Severe midface hypoplasia in patients with various craniofacial anomalies can be corrected with Le Fort III or monobloc advancement. Often additional corrective orthognathic surgery is indicated to achieve Class I occlusion and a normal inter-jaw relationship. This study evaluated the incidence of, and the surgical indications for, secondary orthognathic surgery following Le Fort III/monobloc advancement. The total study group consisted of 41 patients: 36 patients with Le Fort III advancement and 5 patients with monobloc advancement. Seven patients underwent additional orthognathic surgery. Of the resulting 18 non-operated patients older than 18 years at the end of follow-up, Class I occlusion was observed in 11 patients. In the remaining patients malocclusions were dentally compensated with orthodontic treatment. None of the patients was scheduled for additional orthognathic surgery due to the absence of functional complaints and/or resistance to additional surgery. Le Fort III and monobloc advancement aim to correct skeletal deformities on the level of zygoma, orbits, nasal area and forehead, but Class I occlusion is frequently not achieved. Additional orthognathic surgery is often indicated in patients undergoing Le Fort III or monobloc advancement. Naso-endoscopic analysis of the upper airway and the outcomes of sleep studies may influence the orthognathic treatment plan.
Midface hypoplasia in syndromal craniosynostosis (SCS) patients and non-syndromal patients can be associated with upper airway obstruction, ocular proptosis, Class III malocclusion and facial distortion leading to psychosocial problems . There seems to be a relation between obstructive sleep apnea (OSA) and raised intracranial pressure (ICP) . Ideally, Le Fort III and monobloc advancement is planned when skeletal maturity is reached but in cases with OSA, raised ICP and ocular related pathology (inability of complete eyelid closure, (sub-)luxation) surgical intervention can not be postponed until skeletal maturity.
Since the focus of this early surgery is concentrated on this acute pathology, relative indications, such as Class III malocclusion and facial aesthetic disharmony, may not be corrected. In addition, the literature reports a severely diminished intrinsic horizontal growth potential of the midface in SCS patients regardless of surgery . Continuing growth of the mandible may cause pseudorelapse so some degree of overcorrection in growing patients is advised. Nevertheless, correction of the deformity on the occlusal level may not be treated with Le Fort III or monobloc advancement. Frequently, additional orthognathic surgery is indicated later. Various suggestions are reported in literature . There are no clinical guidelines regarding the ideal timing and planning of these surgical procedures and the related orthodontic treatment. The aim of this retrospective study is to report the experience with additional orthognathic surgery as the final procedure to achieve a functional inter-jaw relationship and a Class I occlusion following Le Fort III and monobloc advancement.
Materials and methods
The study group consisted of 41 patients with cleft and various craniofacial anomalies. All patients who underwent Le Fort III or monobloc advancement between 1999 and 2009 were included. 38 SCS patients (16 with Apert syndrome, 17 with Crouzon syndrome and 5 with Pfeiffer syndrome) were reviewed of whom 33 underwent Le Fort III advancement and 5 underwent monobloc advancement. There were 2 patients with frontonasal dysplasia. Besides these patients there was one patient with both a bilateral cleft-lip-alveolus-palate and a median cleft. The last patient had both conditions. 7 patients underwent a conventional Le Fort III osteotomy, 29 patients underwent a Le Fort III distraction osteogenesis (DO) procedure and all monobloc patients underwent DO. In one patient who underwent Le Fort III DO and one patient who underwent conventional Le Fort III osteotomy, simultaneous with the Le Fort III osteotomy, a Le Fort I osteotomy was performed. DO was performed using either internal (14 patients, including all monobloc patients) or external distractors (20 patients). The Marchac–Arnaud distraction system (KLS Martin, Tuttlingen, Germany) was used for internal DO. External DO was achieved using the RED II halo frame (KLS Martin, Tuttlingen, Germany) or external midface distractor (Synthes, Solothurn, Switzerland).
Indications for primary surgery were classified as absolute or relative. Absolute indications were moderate or severe OSA (oxygenation desaturation index > 5 and/or patients requiring tracheotomy), raised ICP and exorbitism including persistent exposure keratitis and (sub-)luxation of the globe. Relative indications were impaired aesthetic appearance, exorbitism without clinical significance, Class III malocclusion and psychosocial considerations.
Le Fort III and monobloc distraction protocol
A latency period of 7 days postoperatively was applied to all patients irrespective of age or degree of advancement. The distraction rate was 1 mm per day for the Le Fort III distraction and 0.5 mm for the monobloc distraction. Distraction time was based on the desired advancement. For the Le Fort III patients vector modifications took place during distraction when necessary. Distraction was terminated when a normal malar and nasal projection was achieved and exorbitism was corrected. After Le Fort III distraction patients underwent a consolidation period of 3 months. The internal devices in the monobloc distraction cases were removed after 6 months of consolidation.
Indications for secondary orthognathic surgery
Indications for additional orthognathic surgery were assessed by clinical evaluation of the occlusion and profile and cephalometric analysis using standardized lateral skull radiographs. Clinical examination was performed by an orthodontist and a maxillofacial surgeon. In case of residual OSA, naso-endoscopic examination was performed by an otolaryngologist to identify the level of upper airway obstruction. Indications for additional orthognathic surgery were frontal open bite, Class II or III malocclusion, transverse discrepancy, evident crowding and residual OSA.
Data were collected retrospectively from the patients’ medical records. Indications, age at primary operation, age at secondary orthognathic surgery (if performed) and interval between primary and secondary surgery were evaluated. In all patients completion of skeletal growth was defined at the age of 18 years.
Data are summarized in Table 1 . In the total group the mean age at operation was 13.9 years (standard deviation (SD) 6.0). The mean age was 14.5 years (SD 5.3) in the Le Fort III group and 9.2 years (SD 8.8) in the monobloc patients. The patients with an absolute indication ( n = 21) were on average operated on at a younger age (mean 11.1, SD 6.4 years) compared with patients undergoing surgery because of a relative indication ( n = 20, mean = 16.8, SD 3.8). In the total patient cohort 17 (13 Le Fort III patients and 4 monobloc patients) of the 41 patients (41.5%) were younger than 18 years at the end of the follow-up period. The mean follow-up period was 4.8 years (SD 3.0).
|Patient||Syndrome||Indication for primary surgery||Young age at time of primary surgery (years)||Orthognathic surgery||Indication for orthognathic surgery||Young age at time of orthognathic surgery (years)||Young age at end of follow-up (years)||No orthognathic surgery performed at the end of this study due to|
|1||Apert||Absolute||16||20||Class II comp; open bite|
|3||Apert||Relative||20||25||Class II comp; open bite|
|4||Apert||Relative||15||19||Class III comp; open bite|
|6||Apert||Relative||19||Bimaxillary advancement||Class II||20||23||–|
|7||Apert||Absolute||7||SARME||Crowding dentition maxilla||15||16||–|
|10||Apert||Absolute||19||Le Fort I||Class III||19||23||–|
|11||Apert||Relative||16||Le Fort I||Class III||20||27||–|
|12||Apert||Absolute||12||19||Class III comp|
|15||Crouzon||Relative||15||Le Fort I||Class III||21||22||–|
|17||Crouzon||Absolute||16||21||Class III comp|
|23||Crouzon||Relative||19||Bimaxillary advancement||Class II||19||21||–|
|27||Crouzon||Relative||18||27||Class III; open bite|
|30||Pfeiffer||Relative||14||19||Class II; open bite|
|*34||NMD||Relative||17||19||Class I; open bite|
|36||CLAP||Absolute||18||22||Class I; open bite|
|1||Apert||Absolute||23||BSSO and nasal septum correction||Class II||23||24||–|