Accuracy of mandibular proximal segment position using virtual surgical planning and custom osteosynthesis plates.

The purpose of this study was to determine whether the use of custom osteosynthesis plates increased the accuracy of proximal segment position following bilateral sagittal split osteotomy in a cohort of 30 patients when compared to a control group of 25 patients who had surgery with conventional plates. Surgery was performed by a single surgeon between October 2015 and December 2017. Post-surgical cone beam computed tomography scans were segmented using Mimics Innovation Suite (Materialise NV), and surface-based superimposition was achieved using ProPlan CMF (Materialise NV). However, there was a tendency for the rotational error to be smaller in the custom group than in the control group. The root mean square error in both groups and for all variables fell within clinical parameters of 2 mm and 4°. In conclusion, the results of this study indicate that customized mandibular fixation plates do not necessarily improve the accuracy of the proximal segments post-surgically; however they may be of benefit in individual patients.

Accuracy of maxillary repositioning surgery using CAD/CAM customized surgical guides and fixation plates.

The advent of three-dimensional imaging and computer-aided surgical simulation (CASS) have brought about a paradigm shift in surgical planning. The aim of this study was to assess the accuracy of maxillary repositioning surgery using computer-aided design and manufacturing (CAD/CAM) customized titanium surgical guides and fixation plates. Thirty consecutive adult patients, 13 male and 17 female, with a mean age of 29.2 years and 25.5 years, respectively, requiring Le Fort I maxillary osteotomy, with or without simultaneous mandibular surgery, were evaluated retrospectively. All orthognathic surgeries were performed by one experienced surgeon. The pre-surgical and post-surgical volumetric imaging were superimposed to assess the linear and angular differences between the planned and actual positions of the maxilla following surgery. With the use of the CAD/CAM titanium surgical guides and fixation plates, all surgical movements were within 2mm and 4° of the planned movements, which is considered clinically insignificant. The overall root mean square error between the planned and actual surgical movements was 0.38mm in the transverse dimension, 0.64mm in the anteroposterior dimension, and 0.55mm in the vertical dimension. In regard to the centroid of the maxilla, the absolute angular difference of the maxillary centroid was 1.06° in pitch, 0.47° in roll, and 0.49° in yaw. Maxillary repositioning surgery can be performed with high accuracy using CAD/CAM titanium surgical guides and fixation plates.

Fractures of the mandible. A 35-year retrospective study.

A retrospective survey was carried out of patients presenting with fractures of the mandible over the 35-year period 1951-1985 in Newcastle, Australia. The age, sex and cause of injury were analysed for each of the 1,162 patients. The male:female ratio was 4.4:1. The highest incidence of trauma was in the 20-29-year age group (38.3% of all patients). The number of 20-29-year-olds sustaining mandibular fractures in each 5-year period of study was 2 to 3 times higher than would be expected from the proportion of that age group in the regional population. The major causes of fractures were assault (38.1% of all patients), road traffic accidents (21.5%) and sport (19.0%). The patterns of causes of injury were similar throughout the period of study. Males accounted for most patients in all causes of trauma. In sports, the male:female ratio was 30.6:1, whilst for assaults it was 6.3:1. The number of patients sustaining fractures increased by 364% over the period of study whilst the population involved increased by 47%.

Orbital abscess of odontogenic origin. Case report and review of the literature.

A case is discussed of a patient with an orbital cellulitis and a post septal abscess secondary to infection from an upper molar tooth. Spread of infection was to the maxillary sinus and thence to the orbit via a defect in the orbital floor. The clinical presentation, differential diagnosis, value of CT scanning, treatment and possible complications are reviewed.

Kaposi's sarcoma of the palate in a patient with AIDS: an unusual presentation.

Kaposi's sarcoma formerly a rare tumour in the western world, is now found frequently in homosexual patients with the Acquired Immune Deficiency Syndrome. A common site of occurrence is the mouth. The characteristic intra-oral appearance of the lesion is of a flat or raised pigmented lesion. An intra-oral Kaposi's sarcoma which was not pigmented and which presented as a painless, soft swelling on the hard palate is reported. The unusual appearance of the lesion is described and the importance of accurate diagnosis of intra-oral lesions in patients with the Acquired Immune Deficiency Syndrome is emphasized.