Patients

All 56 patients undergoing tooth-borne SARPE between January 2013 and December 2014 were evaluated retrospectively for postoperative complications following a standardized multidisciplinary protocol at the Catholic University Leuven, Belgium. Exclusion criteria were prior trauma and craniofacial syndromes involving the maxilla. Fifty-five patients remained after applying the exclusion criteria; 35 were female and 20 were male, and they ranged in age from 13 to 47 years. This study was conducted in accordance with the principles stated in the Declaration of Helsinki and was approved by the Research Ethics Committee of the Faculty of Medicine, University of Leuven.

Technique

Prior to surgery, all patients were screened for any relevant medical and surgical history. Baseline radiographic and clinical imaging was obtained for all patients. All surgeries were performed by one of the authors (CP) following a standardized protocol. All patients underwent SARPE under general anaesthesia with nasotracheal intubation combined with a local anaesthetic (lidocaine), with a vasoconstrictor (epinephrine 1:100,000) given for haemostatic purposes before incision.

A semi-lunar horizontal incision was made using a scalpel and was completed with monopolar diathermy in the upper buccal fold from the canine up to the infrazygomatic crest bilaterally. A corticotomy according to Le Fort I was made from the posterior aperture to the maxillary tuberosity with a Hall drill, 4-mm above the apex of the upper canine, whilst holding the soft tissue of the upper jaw in a cranial direction with a Le Fort I hook, protecting the infraorbital nerve. Disengagement of the pterygomaxillary suture was performed using a curved osteotome. In conjunction with this procedure, a vertical incision was made over the labial frenulum of the maxilla, the anterior nasal spine was loosened, and the transpalatal osteotomy was completed with a spatula osteotome whilst placing a forefinger on the palate for guidance of the osteotome as it transected the mid-palatal suture. Transverse mobility of the maxillary halves was checked by manipulating a chisel in-between the central diastema. Disengagement of the nasal septum then followed using a septum osteotome. Antibiotics (amoxicillin) were administered intraoperatively and given as prophylaxis for up to 5 days postoperatively.

No standard distraction device was used; each patient’s orthodontist inserted a Hyrax-type expander prior to surgery. A latency period of 7 days between surgery and expansion was respected to allow new callus to be formed. The device was activated 0.25 mm twice daily to achieve a daily expansion of 0.5 mm. All patients were assessed for complications clinically and with peri-apical X-rays of the central incisors on a weekly basis by residents at the university hospital under the supervision of one of the authors (CP). This was done for up to 4 weeks postoperatively or until the desired maxillary expansion had been achieved. The continuation of follow-up was then performed by the treating orthodontist.

The weekly clinical examination consisted of adequate anamnesis including an assessment of pain on a visual analogue scale (VAS), extraoral examinations including sensory deficits in the maxillary nerve (V2) region (light touch, pin-prick, and two-point discrimination tests) and an evaluation of the symmetry of expansion, and intraoral examinations including measurement of the central diastema, tooth colour, pocket measurement and mobility of the anchoring teeth (hyrax device) and central incisors using a Periotest M device (DentiSystem, Budapest, Hungary), and inspection of the intraoral wound healing. The weekly examination was concluded with clinical imaging (intraoral and extraoral) to allow comparisons to be made. Additional radiographic images were obtained when indicated after aberrant findings during clinical examination; for example, posterior–anterior films were obtained in the case of asymmetric expansion to allow proper follow-up, and tooth discolouration or mobility was investigated with additional peri-apical images or cone beam computed tomography (CBCT) to exclude direct damage from the burr or the osteotomy. After expansion, the device was blocked and either left in place or replaced with a transpalatal arch for a consolidation period of 6 months.

Outcome

Short-term complications after SARPE refer to unattended and unwanted conditions presenting intraoperatively, during the distraction phase, or postoperatively within 4 weeks after the SARPE procedure. Patients were systematically evaluated for pain, infection, haemorrhage, dental and periodontal changes, nerve injury, and symmetry of expansion, but other complications were also taken into account. Severe postoperative pain was defined as a VAS pain score >7 during the first week after surgery, affecting daily functioning, with only a limited effect of paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs) at the maximum dose allowed. The term ‘haemorrhage’ was used to describe all cases of postoperative bleeding presenting via the emergency or maxillofacial surgery department, with the exception of regular weekly follow-up after discharge from the hospital. All patients in whom the subjective findings of altered sensitivity in the trigeminal region could be confirmed clinically were categorized under ‘nerve injury’. Deviations in the symmetry of expansion were diagnosed based on the comparison of successive extraoral and intraoral images.

Nerve injury

Paresthesia of the infraorbital nerve and related branches was observed in 16 patients (29.1%). Eight of these patients experienced bilateral involvement of the nerve. Of the unilaterally affected patients, two complained of paresthesia of the incisors only, three had involvement of the infraorbital region, and another three patients had numbness of the upper lip in addition to the teeth and the infraorbital region. Four cases of paresthesia resolved within 2 weeks postoperative. After 4 weeks, three patients continued to suffer from unilateral paresthesia. There was no report of dysesthesia or complete anaesthesia ( Table 1 ).

Haemorrhage

A total of six patients presented with postoperative bleeding (10.9%). Intraoral bleeding was observed in one patient on the first evening after surgery. Epistaxis was seen in five patients. Four patients experienced a nosebleed on the day of surgery, whereas one presented with severe late-onset bleeding beginning on postoperative day 8 ( Table 1 ).

Dental and periodontal problems

Dental complications were seen in a total of five patients (9.1%). Two patients presented with increased tooth mobility of the central incisors during the first week postoperative. Discolouration of a central incisor was observed in one patient during distraction. External apical root resorption of the upper central incisors was seen in two patients. None of these complications resulted in tooth loss during follow-up ( Table 1 ).

Pain

Of all 55 patients, four (7.3%) suffered from severe postoperative pain at the surgical site. One patient was hospitalized overnight due to limited oral intake, and lost up to 12 kg during the subsequent 2 weeks. No cases of distraction-related pain were observed ( Table 1 ).

Inadequate/asymmetrical expansion

In this study, three cases of asymmetrical expansion were encountered (5.5%). Two were noticed early on during expansion and were only temporary due to trapping of the upper molars between the buccal cusps of their antagonists. One patient presented with true asymmetrical expansion after finishing the distraction phase. There were no reports of inadequate or unsuccessful expansion in this study cohort ( Table 1 ).

Appliance-related problems

Appliance-related complications were seen in three patients (5.5%). The Hyrax appliance had not been placed prior to surgery in one patient, therefore additional surgical time was required as the appliance had yet to be placed. Two patients had difficulties activating the device resulting in a lag of expansion of 1 week after starting the activation ( Table 1 ).

Other complications

Seven patients encountered complications that could not be classified into the above categories. Four patients reported postoperative nausea and vomiting. Two patients complained of a large, aesthetically disturbing cheek haematoma. A third patient was hospitalized due to iatrogenic gastric bleeding caused by NSAIDs ( Table 1 ).