**10.2 Speech impediment**

It is believed that maxillary advancement in cleft patients has a potential to worsen velopharyngeal function (VPF). Nevertheless, there is still no certain evidence on whether or not the amount of advancement affects velopharyngeal disorder and whether or not preoperative VPF is related to the postoperative outcome. It is most likely that improvements are seen in the articulation of patients after surgery due to the correction of dental arches [69]. In a systematic review of the complications that developed as a result of orthognathic surgery on cleft patients, Yamaguchi et al. [62] reported postoperative velopharyngeal deficiency (VPD) as 16.79%.

Moran et al. [70] examined 79 cleft patients who received treatments of conventional orthognathic surgery or distraction osteogenesis, and they reported that, following maxillary advancement rates from 3 to 11 mm, there was VPD in 5 (6.33%) cases. These five patients were also found to have borderline VPD preoperatively. The results of their study supported those of other studies that there is no relationship between maxillary advancement and the amount of postoperative velopharyngeal disorders [71], and when orthognathic surgery and total maxillary distraction are compared in terms of speech and VPD, there is no significant difference [71–73]. Additionally, the finding that there is no correlation between postoperative speech impediment and preoperative borderline VPD was added to the literature which reported similar findings [71–73].

It is a difficult process to estimate soft tissue changes after orthognathic surgery and prevent them. This is because the adaptation of the velopharyngeal region for compensation of other regions is variable, and it is dependent on the personal characteristics of each patient and the capacity of tissues that are present or transplanted to become functional [74].

## **10.3 Infection**

Infection rates following orthognathic surgery are highly variable due to reasons such as antibiotics usage styles and diagnostic differences [75, 76]. Recent studies on orthognathic surgery in individuals without clefts reported an incidence of less than 1–8% [76–78].

Miloro derived a few results by analyzing 15 previous studies on infections following orthognathic surgery: infection incidence may decrease in the case of using oral antibiotics for more than 1 day after surgery. First-generation cephalosporins are used more frequently before surgery. Mandibular osteotomy regions are where infections are seen the most. Extraction of the third molar may have a small effect on infection incidence, but this is under debate. Most infections that occur after orthognathic surgery are small, and removal of fixation plates and screws is rarely necessary [75].

In an analysis of the USA National Inpatient Samples Database (2012–2013), the rate of emergence for any kind of infectious complication following orthognathic surgery was reported as 7.4% in patients with a craniofacial anomaly and 0.6% in those without a craniofacial anomaly [78]. Recent studies reported rates of from 0to 13.92% for infections emerging after orthognathic surgery in cleft patients without any craniofacial anomaly [61, 62, 68, 70]. In the study that obtained a high rate of incidence as 13.92% despite 5 days of routine antibiotics usage, the authors emphasized the importance of oral hygiene, team collaboration, and patient cooperation [70].

### **10.4 Oronasal fistula**

Segmental maxillary osteotomies may have a risk of postoperative oronasal fistulae. In a systematic review in 2017, the postoperative fistula rate was reported

**75**

*Orthognathic Surgery in Cleft Lip and Palate Patients DOI: http://dx.doi.org/10.5772/intechopen.89556*

blood circulation [80].

**10.5 Nerve damage**

**11. Conclusion**

but their extent is still under debate.

mechanisms to prevent or minimize these complications.

as 19.3% in segmental Le Fort I osteotomy [79]. While residual oronasal fistulae in cleft patients increase the difficult of orthognathic surgery, they may be repaired by adjusting the incision patterns during surgery. In addition to this, according to the systematic review in 2016 by Yamaguchi et al. [62], the closure deficiency of a pre-existing fistulae (28.57% for palatal, 10.74% for alveolar fistulae) was the most frequently encountered complication. Another study reported a residual fistulae rate of 10.53% [70]. Nevertheless, residual fistulae rates may be reduced by careful dissection, unstressed closure, delicate tissue management, and compliance with

The neural disorders that occur as a result of orthognathic surgery mainly affect the infraorbital, inferior alveolar (mandibular), and mental and incisive nerves.

Reports on facial nerve paralysis vary in the range of 0.17–0.75% [81].

alveolar nerve may contribute to the safety of orthognathic surgery [85].

Orthognathic surgery, which is the last stage of CLP treatment, is a highly important step in management of the entire process. Therefore, there should be good communication among the patient, the family, and the cleft team. There are effects of factors that are unique to individuals or clefts on the outcomes of surgery,

Despite the different rates reported in the literature, the rates of complications in cleft surgery are striking. Strategies should be created by focusing on causes and

The incidence of continuation of inferior alveolar nerve disorders varies between 5 and 15% depending on the age of the patient and the technique that is used (piezo-surgery or conventional) [82, 83]. A systematic review in 2017 reported that usage of piezo-surgery in orthognathic operations was associated with significant reductions of loss of blood during surgery and severe nervous disorders [84]. In orthognathic surgery on cleft patients, 70% of the patients may experience paresthesia after surgery, and a permanent sensory disorder may occur in 25% [80]. Bhatia et al. [61] stated that all 25% of patients who experienced cheek paresthesia recovered after a year. Moran et al. [70] reported that the sensory neuropathy of the infraorbital nerve was temporary in 53% of patients and permanent in 1.27%. In addition to this, 3D computer-assisted planning and determination of the inferior

as 19.3% in segmental Le Fort I osteotomy [79]. While residual oronasal fistulae in cleft patients increase the difficult of orthognathic surgery, they may be repaired by adjusting the incision patterns during surgery. In addition to this, according to the systematic review in 2016 by Yamaguchi et al. [62], the closure deficiency of a pre-existing fistulae (28.57% for palatal, 10.74% for alveolar fistulae) was the most frequently encountered complication. Another study reported a residual fistulae rate of 10.53% [70]. Nevertheless, residual fistulae rates may be reduced by careful dissection, unstressed closure, delicate tissue management, and compliance with blood circulation [80].
