Journal Club : Comparison of surgical and fixed functional treatment results in identical twins

Long-term surgical versus functional Class II correction:
A comparison of identical twins
Aditya Chhibbera; Madhur Upadhyayb; Flavio Uribec; Ravindra Nandad 

Angle Orthod. 2015;85:142–156.

This case report interested me because I have personally had a tough time using functional appliances and achieving long term stability of the Class II correction (molar relation and overjet) CONSISTENTLY.



Though relapse of Class II isn't always complete, yet cases that I have treated surgically have stood the test of time compared to Class II correction by other means such as Class II elastics, twin blocks.

Two identical female (age 13 years 3 months) were treated for Class II correction where one patient was treated nonsurgically using a fixed functional appliance, while the other was treated using orthognathic mandibular advancement surgery. The patients were recalled and evaluated 5 years in retention. 
The advantage of using twins for such comparisons is that the difference in outcome can be assumed to be epigenetic and thus directly the result of the intervention provided, i.e, surgery or Fixed Functional Appliance

The key question was ‘‘Are there esthetic differences when Class II correction is achieved with surgical intervention in comparison to camouflage using a fixed functional appliance, both in the short and long term?’’ This twin case report helps to elucidate some answers. 

Both the girls had similar growth status, near similar skeletal patterns and slightly different dental patterns. However one girl agreed to surgery and the other didn't

Patient 1 was thus treated nonsurgically with a Fixed Functional Appliance, twin force bite corrector for 10 months. The treatment objectives for patient 1 were: attempt to maximize the differential jaw growth by nonsurgical correction of the malocclusion, control the vertical dimension and space maintenance for the missing mandibular premolar for subsequent implant replacement, retention, and follow up.

The active treatment duration was 30 months at 16 yrs of age

 Patient 2 was treated with orthognathic surgery for Class II correction. For patient 2, the treatment objectives were: to surgically correct the underlying skeletal discrepancy, correct the vertical dimension by surgically impacting the maxilla, space maintenance for the missing mandibular second premolars and subsequent implant placement, retention, and follow up.

Surgery was planned when the patient was age 18 years and 2 months
The patient was subsequently debonded at the age of 18 years and 8 months after an active treatment time of 62 months

Comparison of Treatment Progress, Results, and Long-term Retention 

The cephalometric and clinical comparison of the twin sisters took place at three time points: pretreatment, posttreatment, and long-term retention

1. At the initial examination (13 years 3 months). Even though the skeletal A and B points were slightly backwardly positioned in patient 2 compared to patient 1, the underlying skeletal discrepancy associated with mandibular retrognathia and vertically maxillary excess was similar in both. The overjet was slightly more pronounced in patient 2 due to proclined maxillary incisors.

2. At the posttreatment level (age 16 years, 5 months for patient 1 and 18 years, 8 months for patient 2). The overall skeletal outcome was superior for patient 2. She showed greater skeletal Class II correction with good vertical control, while her twin had dental compensations. However, the esthetic outcome was similar in both patients.

 3. At the retention level (22 years and 9 months). Interestingly, even though the skeletal outcome of patient 2 remained superior, the soft tissue profile was still remarkably similar even though they underwent different procedures for Class II correction