5.3. Complications and problems

Preoperative phase. Condylar resorption was seen in the panoramic tomographs of 58 patients (11%) preoperatively (Fig. 1). Symptomless root resorption of one or more of the teeth could be identified in 22 patients (3%). Two cases of condylar resorption were seen after preoperative orthodontics. There were no recordings of poor communication, incorrect diagnosis, poor dental laboratory work or defects in the patient’s medical preparation and workup.

Intraoperative phase. Excessive bleeding was the most common problem in the intraoperative phase, as shown in Fig. 1. More than 1000 ml of bleeding was seen in about 10% of patients, and more than 2000 ml in about 1% of patients; 12% of patients needed blood transfusions, but less than 1% of those with BSSO (average bood loss 340 ml), whereas every third patient needed blood transfusion during and after a bimaxillary operation (average blood loss 890 ml). The mean blood loss remained between 300 and 500 ml throughout the study period.

Postoperative phase. The incidence of most postoperative complications and problems is about 5% or less, with the exception of root injuries in segment osteotomies (13%), mild clinical relapse (8%) and neurosensory deficits of the IAN (32%), as shown in Fig. 1. The incidence of other problems was one or two cases of each. Progressive condylar resorption was observed in 28 cases (5%), 7 of whom had already had this problem preoperatively. Twenty one of these patients (75%) were operated with BSSO advancement, with or without genioplasty. Five of the patients had had bimaxillary surgery. In 63% of all condylar resorption cases, the SN-MeGo angle was greater than 32°, which would suggest a tendency towards skeletal open bite. No correlation was found between the patient’s age and condylar resorption.

The most frequent complication was found to be neurosensory deficit of the IAN, which was mild in 32% and severe in 3% of the patients with osteotomy in the mandible. The patients with neurosensory deficit were older (mean, 33 years) than those with no disturbances (mean, 28.4 years, p < 0.01). Only two patients reported disturbance of lingual nerve sensation, and 5 reported mild disturbance of infraorbital nerve sensation. There were no notes of disturbances of facial nerve function.

Prevention of the neurosensory deficits of the IAN with a special surgical instrumentation technique was tested (paper IV). At one week and one year, all the tests showed the neurosensory deficit to be slightly worse on the control side (channel retractor), although the difference was not statistically significant (Fig. 2, 3, 4). The figures show mean values, although the data were skewed towards the left, but they illustrate the trend. VST showed lower values on the test side (Howarth elevator) at all of the 4 control visits, and the difference at 6 months was also statistically significant (p = 0.028) (Fig. 4). There were no differences in subjective sensation between the sides, but there was a correlation between subjective sensation and the 2-PD in the lower lip (p = 0.004 at 6 months and 0.038 at one year).

Both 2-PD and VST showed the maximum deviation from the preoperative test level (normal sensation) to occur at one week postoperatively, after which the sensation gradually normalized. Most patients had restored most sensation by the 3-month control visit, after which slower improvement towards the preoperative level continued. Subjective sensation followed the same trend. Five sides in both groups, i.e. 10 patients, and three patients with both sides continued to have slightly, but not disturbingly, altered sensation at one year. They account for 33% of the total study population. The mean age in this subpopulation was 43 years compared to the mean ages of 38 years in the whole group and 35.5 years in the group of patients with normal sensation, p = 0.05. None reported severe disturbance at this phase.

Age or gender had no influence on the measured neurosensory deficits on either the test or the control side. Subjective sensation had an almost significant correlation with gender at 6 months, but no longer at the one-year control visit.

While studying complications, the patients` motivation to seek treatment was also recorded, because it was thought to be potentially reflected in the overall satisfaction with the treatment and the alleviation of possible complications and side effects. There were 63 official claims concerning orthognathic surgery addressed to the PIC between 1990 and 1999, and the distribution of the types of claims is shown in Table 7.