**6.2 Orthodontic approach**

*Current Treatment of Cleft Lip and Palate*

considered [17].

oral-fistula closure [17].

lateral incisors by closing the cleft-dental gap.

*5.3.2 Modified Le fort I osteotomy (two-segment)*

and name as the modified Le Fort I osteotomy method [46].

required in UCLP patients in addition to Le Fort I osteotomy.

**6. Orthognathic approach on BCLP deformities**

have sufficient alveolar ridge height and volume, a close palate and sufficient periodontal support. Segmental maxillary osteotomy may also be needed in correction of arch width, repairing vertical dimensions or preventing the need for prosthetic

Unfortunately, even in the twenty-first century, alveolar defects and oronasal fistulae are encountered in many adults and adolescents who have UCLP with maxillary hypoplasia. For these patients, a modified Le Fort I osteotomy should be

In UCLP patients, the gap of the missing lateral incisor tooth may be eliminated

In the technique, first, a maxillary circumvestibular incision is made labially from a zygomatic buttress to another. In the residual oronasal fistula region, vertical incisions are made to separate the mucosa on both sides of the cleft as oral and nasal. These incisions are perpendicular to the horizontal vestibular incision, and they follow the line angles of the teeth adjacent to the cleft (central and canine). If the cleft bone was not previously repaired, the segments are already in two pieces with the down-fractured maxilla. If the maxilla is intact and the arch form needs to be adjusted, by using a reciprocating saw with a short and flat tip, the maxilla is divided into two pieces by cutting from the cleft area. The parts need to be brought closer to close the cleft-dental gap. However, this may be achieved only after shaving in the distal direction of the central incisor and along the mesial part of the canine from the alveola. Attention should be paid to ensure avoiding contact with the lamina dura as it would expose the root of teeth and may result in external root resorption. The maxillary segments are then stabilized with wires and acrylic occlusal splints. Repositioning of the segments closes the cleft-dental gap, gathers the alveolar ridges together, and gets the labial and palatal mucosal tissues closer for

The extent of the maxillary advancement that is carried out by the surgeon is based on previously planned occlusion, airway needs, and preoperatively determined facial esthetics. The ideal vertical dimension is achieved based on the preoperative plan, but intraoperative approaches may be considered in some cases [35]. Maxillary osteotomy regions are fixed on all zygomatic buttresses and apertures by using titanium plates and screws based on the principles described by Luhr [48, 49]. If a graft has been used, an extra microplate is additionally applied to stabilize each interpositional cortico-cancellous (iliac) graft. For repairing facial asymmetries and secondary deformities, mandibular and jaw osteotomies are also frequently

In the study that was carried out at Boston Pediatrics Hospital, it was stated that there was a need for maxillary advancement by orthognathic surgery in 76.5% adolescents whose BCLP had been repaired [3]. Moreover, the authors explained

by advancement of the lateral alveolar bone segment, where the canine tooth is placed adjacent to the central incisor tooth. After this, the canine is formed in a similar appearance to that of the lateral incisor [47]. This method that was described by Obwegeser in cases of unilateral cleft was advanced by Posnick in 1992

**68**

**6.1 Prevalence**

Different degrees of dysplasia in the sagittal, vertical, and horizontal directions are observed on the maxilla of patients without an ideal bone graft in the mixed dentition period that is divided into three segments. Before surgical treatment of maxillary segments, each segment is separately treated by an orthodontist. Before orthodontic treatment, cephalometric and panoramic radiography images are taken, and the angles, positions, and morphologies of teeth to soft tissues and bones are examined. In these patients, the volumes of the bones in the cleft region and the detailed position of teeth may be analyzed by additionally taking cone beam computerized tomography (CBCT) images.

BCLP patients have a broad variation in terms of the amount of dentoalveolar bone and the number of permanent teeth. Teeth that resemble lateral incisors are usually observed along the sides of the lateral segments. Due to the usually underdeveloped root structure of these teeth and their deformed crowns, extracting them is reasonable. Because of the deformed crowns and root structures of also the erupted supernumerary teeth found in the premaxilla of BCLP patients, it is usually appropriate to extract these during orthodontic treatment. In addition to this, only 7% of BCLP patients have lateral teeth with regular structure [6], and these are kept in the arch and moved to ideal position by the orthodontist.

Decision to extract the premolar teeth is dependent on the width and height of the present alveolar bone, position of canines, and the degree of crowding on the segments. In cases where inadequate bone and periodontal support remains or this support is substantially weakened after leveling and aligning the canines adjacent to the cleft, decision to extract of premolar teeth may be taken by the orthodontist. Aligning and leveling of the second molar teeth in addition to other maxillary teeth will increase the success of orthognathic surgery by improving the arch form and occlusion [35]. While extractions in the mandibular arch may be required based on the need for space on the arch and during the process of moving the incisors to an ideal angle, extraction is usually not necessary on the mandibular arch.

### **6.3 Surgical approach**

Incomplete, insufficient definitions were presented by previous studies for surgical techniques used for the purpose of warning BCLP patients about possible complications regarding maxillary osteotomy and achieving reliable osteotomy operations [39, 53]. Hugo Obwegeser provided significant contributions which may be considered as milestones about cleft surgery on BCLP patients. However, at the early stages, very few clinicians adopted the methods of Obwegeser. This was because, as one of the eight patients he treated died of airway complications, and the results on the others were not reported in an appropriate manner, relevant studies criticized them [54]. In the mid-1980s, Posnick described a safe method of the segmental Le Fort I osteotomy technique that considers biological principles in BCLP patients with maxillomandibular deformities [17, 55, 56]. This method, for instance, emphasizes preservation of the labial soft tissue mucosal pedicle in the maxillary of patients. The significance of this flap circulation that is achieved by considering biological principles was confirmed in the study by Bell et al. that was carried out on Rhesus monkeys [38].

Mainly, in BCLP patients, clinicians encounter maxillary deformities including those that are intact on both sides (successfully grafted) with one alveolar ridge, those with two segments with one side intact (successfully grafted), and those with three segments that are failed/non-grafted, and they apply different orthognathic surgery methods for these.
