Surgery preceding orthodontics in bimaxillary cases.

Orthognathic surgery is performed to alter the shape of the jaws to increase the facial esthetic and improve the occlusions. Surgery prior orthodontics reduces the total length of the treatment of the patients, followed by orthodontics treatment. Advantages is positive outcome in short period of time. Surgical procedure includes Anterior Maxillary osteotomy and Anterior subapical mandibular osteotomy. Complication includes haemorrhage, paraesthesia, malunion of bone, etc.

Orthognathic surgery is the term used to describe surgical movement of the tooth-bearing segments of the maxilla and mandible. Patients for orthognathic surgery have a dentofacial deformity that cannot be ideally treated with orthodontic therapy alone. Candidates have malocclusions caused by skeletal discrepancies secondary to congenital anomalies or trauma. Patients have high levels of satisfaction with the esthetic and functional outcomes, especially if they were accurately informed about all aspects of their treatment.[1] One study found that one-third of patients rated the orthodontics as the worst part of their orthognatic treatment owing to the appliances visibility and discomfort and the length of treatment.[2] The performance of surgery first prior to orthodontics treatment was first proposed by Nagasaka et al.[2] Patients complains of forwardly placed jaws. Patients wants to fix the problem without undergoing through lengthy process of orthodontics treatment[Figures 1–4]

Figure 1

Preoperative photographs

Figure 4

Operative photograph

Intra oral preoperative photographs

Anterior Segmental Maxillary Osteotomy

The anterior segmental maxillary osteotomy (ASMO) was first published by Cohn Stock in 1921.[34]

Currently three methods have been used the Wassmund, Wunderer, and down fracture methods.[56]

Wassmund - involves only subperiosteal tunneling and no flaps and maintains both the palatal and labial vasculature.

Wunderer - palatal flap elevation with preservation of the labial pedicle. The Wunderer techniques are useful for anteroposterior repositioning

Down-fracture techniques described by Cupar-circum-vestibular incision for labial osteotomies and tunneling for the palatalosteotomy and later modified by Bell and Epker. Down-fracture method is recommended when superior or combined superior and posterior repositioning is required.

Anterior segmental maxillary osteotomy is usually indicated for excessive vertical or sagittal development of the maxillary alveolar process in patients where the posterior teeth relationship is acceptable, this kind of patients have anterior gummy smiles with increased overjet and deep overbite.

Indications for anterior maxillary osteotomy

Bimaxillary dentoalveolar protrusion

Anterior open bite

Excessive inclination of anterior teeth

Excessive vertical or anteroposterior development of the maxillary dentoalveolar process in patients where relationships between the posterior teeth are acceptable and

Duration of treatment, a relative indication in the Asian Indian population, in so far as some patients want quick resultsand do not have adequate time for a formal orthodontic correction.

Surgical procedure

The procedure was carried out under general anesthesia with nasal intubation, local infiltration with 2% lignocaine HCl with adrenaline 1:80000 is administered in maxillary vestibule. Standard Cupar incision was placed from first premolar to premolar [Figures 5 and 6].

Figure 5

Incision in maxilla

Figure 6

Incision in maxilla

The mucoperiosteum was elevated through this incision to expose the pyriform aperture and anterior wall of the maxilla up to the canine fossa.[7] Upper first premolars were extracted on both the sides.

Palatal tunneling was done from the extraction socket converging at midline. Keeping the gingivoperiosteal flap intact and well retracted vertical maxillary osteotomy was carried out from the socket of extracted premolars to pyriform aperture bilaterally followed by the palatal Osteotomy[Figure 7].[7] Elevation is performed[Figure 8]. After completing the Osteotomy[Figures 9–13], anterior maxillary segment was down fractured and Superior and posterior repositioning was done. Excess bone was removed from anterior segment or the adjacent maxilla.

Figure 7

Operative photographs

Figure 8

Elevation

Figure 9

Osteotomy cut in maxilla

Figure 13

Osteotomy cut in mandible

Osteotomy cut

Wound closure was done with 3-0 vicryl.

Severe skeletal open bite malocclusions cannot be corrected by orthodontics means alone. The resistance by tongue and perioral muscle functions, high potential of vertical relapse of extrusion limited the success of mechanotherapy.

The use of anterior maxillary osteotomy for the correction of open bite, closed bite, underdeveloped maxilla, and protruding maxilla was advocated by Mohnac. The procedure could be used concurrently with the mandibular correction of class II and class III malocclusions. According to Parnes (1966) the major advantage of surgical correction over the orthodontics was the “time factor.” The first report of ananterior segmental anterior maxillary osteotomy (ASMO) was published by Cohn-Stock.

Anterior subapical mandibular osteotomy

Hullihen (1949) was the first person to perform an anterior subapical osteotomy to correct anterior open bite.[89]

Indications

To advance or retrude the lower anterior segment

To close anterior open bite.

Procedure

An incision is placed 15 mm in the vestibule of the lower lip [Figures 14–17]. Incision extends from the first premolar to the opposite premolar. Anterior part of the mandible is degloved to the inferior border.

Figure 14

Vestibular incision placed in mandile

Figure 17

Elevation in mandible

Mucoperiosteal flap elevated in mandible

Incision placed in mandible

Dissection is performed till the mental neurovascular bundles is visualized. Osteotomy is performed by straight hand piece [Figures 11 and 13]. After the vertical cut is completed, a horizontal cut is made connecting the vertical cuts 5 mm below the apices of the anterior mandibular teeth. Osteotomy is completed using a thinosteotome or a spatula chisel. Plating is done in maxilla and mandible [Figures 18–20].

Figure 11

Osteotomy cut in mandible

Figure 18

Plating done in maxilla and mandible

Figure 20

Plating done in mandible

Plating done in maxilla

Modified osteotomy – - a midline osteotomy may be incorporated in case of midline diastema

Extended osteotomy – osteotomy can be extended up to the existing edentulous space. Cut segment can be mobilized with gentle pressure at the osteotomy site.

Closure is done in a layered fashion. 4 –0 resorbable chromic sutures are placed submucosally, followed by vertical mattress sutures toclose the mucosal layer.

Discussion

A dramatic improvement in facial esthetics and occlusal function was realized with the completion of treatment. The lip competency, gingival exposure on smile and facial contour was significantly improved in a shorter period. The “surgery first” concept was introduced by Nagasaka et al. in 2005. The patient did not undergo any previous orthodontics preparation.

According to Parnes (1966) the major advantage of surgical correction over the orthodontics was the “time factor.” Surgical orthodontics treatment includes two phases: A preoperative preparation in which most of the orthodontics movements are performed to achieve a precise, stable occlusion and postoperative phase for minor adjustments. Pretreatment last for 15–17 months or up to 2 years.[10] Post phase last for 7 –12 months.[1112]

On other hand if surgery is performed first, the total treatment plan is reduced. Nagasaka et al. reported that the total treatment shortened to 12 months, less than the average time needed for traditional preoperative orthodontics alone.[213]

Conclusion

The surgery first corrects the skeletal problem from the beginning. This concept of surgery first has the advantage of immediate patient satisfaction comparing to traditional orthodontic treatment[Figures 21 and 3]. This gives the patients a better self-esteem and positive satisfaction in a shorter period in surgery first treatment.

Figure 21

Postoperative photographs

Figure 3

(a)Preoperative photograph (b)Postoperative photograph