1 Riolo M et al 1974 Atlas of craniofacial growth. Center for Human Growth and Development, University of Michigan
2 McNamara J A 1984 A method of cephalometric evaluation. American Journal of Orthodontics 86:449-469
3 Sato S, Suzuki Y 1988 Relationship between the development of skeletal mesio-occlusion and posterior tooth-to-denture base discrepancy. Its significance in the orthodontic correction of skeletal Class III malocclusion. Journal of the Japanese Orthodontic Society 48:796-810
4 Bennett J, McLaughlin R P 1997 Orthodontic management of the dentition with the preadjusted appliance. Isis Medical Media, Oxford (ISBN 1 899066 91 8) pp. 344-350. Republished in 2002 by Mosby, Edinburgh (ISBN 07234 32651)
5 Bennett J, McLaughlin R P 1997 Orthodontic management of the dentition with the preadjusted appliance. Isis Medical Media, Oxford (ISBN 1 899066 91 8) pp. 338-343. Republished in 2002 by Mosby, Edinburgh (ISBN 07234 32651)
6 McLaughlin R P, Bennett J 1999 An analysis of orthodontic tooth movement - the dental VTO. Revista Espanola de Ortodoncia 29:2 10-29
7 Pangrazio-Kulbersh V, Berger J, Kersten G 1998 Effects of protraction mechanics on the midface. American Journal of Orthodontics and Dentofacial Orthopedics 114:484-491
8 Ishikawa H et al 1998 Individual growth in Class III malocclusion and its relationship to the chin cap effects. American Journal of Orthodontics and Dentofacial Orthopedics 114:337-346
Standard metal brackets were used for optimal control. The upper arch was fully set up with a .016 11A NT wire. Bracketing of lower incisors was delayed to allow separation and enamel reduction. In this way, proclination of lower incisors during alignment could be restricted. Sectional .015 multistrand wires were used in the lower arch.
q A male patient, aged 13.11 years, with a slight Class III
skeletal pattern (ANB -1°) and MM average (25°). Lower za incisors were retroclined at 84° to the mandibular plane.
Molar relationship was slightly Class III bilaterally, and there was a Class III incisor relationship, with lower incisors m crowded and retroclined. There was mild upper anterior
—I crowding with the left first premolar in crossbite. Good-sized third molars were developing in satisfactory positions. Second molar extraction was considered and discussed, but after discussion with the family, treatment proceeded on a non-extraction basis.
WITS -3 mm
1 to Max Plane 112 0
M.S.Beginning 13.1 iyoars 6/7/96
M.S.Beginning 13.1 iyoars 6/7/96
Here, the case is seen after 10 months of treatment. Upper and lower rectangular 1IANT wires are in place, with a .036 'jockey' wire (p. 82) to assist upper arch expansion. It would have been helpful to have inverted lower canine brackets when setting up this case, to assist torque control.
Lower second molars had erupted sufficiently to permit banding at this stage. The .019/.025 lower HANT wire is effective in producing early correction, and this wire does not permanently distort due to mastication, as can happen with steel wires in the lower second molar region.
After 13 months of treatment, the lower first molar bands and several brackets were repositioned, and rectangular HANT wires were continued in the upper and lower arches.
Normal upper and lower steel .019/.025 rectangular wires were used, with some upper archwire expansion to maintain a correct bucco-lingual molar relationship.
Frontal and buccal view after appliance removal. Active treatment time was 26 months.
A good dental result was obtained, but the panoral radiograph shows impaction of lower third molars. The patient was referred to a surgeon to discuss extraction of third molars. With hindsight, the third molars could have been extracted earlier in the treatment. This could have helped the Class III treatment mechanics and avoided difficult impactions.
A pleasing mild Class 111 profile. Little growth occurred during treatment. There is some risk of relapse from late mandibular growth. Extraction of second molars could have produced a result where slight late growth could be more easily managed, and where surgical extractions could have been avoided.
SN at S
SN at S
WITS -4 mm
MM 27 ° 1 to A-Po 5 mm 1 to A-Po 3 mm to Max Plane 115°
Mand. Symphasis & Mand. Plane
This female patient was aged 13.4 years and showed a slightly high-angle pattern (MM 31°) and mild Class III dental bases (ANB 1°). There was pleasing balance and ^ harmony to the facial profile.
n Molar relationship was Class I, but there was a mild Class 111
incisor relationship, with reduced overbite. I.ower incisors $ were crowded and retroclined, and there was slight upper arch
™ The following features contributed to the extraction decision
z • A good, or maybe slightly flat profile
• Slightly high angle pattern
• Anterior open bite tendency
• Slight to moderate anterior crowding.
There was not sufficient crowding to justify premolar extractions without risking unwanted profile change. On the other hand, non-extraction treatment could lead to anterior bite-opening.
The panoral radiograph confirmed that all teeth were developing, including good-sized third molars in good developmental positions. It was felt that the upper incisors should be torqued from 107° to a figure near to 115°, but that the vertical and A/P positions were satisfactory. Thus, the upper and lower incisor PIP could be close to the starting position, but with some torque change. A decision was made to relieve lower arch crowding by extraction of lower second molars, and to use Class III elastics to align and retract the lower first molars and premolars. Balancing extraction of upper second molars was planned (it would have been difficult to manage this Class III case if upper premolars had been extracted). The patient and parents were informed of the possible need to upright lower third molars after eruption.
All teeth were banded or bracketed with standard metal MBT™ brackets and .015 multistrand wires were placed. The patient was referred for extraction of all second permanent molars.
oo After 1 month, upper and lower .019/.025 11A NT wires were placed with Kobayashi ties on lower canines. The patient was
3> asked to wear full-time Class III elastics (75gm)
£ After 4 months of treatment, a lower .016 IIANT wire was placed, and triangular elastics were used to close the anterior m open bite.
After 7 months of treatment, a lower rectangular HANT wire was resumed, and the patient was asked to wear a cross elastic on the left side molars. Subsequently, upper and lower steel rectangular wires were used to correct the anterior torque, and the incisor relationship was overcorrected. Normal settling procedures (p. 294) were followed. An upper removable acrylic wraparound retainer and a lower bonded retainer were supplied.
Active treatment time was 18 months. The case is seen here after appliance removal.
Occlusal photographs and panoral radiograph taken at the end of treatment.
oo At the end of treatment, there was good facial balance. The
A/I' position of incisors was unchanged relative to APo, and
> torque measurements were close to normal.
;> Superimpositions suggest that some distal movement of molars occurred, and that there was typical counter-clockwise m rotation of the occlusal plane in response to the Class III
Occlusal photographs taken 1 year after treatment and panoral radiographs taken 7 months after treatment. Subsequently all third molars erupted into good position. This does not always happen, and third molar uprighting is needed in some cases. (Case DO, p. 215)
SNA 77 SNB . 76 ANB/ 1 A-N FH -5 Po-N FH -11 WITS -2 GoGnSN 38 FM 29 MM / 31 1 to A-Po 5 1 to A-Po 2 1 to Max Plane 113 1 to Mand Plane, 91
mm mm mm mm mm
Palatal Plane & Palate Curvature
Mand. Symphasis & Mand. Plane
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