Dosimetry-guided virtual surgical planning in the reconstruction of mandibular osteoradionecrosis

Patients with osteoradionecrosis (ORN) of the mandible pose additional challenges to the attending clinician when it comes to major reconstructive head and neck surgery. We present a novel technique to assist in the virtual surgical planning of mandibular ORN, which involves deforming previously delivered radiation dosimetry data on to the virtual mandible to aid in the assessment of surgical resection margins. This is a retrospective case series of patients whose treatment involved a traditional virtual surgical planning approach or dosimetry-guided virtual surgical planning. All the patients whose treatment involved dosimetry-guided virtual surgical planning had evidence of bony consolidation between the native mandible and fibular free flap. In comparison, only three of the nine patients in the traditional virtual surgical planning group demonstrated bony healing on subsequent imaging. In this known cohort of difficult-to-manage patients, any technique that helps to improve outcomes is a welcome addition to the armamentarium of the surgeon.     

The influence of bilateral sagittal split ramus osteotomy on submental‐cervical aesthetics

The effect of orthodontic‐surgical treatment on submental‐cervical region was evaluated in a very limited number of studies. The aim of this study was to evaluate submental‐cervical soft tissue contour changes following mandibular advancement and set‐back procedures via bilateral sagittal split ramus osteotomy. Sixty‐seven patients were included in this study. Group 1 consisted of 27 skeletal Class II patients who underwent mandibular advancement surgery, whereas Group 2 consisted of 40 skeletal Class III patients who underwent mandibular set‐back surgery. Various linear and angular measurements were performed on pre‐operative and sixth month post‐operative cephalometric radiographs. A new method was used to evaluate the amount of sagging at submental region. The submental length did not change in Group 1; however, it decreased significantly in Group 2 (P < 0·05). The angle between submental plane and facial plane decreased to 95·9° from 98·8° in Group 1(P < 0·05), whereas it increased to 93·1° from 88·2° in Group2 (P < 0·05). The change of submental soft tissue sag was almost stable in Group 1, while 0·34 mm increase of sag was observed in Group 2. This increase was not statistically significant (P > 0·05). Mandibular set‐back and advancement procedures do not remarkably change the submental sag following approximately 6 mm jaw movement. Although mandibular advancement did not significantly effect submental length, soft tissue followed mandibular set‐back with a ratio of 1:1 at C‐point to projection of soft tissue pogonion and 1:0·7 at C‐point to soft tissue menton distances.     

Temporomandibular joint reconstruction with medial femoral condyle osseocartilaginous flap: a case series

Reconstruction for large-scale temporomandibular joint (TMJ) defects can be challenging. We have used the medial femoral condyle (MFC) osseocartilaginous flap for repair of TMJ defects. The aim of this paper was to describe our technique and to present the preliminary results. The MFC osseocartilaginous flap was used as a free vascularized graft for TMJ defect in four patients who had undergone resection for benign tumor of the TMJ region (n = 2) or TMJ ankylosis (n = 2). A computer-assisted technique was used in all cases. Symmetry of the mandible was objectively evaluated by postoperative computed tomography. Complications were recorded during follow-up visits. Lower extremity functional status was assessed by the Lower Extremity Functional Scale (LEFC) questionnaire. The MFC osseocartilaginous flap success rate was 100%; bony union was obtained in all four patients, and normal occlusion was achieved within 6–11 months after surgery. No flap-related complications occurred. All patients were satisfied with their postoperative facial symmetry and oral function. The LEFC score ranged from 72 to 80, indicating normal lower extremity function. Vascularized MFC osseocartilaginous flap appears to be a reliable option for reconstruction of large-scale TMJ defects.     

Reconstruction of the mandibular condyle using the microvascular lateral femoral condyle flap

The lateral femoral condyle (LFC) flap is a new flap first reported in 2015 for the treatment of osteomyelitis in hand surgery. This paper introduces a technique of osteochondral LFC flap harvest for mandibular condyle reconstruction and reports on the use of this flap in temporomandibular joint reconstruction. For condyle resection, a pre-auricular approach saving the temporal artery and vein is performed. A step osteotomy technique is used for condyle resection. LFC harvesting starts with dissection of the popliteal artery and vein. The superior genicular artery and vein are identified and followed along their periosteal branches. An osteochondral flap according to the condyle defect is harvested from the anterior pole of the knee. The flap is banded according to the defect and fixed to the mandibular neck with three miniscrews. Follow-up computed tomography scans should be performed at 1 week, 6 months, and 1 year after surgery. The case of a 58-year-old female patient with osteomyelitis of the left mandibular condyle after multiple preoperative therapies is reported. The LFC flap technique was used for left condyle reconstruction, resulting in good functional and morphological outcomes at the 6-month postoperative follow-up. In conclusion, the osteochondral LFC flap is a new and promising technique for mandibular condyle reconstruction for special indications.     

Reconstruction of the extremely atrophied mandible with iliac crest onlay grafts followed by two endosteal implants: a retrospective study with long-term follow-up

Treatment outcomes of implant-retained lower dentures on two endosseous implants placed in severely atrophied mandibles after reconstruction with iliac crest onlay grafts were assessed in a retrospective observational study. All consecutive patients treated between 2000 and 2007 were recalled in 2012 (n = 40). Survival of the implants, the condition of hard and soft peri-implant tissues, and patient satisfaction were scored. One implant was lost after 5.5 years. The mean mandibular symphysis height was 8.9 ± 2.2, 16.4 ± 2.7, 15.7 ± 2.7, and 15.4 ± 2.5 mm at intake, after augmentation, after implantation, and at the last recall visit, respectively. Mean radiographic peri-implant bone loss was 0.6 ± 0.7 mm. Mean clinical index scores were very low. Patient satisfaction was high. Surgical complications related to the donor site were seroma (n = 1), haematoma (n = 2), and sensory disturbance of the lateral femoral cutaneous nerve (n = 1); all had resolved before placement of the implants. Eleven patients reported postsurgical sensory disturbances of the mental nerve, of whom five still experienced some sensory disturbance at the last recall visit. Augmentation of the extremely resorbed mandible with an iliac crest onlay graft followed by placement of two implants 4 months later provides a solid basis for a bar-retained overdenture with favourable clinical and radiographic results.     

Finite element evaluation of three methods of stable fixation of condyle base fractures

The surgical treatment of mandibular condyle fractures currently offers several possibilities for stable internal fixation. In this study, a finite element model evaluation was performed of three different methods for osteosynthesis of low subcondylar fractures: (1) two four-hole straight plates, (2) one seven-hole lambda plate, and (3) one four-hole trapezoidal plate. The finite element model evaluation considered a load applied to the first molar on the contralateral side to the fracture. Results showed that, although the three methods are capable of withstanding functional loading, the lambda plate displayed a more homogeneous stress distribution for both osteosynthesis material and bone and may be a better method when single-plate fixation is the option.     

Soft tissue assessment before and after mandibular advancement or setback surgery using three-dimensional images: systematic review and meta-analysis

The aim of this systematic review was to evaluate the effects of mandibular advancement or setback surgery on the facial soft tissue assessed using three-dimensional images. An electronic search was performed in the MEDLINE, Cochrane Library, Scopus, Virtual Health Library (VHL), Web of Science, and OpenGrey databases. Inclusion criteria comprised studies that evaluated the soft tissues of adult patients before and after mandibular advancement or setback surgery using computed tomography or magnetic resonance imaging. The risk of bias was analyzed. A total of 3501 studies were retrieved. The titles and abstracts of 2071 studies were read and 2040 of them were excluded. Thirty-one articles were read in full and six fulfilled the eligibility criteria and were included. A meta-analysis was performed using three of these articles. The correlation was significant and strong in the chin area (r = 0.876 and r = 0.868) and moderate for the lower lip/lower incisor (r = 0.690). The ratio for lower lip/infradentale was 78% and for Pog′/Pog was 98%. Due to the limited number of articles included, there is weak evidence to infer that changes in the facial soft tissue due to mandibular advancement or setback are significant, but changes in the lower lip tend to be smaller than changes in the chin area.     

The relationship between various parameters of complete denture quality and patients’ satisfaction

BackgroundPatients’ appreciation of their conventional complete dentures might be affected by the quality of the dentures.MethodsA random sample of 33 edentulous patients who were rehabilitated by means of conventional complete dentures participated in the study. Three independent investigators who underwent technique calibration evaluated the dentures on the basis of seven clinical criteria by using a validated examination form. The patients filled out a validated denture satisfaction scale. The author used Pearson product-moment correlation and analysis of covariance to identify possible correlations.ResultsThe study results showed that most patients were between “reasonably satisfied” and “very satisfied” with their dentures. The author found nominally higher satisfaction among those receiving both mandibular and maxillary dentures and significant positive correlations between the overall denture satisfaction score and the stability of the mandibular denture (P = .039) and retention of the mandibular denture (P = .005). In contrast, esthetic lip support and lower lip line, occlusion, and maxillary stability and retention were not correlated with participants’ overall satisfaction level (P > .064).ConclusionsThe results of this study show that a clinically stable mandibular denture was the most important determinant of patients’ satisfaction.Practical ImplicationsThe study findings highlight the most important denture quality parameters that can aid clinicians in meeting their patients’ expectations.