Orthodontics or surgery? – what to do first

Case report

Pretreatment evaluation

A 21-year-old male patient reported to the orthodontic clinic with the chief complaint of forward placed upper front teeth. Extra-oral examination revealed that the patient had an apparently symmetrical mesoprosopic face, potentially incompetent and protruded lips with more protrusion of the lower lip, an interlabial gap of 6 mm and an incisal display of 4.5 mm at rest. His smile was a consonant type with 100% upper incisor and 3.5 mm of upper gingiva visible (gummy smile) (Figure 1a).

Intra-oral examination revealed a full complement of permanent teeth except the third molars on the left side. The periodontium appeared healthy. Both upper and lower incisors were proclined with mild spacing in the upper arch anterior segment (Figure 1b–d). There was mild crowding in the lower anterior segment. Overjet and overbite was increased, with a Class I molar and canine relation on both sides. The upper left central incisor was fractured and the upper midline was not coincident with the lower.

Examination of study models showed an overjet of 6 mm and an overbite of 4 mm. The Curve of Spee was 4.5 mm with a space discrepancy in the upper arch of 24 mm and in the lower arch of 20 mm. Radiographic examinations showed Class II skeletal bases with both jaws prognathic. Both maxillary and mandibular incisors were proclined. The soft tissue analysis revealed significantly protrusive upper and lower lips in relation to the E line with a severely decreased nasolabial angle.

Treatment plan

The virtual orthodontic set-up ruled out the need for extractions and verified the adequate position and axial inclination of the upper incisors. The virtual surgical treatment plan included a Le Fort I maxillary osteotomy with a 8 mm setback, with superior repositioning and subapical anterior osteotomy in the lower jaw with 7mm of setback and the extraction of bilateral upper and lower first premolars. His post-operative recovery was uneventful, and the patient was discharged from the hospital after 4 days (Figure 2a–c). His orthodontics began a month later with a Standard Edgewise technique – 0.018”slot – after surgery and involved arch alignment and levelling, with decompensation of the lower arch (Figure 3a–d).

Discussion

The ‘Surgery First’ concept in orthognathic surgery was introduced by Nagasaka et al in 2009. They reported the correction of a Class III skeletal malocclusion with mandibular setback surgery and subsequent orthodontic alignment with the aid of temporary anchorage devices. The patient did not undergo any previous orthodontic preparation.⁵ Because of their excellent clinical results and substantial reduction in total treatment time, the investigators postulated that this new treatment approach could become a standard procedure in the future. Taking into consideration the number of patients requesting orthognathic surgery for primarily aesthetic concerns and time limitations for long treatment, the ‘Surgery First’ approach could represent a reasonable, cost-effective method to manage skeletal maloclusion in selected cases.

Traditional surgical-orthodontic treatment has included two orthodontic phases: a pre-operative preparation in which most of the orthodontic movements are performed to achieve a precise, stable occlusion and a post-operative phase for minor adjustments. Pre-operative orthodontic treatment usually lasts 15 to 17 months,^4,6 or even up to 24 months.⁷ However, the total pre-operative treatment is frequently longer than that initially indicated to the patient.⁴ The average duration of the post-operative orthodontic phase has varied from 7 months⁸ to 12 months.⁹ No statistically significant differences regarding patient age, gender, or type of malocclusion have been detected.^4,7,8,9 These orthodontic phases often cause significant discomfort to the patient.^4,10 One study found that one-third of patients rated the orthodontics as the worst part of their orthognathic treatment owing to the visibility and discomfort of the appliance and the length of treatment.³ In contrast, if the surgery is performed before the orthodontic treatment, the total treatment time will be noticeably reduced. Nagasaka et al⁵ reported that the treatment could be shortened to about 12 months, less than the average time needed for traditional pre-operative orthodontics alone.^4,7,8 In the present case, the total treatment time was 180 days. These data, although lacking statistical significance, have illustrated that a ‘Surgery First’ approach tends to condense the treatment time considerably, mainly by shortening the total orthodontic period.

In 2001, Wilcko et al suggested that rapid tooth movement in the context of corticotomy-facilitated orthodontics was the result of a demineralization–remineralization process consistent with the wound healing pattern of the regional acceleratory phenomenon.¹¹ It seems that selective bone injury results in an overwhelming activating stimulus for both catabolic and anabolic responses in the periodontium.¹² It is possible that the alveolar bone adjacent to the osteotomies performed during orthognathic surgery also undergoes increased bone turnover. This could account for the more efficient post-operative orthodontic movements and hence contribute to the total treatment time reduction in a ‘Surgery First’ sequence.¹² Moreover, routine pre-operative orthodontics involves dental alignment, arch co-ordination, and incisor decompensation; very often, the latter tends to prolong the treatment time with little or no significant benefit to the patient.⁵ In addition, axial correction of the incisors exacerbates an anterior crossbite and tends to unmask the patient's underlying skeletal deformity. Especially in the case of Class III patients, the prognathic profile will be greatly accentuated as the pre-operative orthodontics progresses. This intensifies the patient's perception of facial disharmony. The ‘Surgery First’ approach, in contrast, corrects the skeletal problem (and hence the aesthetic concern) from the outset. This clearly accounted for the favourable evaluation of the treatment by our second patient.

Another advantage of the ‘Surgery First’ approach compared with traditional surgical-orthodontic treatment includes the rapid profile improvement with subsequent immediate patient satisfaction. In contrast, several difficulties and disadvantages must be considered. First, the occlusion cannot serve as a guide for the designation of treatment goals. Secondly, the immediate post-operative occlusion is often unstable; thus, an occlusal splint while eating has been recommended.⁵ Temporary anchorage devices can be considered to help stabilize the osteotomies when no solid orthodontic appliances are present during surgery.^5,11

This treatment concept requires a precise diagnosis and detailed treatment planning. The post-operative orthodontic movements must be accurately planned with the surgical plan, implying constant communication between the surgeon and orthodontist. It is important that the orthodontist be skilled in orthognathic surgery cases, because the orthodontist is often confronted with a rather complex scenario.

Conclusion

A thorough diagnosis, planning, and execution could render the ‘Surgery First’ approach appropriate for a significantproportion of our routine cases.