This 12-year-3-month-old boy was referred to our clinic for the treatment of dentition crowding. He was in good general health, but allergic to penicillin. His pretreatment frontal photographs indicated chin deviation to her right side. Lateral view illustrated a convex facial profile, lip incompetence and mentalis strain (Figure 1
Intraoral examination revealed that the patient was in late mixed dentition with retained upper deciduous canines and second molars at both sides. It was also found that his upper left teeth, including lateral incisors, deciduous canine and first premolar were all palatally in-clined to form a crossbite with lower dentition. While upper left canine was blocked out, lo-cated at the buccal side of the upper left first premolar.
Lower dental midline shifted 1 mm to the right. His overbite was 4 mm on the right and 3 mm on the left, and overjet was 4 mm on the right and 5 mm on the left. Bilateral Class I mo-lar relationship was noted (Figure 2
Panoramic radiograph demonstrated upper right canine was impacted with a large follicle, and left canine was transposed with first premolar (Figure 3
). All second molars were une-rupted and tooth buds of lower third molars are present.
Pretreatment lateral cephalometric tracing and analysis demonstrated increased ∠ANB (5˚), high mandibular plane angle (MP-SN = 38˚), retroclination of upper and lower incisors (U1-NA = 2 mm, U1-SN = 100˚; L1-MP = 85.5˚) (Figure 4
). Lower lip was 5 mm protrusion beyond E-line. Diagnosis
The patient was diagnosed as skeletal Class II malocclusion, with high mandibular plane angle. Dental Class I malocclusion, with upper right canine impaction and upper left canine and first premolar complete transposition. Treatment objectives
The treatment objectives for this patient were to:
- Correct upper left canine and premolar transposition into normal tooth position.
- Correct of upper right canine position.
- Achieve of normal overjet and overbite.
- Establish Angle’s Class I canine and molar relationship.
- Achieve maximum intercuspation.
Upper brackets were bonded on the first appointment. The initial leveling archwire by-passed the upper right second premolar, left lateral incisor and first premolar. Then the patient was transferred to the oral surgeon for the surgical exposure and follicle enucleation of upper right canine. The 016 stainless steel main archwire was used for upper right canine occlusal traction and first premolar retraction (Figure 5
). Lateral incisor labial traction on the left side was started on the next appointment. Meanwhile, a bite plane was made for preventing occlusal interferences and facilitate teeth movements. The upper left canine was then pro-tracted to correct the transposition before first premolar was bonded. After 7 months of treatment, upper left first premolar was bonded for labial movement. Elastomeric chains were used from the first premolar to the first molar both in buccal and lingual sides (Figure 6
). At the 16th month, the upper right canine was surgically exposed again with apically repositioned flap. Upper arch was leveled and aligned well after 21 months of treatment, then the lower arch was bonded at the 22nd month for finishing (Figure 7
). Total treatment duration was 3 years and 5 months.
The upper left canine and the first premolar were properly aligned in correct tooth position. Moreover, the impacted upper right canine was successfully exposed and aligned. Ideal over-jet and overbite were also achieved. Class I canine and molar relationships were established with correction of the crossbites. A small space remained between the upper left lateral incisor and the canine for resin build up to compensate the Bolton’s discrepancy. The panoramic radiograph showed root proximity between upper left canine and the premolar (Figure 8-11
Patient came back for follow-up observation for more than 2 years after deboned. The cephalometric radiograph superimposition showed some more growth occurred. His overjet and overbite got better, and the occlusion is stable (Figure 12-14
Initial extraoral photographs. Patient had convex profile with mentalis strain and lip incompetence. His chin deviated to his right side. View Hi-Res Image
Initial intraoral photographs, indicated deep bite, retained 53, 55 63, 65, 22 palatally locked-in, 23 buccally blocked-out and 22, 63, 24 crossbite. View Hi-Res Image
Initial panoramic radiograph. 13 impaction with large follicle. 23 and 24 roots complete transposition; 23 displaced buccally and 24 palatally. All second molars erupting and lower third molar tooth buds exist. View Hi-Res Image
Initial cephalometric radiograph. ∠ANB= 5°, high mandibular plane angle, retroclined incisors and protrusive lower lip. View Hi-Res Image
Intraoral photographs at 2nd month. 13 was surgically exposed and started force eruption. View Hi-Res Image
Intraoral photographs at 10th month. 13 extrusion by power chains linked to main archwire. 22 already aligned, and 23 protraction by coil spring. 24 retraction and de-rotation by power chain both buccally and lingually View Hi-Res Image
Intraoral photographs at 1 year 10th month. 13 extruded and aligned. 23 and 24 transposition and all crossbite corrected. View Hi-Res Image
Finished extraoral photographs. More harmonious facial profile was achieved with lower lip retraction, and lips were able to close more easily at rest. View Hi-Res Image
Finished intraoral photographs. Optimal overjet and overbite were achieved with stable occlusion. View Hi-Res Image
Finished panoramic radiographs. Acceptable root parallelism and no obvious root resorption noted. View Hi-Res Image
Finished cephalometric radiographs. Upper incisors were retracted, while lower incisors proclined. More harmonious facial profile was achieved with lower lip retraction. View Hi-Res Image
Two years and three months follow-up extraoral photographs. Profile changed from convex to straight with the mandible and chin growth. View Hi-Res Image
Two years and three months follow-up intraoral photographs. Better overjet and overbite with stable occlusion. View Hi-Res Image
Two years and three months follow-up cephalometric radiograph. More mandible and chin growth. Cephalometric superimposition of (a) initial and finish. Upper incisors retroclined while lower incisors proclined. (b) finish and followup. Mandible continued growth. View Hi-Res Image