Comparison of condylar displacement between single-jaw and double-jaw surgery-first orthognathic surgery in mandibular prognathism

327 deformation or absence of the TMJ, other end-stage TMJ pathologies, etc. Studies have shown that both custom and stock alloplastic TMJ replacements resulted in statistically significant improvement in pain level, jaw function, and incisal opening. The TMJ stock prosthesis has the advantage of having a more flexible adjustment and lower cost compared to custom made prosthesis, also has immediate placement availability. Objective: The aim of this study is to describe stock alloplastic TMJ total replacement with orthognathic surgery in patients with DFD and concomitant facial asymmetry. Methods: Two patients presenting with congenital and acquired disease DFD and facial asymmetry underwent orthognathic surgery with TMJ alloplastic replacement with stock prosthesis. All patients were planned by traditional model surgery. Conclusions: The TMJ is the basis of the mandibular position, the function, occlusion and facial balance. Several authors have described the performance of orthognathic surgery in conjunction with TMJ alloplastic replacement with custom-made prosthesis, however, there is little literature on performing orthognathic surgery concomitant with stock prosthetic. http://dx.doi.org/10.1016/j.ijom.2017.02.1102 Anterior segmental osteotomies: throwback to a timeless procedure S. Mohanty Maulana Azad Institute of Dental Sciences, New Delhi, India Anterior segmental osteotomies (ASO) have been historically popular in orthognathic surgery due to their ability to move the anterior dentoalveolar segments in almost every conceivable direction. These are highly useful in clinical situations like bimaxillary protrusion, anterior open bite and skeletal class II or III situation with satisfactory posterior occlusion. We retrospectively analysed the outcome in subjects treated by anterior maxillary/mandibular segmental osteotomies in our department in the past 12 years (October 2003–2015). 25 subjects were included in the study (17 females and 8 males) with a mean age of 21.3 years. 10 subjects underwent maxillary ASO, two underwent mandibular ASO whereas 13 subjects underwent both osteotomies. Clinical outcomes were assessed in terms of patients satisfaction regarding aesthetics and function postoperatively. All patients were found to have attained satisfactory results with these minimally invasive procedures. The procedure was found to be effective, relatively safe and simple. We are presenting our surgical technique, results and encountered complications, if any. http://dx.doi.org/10.1016/j.ijom.2017.02.1103

A case of maxillary protrusion and gummy smile treated by multi-segmental horseshoe le fort i osteotomy A. Nishiyama ∗ , S. Ibaragi, N. Yoshioka, T. Shimo, A. Sasaki Department of Oral and Maxillofacial Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan Background: We have treated maxillary protrusion by premolar extraction and multi-segmental Le Fort I osteotomy. However, in severe gummy smile which shows not only horizontal but vertical excess of the maxilla, an improvement by this method is insufficient due to a difficulty of superior repositioning of the maxilla. We treated such a patient by horseshoe Le Fort I osteotomy (HLFO) with multi-segmental alveolar osteotomy (MSAO), and got a good result. Methods: An 18-year-old female came to an orthognathic clinic complaining maxillary protrusion and gummy smile. She was diagnosed indication of orthognathic surgery, and referred to our department. She showed over 7 mm gum exposure at smiling and class II malocclusion by maxillary protrusion. 7 mm upward repositioning and 5 mm setback at U1 was needed for the correction of gummy smile. Therefore, HLFO with MSAO was planned. Findings and Conclusion: HLFO was performed following bilateral first premolars extraction and alveolar multi-segmental osteotomy. We could reposition the maxilla as we planned without any complications. She got a good aesthetical improvement and occlusal stability more than 1 year after the operation. We need to pay enough attention to stability of bone fixation and blood supply. This surgical method seems to be effective for a maxillary protrusion with severe gummy smile patient. http://dx.doi.org/10.1016/j.ijom.2017.02.1104 Comparison of condylar displacement between single-jaw and double-jaw surgery-first orthognathic surgery in mandibular prognathism H.K. Oh School of Dentistry, Chonnam National University, South Korea Objectives: To compare the postoperative positional change of the condyle between single-and double-jaw orthognathic surgery via surgery-first approach (SFA) in mandibular prognathism with facial asymmetry. Methods: A retrospective study of 18 mandibular prognathism (12 males, 6 females; mean age, 21 years) with facial asymmetry, who underwent orthognathic surgery via SFA, was conducted. Using serial three-dimensional facial computed tomography, which was taken preoperatively (T0), 2 weeks postoperatively (T1), and 6 months postoperatively (T2), skeletal landmarks in the maxilla and mandible were analysed. Results: The condyle exhibited lateral bodily displacement and inward and inferior rotation 2 weeks after surgery in both single-and double-jaw groups. There is no significant difference between two groups. During the retention time, the condyle showed a medial return, but the double-jaw group showed more obvious returning movement than the single-jaw group (P < 0.05). Although the condyle positioned slightly medially in the single-jaw group and laterally in the double-jaw group, both groups showed no significant difference in the condylar position

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Prediction of mandibular position after bilateral sagittal split ramus osteotomy via surgery first approach in patients with mandibular prognathism

(range, 17–31). Polysomnography was performed before treatment. Apnoea–hypopnoea index (AHI), lowest arterial oxygen saturation (LoSpO2 ), cumulative percentage time at SpO2 below 90% during the measurement (CT90), oxygen desaturation index (ODI), longest apnoea time (LAT) and sleep state were measured. Findings: Median and range of measurements was follows: AHI, 0.4/h (0–12.1/h); LoSpO2 , 92% (85–95%); CT90, 0 min (0–0.9 min); ODI, 0.2/h (0–21.6/h); LAT, 0 s (0–25.9 s); rapid eye movement (REM) 20.1% (0–34.1%); NREM, 79.9% (65.9–100%); S1, 6.8% (2.2–22.6%); S2, 60.8% (54.1–70%); S3, 7.9% (0.6–19.3%); S4, 2.4 (0–10.4). One patient was diagnosed with mild OSA. AHI during REM 1.8 (0–21) was higher than AHI during NREM 0.2 (0–9.7). Conclusions: We require attention to OSA in patients with Class III even without the symptoms of OSA and obstruction during REM sleep periods in perioperative orthognathic surgery.

H.K. Oh

http://dx.doi.org/10.1016/j.ijom.2017.02.1107

School of Dentistry, Chonnam National University, South Korea

Duration of orthognathic treatment

Objectives: To predict the mandibular position after bilateral sagittal split ramus osteotomy (BSSRO) via surgery-first approach and following postoperative orthodontic treatment, and to compare it with actual mandibular position in patients with mandibular prognathism. Methods: We evaluated 29 mandibular prognathic patients who underwent BSSRO using lateral cephalograms which were taken in preoperative, immediately after surgery and immediately after debonding. To predict mandibular position at post-treatment stage, we preoperatively measured the increase of vertical dimension on surgical occlusion and calculated mandibular forward movement due to the postoperative clockwise autorotation during postoperative orthodontic treatment. Results: Actual mandibular forward movement (2.1 mm) was significantly greater than preoperatively predicted forward movement (0.9 mm; P 10 mm) or greater vertical dimension increase (>2 mm), even though there was no statistical difference. Conclusions: This study suggested that postoperative mandibular rotational movement and additional relapse should be considered in surgery-first orthognathic surgery.

J. Paunonen ∗ , M. Helminen, T. Peltomäki

compared with preoperative position. Regarding rotational movement, both groups showed inward and inferior rotation 2 weeks after surgery. During retention time both groups rotated to its original condylar axis. However, at 6 months postoperatively, single-jaw group and double-jaw group still showed inward rotation compared with preoperative condylar axis. There is no statistical difference in two groups. Conclusions: This study suggests that, the postoperative condylar positional changes are similar between the single-jaw and doublejaw orthognathic surgery via SFA. http://dx.doi.org/10.1016/j.ijom.2017.02.1105

http://dx.doi.org/10.1016/j.ijom.2017.02.1106 Evaluation of obstructive sleep apnoea and sleep quality in patients with skeletal class III malocclusion K. Ooi ∗ , R. Jokaji, K. Ide, Y. Kobayashi, N. Noguchi, K. Katoh, H. Nakamura, S. Takamichi, M. Nakata, K. Kasahara, S. Kawashiri University of Kanazawa, Kanazawa, Japan Background: Maintenance of airway is most important perioperative management in orthognathic surgery. Obstructive sleep apnoea (OSA) of skeletal class III malocclusion is unknown, however OSA is severe risk of airway obstruction. Objective: The aim of this study was to evaluate OSA and sleep quality in patients with skeletal class III. Methods: Subjects in this study comprised 14 patients with skeletal class III who were treated orthognathic surgery at Kanazawa University Hospital, Kanazawa, Japan. They had no symptoms of OSA. The median age at the time of examination was 23 years

Tampere University Hospital, Tampere, Finland Background: One of the most important factors influencing patient’s post-treatment satisfaction in orthognathic treatment is the accuracy and comprehension of information patient has received. For adult patients it is important to know the total duration of the treatment and particularly how long orthodontic treatment takes. Objectives: The aim was to study the duration of orthognathic treatment conducted with conventional pre- and postsurgical orthodontic treatment phases. Methods: Study material comprised files of 185 patients who had undergone orthognathic treatment at the Oral and Maxillofacial Unit, Tampere University Hospital, Finland between 2007 and 2014. Data was obtained on gender and age, duration of presurgical treatment (until operation), duration of postsurgical treatment (from operation until fixed orthodontic appliances were removed), information about orthodontic tooth extractions and type of surgery. Pretreatment digital cephalograms were used to study severity of malocclusion. Findings: Average presurgical and postsurgical treatment durations were 26 months and 8 months, respectively. If orthodontic treatment included tooth extractions, duration of presurgical treatment was in the average 10 months longer (P < 0.001, linear regression). Age (range 17–70 years) or initial severity of malocclusion did not affect treatment time. Treatment duration was almost the same in each type of surgery (Le Fort I osteotomy 2.6 years, bilateral sagittal split osteotomy 2.8 years and bimaxillary osteotomy 2.8 years). Conclusions: Orthodontic extractions have clinically important impact on the duration of orthognathic treatment. Initial severity of malocclusion, type of surgery, age or gender of patients does not seem to have an impact on treatment time. http://dx.doi.org/10.1016/j.ijom.2017.02.1108