[A neonate with a swelling in the floor of the mouth]. / Een pasgeborene met een zwelling in de mondbodem.

A significant swelling was seen in the floor of the mouth of a newborn girl. The girl could only drink with difficulty. On examination, a soft-elastic swelling was seen beneath the tongue. Ultrasonography and MRI showed a mass located above the hyoid bone. Upon the initial differential diagnosis of a dermoid cyst, an enucleation of the lesion was performed. Histopathological examination suggested a branchiogenic cyst or a digestive duplication cyst. Given the inconclusiveness of additional diagnostic examination, the lesion was diagnosed as a developmental cyst. Six months after enucleation, the infant girl's tongue motility was not restricted and there were no indications of a recurrence. This rare case illustrates the variety in differential diagnosis and the limitations of additional diagnostic examination.

Effects of maxillomandibular advancement on respiratory function and facial aesthetics in obstructive sleep apnoea patients with versus without maxillomandibular deficiency.

The aim of this study was to compare the effects of maxillomandibular advancement (MMA) on respiratory function between obstructive sleep apnoea (OSA) patients with and without maxillomandibular deficiency, and to compare the changes in facial aesthetics after MMA between the two groups. MMA-treated patients who had both baseline and follow-up polysomnography (PSG) data and lateral cephalograms were enrolled in this retrospective study. In addition to PSG and cephalometric data, patient satisfaction with postoperative breathing and facial aesthetics, and overall satisfaction with the treatment were assessed. Twenty-one patients were classified as not having maxillomandibular deficiency (without-deficiency group) and 40 patients as having maxillomandibular deficiency (with-deficiency group). The improvements in respiratory parameters (e.g., apnoea-hypopnoea index) and patient satisfaction with postoperative breathing were comparable in the two groups (P = 0.094-0.713). The changes in facial profile measurements (e.g., nasal prominence, nasolabial angel, and lip positions relative to the true vertical line) and patient satisfaction with postoperative facial aesthetics were also comparable in the two groups (P = 0.148-0.983). In conclusion, no significant difference in the effects of MMA on respiratory function and facial aesthetics between OSA patients with and without maxillomandibular deficiency was observed.

[Patient-specific joint prothesis for ankylotic temporomandibular joints]. / Individueel vervaardigde prothesen voor ankylotische kaakgewrichten.

A 49-year-old woman who suffered from severe obstructive sleep apnea (OSA) was referred to the department of Oral-, Maxillofacial Surgery department due to progressive limitation of the mouth opening and chronic pain in both temporomandibular joints. Based on clinical and radiological examinations, the patient was diagnosed with recurrent ankylosis of the temporomandibular joints. The patient was treated with 2 patient-specific implants of the temporomandibular joint combined with a Le Fort I osteotomy, and a genioplasty including a genioglossus advancement. This treatment may have advantages for the patient such as a lower recurrence rate of ankylosis, improved maximal mouth opening, pain reduction and improved aesthetic results.

Power chains as an alternative to steel-wire ligatures in temporary maxillomandibular fixation: a pilot study.

The aim of this study was to compare two techniques for temporary intraoperative maxillomandibular fixation (TIO-MMF) during orthognathic surgery: steel-wire ligatures versus power chains. Patients undergoing orthognathic surgery between October 2019 and March 2020 were included in a prospective cross-sectional study conducted in three participating hospitals. Data were collected using a standardized measurement form. A total of 44 patients were included, in whom TIO-MMF was applied 79 times. A statistically significant difference in intraoperative loss of stability of the segment relationship was found between steel-wire ligatures (11.4%) and power chains (0%). The mean application time of TIO-MMF differed significantly between steel-wire ligatures (99 seconds) and power chains (157 seconds) (P < 0.001). There was no statistical difference in occurrence of adverse events between the two techniques. This study found that the application of TIO-MMF with power chains is more stable compared to steel-wire ligatures. Steel-wire ligatures were significantly faster to apply, although the absolute difference (less than 1 minute) was small. Other possible advantages of the proposed technique are discussed. The results of this study suggest that power chains for the application of TIO-MMF in orthognathic surgery are a valuable alternative to steel-wire ligatures.

[Solitary angiokeratoma of the tongue]. / Solitair angiokeratoom van de tong.

A 41-year-old woman, who was referred with a reddish purple like lesion on the left side of the tongue, appeared to have an angiokeratoma after histopathological examination. Because of the benign character of this lesion and the absence of any complaints, no adjuvant treatment after excisional biopsy was indicated. Angiokeratomas rarely appear as solitary oral lesions. More often they are seen as part of an underlying systemic disease, mostly Fabry disease. Due to widespread skin involvement of angiokeratomas with Fabry disease, referral to a dermatologist is indicated when oral lesions are encountered. Esthetically unpleasing or painful angiokeratomas can be locally excised or treated by laser- or cryotherapy.

Association between the degree of obstructive sleep apnea and the severity of COVID-19: An explorative retrospective cross-sectional study.

Obstructive sleep apnea (OSA) on its own, as well as its risk factors, have been found to be associated with the outcome of Coronavirus disease 2019 (COVID-19). However, the association between the degree of OSA and COVID-19 severity is unclear. Therefore, the aim of the study was to evaluate whether or not parameters to clinically evaluate OSA severity and the type of OSA treatment are associated with COVID-19 severity. Patient data from OSA patients diagnosed with COVID-19 were reviewed from outpatients from the Isala Hospital and patients admitted to the Isala Hospital, starting from March until December 2020. Baseline patient data, sleep study parameters, OSA treatment information and hospital admission data were collected. Apnea hypopnea index (AHI), low oxyhemoglobin desaturation (LSAT), oxygen desaturation index (ODI), respiratory disturbance index (RDI), and the type of OSA treatment were regarded as the independent variables. COVID-19 severity-based on hospital or intensive care unit (ICU) admission, the number of days of hospitalization, and number of intubation and mechanical ventilation days-were regarded as the outcome variables. Multinomial regression analysis, binary logistic regression analysis, and zero-inflated negative binomial regression analysis were used to assess the association between the parameters to clinically evaluate OSA severity and COVID-19 severity. A total of 137 patients were included. Only LSAT was found to be significantly associated with the COVID-19 severity (p<0.05) when COVID-19 severity was dichotomized as non-hospitalized or hospitalized and ICU admission or death. Therefore, our findings showed that LSAT seems to be a significant risk factor for COVID-19 severity. However, the degree of OSA-based on AHI, ODI, and RDI-and OSA treatment were not found to be risk factors for COVID-19 severity when looking at hospital or ICU admission, the number of days of hospitalization, and number of intubation and mechanical ventilation days.

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.

Splintless orthognathic surgery in edentulous patients-a pilot study.

The aim of this pilot study was to evaluate the accuracy and predictability of a splintless treatment protocol for edentulous patients undergoing orthognathic surgery in four consecutive cases. All operations were virtually planned, followed by computer-aided design of individual osteotomy guides and patient-specific fixation implants, which were three-dimensionally printed in titanium. In order to evaluate the discrepancy between the planned and the achieved postoperative result, the postoperative outcome was compared to the virtual treatment plan. Rotational and translational movement and discrepancies with the planned movements were quantified for the maxilla; the advancement was quantified for the mandible. For the maxilla, there was a mean translation discrepancy of 0.6mm. With regard to rotation, there was a mean discrepancy of 1.9°, 0.1°, and 0.4° for pitch, yaw, and roll, respectively. The mean discrepancy in translation of the mandible was 0.4mm. The results of this pilot study indicate that the splintless treatment protocol for orthognathic surgery in edentulous patients presented here is accurate and predictable.

Implant-oriented navigation in orbital reconstruction part II: preclinical cadaver study.

In orbital reconstruction, the acquired position of an orbital implant can be evaluated with the aid of intraoperative navigation. Feedback of the navigation system is only obtained after positioning of the implant: the implant's position is not tracked in real time during positioning. The surgeon has to interpret the navigation feedback and translate it to desired adjustments of the implant's position. In a previous study, a real-time implant-oriented navigation approach was introduced and the system's accuracy was evaluated. In this study, this real-time navigation approach was compared to a marker-based navigation approach in a preclinical set-up. Ten cadavers (20 orbital defects) were reconstructed twice, by two surgeons (total: 80 reconstructions). Implant positioning was significantly improved in the real-time implant-oriented approach in terms of roll (2.0° vs. 3.2°, P=0.03), yaw (2.2° vs. 3.4°, P=0.01) and translation (1.3mm vs. 1.8mm, P=0.005). Duration of the real-time navigation procedure was reduced (median 4.5 min vs. 7.5 min). Subjective appreciation of the navigation technique was higher for real-time implant-oriented navigation (mean 7.5 vs. 9.0). Real-time implant-oriented navigation feedback provides real-time, intuitive feedback to the surgeon, which leads to improved implant positioning and shortens duration of the navigation procedure.

[An (un)conventional autogenous tooth transplantation]. / Een (on)conventionele autotransplantatie.

A 15-year-old boy was referred to an Oral and Maxillofacial Surgery department because of a persistent tooth 85 and a malposition of tooth 45. Following additional examination, it was concluded that the root formation of tooth 45 was already completed. Furthermore, it was horizontally impacted against the inferior border of the mandible. The decision was made to extract tooth 85 and to autotransplant tooth 45. Post-operatively, tooth 45 was fixed to the orthodontic equipment already in place and later treated endodontically. The success rate of this kind of autotransplantation of teeth with already closed apices (94%) is comparable in the literature to the success rate of autotransplantation of teeth with open apices (98%). Autotransplantation should be considered, especially in patients who are still growing and for whom dental implants do not (yet) offer a solution.