Peri-articular bone formation involving the temporomandibular joint: a narrative summary and Delphi consensus of a new classification system

Heterotopic ossification (HO) is defined as 'bone where it does not belong'. Given the historical variety of nomenclature and eponyms, there is significant confusion about the etiology, pathogenesis, classification, and treatment of HO related to the temporomandibular joint (TMJ). The existing classifications for TMJ HO have shortcomings: they relate to specific populations, use differing imaging studies and demographic data, do not universally include alloplastic/autologous replacements, are based variously on radiological and/or clinical presentations that cannot always be combined, and were largely developed to assist oral and maxillofacial surgeons in surgical management. These deficiencies make it problematic to compare studies, draw valid conclusions, and pursue research. The aim of this study was to develop a new, more inclusive classification for TMJ HO. Currently available classifications were evaluated and a Delphi-type system used to build consensus from clinicians and researchers to develop a new system. Fourteen unique classifications for TMJ ankylosis/HO were identified. In light of the biological specifics related to heterotopic calcification of extracellular matrix versus heterotopic formation of actual bone, the group recommends a more unambiguous term - peri-articular bone formation - and proposes a new classification. This will help clinicians and researchers to study, describe, and manage various types of ectopic bone associated with the TMJ.

Is the risk of chronic pain after total temporomandibular joint replacement independent of its indications? A prospective cohort study

Chronic pain is a possible long-term complication after alloplastic temporomandibular joint reconstruction (TMJR). This study was developed to evaluate various subjective and objective measurements to determine the presence and degree of TMJ pain in patients treated with TMJR regardless of the indication for the operation. A prospective, single-centre study was performed. Data on 36 patients (56 TMJR) were collected preoperatively and at follow up two to three years postoperatively. The primary outcome variable was subjective TMJ pain (none/mild, moderate/severe) at follow up. The predictor variables were objective pressure pain thresholds (PPTs) at the ipsilateral joint(s) and muscle(s), functional parameters (incisal range of motion, maximum voluntary clenching), subjective oral health-related quality of life (OHRQoL), and demographic and surgical variables. The number of patients with moderate/severe pain decreased from 17 preoperatively to 10 at follow up. Self-reported TMJ pain was significantly reduced in the entire group (p = 0.001). Patients with moderate/severe pain at follow up were more restricted in their OHRQoL but did not differ in PPT and functional parameters from the no/mild pain group. Moderate/severe TMJ pain at follow up was associated with unilateral TMJR and more preoperative pain. This study provides preliminary evidence that despite good pain reduction in most patients, persistent pain after TMJR is common and, in rare cases, may even worsen regardless of the original diagnosis. At follow up there was a close relation between OHRQoL and TMJ pain. TMJ pain after TMJR cannot be confirmed by objective measurement methods (PPTs and functional parameters).

Alloplastic temporomandibular joint replacement: present status and future perspectives of the elements of embodiment

Medical device embodiment involves the following elements: materials, design, and manufacturing. Failure of any one of these elements can result in failure of the device, despite the others being satisfactory. The abundance of clinical and basic science literature published since 1986, demonstrates the safety and efficacy of alloplastic temporomandibular joint replacement (TMJR). Currently, there are 19 countries producing 41 TMJR devices. More than 75% are custom designed, and 27% are additively manufactured. In light of the increasing number of TMJR devices being designed and manufactured around the world, this paper will discuss TMJR embodiment so that clinicians understand their present status as well as the prospects for the future of new and/or improved TMJR devices, to ensure that these devices continue to be safe and effective long-term surgical options for the management of end-stage TMJ pathologies.

Impact of COVID-19 on maxillofacial surgery practice: a worldwide survey

The outbreak of coronavirus disease 2019 (COVID-19) is rapidly changing our habits. To date, April 12, 2020, the virus has reached 209 nations, affecting 1.8 million people and causing more than 110,000 deaths. Maxillofacial surgery represents an example of a specialty that has had to adapt to this outbreak, because of the subspecialties of oncology and traumatology. The aim of this study was to examine the effect of this outbreak on the specialty of maxillofacial surgery and how the current situation is being managed on a worldwide scale. To achieve this goal, the authors developed an anonymous questionnaire which was posted on the internet and also sent to maxillofacial surgeons around the globe using membership lists from various subspecialty associations. The questionnaire asked for information about the COVID-19 situation in the respondent's country and in their workplace, and what changes they were facing in their practices in light of the outbreak. The objective was not only to collect and analyse data, but also to highlight what the specialty is facing and how it is handling the situation, in the hope that this information will be useful as a reference in the future, not only for this specialty, but also for others, should COVID-19 or a similar global threat arise again.

Prevention and detection of prosthetic temporomandibular joint infections-update

Prosthetic joint infections are not only distressing complications for patients and surgeons, but also have an enormous financial impact on healthcare systems. The reported incidence of prosthetic joint infection is likely underestimated due to difficulties in their diagnosis. This unfortunate complication has challenged joint replacement surgeons for years, despite all the advances made in this surgical discipline. Since eradication of these infections can be very difficult, prevention remains the primary objective. Identifying recipient risk factors, adopting a proper surgical technique, appropriate wound care, optimizing the operating room environment, and appropriate postoperative care have become some of the core elements that can help to minimize the overall incidence of this complication. The purpose of this article is to provide the temporomandibular joint replacement surgeon with an update on the prevention and detection of prosthetic joint infections based on a review of the most recent information published in the orthopedic and surgical literature.

Acquired heterotopic ossification of the temporomandibular joint

Although the risk factors and diagnosis of heterotopic ossification (HO) are discussed in the orthopedics literature, the etiology of HO, as well as its prevention and management, remain theoretical. Furthermore, there is a lack of information in the literature regarding HO in temporomandibular joint replacement (TMJR). This article provides a qualitative review of information relative to the etiology, diagnosis, and management of HO to inform and encourage further investigation in TMJR. The orthopedic HO literature considered for this qualitative review was drawn from a comprehensive examination of the subject published previously by one of the authors. Using the key words "heterotopic ossification" or "heterotopic bone", citations in the PubMed database from both the dental and oral and maxillofacial surgery literature were reviewed. Based on this, it appears that the etiology, diagnosis, imaging, laboratory testing, risk factors, prophylaxis, and non-surgical and surgical options available for the management of TMJR-related HO are similar to those for orthopedic HO, but further elucidation is required for TMJR. There is a lack of published information in the literature on TMJR. Therefore, using the literature from this review as a foundation, studies should be developed and reported so that alloplastic TMJ surgeons have evidence-based protocols that will lead to the early detection and potential prevention of HO.

Examination of failed retrieved temporomandibular joint (TMJ) implants

In the management of end-stage temporomandibular joint disorders (TMD), surgeons must often resort to alloplastic temporomandibular joint (TMJ) total joint replacement (TJR) to increase mandibular function and form, as well as reduce pain. Understanding wear and failure mechanisms of TMJ TJR implants is important to their in vivo longevity. However, compared to orthopedic TJR devices, functional wear of failed TMJ TJR implants has not been examined. Not only do wear and corrosion influence TJR implant in vivo longevity, but so does reactivity of peri-implant tissue to these two events. The aim of this study was to examine and report on the wear of retrieved, failed metal-on-metal (MoM), metal-on-polymer (MoP), and titanium-nitride coated (TiN Coated) TMJ TJR implant components. A total cohort of 31 TMJ TJR devices were studied of which 28 were failed, retrieved TMJ TJRs, 3 were never implanted devices that served as controls. The mean time from implantation to removal was 7.24 years (range 3-15), SD 3.01. Optical microscopy, White Light Interferometry (WLI), Scanning Electron Microscopy (SEM), and Raman spectroscopy were utilized to characterize the surfaces of the devices. Data was acquired and evaluated by analyzing alloy microstructure. Substantial surface damage was observed between the articulating areas of the condylar head and the glenoid fossa components. Damage included pitting corrosion, evidence of deposited corrosion products, specific wear patterns, hard phases, surface depressions, and bi-directional scratches. Electrochemical analysis was performed on the MoM Control, retrieved, failed MoM, and TiN Coated devices. Electrochemical tests consisted of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) tests conducted using the condylar head of the retrieved failed devices. EIS confirmed material properties as well as corrosion kinetics in vivo help to mitigate corrosion as reflected by the Raman spectroscopy results. In summary, this study demonstrated the role of wear and corrosion interactions on the early failure of TMJ TJR devices. Since the materials employed in most orthopedic TJR devices are similar to those used in TMJ TJR implants, studies such as this can provide data that will improve future embodiment paradigms for both. Further studies will include in vitro investigation of corrosion kinetics and the underlying tribocorrosion mechanism of TMJ TJR devices.

STATEMENT OF SIGNIFICANCE

An attempt is made in this study, to examine the retrieved TMJ implants and conduct surface and electrochemical analysis; further a translation research approach is employed to compare the observations from the total hip replacement (THR) retrievals. A total cohort of 31 TMJ TJR devices were studied of which 28 were failed, retrieved TMJ TJRs, 3 were never implanted devices that served as controls. Data was acquired and evaluated by analyzing alloy microstructure. Substantial surface damage was observed between the articulating areas of the condylar head and the glenoid fossa components. Electrochemical analysis was performed on the MoM Control, retrieved, failed MoM, and TiN Coated devices. This study demonstrated the role of wear and corrosion interactions on the early failure of TMJ TJR devices. Since the materials employed in most orthopedic TJR devices are similar to those used in TMJ TJR implants, a comparison study was conducted.

Subjective and objective outcomes in patients reconstructed with a custom-fitted alloplastic temporomandibular joint prosthesis

PURPOSE

This study looked at prospective subjective and objective preoperative and postoperative outcome data from a set of multiply operated, anatomically mutilated, functionless, chronic temporomandibular joint (TMJ) pain patients who have undergone TMJ reconstruction with a custom-fitted prosthetic system.

PATIENTS AND METHODS

Two hundred fifteen patients (363 joints: 296 bilateral, 67 unilateral) who had undergone total TMJ reconstruction with a custom-fitted TMJ prosthesis (Techmedica; now TMJ Concepts, Camarillo, CA) made up the subjects reviewed in this study. The mean follow-up period was 30.7 months. The patients were divided into 3 groups based on the number of prior unsuccessful TMJ arthrotomies they had undergone (group 1 = 0 to 2; group 2 = 3 to 8; and group 3 = 9 or more)

RESULTS

Subjective improvement ratio data indicated that postoperatively group 1 had a 61.3% improvement in subjective parameters, group 2 had a 51.0% improvement, and group 3 had only a 27.5% improvement. Objective improvement ratio data showed that postoperatively group 3 had the largest increase in maximum interincisal opening, whereas the other groups had less improvement.

CONCLUSION

The data from this study confirm, as previously reported in the literature, that the greater the number of surgical procedures performed on the TMJ, the less the chance of significant subjective improvement.

Considering total temporomandibular joint replacement

Patients with very advanced degenerative disease, ankylosis, post-traumatic condylar destruction, and multi-operated patients may be candidates for joint replacement with fossa and condylar prostheses. Great advances have been made in developing biocompatible materials, improved designs for patient-fitted prostheses. These devices have treated internal derangement cases after multiple surgical and nonsurgical treatment failures, as well as restoring form and function following the removal of failed Vitek Proplast-Teflon (Houston, Texas) containing temporomandibular joint implants. This paper will provide practitioners dealing with complex, debilitated, functionless temporomandibular joint (TMJ) patients with information related to this treatment modality. They will then be able to address the indications for the use of alloplastic temporomandibular joint replacement devices, the devices presently available, the surgery involved in their placement, possible complications of implantation and post-operative outcomes and expectations with patients who would benefit from the implantation of these devices.

Central mucoepidermoid carcinoma

A case of central mucoepidermoid carcinoma of the mandible is presented along with a review of the literature. The histogenesis of this tumor and the histologic similarity of the predominantly cystic low-grade central mucoepidermoid carcinoma to the glandular odontogenic cyst are discussed.

Custom CAD/CAM total temporomandibular joint reconstruction system: preliminary multicenter report

PURPOSE

The purpose was to test the outcome of a custom computer assisted design/computer assisted manufactured (CAD/CAM) total temporomandibular joint (TMJ) reconstruction system.

PATIENTS AND METHODS

There were 215 patients (13 males and 202 females); the average age at reconstruction was 40.9 +/- 10.3 years (range, 15 to 77 years). There were 363 joints placed, 296 bilateral and 67 unilateral. The patients had TMJ problems for an average of 10.3 +/- 7.0 years (range, 1 to 44 years), and had undergone a mean of 5.4 +/- 4.8 (range, 0 to 28) prior unsuccessful surgeries. Preoperative and postoperative data were collected for up to 48 months using a standardized data collection format. Subjective data related to pain, function of the lower jaw, and diet, were obtained using a visual analogue scale. Objective measures of mandibular range of motion were made directly on the patient preoperatively and postoperatively.

RESULTS

Preliminary analysis of these data reveals a statistically significant decrease in pain, an increase in function, and improvement in diet (P < .0001) from the preoperative measurements to 1 and 2 years postoperatively. There was also improvement in mandibular vertical range of motion. The number of previous surgeries was a strong predictor of postoperative pain, function, and diet scores, as well as of maximal interincisal opening. A life table analysis of failures indicates good durability of the prosthesis over time.

CONCLUSION

These preliminary data indicate that this custom CAD/CAM total TMJ reconstruction system seems to be useful in the treatment of the multiply operated, and/or anatomically mutilated TMJ.

Outcome assessment in oral and maxillofacial surgery advanced education programs

Outcome assessments are becoming a standard by which predoctoral and postdoctoral advanced dental educational programs are being evaluated internally and externally. This article presents an overview of the process of development of an outcome assessment document for oral and maxillofacial surgery residency programs and provides an example of its value in the evaluation of two different types of oral and maxillofacial surgery programs.

Measurement of the heat of reaction transmitted intracranially during polymerization of methylmethacrylate cranial bone cement used in stabilization of the fossa component of an alloplastic temporomandibular joint prosthesis

Temporomandibular joint alloplastic fossa replacements have always been difficult to stabilize because of the variability of the anatomy in the area both in normal and especially in pathologic states. Total joint reconstruction and stabilization in orthopedic surgery have been aided by the use of methylmethacrylate, which is used both as a cementing substance and as a filler material when there are voids between the implant and the basilar bone. The concept of the use of a filler material to aid in the stabilization of the alloplastic temporomandibular joint fossa is attractive, but of concern because of the exothermic reaction this material undergoes as it sets in proximity to the middle cranial fossa. This study was designed to measure the temperature gradient that exists in such a procedure when used with cadaver specimens. The results indicate that the heat of reaction was not significantly transmitted intracranially in the cadavers studied. However, I recommend care in the use of this material for this purpose with patients.

Family therapy in complex temporomandibular joint dysfunction. A case study in collaboration

The purpose of this paper is to offer the oral and maxillofacial surgeon a collaborative approach to the treatment of complex temporomandibular joint (TMJ) dysfunction. Through a positive relationship with a family therapist, the oral and maxillofacial surgeon in this case reports family therapy intervention as an additive solution to resolving apparent recurrent surgical failures. After three surgical procedures, the oral and maxillofacial surgeon noted continued muscle hyperactivity brought on by family environmental stress and arranged for family therapy treatment before a fourth surgical procedure. This paper presents a complicated TMJ case history, documentation for including the family in treatment of pain problems, collaborative efforts necessary for acceptance of referral for psychological intervention, and a family therapy approach to treatment in complex TMJ dysfunction.

Pneumatization of the articular eminence of the temporal bone: prevalence, development, and surgical treatment

Routine panoramic radiographs of 784 patients were evaluated retrospectively for the presence of pneumatization of the articular eminence of the temporal bone (PAT). The radiographs of eight patients showed signs of PAT. These eight patients ranged in age from 32 to 69 years, and four patients had bilateral involvement of the temporal bone. The use of tomography is recommended before surgical procedures involving the eminence to determine the extent of the pneumatization.

The relationship between blood ordered and blood administered in orthognathic surgery: a retrospective study

A retrospective study was performed to determine the appropriateness and efficiency of preoperative blood ordering practices in orthognathic surgery. Results obtained showed that preoperative blood typing and crossmatching should be performed on patients who will be receiving combined maxillary and mandibular osteotomies with iliac crest grafts. Patients receiving all other types of osteotomies should have only preoperative blood typing and screening. This will serve to reduce cost to the patient, blood wastage, and the laboratory work load.

Autogenous third molar transplantation: report of case

This case reports the surgical autogenous transplant of a third molar into a first molar recipient site. No antibiotic therapy was prescribed. Mechanical stabilization was minimal, because most of the splinting was provided by the adjacent teeth. Twenty-one months postoperatively, the tooth exhibited normal growth and absence of morbidity. The only abnormality was a decrease in the size of the pulp chamber.

Intraoral vertical subcondylar osteotomy: a national survey

The results of a national survey pertaining to the IVSO are presented and the findings are contrasted with the literature on the procedure. It was found that the IVSO is a popular procedure for mandibular setback, that the value of determining the mandibular divergence angle is equivocal, that the Stryker oscillating saw is the most popular instrument for performing the osteotomy, that most operators leave the segments unfixed, and that the intraoral approach to the correction of mandibular prognathism is preferred. There were no geographic trends noted.

External fixation of the unstable zygomatic arch fracture

Fixation of unstable zygomatic arch fractures may be accomplished with a relatively noninvasive approach using 24-gauge wire and modification of a readily available material, the orthopedic finger splint.

Psychological factors in adjustment to orthognathic surgery

The psychological adjustment of 30 orthognathic surgery patients was evaluated before and on three occasions after surgery. Results of preoperative testing showed the group to be well adjusted, and there were no major changes in psychological functioning as a result of surgery. Motivation for surgery included both functional and esthetic goals, and the majority of patients were satisfied with the results of surgery. The patient's perception of the surgeon was significantly related to pre- and postoperative adjustment. Two of the measures used, the Health Opinion Survey and the Impact Message Inventory, have potential as brief early screening devices to identify patients who may experience problems in psychological adjustment to orthognathic surgery.

Anxiety, information, interpersonal impacts, and adjustment to a stressful health care situation

Forty patients scheduled for dental extraction surgery were given either specific or general preparatory information, and this information was presented in either a personalized or relatively impersonal fashion using nonverbal cues. Changes in state anxiety over the course of the experiment were accounted for by individual differences in the Dental Anxiety Scale. The most important determinant of adjustment during surgery was the congruence between specificity of information received and individual differences in preference for information as measured by the Information subscale of the Krantz Health Opinion Survey (KHOS; Krantz, Baum, & Wideman, 1980). Findings with the KHOS and the Dental Anxiety Scale are examples of the growing importance of situation-specific personality-trait measures. The finding that high levels of presurgery anxiety are associated with poor adjustment is discussed in terms of Janis's (1958) model. Patients' perceptions of information-giver hostility and dominance were also significantly (inversely) related to adjustment; the differential impact of informational versus interpersonal variables is discussed in terms of moderating characteristics of health care settings.

Intra-articular meniscus dysfunction surgery. A preliminary report

Surgical management of painful intra-articular functional disorders of the temporomandibular joint has become a topic of much discussion. Data concerning the results of surgery are lacking not only because of the recent renewed interest in this surgery but also because of the small number of cases reported. The present study was undertaken to review the experience at the Medical College of Virginia/Virginia Commonwealth University Temporomandibular Joint and Facial Pain Center with surgical management of intra-articular meniscus dysfunction (IMD) as a specific entity. A review of IMD, criteria for establishment of the diagnosis, initial management, rationale for the surgery, type of surgery, and postoperative results in twenty-three cases will be discussed.

The Hecht, Beals, and Wilson syndrome: report of case

An unusual and rarely reported syndrome having as one of its features restricted mandibular opening has been reported. The diagnostic and treatment problems are discussed.

The specificity of response to experimental stress in patients with myofascial pain dysfunction syndrome

Comparison of autonomic and muscular response to experimentally induced stress in normal individuals and patients with myofascial pain dysfunction (MPD) syndrome revealed greater masseter and frontalis activity in the patient group, higher gastrocnemius activity in control subjects, and no significant difference in skin conductance and heart rate. This specificity of response to stress supports the psychophysiologic theory of MPD syndrome.

Cervical sympathetic block following intraoral local anesthesia

The sympathetic block of the nerves supplying the head, neck, and arm (Horner's syndrome) resulted from a misdirected intraoral local anesthetic injection. The anatomy of the fascial spaces and the potential risk of infection are discussed.

Intraoral second division nerve block

The second division of the trigeminal nerve can be easily blocked by the intraoral route. The technique presented involves entering the greater palatine foramen, traversing the pterygopalatine canal with a needle, and depositing the local anesthetic solution into the superior aspect of the pterygopalatine fossa, where the trunk of the second division lies after the nerve exits the foramen rotundum. The indications, contraindications, technique, and anatomic considerations are presented. This is followed by a discussion of the possible complications as well as their prevention and remedy should they occur. While this is not a new technique, it as been a forgotten one.