Root contact with maxillomandibular fixation screws in orthognathic surgery: incidence and consequences

Postoperative CT findings of orthognathic surgery and its complications: A guide for radiologists

Orthognathic surgery is the standard procedure to correct congenital, developmental, or acquired dentofacial deformities. The maxillomandibular relationship corrected by orthognathic surgery can improve facial esthetics, masticatory function, articulation, and breathing. The most common types of osteotomies include the combination of Le Fort I osteotomy, bilateral sagittal split mandibular ramus osteotomy, and genioplasty. High-resolution low-dose computed tomography is useful for evaluating the facial skeleton and soft tissues after surgery as well as for depicting a variety of possible complications. This article reviews the postoperative imaging findings of the most common orthognathic surgeries and their potential complications on multidetector-row computed tomography.

Radiographic assessment of the response of teeth following trauma during screw placement for maxillo-mandibular fixation

BACKGROUND/AIM

Maxillo-mandibular fixation (MMF) screws have gained popularity in recent years for inter-maxillary fixation. MMF screw application involves the risk of dental injury. However, knowledge about the healing responses after root damage in humans is limited, thereby warranting the need to classify the radiographic assessment of healing to enable better prediction of the healing response and effective management of the potential complications. The aim of this study was to assess and classify the radiographic assessment of the responses after root damage to evaluate the long-term outcomes.

MATERIAL AND METHODS

The dental records of patients who underwent orthognathic surgery or trauma management during 2014-2016 at an Oral and Maxillofacial Surgery Department were retrospectively analyzed. The data regarding dental injuries resulting from MMF screw application were evaluated. In total, 16 patients with 34 roots damaged from MMF screw application were enrolled. Post-operative orthopantomographs were analyzed by visual inspection of the affected areas to clarify the extent of root healing. The inter- and intra-rater reliability assessments were subsequently performed.

RESULTS

The results indicated substantial inter- and intra-rater reliability of the responses. Most cases of root damage that were not radiographically related to the pulp (Schulte-Geers Class III defects) had complete or partial healing responses. In addition, 20% of the defects related to the pulp had additional resorption of the bone/dental tissues during the follow-up period.

CONCLUSIONS

Three different radiographic responses of root damage following MMF screw trauma were identified. Understanding these different responses is important to guide the management of the potential complications. This proposed radiographic assessment can be used to present root healing data in a more standardized and reliable manner.

Current status of surgery first approach (part II): precautions and complications

The choice of surgical technique in orthognathic surgery is based primarily on the surgical treatment objectives (STO), which is a fundamental component of the orthognathic treatment process. In the conventional orthodontics-first approach, presurgical planning can be performed twice, during the preorthodontic (initial STO) and presurgical phases (final STO). Recently, a surgery-first orthognathic approach (SFA) without presurgical orthodontic treatment has been introduced and combined initial and final STO at the same time. In contrast to the conventional surgical-orthodontic treatment protocol that includes preoperative orthodontics for dental decompensations to maximize stable postoperative occlusion, the SFA potentially shortens the treatment period and minimizes esthetic concerns during the decompensation period because skeletal problems are corrected from the beginning. The indications for the SFA have been proposed in the literature, but no consensus exists. Moreover, because dental occlusion of the pre-orthodontic arches cannot be used as a guide for establishing the surgical treatment plan, there are fundamental limitations in accurate prediction of postsurgical results in the SFA. Recently, the concepts of postsurgical orthodontic treatment are continuously changing and evolving to overcome this inherent limitation of the SFA. The elimination of presurgical orthodontics can change the paradigm of orthognathic surgery but still requires cautious case selection and thorough discussion and collaboration between orthodontists and surgeons regarding the goals and postoperative management of the orthognathic procedure.

Safety and Stability of Postponed Maxillomandibular Fixation After Intraoral Vertical Ramus Osteotomy

The purpose of this study was to evaluate the postoperative safety and long-term stability of bimaxillary orthognathic patients with postponed maxillomandibular fixation (MMF) after intraoral vertical ramus osteotomy.A total of 61 patients (21 male and 40 female patients; average age [SD], 21.7 [4.7]) were enrolled. All patients underwent maxillary LeFort I osteotomy and bilateral intraoral vertical ramus osteotomy for mandibular prognathism. During the hospital stay, postoperative airway compromise was observed and patients underwent MMF with wire at the second postoperative day. Stability was evaluated by measuring the position at each period: preoperative (T0), 2-day postoperative (T1), and 1-year postoperative.Postoperative dyspnea and respiratory distress were absent in all patients. The mean number of refixations in physiotherapy was 0.62 (0.86) and the mean duration of physiotherapy was 11.6 (5.5) days. The mean amount of mandibular setback was 12.56 (5.76) mm and menton movement 0.98 (2.36) mm superiorly (T1). The mean mandibular relapse at Pog was 0.87 (1.96) mm anteriorly. Menton showed 1.11 (1.41) mm superiorly movement 1-year postoperatively (T2).Despite its many advantages, intraoral vertical ramus osteotomy requires a period of MMF which can lead to early discomfort and airway-related emergency. In this study, the physiotherapy procedure and postoperative long-term stability in the postponed MMF group were not different from those of an immediate MMF group studied previously. It therefore constitutes a viable option for oral breathers and other compromised patients.

Complications associated with orthognathic surgery

While most patients undergo orthognathic surgery for aesthetic purposes, aesthetic improvements are most often followed by postoperative functional complications. Therefore, patients must carefully decide whether their purpose of undergoing orthognathic surgery lies on the aesthetic side or the functional side. There is a wide variety of complications associated with orthognathic surgery. There should be a clear distinction between malpractice and complications. Complications can be resolved without any serious problems if the cause is detected early and adequate treatment provided. Oral and maxillofacial surgeons must have a full understanding of the types, causes, and treatment of complications, and should deliver this information to patients who develop these complications.