Impact of Bone Volume Upon Condylar Activity in Patients With Unilateral Condylar Hyperplasia.

PURPOSE: Unilateral condylar hyperplasia or hyperactivity (UCH) is a bone overgrowth disorder affecting the mandible. The purpose of this study was to determine the relations among age, condylar bone structure, condylar bone volume, and condylar bone activity on single-photon emission computed tomographic (SPECT) scans in patients with UCH. MATERIALS AND METHODS: This study included 20 patients with a clinical presentation of progressive mandibular asymmetry and a positive bone SPECT scan. A bone SPECT-derived standardized uptake value (bSUV) for the condylar region was determined. All patients underwent condylectomy to arrest further progression of the disease. The resected condyles were scanned with a micro-computed tomographic scanner (18-µm resolution). Bone architectural parameters were calculated with routine morphometric software. RESULTS: The mean bSUV of the condyle on the affected side was 15.32 (standard deviation [SD], 8.98) compared with 9.85 (SD, 4.40) on the nonaffected side (P = .0007). For trabecular bone structure, there was a nonsignificant correlation between the SUV of the affected condyle and the measured bone volume fraction (r = 0.13; P = .58) and trabecular thickness (r = 0.03; P = .90). CONCLUSION: No meaningful relation was found between condylar bone volume fraction and condylar activity on bone scan; therefore, the impact of bone volume fraction on the results of bone scans is limited. The measured condylar activity on SPECT scan seems to be primarily a reflection of the remodeling rate of bone.

Value of informed consent in surgical orthodontics.

PURPOSE: Informed consent forms an important part of treatment, especially in the case of elective treatment. The aim of this survey was to establish how much patients can recall of the information given during an informed consent interview before orthognathic surgery. During the consultation, attention was given to all aspects of the treatment. However, because of "insurance-related factors," the need for treatment because of functional reasons was stressed over esthetics. The recall of information given during an informed consent interview before orthognathic surgery was measured using a questionnaire. MATERIALS AND METHODS: Patients with a mandibular deficiency with a low mandibular plane angle were questioned after an informed consent interview regarding surgical orthodontic treatment. RESULTS: Esthetics were more frequently and functional problems were less frequently recalled as the reason for operation than was expected. The risk of a change in the sensation of the lower lip by surgery was frequently recalled as a reason to refrain from the operation. The overall recall rate of the possible risks and complications of orthodontic surgery was 40%. CONCLUSIONS: No reports were found of comparable research on the preoperative recall after consultation before surgical orthodontic surgery. The aspects of communication that can improve recall must be clarified. A recall rate of 100% seems a utopia, although an arbitrary line is needed to determine the quality of an informed consent interview.

Effect of vasoconstriction on pain after mandibular third molar surgery: A single-blind, randomized controlled trial.

OBJECTIVES: Previous research has demonstrated the efficacy of using local compression to reduce postoperative pain after third molar surgery. It has been theorized that compression reduces pain intensity through vasoconstriction. The current research tests the veracity of this vasoconstriction hypothesis by testing the impact of local epinephrine (a local vasoconstrictor) versus a control on patients' pain ratings over 7 days following surgery. METHOD AND MATERIALS: Fifty patients scheduled for mandibular third molar surgery were randomly assigned to receive one cartridge of Ultracaine DS Forte (the treatment group) or one cartridge of Ultracaine DS (the control group) after surgical removal of the third molar. Participants used the visual analog scale (VAS) to provide daily ratings of pain intensity for 7 days following surgery. In addition, on day 7, the perceived effectiveness of the pain treatment was measured with the global perceived effect (GPE) scale. A quality- of-life questionnaire was also completed. RESULTS: A repeated-measures ANOVA indicated that the treatment group perceived significantly less pain than the control group on days 2 to 7 following surgery. In addition, 77.8% of the treatment group perceived their pain treatment to be successful, while only 69.6% of the control group reported that their pain was reduced successfully by day 7. CONCLUSION: The results of this study provide an initial proof of concept that epinephrine may have an analgesic effect on the period following third molar surgery. Further research with larger sample sizes is needed to strengthen evidence for the clinical utility of offering localized epinephrine to patients following third molar surgery.

The overbite and intraoral mandibular distraction osteogenesis.

PURPOSE: The purpose of this study was to quantify the overbite reduction in skeletal Angle Class II malocclusions and discuss the management of the overbite during and after intraoral distraction of the mandible, and during orthodontic treatment with fixed appliances. MATERIAL AND METHODS: Cephalograms of 26 patients with an Angle Class II malocclusion and orthodontic appliances and distraction osteogenesis of the horizontal part of the mandible before (T0) and at least 1 year after treatment (T1) were evaluated. Mean age of the patients at the time of distraction was 14.6 years (range 12.8-15.9 years) and at the final registration 17.3 years (range 14.6-20.4 years). RESULTS: The overbite decreased significantly and the SpP/MP value increased significantly. The increase in the value of the Y-axis and the MP/SN angle before and after treatment was statistically insignificant. CONCLUSION: Opening of the bite during distraction of the mandible can be expected. The use of the 'floating bone' technique did not correct the overbite permanently. The patients in whom an open bite has already been treated are not ideal for mandibular lengthening by means of distraction osteogenesis.

Observer consistency in radiographic assessment of condylar resorption.

OBJECTIVES: This study evaluates interobserver and intraobserver agreement with respect to the determination of the shape and surface of the condylar head on panoramic views. STUDY DESIGN: Detailed frames (n = 632) were made from preoperative and postoperative panoramic views of 158 consecutive patients, who underwent orthognathic surgery. The intraobserver and interobserver agreement were calculated by using Cohen's kappa. RESULTS: By using Cohen's kappa, the intraobserver agreement was determined to be reasonable or good for surface and shape of the condyle. The interobserver agreement was mediocre or poor for surface and shape of the condyle. CONCLUSION: Because of the subjectivity of using panoramic views to determine the shape and surface of the condylar head, considerable interobserver disagreement is possible.

Adaptation of lateral pterygoid and anterior digastric muscles after surgical mandibular advancement procedures in different vertical craniofacial types: a magnetic resonance imaging study.

OBJECTIVE: Surgical mandibular advancement procedures induce major adaptations of jaw-closing muscles. In this study, adaptation of antagonist muscles, the lateral pterygoid (LPM) and anterior digastric (DigA) muscles, was evaluated. STUDY DESIGN: Eighteen adult patients with mandibular retrognathia and individually varying vertical craniofacial dimensions were treated with bilateral sagittal split osteotomies (BSSO), in some cases combined with a Le Fort I osteotomy (LF Bimax). The sample was divided into 1 short-face (SF, n = 7) and 2 long-face groups (LF BSSO, n = 3; and LF Bimax, n = 8). Pre- and postoperative maximum cross-sectional areas (CSA) and volumes were compared in these groups. RESULTS: Postoperatively, CSA and volume of LPM increased in BSSO cases and decreased in bimaxillary cases. Inconsistent increases and decreases of CSA and volume of DigA were seen in all groups. CONCLUSIONS: The LPM became larger in SF and LF BSSO patients and smaller in LF Bimax patients. The DigA adapted unpredictably.

The surgical management of post-traumatic malocclusion.

Facial skeleton fractures should be reduced as early as possible to restore optimal function and minimize skeletal and soft-tissue deformity. With unsatisfactory outcome from delayed treatment because of comorbidity, or despite optimal management, late reconstruction can succeed with conventional orthognathic surgical procedures. Management follows well-established principles of correcting dentofacial deformities, coordinated with orthodontic and prosthodontic support. Planning should include dental records when available, and clinical photographs. The late deformity of midfacial fractures can be corrected by following initial fracture lines; condylar fracture patients can be treated by remote osteotomies. Before surgical intervention, diminished temporomandibular joint (TMJ) mobility should be managed with aggressive physiotherapy to maximize stomal opening. Additionally, successful outcome will depend on a stable TMJ relation without ongoing remodeling.

Transgender feminization of the facial skeleton.

In transsexualism, there is a strong and ongoing cross-gender identification, and a desire to live and be accepted as a member of the opposite gender; thus there is a wish for somatic treatment to make one's body as congruent as possible with gender identity. Makeup and change in hairstyle and accessories further feminize the face, and in time, most persons became more adapted to their life as a member of the opposite gender. There is a need for more objective standardization of the differences in the facial features of the two sexes, to facilitate surgical treatment planning and more objectively assess the outcome of the facial surgery on psychosocial functioning and appearance.

Adaptation of jaw closing muscles after surgical mandibular advancement procedures in different vertical craniofacial types: a magnetic resonance imaging study.

OBJECTIVE: Surgical mandibular advancement influences the biomechanics of the mandible and as a result may provoke relapse. In this study, the adaptation of the masseter (MAS) and medial pterygoid muscles (MPM) after surgical mandibular advancement was evaluated. STUDY DESIGN: Of 12 patients with mandibular retrognathia and varying vertical craniofacial morphology, axial and 30 degrees angulated magnetic resonance imaging (MRI) scan series were taken preoperatively and 10 to 48 months postoperatively. Using cluster analysis, subjects were assigned to a long-face (LF) and a short-face (SF) cluster. Subsequently, preoperative and postoperative maximum cross-sectional areas and volumes of the MAS and MPM were compared in these groups. RESULTS: The cross-sectional area and volume of the MAS decreased significantly in both the SF and LF cluster (up to 18%). Although not significantly, this phenomenon tended to be more pronounced in LF patients. The cross-sectional area of the MPM showed less adaptation. CONCLUSION: The jaw-closing muscles become significantly smaller after surgical mandibular advancement, irrespective of the vertical craniofacial type.

Duration of orthodontic treatment and mandibular lengthening by means of distraction or bilateral sagittal split osteotomy in patients with Angle Class II malocclusions.

BACKGROUND: The purpose of this study was to investigate the duration of treatment of patients with skeletal Angle Class II malocclusions treated with orthodontic appliances and surgical lengthening of the mandible to close residual overjets. METHODS: In this retrospective study, the patients were divided into 3 groups. Group A consisted of 10 patients (5 boys, 5 girls; mean age, 10.11 years; range, 9.1-13.9 years at the beginning of treatment) who were treated with a headgear-activator, fixed appliances, and intraoral osteodistraction of the mandible. Group B consisted of 19 patients (10 boys, 9 girls; mean age, 12.3 years; range, 9.6-16.1 years) treated with fixed appliances and intraoral distraction. In group C, 13 patients (4 men, 9 women; mean age, 27.3 years; range, 12.11-40.7 years) were treated with fixed appliances and bilateral sagittal split osteotomy (BSSO). RESULTS: In patients treated with orthodontic appliances and surgical lengthening of the mandible, treatment time was influenced by the appliances and the surgical technique used. Patients treated with a headgear-activator, fixed appliances, and intraoral distraction osteogenesis (group A) needed significantly more treatment time than patients treated with fixed orthodontic appliances and intraoral distraction (group B) or fixed appliances and BSSO (group C). Duration of treatment with intraoral mandibular distraction (group B) was significantly (P < .05) shorter compared with mandibular lengthening with BSSO (group C). However, no definitive conclusions can be drawn, because of the retrospective study design. CONCLUSIONS: The best time and the best surgical procedure for correcting mandibular length have yet to be determined, and a prospective randomized trial is recommended.