Stability of fixation methods in large mandibular advancements after sagittal split ramus osteotomy: an in vitro biomechanical study.

Sagittal split ramus osteotomy (SSRO) with large mandibular advancements is a common surgical procedure and could be indicated for patients with sleep apnoea. As a large variety of fixation methods is used for the stabilisation of SSRO, a biomechanical test model was used to analyse which fixation technique was most stable. For this in vitro study, 80 polyurethane hemimandibles with a prefabricated SSRO were used as substrates. Loads in Newtons were recorded at displacements of the mandibular incisive edge at 1mm, 3mm and 5mm. The samples were divided into two groups: mandibular advancements of 10mm and 15mm. In both groups, four fixation techniques were used: (A) one four-hole miniplate; (B) two four-hole miniplates; (C) one four-hole miniplate plus one bicortical screw; and (D) three bicortical screws in an inverted-L arrangement. In group 1, three bicortical screws resulted in the best stability, and in group 2, two miniplates resulted in the best stability. The use of two miniplates did not show significant differences between both groups. Other fixation methods showed more stability with 10mm advancements. This study therefore suggests that in SSRO with advancements exceeding 10mm, the use of two miniplates is the optimal means of providing rigid fixation.

A stepwise titration protocol for oral appliance therapy in positional obstructive sleep apnea patients: proof of concept.

PURPOSE: In patients with positional obstructive sleep apnea (POSA), oral appliance therapy (OAT) is among the first-line treatments. The aim of this study was to evaluate the effects of a new standardized stepwise titration protocol for OAT in a group of patients with POSA. METHODS: This was an observational intervention trial. Patients who were previously randomized to the OAT intervention arm of a comparison study comprised the subjects for this study. These patients, who had mild to moderate POSA, were assessed after 3 and 12 months for treatment efficacy, objective adherence by temperature microsensor, and side effects. The titration of OAT was performed using a standardized stepwise titration protocol including advancement levels of 60%, 75%, and 90% of the maximum mandibular protrusion. The optimal advancement level per individual was based on a weighted compromise between efficacy and side effects. RESULTS: In total, 36 patients were included and all completed the titration protocol after 3 months. At baseline, the OAT was set at 60% of the maximal mandibular protrusion position. At a 3-month evaluation, the advancement remained at 60% in 16 patients (44%) and reached 75% advancement in 20 patients (56%). Mean apnea-hypopnea index decreased from 12.9 events per hour (9.1-16.7) to 6.9 (3.7-10.3) (P < 0.001), and median objective adherence was 97.4 (61.4-100.00) after 3 months. The 12-month analysis showed consistent results and good OAT tolerance. Six patients (16.7%) terminated OAT and one patient (2.8%) was lost to follow-up. CONCLUSIONS: This standardized stepwise titration protocol for OAT showed good efficacy, good OAT tolerance, and good objective adherence in patients with mild to moderate POSA. Therefore, the protocol is recommended in research projects to improve standardization of methods between studies and in clinical practice for its practical feasibility.

Fixation methods in sagittal split ramus osteotomy: a systematic review on in vitro biomechanical assessments.

The aim of this systematic review was to assess the stability of rigid internal fixation (RIF) techniques in sagittal split ramus osteotomy (SSRO) based on in vitro biomechanical assessments, with particular interest in large mandibular advancements. In general, RIF methods can be divided into three groups: bicortical screws, miniplates, and a combination of the two. An electronic search of the PubMed, CINAHL, and Embase databases was performed, and studies published between January 2003 and March 2018 were screened for inclusion. Comparative studies with an in vitro experimental design, using biomechanical assessments to measure the stability of RIF methods in SSRO, were included. Of 104 unique studies identified in the initial search, 24 were included. Twenty-two of these 24 studies analyzed an advancement of the mandible of 7mm or less. The use of a single four-hole or six-hole miniplate was less stable than the use of bicortical screws, hybrid techniques, double miniplates, or grid plates. Two studies analyzed advancements of 10mm, for which two miniplates placed in parallel and a grid plate showed most stability. Although there was agreement between studies with regard to results, more biomechanical studies are required to quantify the stability of fixation methods in larger mandibular advancements.

Fulminant presentation of oral mucosal leishmaniasis as severe stomatitis and periodontitis.

This case report shows an atypical presentation of mucosal leishmaniasis infantum in the oral cavity resulting in severe stomatitis and periodontitis. The patient was immunocompromised because of rheumatoid arthritis for which he used prednisone and methotrexate. He was treated with intravenous liposomal amphotericin B and recovered within four weeks.

Assessment of obstructive sleep apnoea treatment success or failure after maxillomandibular advancement.

Maxillomandibular advancement (MMA) is an alternative therapeutic option that is highly effective for treating obstructive sleep apnoea (OSA). MMA provides a solution for OSA patients that have difficulty accepting lifelong treatments with continuous positive airway pressure or mandibular advancement devices. The goal of this study was to investigate the different characteristics that determine OSA treatment success/failure after MMA. The apnoea-hypopnoea index (AHI) was used to determine the success or failure of OSA treatment after MMA. Sixty-two patients underwent MMA for moderate and severe OSA. A 71% success rate was observed with a mean AHI reduction of 69%. A statistically significant larger neck circumference was measured in patients with failed OSA treatments following MMA (P=0.008), and older patients had failed OSA treatments with MMA: 58 vs. 53 years respectively (P=0.037). Cephalometric analysis revealed no differences between successful and failed OSA treatment outcomes. There was no difference in maxillary and mandibular advancements between success and failed MMA-treated OSA patients. The complications most frequently reported following MMA were sensory disturbances in the inferior alveolar nerve (60%) and malocclusion (24%). The results suggest that age and neck girth may be important factors that could predict susceptibility to OSA treatment failures by MMA.

[Unilateral angioedema of the tongue and the floor of the mouth as a side-effect of ACE-inhibitors]. / Unilateraal angio-oedeem van de tong en de mondbodem door ACE-remmers.

An 80-year-old woman who was medically compromised had recurrent diffuse unilateral swelling of the tongue and the floor of the mouth. The clinical working diagnosis of angioedema as a result of the use of ACE-inhibitors (lisinopril) was made. In consultation with the cardiologist in charge of her case and the general practitioner, the ACE-inhibitor was discontinued. The patient's complaints subsequently ceased.

[Maxillomandibular advancement surgery as an optional therapy for patiens with severe obstructive sleep apnoea]. / Bimaxillaire osteotomie als mogelijke behandeling voor ernstig obstructieve slaapapneu.

Obstructive sleep apnoea (OSA) is a common chronic disorder which often requires lifelong treatment. Its prevalence in the Netherlands is estimated to be around 300.000 people. In this study 12 patients with severe OSA were treated with maxillomandibular advancement surgery between 2011 and 2012. The mean advancement during surgery was 8.7 mm and the mean postoperative admission was 4 days. All patients underwent polysomnography at 3 months. Three months after surgical treatment, the apnoea-hypopnea index had decreased with 74.9% (57.3 to 14.4). The subjective sleepiness of the patients had also decreased with a mean of 57.5%. The literature indicates comparable results in patients with severe OSAS, specifically a reduction of the apnoea-hypopnea index of 80-90%. Considering the successful results following maxillomandibular advancement surgery, this therapy is an appropriate alternative for patients who cannot cope with 'continuous positive airway pressure' or patients who want a permanent therapeutic solution. Further research is recommended to achieve higher levels ofevidence for maxillomandibular advancement surgery in patients with OSA.

[Serious complications following (removal after) ingestion of a partial denture]. / Ernstige verwikkelingen door een ingeslikte gebitsprothese.

Complications occurred in a 41-year-old woman (case 1) following a first attempt to remove a partial denture by oesophagoscopy. These were: laceration of the oesophagus with subsequent mediastinitis, pneumothorax, and pneumopericardium. With a second oesophagoscopy the denture was removed from the oesophagus using a flexible endoscope with a latex hood. Following antibiotic treatment the patient recovered. With a 45-year-old man (case 2) who had also swallowed a denture, the denture initially could not be localized. It was eventually recovered from the gastric antrum using a flexible scope with a latex hood, also in the second attempt. Psychiatric and mentally handicapped patients run a high risk of denture ingestion. Ingested dental prostheses are often radiolucent, and are difficult to visualize using conventional radiological methods. Extraction of the ingested foreign objects can lead to severe complications. This is why in this type of case, we recommend having an expert remove from a foreign object with the use of a flexible scope fitted with a latex hood. It is advisable to make removable dental prostheses radiopaque or to avoid using them with the identified risk-group.

[Serious complications following removal of an ingested partial denture]. / Ernstige complicaties door verwijdering van ingeslikte gebitsprothesen.

Complications occurred in a 41-year-old woman following an attempt to remove a partial denture by oesophagoscopy. These were: laceration of the oesophagus with subsequent mediastinitis, pneumothorax, and pneumopericardium. At a second oesophagoscopy the denture was removed from the oesophagus using a flexible hood. Following antibiotic treatment the patient recovered. In a 45-year-old man who had also swallowed a denture, the denture could not initially be localized. It was eventually recovered from the antrum using a flexible scope with a flexible hood. The patient was discharged from hospital in a good condition. Psychiatric and mentally handicapped patients run a high risk of denture ingestion. Ingested dental prostheses are often radiolucent, and are difficult to visualize using radiological methods. Extraction of the ingested foreign objects can lead to severe complications. This is why in this type of case, we recommend the use of a flexible scope and a flexible hood attachment.