in initial and treatment progress stage. View Hi-Res Image
Initial models and photographs. The mandible right and left side second molars were mesially tipped. View Hi-Res Image
a , A self-bending lever arm uprighting appliance of 0.017 ×0.0 25 TMA wire was bended and placed on 47 (right). A prefabricated Memory Titanol® upright spring was placed on 37 (left); b , With auxiliary uprighting springs placing on both side for 4 months, both impacted second molars were uprighted; c , Intraoral photos in finishing and detailing stage. View Hi-Res Image
a , initial panoramic film; b , progressive panoramic film; c , panoramic film in the finishing stage. View Hi-Res Image
a , initial and progressive cephalometric films; b , superimposition of the initial and progressive cephalometric tracing, overall superimposition (left), maxillary superimposition (right upper), and mandibular superimposition (right lower) View Hi-Res Image