A study of Class III treatment: orthodontic camouflage vs orthognathic surgery

Abstract

Aim To evaluate the differences in pretreatment and post-treatment characteristics of Class III patients treated with orthodontic camouflage or orthognathic surgery, and to compare the range of skeletal, dental and soft tissue changes that are likely to occur with treatment, with particular reference to the influence of extractions on the resultant incisor angulations. Method Pretreatment and post-treatment cephalograms of 31 Class III orthodontically-camouflaged patients and 36 Class III surgical patients (without genioplasty) were obtained from one specialist practice. From the surgical group, 26 pre-surgical lateral cephalograms were also obtained. Inclusion criteria for the two groups were at least three of the following: (1) an ANB angle of 1 degree or less, (2) a Wits appraisal less than -4 mm, (3) an incisal overjet ≤0 mm, and (4) a Class III molar relationship. All lateral cephalograms were traced and digitised and a number of skeletal, dental and soft tissue variables were measured. The camouflage and surgical groups were also divided into premolar extraction and non-extraction subgroups to allow for a specific analysis of extraction effects. Results Before treatment, the surgical group demonstrated, on average, a more severe skeletal discrepancy and increased dental compensations, compared with the orthodontically camouflaged group. After treatment, the mean SNA angle was greater, the ANB angle was more positive, the Wits appraisal was closer to ideal and the lower incisors were less retroclined in the surgery group. There was a small mean reduction in horizontal chin projection in the surgery group compared with a small increase in the camouflage group. The mentolabial fold and the lower lip curve were deeper, on average, and the lips less retrusive after surgery. There was a mean increase in upper incisor proclination during treatment in both the surgical and camouflage groups with a greater increase in the camouflage group. There was a significant reduction in upper incisor proclination and a subsequent greater increase in the ANB angle associated with upper premolar extractions in the surgical group compared with the non-extraction group. Lower premolar extractions in the camouflage group resulted only in a deeper mentolabial fold compared with those treated without lower extractions. Conclusions Class III patients selected for surgical treatment are likely to have more severe pretreatment dental and skeletal discrepancies than those selected for camouflage treatment. Surgical treatment is associated with significant decompensation of the lower incisors but, ultimately, not the upper incisors. Class III patients treated with either camouflage or surgery treatment are likely to finish with slightly proclined upper incisors. Generally, surgical treatment results in greater skeletal change, involving normalisation of the skeletal base relationship, a reduction in chin prominence, fuller lips, and a more favourable lip and chin contour.

Comparison of soft tissue changes between incisor tipping and translation after premolar extraction

“…However, several previous studies on Class III camouflage treatment showed that the retroclination of the lower incisors is typically accompanied during retraction, with an average degree between 6.5 and 8.1°, making a more retrusive and flat lower lip profile. 19 - 21 Therefore, considering the results of this study, the translational retraction of the lower incisor along with the posterior movement of the root apex is recommended, especially in Class III camouflage treatment for the establishment of the esthetic lower lip contour line.…”

Evaluation of maxillary and mandibular growth patterns with cephalometric analysis based on cervical vertebral maturation: A Japanese cross-sectional study

“…However, a normal overbite and overjet cannot be constructed by dental compensation alone when a large skeletal discrepancy is present. To correct the anteroposterior jaw position and realign the intermaxillary relation with consideration for the mandible (toward the tendency of elimination of dental compensation) after tooth movement, orthognathic surgery can be used to achieve an adequate maxillo-mandibular relation by splitting the maxillo-mandibular jaw bone in combination with orthodontic treatment [ 26 , 27 ]. Specifically, the decompensation direction in maxillary and mandibular anterior teeth revealed the opposite from dental compensation in non-surgery mandibular prognathism cases.…”

Orthodontic camouflage versus orthodontic-orthognathic surgical treatment in borderline class III malocclusion: a systematic review

“…In OOS, two studies [16,19] reported performing bimaxillary surgery for all participants, while the remaining studies conducted either maxillary advancement, mandibular setback, or bimaxillary surgery. Regarding the extraction treatment in the pre-surgical orthodontic phase, one study [14] reported extraction or non-extraction based on the selected case, one study [15] reported that no extraction was done during this phase, while four studies [16][17][18][19] did not report this point. One study [14] reported that genioplasty was not part of the surgical intervention while the other five studies [15][16][17][18][19] did not report this.…”

“…Regarding the extraction treatment in the pre-surgical orthodontic phase, one study [14] reported extraction or non-extraction based on the selected case, one study [15] reported that no extraction was done during this phase, while four studies [16][17][18][19] did not report this point. One study [14] reported that genioplasty was not part of the surgical intervention while the other five studies [15][16][17][18][19] did not report this. Three studies [16,18,19] mentioned that rigid fixation was performed during the surgery while the other studies [14,15,17] did not report the used fixation technique.…”