Suggestion of a new standard in measuring the mandible via MRI and an overview of reference values in young women.

PURPOSE: Adult idiopathic condylar resorption (AICR) mainly affects young women, but generally accepted diagnostic standards are lacking. Patients often need temporomandibular joint (TMJ) surgery, and often jaw anatomy is assessed by CT as well as MRI to observe both bone and soft tissue. This study aims to establish reference values for mandible dimensions in women from MRI only and correlate them to, e.g., laboratory parameters and lifestyle, to explore new putative parameters relevant in AICR. MRI-derived reference values could reduce preoperative effort by allowing physicians to rely on only the MRI without additional CT scan. METHODS: We analyzed MRI data from a previous study (LIFE-Adult-Study, Leipzig, Germany) of 158 female participants aged 15-40 years (as AICR typically affects young women). The MR images were segmented, and standardized measuring of the mandibles was established. We correlated morphological features of the mandible with a large variety of other parameters documented in the LIFE-Adult study. RESULTS: We established new reference values for mandible morphology in MRI, which are consistent with previous CT-based studies. Our results allow assessment of both mandible and soft tissue without radiation exposure. Correlations with BMI, lifestyle, or laboratory parameters could not be observed. Of note, correlation between SNB angle, a parameter often used for AICR assessment, and condylar volume, was also not observed, opening up the question if these parameters behave differently in AICR patients. CONCLUSION: These efforts constitute a first step towards establishing MRI as a viable method for condylar resorption assessment.

Considerations for the Use of Alloplastic Temporomandibular Joint Replacement in Irradiated Patients: Report of an Off-Label Indication.

BACKGROUND: Custom-made alloplastic temporomandibular joint replacement (ATMJR) is not validated in irradiated patients. However, in specific situations, after previous reconstructive surgical failures, the authors hypothesized the role of a customized ATMJR after radiotherapy. METHODS: A 65-year-old male patient was referred to Instituto Português da Face-Lisbon, Portugal-after failed attempts of mandibular reconstruction secondary to oral carcinoma resection and partial hemi-mandibulectomy plus radiotherapy of 60 total Grays. Primary reconstruction was performed with fibula free flap. Due to failure, secondary reconstructions were performed with osteosynthesis plate without success. The patient was unable to have adequate mastication and deglutition due to a severe crossbite. The authors treated the patient with an extended customized alloplastic temporomandibular joint replacement (F0M2). RESULTS: With 3 years of follow-up, the patient showed an improvement in masticatory function, mandibular motion, pain levels, and overall quality of life. No complications were observed related to ATMJR. CONCLUSIONS: The presented case described how ATMJR, although not a validated option after radiotherapy, can be considered to restore functionality in complex cases with bone and soft tissues problems.

Controversial Aspects of Diagnostics and Therapy of Idiopathic Condylar Resorption: An Analysis of Evidence- and Consensus-Based Recommendations Based on an Interdisciplinary Guideline Project.

Idiopathic condylar resorption (ICR), though a rare event, is associated with severe detrimental sequelae for the patient. To date, the etiology remains unknown, and treatment strategies are highly controversial. Therefore, the aim of this study is to present an analysis of the consensus- and evidence-based approach to ICR by a German interdisciplinary guideline project of the AWMF (Association of the Scientific Medical Societies in Germany). Following a systematic literature search, including 56 (out of an initial 97) publications, with a predominantly low level of evidence (LoE), two independent working groups (oral and maxillofacial surgery and interdisciplinary, respectively) voted on a draft comprising 25 recommendations in a standardized anonymized and blinded Delphi procedure. While the results of the votes were relatively homogeneous, the interdisciplinary phase required a significantly higher number of rounds (p < 0.001). Most of the controversial recommendations were related to initial imaging (with consensus on CT/CBCT as the current diagnostic standard for imaging), pharmacotherapy (no recommendation due to lack of evidence), discopexy (no recommendation possible due to low LoE) and timing of orthognathic surgery (with consensus on two-staged procedures after invasive TMJ surgery, except for single-stage procedures if combined with total joint reconstruction). Overall, the Delphi procedure resulted in an interdisciplinary guideline offering the best possible evidence- and consensus-based expertise to date in the diagnosis and treatment of ICR.

Controversial Aspects of Diagnostics and Therapy of Arthritis of the Temporomandibular Joint in Rheumatoid and Juvenile Idiopathic Arthritis-An Analysis of Evidence- and Consensus-Based Recommendations Based on an Interdisciplinary Guideline Project.

Introduction: Due to potentially severe sequelae (impaired growth, condylar resorption, and ankylosis) early diagnosis of chronic rheumatic arthritis of the temporomandibular joint (TMJ) and timely onset of therapy are essential. Aim: Owing to very limited evidence the aim of the study was to identify and discuss controversial topics in the guideline development to promote further focused research. Methods: Through a systematic literature search, 394 out of 3771 publications were included in a German interdisciplinary guideline draft. Two workgroups (1: oral and maxillofacial surgery, 2: interdisciplinary) voted on 77 recommendations/statements, in 2 independent anonymized and blinded consensus phases (Delphi process). Results: The voting results were relatively homogenous, except for a greater proportion of abstentions amongst the interdisciplinary group (p < 0.001). Eighty-four percent of recommendations/statements were approved in the first round, 89% with strong consensus. Fourteen recommendations/statements (18.2%) required a prolonged consensus phase and further discussion. Discussion: Contrast-enhanced MRI was confirmed as the method of choice for the diagnosis of TMJ arthritis. Intraarticular corticosteroid injection is to be limited to therapy-refractory cases and single injection only. In adults, alloplastic joint replacement is preferable to autologous replacement. In children/adolescents, autologous reconstruction may be performed lacking viable alternatives. Alloplastic options are currently still considered experimental.

Does Maximum Voluntary Clenching Force Pose a Risk to Overloading Alloplastic Temporomandibular Joint Replacement?-A Prospective Cohort Study.

PURPOSE: The amount of maximum voluntary clenching (MVC) force may influence functional loading at the polyethylene/metal bearing surfaces in alloplastic total temporomandibular joint replacement (TMJR). The aim of this study was to measure ipsilateral MVC and estimate the risk for revision due to overloading of the TMJR. METHODS: A prospective cohort study design was used to study patients who underwent alloplastic TMJR. The primary predictor was time after TMJR, the secondary predictors were age at TMJR placement, coronoidectomy, prior ipsilateral TMJ surgeries, TMJR design (custom, stock), and bite location. The primary outcome variable was MVC, the secondary outcome was need for TMJR revision. Data were collected preoperatively (T0), and 1 year (T1), 2 to 3 years (T2) and ≥4 years postoperatively (T3). Analysis of variance (ANOVA) with post hoc Tukey-HSD and regression analysis was used for statistical analysis. P < .05 was considered significant. RESULTS: Thirty-seven patients (58 TMJR) with unilateral (n = 16) and bilateral (n = 21) TMJR were enrolled; 8 males (12 TMJR) and 29 females (46 TMJR). Average age was 46.4 ± 14.9 years. MVC increased significantly over the observation period (P = .000). At all observation time points, age at TMJR placement and bite location significantly influenced MVC (P = .000). Coronoidectomy and prior ipsilateral TMJ surgeries did not demonstrate a significant influence on MVC. TMJR design influenced MVC significantly at T3 (P = .006). Regression analysis identified age as a significant factor for higher MVC. No TMJR required revision or replacement. CONCLUSIONS: Based on this study, ipsilateral MVC increases significantly after TMJR. However, since MVC is significantly lower than in healthy test-patients, a considerably lower functional loading at the polyethylene/metal bearing surfaces can be assumed. Lower loading at the TMJR bearing surfaces and at the cortical screw fixation sites suggest a potential longer lifespan compared to other artificial joints like hip and knee prostheses.

Digitally designed, personalized bone cement spacer for staged TMJ and mandibular reconstruction - Introduction of a new technique.

The aim of this paper is to introduce an innovative workflow for staged reconstruction of the mandible, including the temporomandibular joint (TMJ), using a temporary, patient-specific spacer. In cases of partial mandibular resection including disarticulation, sometimes needed to treat inflammatory bone disease, the spacer is intended to retain symmetry of the hard tissues, to preserve the soft tissues, and to act as a bactericidal agent. When complete healing of the affected surrounding tissues has occurred, final reconstruction using a patient-matched total TMJ endoprosthesis, in combination with an autogenous free bone flap, can be performed as a second-stage procedure. The crucial steps of the workflow are virtual surgical planning, manufacturing of a two-part silicone mold, and chairside manufacturing of the spacer using an established bone cement with gentamycin. The method was first introduced in two patients suffering from therapy-resistant chronic osteomyelitis. The presented protocol of staged surgery allows a much safer and predictable reconstruction compared with immediate reconstruction. The workflow also minimizes the potential risk of endoprosthesis infection - one of the major risks of implant failure.

Unilateral, Alloplastic Temporomandibular Joint Reconstruction, Biomechanically What Happens to the Contralateral Temporomandibular Joint?-A Prospective Cohort Study.

PURPOSE: Unilateral alloplastic total temporomandibular joint reconstruction (TMJR) might influence the contralateral side joint function. This study's purpose was to estimate the risk for contralateral TMJR and the jaw function of the contralateral untreated temporomandibular joint (TMJ). PATIENTS AND METHODS: A prospective cohort study design was used for patients who underwent unilateral alloplastic TMJR. The primary predictor was time after TMJR, and the secondary predictors were pre-TMJR mandibular angle resection, prior ipsilateral TMJ surgeries, and TMJR design (custom, stock). The primary outcome variable was the need for contralateral TMJR. The secondary outcome variables were the results of jaw function-jaw tracking, maximum voluntary clenching, surface electromyography, and pressure pain thresholds (PPT) and patient's quality-of-life (oral health-related quality-of-life [OHrQoL]). Data were collected preoperatively (T0), and 1 year (T1), 2-3 years (T2), and ≥ 4 years postoperatively (T4). Analysis of variance with post hoc Tukey -HSD test and multiple linear regression analysis were used for statistical analysis. P < .05 was considered significant. RESULTS: Thirty-nine patients were enrolled, 15 males and 24 females, with an average age of 48.9 ± 16.2 years. Two patients (5.1%) required a contralateral TMJR. Contralateral condylar motion, incisal laterotrusion, and protrusion slightly decreased, while incisal opening (P = .003), rotation angle (P = .013), opening deflection, surface electromyography activity, maximum voluntary clenching (P = .01), PPTs, and OHrQoL all increased. Pre-TMJR mandibular angle resection had an impact on PPTs and subjective outcomes and prior ipsilateral TMJ surgeries on the opening rotation angle. CONCLUSIONS: Based on this study, bilateral TMJR does not appear necessary when the contralateral TMJ is healthy. Unilateral alloplastic TMJR is associated with improved contralateral jaw function and OHrQoL.

How Does a Unilateral Temporomandibular Joint Replacement Affect Bilateral Masseter and Temporalis Muscle Activity?-A Prospective Study.

PURPOSE: Total alloplastic temporomandibular joint replacement (TMJR) requires the detachment of the masseter muscle (MM) at its insertion to the lateral ramus and often the resection of the coronoid process (insertion of the temporalis muscle). There is little literature on how a detachment affects the muscles. The present study evaluates the long-term masticatory muscle activities and maximum voluntary bite force (MVC) in patients with unilateral TMJR. PATIENTS AND METHODS: Surface electromyography of the MM and anterior temporalis muscle during bite force testing and MVC were evaluated bilateral preoperatively (T0), 1 (T3), 2 (T4), 3 (T5), and 4 years (T6) postoperatively. The percentage overlapping coefficient (index of the symmetric distribution of muscular activity) was calculated. Differences between stock or custom devices were evaluated. RESULTS: Fourteen patients were enrolled, 4 males and 10 females, age 47.3 ± 14.3 years at TMJR placement. In 11 patients, the coronoid process was resected, 5 patients received stock, and 9 custom prostheses. After surgery, a trend in the improvement of bilateral surface electromyography activities and MVC was found without statistical significance for the side comparison or the time of the investigation. The percentage overlapping coefficient values showed postoperatively relative (>72%) symmetry in both muscles. Up to T5 on the TMJR side, MM showed higher activity when custom prostheses were used. There was no significant difference between stock and custom prostheses. CONCLUSIONS: The vertical (anterior) fibers of the temporalis muscle are preserved despite the resection of the coronoid process. The anterior temporalis muscle, as a synergist of the MM on the TMJR side, postoperatively partially assumes its abduction function. The detached MM appears to reattach. Generally, the bilateral increase in muscle activity and MVC of both muscles suggests regeneration of the investigated muscles. Custom prostheses seem to have an initial advantage for the reattachment of the MM compared with stock prostheses.

Mandibular kinematics and maximum voluntary bite force following segmental resection of the mandible without or with reconstruction.

OBJECTIVES: The purpose was to analyze mandibular kinematics and maximum voluntary bite force in patients following segmental resection of the mandible without and with reconstruction (autologous bone, alloplastic total temporomandibular joint replacement (TMJ TJR)). MATERIALS AND METHODS: Subjects operated from April 2002 to August 2014 were enrolled in the study. Condylar (CRoM) and incisal (InRoM) range of motion and deflection during opening, condylar retrusion, incisal lateral excursion, mandibular rotation angle during opening, and maximum voluntary bite force were determined on the non-affected site and compared between groups. Influence of co-factors (defect size, soft tissue deficit, neck dissection, radiotherapy, occlusal contact zones (OCZ), and time) was determined. RESULTS: Twelve non-reconstructed and 26 reconstructed patients (13 autologous, 13 TMJ TJR) were included in the study. InRoM opening and bite force were significantly higher (P ≤ .024), and both condylar and incisal deflection during opening significantly lower (P ≤ .027) in reconstructed patients compared with non-reconstructed. Differences between the autologous and the TMJ TJR group were statistically not significant. Co-factors defect size, soft tissue deficit, and neck dissection had the greatest impact on kinematics and number of OCZs on bite force. CONCLUSIONS: Reconstructed patients (both autologous and TMJ TJR) have better overall function than non-reconstructed patients. CLINICAL RELEVANCE: Reconstruction of segmental mandibular resection has positive effects on mandibular function. TMJ TJR seems to be a suitable technique for the reconstruction of mandibular defects including the TMJ complex.

Free-Circulating Methylated DNA in Blood for Diagnosis, Staging, Prognosis, and Monitoring of Head and Neck Squamous Cell Carcinoma Patients: An Observational Prospective Cohort Study.

BACKGROUND: Circulating cell-free DNA methylation testing in blood has recently received regulatory approval for screening of colorectal cancer. Its application in other clinical settings, including staging, prognosis, prediction, and recurrence monitoring is highly promising, and of particular interest in head and neck squamous cell carcinomas (HNSCCs) that represent a heterogeneous group of cancers with unsatisfactory treatment guidelines. METHODS: Short stature homeobox 2 (SHOX2) and septin 9 (SEPT9) DNA methylation in plasma from 649 prospectively enrolled patients (training study: 284 HNSCC/122 control patients; testing study: 141 HNSCC/102 control patients) was quantified before treatment and longitudinally during surveillance. RESULTS: In the training study, 59% of HNSCC patients were methylation-positive at 96% specificity. Methylation levels correlated with tumor and nodal category (P < 0.001). Initially increased methylation levels were associated with a higher risk of death [SEPT9: hazard ratio (HR) = 5.27, P = 0.001; SHOX2: HR = 2.32, P = 0.024]. Disease recurrence/metastases were detected in 47% of patients up to 377 days earlier compared to current clinical practice. The onset of second cancers was detected up to 343 days earlier. In the testing study, sensitivity (52%), specificity (95%), prediction of overall survival (SEPT9: HR = 2.78, P = 0.022; SHOX2: HR = 2.50, P = 0.026), and correlation with tumor and nodal category (P <0.001) were successfully validated. CONCLUSIONS: Methylation testing in plasma is a powerful diagnostic tool for molecular disease staging, risk stratification, and disease monitoring. Patients with initially high biomarker levels might benefit from intensified treatment and posttherapeutic surveillance. The early detection of a recurrent/metastatic disease or a second malignancy could lead to an earlier consecutive treatment, thereby improving patients' outcomes.

Synovial chondromatosis of the temporomandibular joint: Immunohistochemical examinations regarding the role of insulin-like growth factors and their binding proteins in the etiology of this disease.

Synovial chondromatosis (SC) is a benign disease of the joints without a known cause. It sometimes affects the temporomandibular joint (TMJ) and is accompanied by pain, swelling, malocclusion, and crepitation. It has been divided into three stages by Milgram and is supposed to originate from the synovia and cartilage of a joint (Milgram, 1977b). The aim of this study was to examine an involvement of the insulin-like growth factors (IGF-I/-II) and their binding proteins (IGFBP-1 to -6) in the etiology of this disease. Therefore 23 specimen of SC from 16 patients were immunohistochemically stained and microscopically examined. Staining was assessed semiquantitatively: negative (-), weakly positive ((+)), moderately positive (+), strongly positive (++) and very strongly positive (+++). It could be seen that especially the chondro- and fibrocytes and the synovia showed positive staining for almost all IGFs and IGFBPs. The underlying tissue, consisting of connective tissue or chondroid matrix, was stained as well but more weakly so. We conclude that the IGF/IGFBP system seems to contribute to the pathogenesis of SC, especially IGF-I and -II, and their effects enhancing binding protein 5.

The Vermilionectomy and the Subsequent Lower Lip Reconstruction Were Introduced by Victor von Bruns and not by von Langenbeck or von Esmarch as Reported Previously.

Vermilionectomy is an established procedure for the management of precancerous lesions of the lip and is often performed simultaneously with a lower lip resection for the treatment of a malignancy. The literature suggests that Dieffenbach or von Langenbeck or von Esmarch was the first to introduce this procedure. A systematic review of the German literature from the 19th century revealed that it was von Bruns who performed the vermilionectomy for the management of lip malignancies for the first time.

Temporomandibular Joint Ankylosis Can Be Successfully Treated With TMJ Concepts Patient-Fitted Total Joint Prosthesis and Autogenous Fat Grafts.

PURPOSE: To measure and identify factors associated with treatment outcomes for patients with temporomandibular joint (TMJ) ankylosis treated with TMJ Concepts patient-fitted total joint prostheses and autogenous fat grafts. PATIENTS AND METHODS: This retrospective cohort study evaluated records of patients with TMJ ankylosis from a single private practice, treated from 1992 to 2011, who met the following inclusion criteria: 1) radiographic evidence of bony ankylosis, 2) limited incisal opening, 3) minimum of 12 months' follow-up, and 4) treatment with TMJ Concepts (Ventura, CA)/Techmedica (Camarillo, CA) total joint prostheses and fat grafts. For each patient, the number of previous TMJ surgical procedures, as well as the estimated age of ankylosis onset, age at surgery, and length of postoperative follow-up, was recorded. Subjective evaluations were made with Likert-like scales (from 0 to 10) for 1) TMJ pain, 2) headache and facial pain, 3) jaw function, 4) diet, and 5) disability. Objective evaluations included maximal incisal opening and excursion movements. Nonparametric statistics were used for analysis. RESULTS: There were 32 patients (22 female and 10 male patients) with 48 ankylosed TMJs (16 bilateral and 16 unilateral) in this study, with a mean age of 39 years (range, 11 to 68 years), 2 or more previous TMJ surgical procedures in 69%, and a mean follow-up period of 68 months (range, 12 to 168 months). Trauma was the major etiology of TMJ ankylosis, occurring in 17 of 32 patients (53%). The following improvements occurred: The median value for TMJ pain changed from 8.0 preoperatively to 1.5 at longest follow-up; headache, from 8 to 3.5; facial pain, from 8 to 4; jaw function, from 8 to 2.5; diet, from 7 to 3; and disability, from 7 to 1.5. The median incisal opening was 14.5 mm (interquartile range, 6.3 to 20 mm) preoperatively and 35 mm (interquartile range, 30 to 40 mm) at longest follow-up. The median left lateral excursion improved from 0.5 to 2 mm, and the median right lateral excursion improved from 1 to 1.3 mm. All of these improvements were highly significant (P < .001, Wilcoxon tests). Equally favorable outcomes were found in patients with 12 to 48 months of maximal follow-up and patients with more than 48 months of maximal follow-up. CONCLUSIONS: The treatment of TMJ ankylosis with the TMJ Concepts patient-fitted total joint prosthesis in combination with fat grafting around the articulation area of the prosthesis is a viable and predictable method for improving pain levels, function, and quality of life, as well as prevention of reankylosis of the TMJ.

Protocol for concomitant temporomandibular joint custom-fitted total joint reconstruction and orthognathic surgery utilizing computer-assisted surgical simulation.

Clinicians who address temporomandibular joint (TMJ) pathology and dentofacial deformities surgically can perform the surgery in 1 stage or 2 separate stages. The 2-stage approach requires the patient to undergo 2 separate operations and anesthesia, significantly prolonging the overall treatment. However, performing concomitant TMJ and orthognathic surgery (CTOS) in these cases requires careful treatment planning and surgical proficiency in the 2 surgical areas. This article presents a new treatment protocol for the application of computer-assisted surgical simulation in CTOS cases requiring reconstruction with patient-fitted total joint prostheses. The traditional and new CTOS protocols are described and compared. The new CTOS protocol helps decrease the preoperative workup time and increase the accuracy of model surgery.

Maximum voluntary bite force in patients with alloplastic total TMJ replacement--a prospective study.

Alloplastic temporomandibular total joint replacement (TJR) for end-stage disease, congenital disorders and following ablative oncological surgery has been shown to reduce pain and improve function. The purpose was to assess the maximum voluntary bite force and maximum interincisal opening (MIO) in patients undergoing alloplastic total temporomandibular joint replacement (TJR). Seventeen patients with different diagnoses resulting in condylar hypomobility (8 patients; 15 joints) and condylar instability (9 patients; 12 joints) had undergone alloplastic TMJ reconstruction. Maximum voluntary bite force and MIO were measured at pre-operatively (T0), 2 (T1), 6 (T2) and 12 (T3) months. For ordinal data comparison at different time-points, the Wilcoxon signed-ranks test was used. There was a significant improvement in maximum voluntary bite force for both, patients with condylar hypomobility (P = 0.003) and condylar instability (P = 0.007). Analysis of MIO revealed a significant improvement at T3 (P = 0.002). Alloplastic TJR would appear to increase maximum voluntary bite force and MIO. Biomechanical integrity of the stomatognathic system and the ability of the patient to triturate food could be improved by alloplastic temporomandibular joint (TMJ) replacement.

Pressure pain threshold and oral health-related quality of life implications of patients with alloplastic temporomandibular joint replacement--a prospective study.

PURPOSE: Alloplastic total temporomandibular joint replacement (TJR) for end-stage disease, congenital disorders, and after ablative surgery has been shown improve function and to decrease pain. The purpose of this study was to evaluate the pain pressure threshold (PPT) and oral health-related quality of life (OHRQoL) in patients undergoing alloplastic TJR. MATERIALS AND METHODS: Subjects requiring TJR from May 2007 through February 2011 were enrolled in the study. The PPT and OHRQoL were measured preoperatively and 2, 6, and 12 months postoperatively. The primary predictor variable was postoperative time (preoperatively and 2, 6, and 12 months postoperatively). The primary outcome variables were the PPT and OHRQoL. RESULTS: Seventeen subjects requiring TJR were enrolled in and completed the required 12-month follow-up. There was no difference in the PPT at any time point. There was a significant improvement in the OHRQoL domain of psychological discomfort (P = .04) at 12 months. Facial pain intensity, temporomandibular joint pain, mandibular function, and diet were also significantly improved at 12 months (P = .001). CONCLUSION: Alloplastic TJR appears to decrease pain, improve function and diet, and decrease psychological discomfort.

Mandibular kinematics in patients with alloplastic total temporomandibular joint replacement--a prospective study.

PURPOSE: The purpose was to analyze the mandibular patterns (condylar range of motion during opening; incisal range of motion during opening, lateral excursion, and protrusion; velocity during opening and closing; mandibular rotation angle during opening and closing) in patients with alloplastic total joint replacement (TJR). MATERIALS AND METHODS: Seventeen patients with different diagnoses resulting in condylar hypomobility (8 patients, 15 joints) and condylar instability (9 patients, 12 joints) had undergone alloplastic TJR. Data were recorded preoperatively and 2, 6, and at least 12 months postoperatively. For ordinal data comparison at different time points, the Wilcoxon signed-ranks test was used. RESULTS: Analysis of the kinematic data at least 12 months postoperatively showed in patients with condylar hypomobility a statistically significant increase in all measured data except the incisal range of motion lateral excursion. In patients with condylar instability, the results showed a statistically significant decrease for incisal range of motion protrusion and laterotrusion. A slight increase in condylar range of motion, incisal range of motion linear distance, and velocity during opening and closing was found. CONCLUSIONS: Even after successful alloplastic TJR, a complete restoration of normal joint function is not achievable. Nevertheless, the kinematic data indicate that alloplastic TJR results in an improved function in patients with joint hypomobility and in a decrease of abnormal hypermobility in patients with condylar instability.

Reconstruction of the lower lip: rationale to preserve the aesthetic units of the face.

BACKGROUND: The boundaries of the aesthetic units of the face are often crossed after lower lip cancer surgery. The aim of this study was to compare the aesthetic and functional outcome after use of different operative techniques based on the concept of the aesthetic units of the face. MATERIALS: Sixty-three patients were evaluated after lower lip reconstruction. The aesthetic outcome was recorded by standard photography evaluating the disruption of the boundaries of the aesthetic units of the face, lip projection, and the resulting facial expression. The functional outcome consisted of the evaluation of mouth opening, pouting, and lips at rest for the evaluation of mouth continence. Three techniques were used: wedge excision, the Webster-Fries method, and the step technique. The step technique was combined with an Abbé or an Estlander flap in defects involving more than two-thirds of the lip. RESULTS: In defects involving up to one-third of the lip, the aesthetic outcome was better for the step technique than for wedge excision (a statistical trend was observed, p = 0.088). In defects involving two-thirds of the lip, the aesthetic and functional outcome was better using the step technique than the Webster-Fries method (p = 0.002), because the boundaries of the aesthetic units are respected. In defects involving more than two-thirds of the lip, the result was better using the step technique combined with the Abbé flap. CONCLUSION: The authors have shown that the step technique alone or combined with a flap of the opposite lip is a rational approach for preserving the aesthetic units of the face and its function.