Abstract

The purpose of this investigation was to assess the dentoskeletal effects and facial profile changes as well as the mechanism of Class II correction in adult Class II subjects treated by surgical mandibular advancement in combination with orthodontics. The subject material comprised 46 adults with a Class II, division 1 malocclusion treated by nonextraction with a mandibular sagittal split osteotomy as well as with pre- and postsurgical multibracket appliances. Lateral head films from before treatment and after treatment were analyzed. The results revealed the following statistically significant (P < .001) treatment changes: (1) the mandibular prognathism enhanced; (2) the sagittal interjaw base relationship improved; (3) the mandibular plane angle increased; (4) the lower anterior facial height increased; (5) the lower posterior facial height decreased; (6) the facial profile straightened; (7) the overjet and Class II molar relationship were corrected. Overjet reduction was accomplished by 63% skeletal and 37% dental changes. The Class II molar correction was accomplished by 81% skeletal 19% dental changes. In conclusion, it can be said that mandibular sagittal split osteotomy in combination with pre- and postsurgical orthodontics is an effective and consistent method for the correction of Class II, division 1 malocclusions and for the straightening of the facial profile. A negative effect of treatment counteracting Class II correction is an increase in the mandibular plane angle.

INTRODUCTION

In the literature, a large number of surgical mandibular advancement procedures have been described for the therapy of skeletal Class II malocclusions with mandibular deficiency.1 However, the current standard method is the retromolar mandibular sagittal split osteotomy introduced originally by Schloessmann in 1922.2 The most frequently used modifications of this method are those of Obwegeser3 and Dal Pont4 and of Hunsuck5 and Epker.6 

Many studies have been performed evaluating the skeletofacial changes occurring during surgical–orthodontic treatment of Class II malocclusions.7–12 However, no study has ever addressed the relative contribution of the skeletal and dental components involved in the changes of the sagittal occlusion.

Therefore, the purpose of this investigation was to analyze the effects of a sagittal split osteotomy in combination with pre- and postsurgical orthodontics on the facial hard and soft tissue structures in adult Class II, division 1 malocclusions.

METHODS AND MATERIALS

The subject material in this study comprised 46 (38 females and eight males) adult Class II, division 1 malocclusions treated surgically; exclusively by a mandibular retromolar sagittal split osteotomy. For the tooth alignment pre- and postsurgery fixed (multibracket) appliances were used for different periods of time. The mean pretreatment age of the subjects was 26 years (SD 8.1 years). The youngest subject (a female) was 16 years old (skeletal maturity stage R-J according to Hägg and Taranger,13 indicating that growth was completed). Total treatment time (surgery plus pre- and postsurgical orthodontics) for the 46 subjects amounted to an average of 1.7 years (SD 0.7 years).

Twenty-three of the 46 subjects were treated at the Orthognathic Surgery Department in Malmö, Sweden, using the Hunsuck5 and Epker6 sagittal split osteotomy. The other 23 subjects were treated at the Orthognathic Surgery Clinic in Minden, Germany, with the Obwegeser3 and Dal Pont4 procedure.

Lateral head films in habitual (centric) occlusion from before treatment and after all treatments (which means from after postsurgical orthodontics) were analyzed. All registrations were performed twice, and the mean value of the duplicate registrations was used in the final evaluation. No correction was made for linear enlargement (approximately 8% in the median plane for both the Swedish and German head films).

Standard cephalometrics

Changes of sagittal and vertical jaw base relationship, overbite, facial height, facial profile convexity, and lip position were assessed using standard variables. The cephalometric landmarks used are shown in Figure 1.

FIGURE 1.

Reference points and lines used in the standard cephalometric analysis

FIGURE 1.

Reference points and lines used in the standard cephalometric analysis

SO-Analysis

The SO-Analysis of Pancherz14 was used for the assessment of sagittal occlusal changes (Figure 2).

FIGURE 2.

SO-Analysis. The OL/OLp reference grid and the measuring landmarks are shown

FIGURE 2.

SO-Analysis. The OL/OLp reference grid and the measuring landmarks are shown

Individual changes

For the assessment of the clinical significance of individual changes only those exceeding ±0.5 mm, ±0.5° or ±0.5 Index values were considered.

Statistical methods

For the different variables, the arithmetic mean (Mean) and standard deviation were calculated. Student's t-test for paired samples was used to assess the significance of treatment changes. The statistical significance was determined on the confidence levels of 0.1%, 1%, and 5%. A confidence level larger than 5% was considered not significant (NS).

RESULTS

No differences in pre- and posttreatment cephalometric records existed when comparing the 23 subjects treated in Sweden and the 23 subjects treated in Germany. Therefore, the two subject samples were pooled in the presentation of the results. Furthermore, no sex differentiation was made because only eight of the 46 subjects (17%) were males.

Standard cephalometrics

The standard cephalometrics in 46 adult subjects are shown in Table 1.

TABLE 1.

Standard Cephalometrics in 46 Adult Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics

Standard Cephalometrics in 46 Adult Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics
Standard Cephalometrics in 46 Adult Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics

Sagittal jaw relation

The surgical mandibular advancement resulted in a significant (P < .001) increase in the angles SNB (mean 2.12°) and SNPg (mean 1.60°). There was a significant (P < .001) reduction in the angles ANB (mean 2.41°), ANPg (mean 1.89°), and in the Wits (mean 4.11 mm). Considering clinical significant individual changes, there was an increase of the SNPg angle in 78% (36 of 46) and a reduction of the ANPg angle in 89% (41 of 46) of the subjects (Figures 3 and 4, respectively).

FIGURE 3.

SNPg angle (sagittal mandibular position). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 3.

SNPg angle (sagittal mandibular position). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 4.

ANPg angle (sagittal interjaw base relationship). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 4.

ANPg angle (sagittal interjaw base relationship). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Vertical jaw relation

The mandibular plane angle (ML/ NSL) and interjaw base angle (ML/NL) were increased significantly (P < .001) by an average of 3.33° and 3.71°, respectively. With respect to clinical significant individual changes, the ML/NSL was increased in 89% (41 of 46) of the subjects (Figure 5).

FIGURE 5.

ML/NSL angle (mandibular plane angle). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 5.

ML/NSL angle (mandibular plane angle). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Facial height

The lower anterior facial height was, on average, increased by an Index value of 1.27 (P < .001), whereas the lower posterior facial height was reduced by an Index value of 2.01 (P < .001). Considering clinical significant individual changes, lower anterior facial height was increased in 80% (37 of 46) and lower posterior facial height was reduced in 72% (37 of 46) of the subjects (Figures 6 and 7, respectively).

FIGURE 6.

Spa-Gn × 100/N-Gn (lower anterior facial height index). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 6.

Spa-Gn × 100/N-Gn (lower anterior facial height index). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 7.

Spp-Go′ × 100/S-Go′ (lower posterior facial height index). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 7.

Spp-Go′ × 100/S-Go′ (lower posterior facial height index). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Profile convexity

The convexity of the hard and soft tissue facial profiles were significantly (P < .001) reduced. The average reduction in the hard tissue profile convexity (NAPg) was 4.45°, in the soft tissue profile excluding the nose (NS/SN/PgS) 5.45°, and in the soft tissue profile including the nose (Ns/No/PgS) 3.20°. With respect to clinical significant individual changes, the straightening of the hard tissue profile occurred in 91% (42 of 46), the soft tissue profile excluding the nose in 98% (45 of 46), and of the soft tissue profile including the nose in 76% (35 of 46) of the subjects (Figures 8–10, respectively).

FIGURE 8.

NAPg angle (hard tissue profile convexity). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 8.

NAPg angle (hard tissue profile convexity). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Lip position

The upper (UL) and lower (LL) lips became significantly more retrusive in relation to the Esthetic (E) line of Ricketts.15 Average changes were: for UL, 2.49 mm (P < .001) and for LL, 1.12 mm (P < .05).

SO-Analysis

The results of SO-Analysis are shown in Figures 11 and 12 and Table 2.

FIGURE 11.

Mechanism of overjet correction in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 11.

Mechanism of overjet correction in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 12.

Mechanism of Class II molar correction in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 12.

Mechanism of Class II molar correction in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

TABLE 2.

The Mechanism of Class II Correction (SO-analysis) in 46 Adult Class II, Division 1 Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics

The Mechanism of Class II Correction (SO-analysis) in 46 Adult Class II, Division 1 Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics
The Mechanism of Class II Correction (SO-analysis) in 46 Adult Class II, Division 1 Subjects Treated by Orthognathic Surgery (Mandibular Sagittal Split) in Combination with Pre- and Postsurgical Orthodontics

Mechanism of overjet correction

The overjet was, on average, reduced by 6.31 mm. This was accomplished by 63% skeletal and 37% dental changes. When considering clinical significant individual changes, overjet reduction was achieved in 98% (45 of 46) of the subjects (Figure 13).

FIGURE 13.

Overjet. Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 13.

Overjet. Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Mechanism of class II molar correction

The sagittal molar relation was, on average, improved by 5 mm. This was accomplished by 81% skeletal and 19% dental changes. With respect to clinical significant individual changes, the molar relation was improved in 96% (44 of 46) of the subjects (Figure 14).

FIGURE 14.

Molar relation. Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 14.

Molar relation. Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

A clinically significant individual mandibular base (Pg/ OLp) advancement was seen in 89% (41 of 46) of the subjects (Figure 15).

FIGURE 15.

Pg/OLp (sagittal mandibular position). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 15.

Pg/OLp (sagittal mandibular position). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

DISCUSSION

In the literature, there is general agreement that one of the main reasons for adult Class II subjects seeking treatment are dental and facial esthetics.16–18 The more dissatisfied the patients are with their facial appearance, the more likely they will choose a surgical instead of an orthodontic approach.19,20 

No difference in the outcome of treatment was found when comparing the Swedish sample in which the Hunsuck5 and Epker6 method was used with the German sample treated by the surgical procedure according to Obwegeser3 and Dal Pont.4 This was somewhat surprising because the two surgical approaches differed in terms of the preservation (Hunsuck and Epker procedure) and the nonpreservation (Obwegeser or Dal Pont) of the chewing muscle attachments at the proximal mandibular bone fragments. It would, namely, have been expected that the more the elevator muscles are detached during surgery, the more the remodeling of the gonial area and the shortening of ramus height will occur.

In accordance with earlier studies in adult orthodontic and orthognathic subjects,7,9,10,21,22 there was an overrepresentation of females. This might be associated with the observation that women are more interested in their facial appearance than men.23 

An interesting finding in the present subjects was the increase in anterior facial height and the decrease in posterior facial height. These changes were also reflected in the increase of the mandibular plane angle (ML/NSL), an observation which has been described earlier.7 As the mandibular plane angle and the anterior as well as the posterior facial heights were, on average, normal pretreatment,24 the observed changes counteract the mandible coming forward, which is one of the goals in surgical Class II treatment. Furthermore, an increase in the mandibular plane angle would be disadvantageous in especially those Class II subjects with an increased anterior facial height pretreatment.

The increase in the anterior facial height was most likely due to the bite rising effect in conjunction with the surgical mandibular advancement procedure. The reduction of the posterior facial height could be explained by the bone remodeling processes at Gonion taking place after mandibular surgery. Possible causes discussed are an inadequate overlap between the two bony fragments,25,26 the postsurgical adaptive processes of the soft tissues, tendons, and muscles that have been directly or indirectly affected by the surgical procedure and the jaw displacement.8,11,27,28 Finally, the possibility of a condylar resorption can not be excluded as a cause for the lower posterior facial height reduction. Such a resorption has been reported to occur rather frequently in orthognathic surgery subjects8,22 and especially in those with a pretreatment derangement of the TMJ.29 

In the present Class II subjects, the surgical advancement of the mandible and thereby also of the chin resulted in a straightening of the hard and soft tissue profiles, which is one of the main treatment objectives in Class II subjects with a convex facial profile. However, by a mandibular advancement, the distances of the UL and LL to the E-line will increase.30 Such a retrusion of the lips in relation to the E-line may result in a disadvantageous older appearence of the face.

In the therapy of the present Class II subjects, surgical– orthodontic treatment was most successful. When considering individual cases, overjet was reduced in 98% and sagittal molar relationship was improved in 96% of the subjects. Furthermore, both standard cephalometrics and the SO-Analysis demonstrated that the Class II correction was accomplished mainly by skeletal changes. Mandibular advancement contributed 63% to overjet correction and 81% to Class II molar correction. All dental changes seen were certainly a result of both the multibracket appliance treatment and the postsurgical dental compensation of the skeletal relapse.31 

In adult skeletal Class II treatment, two alternatives to surgery are possible, either camouflage orthodontics with the extractions of maxillary teeth9,32 or dentofacial orthopedics using the Herbst appliance.33–38 However, in camouflage orthodontics, only the main symptom of the Class II malocclusion (the large overjet) is dealt with whereas the basic mandibular and facial esthetic problems remain. On the other hand, in adult Herbst treatment, the mandibular and esthetic problems are attacked and also solved, although to a lesser extent as compared with mandibular surgery (S. Ruf and H. Pancherz; in preparation). When choosing between the different treatment options of surgery, Herbst, or camouflage, one should not forget the costs and risks11,12,39–41 involved, which are clearly larger with the surgical approach.

CONCLUSIONS

Mandibular sagittal split osteotomy in combination with pre- and postsurgical orthodontics is an efficient approach in the therapy of adult Class II, division 1 malocclusions. Sagittal occlusal malrelationships are corrected and the hard- and soft tissue profiles straightened in a consistent way. A negative effect of treatment counteracting Class II correction is an increase in the mandibular plane angle. Such an angular increase would also be a disadvantage, especially in those Class II subjects with a pretreatment increased anterior facial height.

FIGURE 9.

NS/Sn/PgS angle (soft tissue profile convexity excluding the nose). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 9.

NS/Sn/PgS angle (soft tissue profile convexity excluding the nose). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 10.

NS/No/PgS angle (soft tissue profile convexity including the nose). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

FIGURE 10.

NS/No/PgS angle (soft tissue profile convexity including the nose). Individual treatment changes in 46 adult subjects treated by orthognathic surgery (mandibular sagittal split) in combination with pre- and postsurgical orthodontics

Acknowledgments

The authors want to express appreciation to Dr. Hansen (Sweden) and Dr. Witschel (Germany) for making available the head film samples from the two countries.

REFERENCES

REFERENCES
1
Proffit
,
W. R.
,
R. P.
White
, and
D. M. D.
Sarver
.
Contemporary Treatment of Dentofacial Deformity.
St. Louis, Mo: Mosby; 2003:312–344
.
2
Hoffmann-Axthelm
,
W.
Chirurgie der Zahnstellung und Kieferanomalien.
Die Geschichte der Mund-, Kiefer- und Gesichtschirurgie. Berlin: Quintessence; 1995:121–142
.
3
Obwegeser
,
H.
The surgical correction of mandibular prognathism and retrognathia with consideration of genioplasty.
Oral Surg
1957
.
10
:
677
689
.
4
Dal Pont
,
G.
Retromolar osteotomy for the correction of prognathism.
J Oral Surg
1961
.
19
:
42
47
.
5
Hunsuck
,
E. E.
A modified intraoral sagittal splitting technique for correction of mandibular prognathism.
J Oral Surg
1968
.
26
:
250
253
.
6
Epker
,
B. N.
Modifications in the sagittal osteotomy of the mandible.
J Oral Surg
1977
.
35
:
157
159
.
7
Proffit
,
W. R.
,
C.
Phillips
, and
N.
Douvartzidis
.
A comparison of outcomes of orthodontic and surgical-orthodontic treatment of Class II malocclusion in adults.
Am J Orthod Dentofacial Orthop
1992
.
101
:
556
565
.
8
Schubert
,
P.
,
L. T. J.
Bailey
,
R. P.
White
, and
W. R.
Proffit
.
Long-term cephalometric changes in untreated adults compared to those treated with orthognathic surgery.
J Adult Orthod Orthognath Surg
1999
.
14
:
91
99
.
9
Mihalik
,
C. A.
,
W. R.
Proffit
, and
C.
Phillips
.
Long-term follow-up of Class II adults treated with orthodontic camouflage: a comparison with orthognathic surgery outcome.
Am J Orthod Dentofacial Orthop
2003
.
123
:
266
278
.
10
Lawrence
,
T. N.
,
E.
Ellis
, and
J. A.
McNamara
Jr.
.
The frequency and distribution pf skeletal and dental components in Class II surgery patients.
J Oral Maxillofac Surg
1985
.
43
:
24
34
.
11
Schendel
,
S. A.
and
N.
Epker
.
Results after mandibular advancement surgery and analysis of 87 cases.
J Oral Surg
1980
.
38
:
255
282
.
12
Freihofer
,
H. P.
and
D.
Petresevic
.
Late results after advancing the mandible by sagittal splitting of the rami.
J Maxillofac Surg
1975
.
3
:
250
257
.
13
Hägg
,
U.
and
J.
Taranger
.
Skeletal stages of the hand and wrist as indicators of the pubertal growth spurt.
Acta Odontol Scand
1980
.
38
:
187
200
.
14
Pancherz
,
H.
The mechanism of Class II correction in Herbst appliance treatment.
Am J Orthod
1982
.
82
:
104
113
.
15
Ricketts
,
R. M.
Esthetics, environment, and the law of lip relation.
Am J Orthod
1968
.
54
:
272
289
.
16
Wilmot
,
J. J.
,
H. D.
Barber
,
D. G.
Chou
, and
K. W. L.
Vig
.
Associations between severity of dentofacial deformity and motivation for orthodontic-orthognathic surgery treatment.
Angle Orthod
1993
.
63
:
283
288
.
17
Flanery
,
C. M.
,
G. M.
Barnwell
, and
J. M.
Alexander
.
Patients perceptions of orthognathic surgery.
Am J Orthod
1985
.
88
:
137
145
.
18
Mayo
,
K. H.
,
K. W. L.
Dryland-Vig
,
P. S.
Vig
, and
C. J.
Kowalski
.
Attitude variables of dentofacial deformity patients: demographic characteristics and associations.
J Oral Maxillofac Surg
1991
.
49
:
594
602
.
19
Kiyak
,
H. A.
,
R. W.
McNeill
,
R. A.
West
, and
T.
Hohl
.
Personality characteristics as predictors and sequale of surgical and conventional orthodontics.
Am J Orthod
1986
.
89
:
383
392
.
20
Bell
,
R.
,
H. A.
Kiyak
,
D. R.
Joondeph
,
R. W.
McNeill
, and
T. R.
Wallen
.
Perceptions of facial profile and their influence on the decision to undergo orthognathic surgery.
Am J Orthod
1985
.
88
:
323
332
.
21
Gerzanic
,
L.
,
R.
Jagsch
, and
I. M.
Watzke
.
Psychologic implications of orthognathic surgery in patients with skeletal Class II or Class III malocclusion.
Int J Adult Orthod Orthognath Surg
2002
.
17
:
75
81
.
22
Cassidy
,
D. W.
,
E. G.
Herbosa
,
K. S.
Rotskoff
, and
L. E.
Johnston
.
A comparison of surgery and orthodontics in “borderline” adults with Class II, division 1 malocclusions.
Am J Orthod Dentofacial Orthop
1993
.
104
:
455
470
.
23
Hoppenreijs
,
T. J.
,
E. C.
Hakman
,
M. A.
van't Hof
,
P. J.
Stoelinga
,
D. B.
Tuinzing
, and
H. P.
Freihofer
.
Psychologic implications of surgical orthodontic treatment in patients with anterior open bite.
Int J Adult Orthod Orthognath Surg
1999
.
14
:
101
112
.
24
Bhatia
,
S. N.
and
B. C.
Leighton
.
A Manual of Facial Growth.
Oxford, UK: Oxford University Press; 1993
.
25
Kohn
,
M. W.
Analysis of relapse after mandibular advancement surgery.
J Oral Surg
1978
.
9
:
676
684
.
26
La Blanc
,
J. P.
,
T.
Turvey
,
B. N.
Epker
, and
C.
Hill
.
Results following simultaneous mobilization of the maxilla and mandible for the correction of dentofacial deformities.
Oral Surg Oral Med Oral Pathol
1982
.
54
:
607
612
.
27
Turvey
,
T.
,
C.
Phillips
,
H. S.
Laytown
, and
W. R.
Proffit
.
Simultaneous superior repositioning of the maxilla and mandibular advancement. A report on stability.
Am J Orthod Dentofacial Orthop
1988
.
94
:
372
383
.
28
Epker
,
B. N.
and
G.
Wessberg
.
Mechanisms of early skeletal relapse following surgical advancement of the mandible.
Br J Oral Surg
1982
.
20
:
175
182
.
29
Schellhas
,
K. P.
,
M. A.
Piper
,
R. W.
Bessette
, and
C. H.
Wilkes
.
Mandibular retrusion, temporomandibular joint derangement, and orthognathic surgery planning.
Plast Reconstr Surg
1992
.
90
:
218
229
.
30
Pancherz
,
H.
and
M.
Anehus-Pancherz
.
Facial profile changes during and after Herbst appliance treatment.
Eur J Orthod
1994
.
16
:
275
286
.
31
Proffit
,
W. R.
,
T. A.
Turvey
, and
C.
Philips
.
Orthognathic surgery: a hierarchy of stability.
Int J Adult Orthod Orthognath Surg
1996
.
11
:
191
204
.
32
Weaver
,
N.
,
K.
Glover
,
P.
Major
,
C.
Varnhagen
, and
M.
Grace
.
Age limitation on provision of orthopedic therapy and orthognathic surgery.
Am J Orthod Dentofacial Orthop
1998
.
113
:
156
164
.
33
Ruf
,
S.
and
H.
Pancherz
.
Kiefergelenkswachstumsadaptation bei jungen Erwachsenen während Behandlung mit der Herbst Apparatur. Eine prospektive magnetresonanztomographische und kephalometrische Studie.
Inf Orthod Kieferorthop
1998
.
30
:
735
750
.
34
Ruf
,
S.
and
H.
Pancherz
.
Dentoskeletal effects and facial profile changes in young adults treated with the Herbst appliance.
Angle Orthod
1999
.
69
:
239
246
.
35
Ruf
,
S.
and
H.
Pancherz
.
Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: a prospective longitudinal magnetic resonance imaging and cephalometric radiographic investigation.
Am J Orthod Dentofacial Orthop
1999
.
115
:
607
618
.
36
Ruf
,
S.
and
H.
Pancherz
.
When is the ideal period for Herbst therapy— early or late?
Semin Orthod
2003
.
9
:
47
56
.
37
Pancherz
,
H.
Dentofacial orthopedics or orthognathic surgery: is it a matter of age?
Am J Orthod Dentofacial Orthop
2000
.
117
:
571
574
.
38
Pancherz
,
H.
and
S.
Ruf
.
The Herbst appliance—research based updated clinical possibilities.
World J Orthod
2000
.
1
:
17
31
.
39
Broadbent
,
T. R.
and
R. M.
Woolf
.
Our experience with the sagittal split osteotomie for retrognathia.
Plast Reconstr Surg
1977
.
66
:
860
867
.
40
Heydarian
,
F.
and
M.
Perko
.
Resultate beim Vorbringen des Unterkiefers durch sagittale Spaltung des Ramus.
Fortschr Kiefer Gesichtschir
1981
.
26
:
44
46
.
41
Paulus
,
G. W.
and
E. W.
Steinhäuser
.
A comparative study of wire osteosynthesis versus bone screws in the treatment of mandibular prognathism.
J Oral Surg
1982
.
54
:
2
6
.

Author notes

Corresponding author: Hans Pancherz, DDS, Odont Dr, Department of Orthodontics, University of Giessen, Schlangenzahl 14, Giessen, D-35392, Germany (hans.pancherz@dentist.med.uni-giessen.de)