Placing the maxilla in the most aesthetic sagittal position: validation of several reference lines in relation to the forehead shape

The ideal sagittal position of the maxilla is highly subjective in orthognathic surgical treatment planning. There is no consensus on an analysis to predict the ideal sagittal position of the maxilla. The objective of this study was to determine the preferred maxillary position in relation to the forehead shape, in the Southern Chinese population. The maxilla position of eight patients was simulated based on Steiner's analysis (SA), glabella vertical (GV), Andrews' Element II (AE2), and the Barcelona reference (BR). The simulations were then used in an electronic survey, where respondents ranked the images for each patient from to 1-4 (most to least attractive). A total of 128 responses were collected from dental professionals and laypersons. The most preferred to the least preferred simulation was as follows (mean rank scores for the male and female patients in parenthesis): BR (males 2.06; females 1.98), GV (males 2.11; females 2.21), SA (males 2.59; females 2.40), and AE2 (males 3.24; females 3.41). There was no significant difference in the results according to the sex, age group, or profession of the respondents. The Barcelona reference and glabella vertical are useful in predicting the ideal maxillary position in patients with a flat forehead, and the Barcelona reference is the most preferred in patients with a rounded forehead.

Modified maxillomandibular advancement surgery for the treatment of obstructive sleep apnoea: a scoping review

Modified maxillomandibular advancement (MMMA) has been proposed as an alternative to the classic maxillomandibular advancement (MMA) in East and Southeast Asian populations in which bimaxillary protrusion is a prevalent trait. The key difference between MMMA and MMA is the inclusion of anterior segmental osteotomies to reduce the protrusion of the perioral region. The aim of this scoping review was to identify the variations in MMMA and treatment outcomes. A search was conducted in the PubMed, Embase, and Cochrane electronic databases for articles published up to January 2023. Ten articles were included in this review. Three variations of MMMA have been reported in the literature. Treatment outcomes have mostly been favourable for all of these variations. Mandibular advancement of >10 mm and a greater than 50% reduction in the apnoea-hypopnoea index (AHI) have been well reported. Improvements in other outcome measures, such as enlargement of the airway dimension on computed tomography and the Epworth Sleepiness Scale score, have also been shown. Despite additional surgical procedures, complications have been uncommon and mostly minor in nature. It is necessary to be cognizant of MMMA and its variations when providing sleep surgery for East and Southeast Asian patients, tailoring this to the patient's profile and needs.

The role of anterior segmental osteotomies in orthognathic surgery for protrusive faces in a Southeast Asian population: 10-year retrospective data of 51 patients treated in a single centre

Bimaxillary protrusion is a dentofacial deformity common in the East Asian population. It is often difficult to decide between orthodontic and surgical retraction to treat patients with bimaxillary protrusion, especially if surgery to correct skeletal base discrepancies is also required. The objective of this study was to investigate the treatment outcomes of surgical versus orthodontic retraction in patients with bimaxillary protrusion undergoing orthognathic surgery. A retrospective cohort study was conducted, where the medical records and radiographs of 51 patients with bimaxillary protrusion who had an anterior segmental osteotomy concomitant with orthognathic surgery were examined. Patients who had bimaxillary anterior segmental osteotomies were more likely to achieve an inter-incisal angle of 135 ± 5° at the end of treatment, when compared to patients who had orthodontic retraction (P < 0.01). The total treatment duration of patients who had bimaxillary anterior segmental osteotomies was significantly shorter as compared to that of the patients who only had these osteotomies in the maxilla (P < 0.001) or mandible (P = 0.012). Complications and permanent long-term sequelae following anterior segmental osteotomies were uncommon. It is concluded that bimaxillary anterior segmental osteotomies are a viable alternative for patients with concomitant bimaxillary protrusion and skeletal base discrepancies. This allows for a significantly shorter treatment time and greater correction of inter-incisal angles, without a significant increase in complications.

Wire loop sinus membrane elevator: a novel instrument for lateral window sinus lift

This technical note introduces a novel instrument to facilitate lateral window sinus membrane elevation. The fabrication and use of the instrument are reported. The features of this instrument include easy control, good tactile sensation, flexibility in adjusting the instrument, and simple to replicate. Since its introduction, it has been the preferred instrument of our implant surgical trainees. Most importantly, it has proved to be an invaluable teaching tool, as it has helped not only to boost trainee confidence in the procedure, but also in their use of other sinus elevation instruments.

Unusual metastatic presentations of a primary right parapharyngeal acinic cell adenocarcinoma

Acinic cell adenocarcinoma (ACA) is a malignant epithelial neoplasm of the salivary glands. The patient reported herein presented with an unusual case of a metastatic ACA originating from the right parapharyngeal region, which eventually metastasized to the ipsilateral cavernous sinus and the contralateral mandibular ramus. The trigeminal nerve may have served as a channel for the spread of the cancer from the right parapharyngeal region to the cavernous sinus, and subsequently to the left mandibular ramus. The widening of the left inferior alveolar nerve canal was an early sign of metastasis in this case.

Psychogenic coma after dental surgery under general anaesthesia

Delayed awakening after general anaesthesia due to psychogenic coma is a phenomenon that rarely presents to the oral and maxillofacial surgeon. A case of psychogenic coma following general anaesthesia for dental extractions is presented here. It is recommended that patients at risk of conversion disorder should be counselled about the risks of psychogenic coma. Early diagnosis of this condition could lead to better patient management.