Changes in masticatory patterns after bilateral fracture of the mandibular condylar process

Quantitative Assessment of Condylar Remodeling After Open Reduction and Internal Fixation in Mandibular Condylar Head Fractures

Open reduction and internal fixation (OR/IF) and closed treatments are viable options, with OR/IF gaining popularity in mandibular condylar head fracture (CHF). Sufficient research is lacking on long-term condylar morphologic changes. This study quantitatively evaluated the morphologic changes in the condylar head in patients who underwent OR/IF for CHF without the removal of osteosynthesis material. A retrospective study analyzed patients who underwent OR/IF for CHF between November 2010 and August 2022. The transverse/lateral condyle width and condyle height were radiologically analyzed using panoramic and reverse Towne view x-ray images at immediate (T0), short-term (T1), and long-term (T2) postoperative periods. The study involved 29 patients with 32 surgically treated CHF. Long-term condyle height decreased significantly from 18.9±0.8 mm at T0 to 18.1±0.8 mm at T1 (P=0.042), and further to 17.3±0.7 mm at T2 (P=0.034). Transverse width slightly reduced from 18.7±0.7 mm at T0 to 17.9±0.8 mm at T1 (P=0.001) but remained stable from T1 to T2 (17.6±1.0 mm, P=0.756). Following surgery, maximal mouth opening averaged 39.5±6.1 mm, with one case of chin deviation and three cases of joint pain. The condyle undergoes long-term shortening without altering its width. Nevertheless, patients experience favorable functional outcomes, including satisfactory mouth opening and occlusion. In addition, it is advisable not to remove the osteosynthesis material, as the remaining material causes minimal functional impairment and bone resorption.

Analysis of Mandibular Muscle Variations Following Condylar Fractures: A Systematic Review

This review analyzes muscle activity following mandibular condylar fracture (CF), with a focus on understanding the changes in masticatory muscles and temporomandibular joint (TMJ) functioning.

MATERIALS AND METHODS

The review was conducted following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A search was performed on online databases using the keywords "masticatory muscles" AND ("mandibular fracture" OR "condylar fracture"). The eligibility criteria included clinical trials involving human intervention and focusing on muscle activity following a condylar fracture.

RESULTS

A total of 13 relevant studies were reviewed. Various studies evaluated muscle activity using clinical evaluation, bite force measurement, electromyography (EMG), magnetic sensors and radiological examinations to assess the impact of mandibular fractures on masticatory muscles.

CONCLUSIONS

Mandibular condylar fractures can lead to significant changes in muscle activity, affecting mastication and TMJ functioning. EMG and computed tomography (CT) imaging play crucial roles in assessing muscle changes and adaptations following fractures, providing valuable information for treatment planning and post-fracture management. Further research is required to explore long-term outcomes and functional performance after oral motor rehabilitation in patients with facial fractures. Standardized classifications and treatment approaches may help improve the comparability of future studies in this field.

Treatment of pediatric bilateral condylar fractures: A comprehensive analysis

Pediatric bilateral condylar fractures (PBCF) is a rare clinical pathology, where the management is carried out with both conservative and surgical approaches. The purpose of this study was to analyze and compare these two treatment approaches and their associated long term complications in PBCF. An extensive literature review- through the search of online databases- was conducted to survey, collect, analyze and compare the reported outcomes of different treatment modalities for PBCF. The number of studies presenting PBCF case reports was 16, while the number of such retrospective studies included here was 19. Analyses of these studies revealed that the conservative treatment is preferred in PBCF patients younger than 12 years of age. Moreover, a composite approach where the open reduction and internal fixation (ORIF) is carried out for one side while the intermaxillary fixation (IMF) for the contralateral side is frequently reported for the management of PBCF cases; this approach appears effective in improving daily functioning of temporomandibular joint and reducing long term complications. Performing ORIF for one side while IMF for the contralateral side seems the most common treatment approach in PBCF. This study may help in rapid decision making for treatment selection of PBCF patients while minimizing the risk for late complications.

In Vitro and In Vivo Assessment of a New Workflow for the Acquisition of Mandibular Kinematics Based on Portable Tracking System with Passive Optical Reflective Markers

Clinical use of portable optical tracking system in dentistry could improve the analysis of mandibular movements for diagnostic and therapeutic purposes. A new workflow for the acquisition of mandibular kinematics was developed. Reproducibility of measurements was tested in vitro and intra- and inter-rater repeatability were assessed in vivo in healthy volunteers. Prescribed repeated movements (n = 10) in three perpendicular directions of the tracking-device coordinate system were performed. Measurement error and coefficient of variation (CV) among repetitions were determined. Mandibular kinematics of maximum opening, left and right laterality, protrusion and retrusion of five healthy subjects were recorded in separate sessions by three different operators. Obtained records were blindly examined by three observers. Intraclass correlation coefficient (ICC) was calculated to estimate inter-rater and intra-rater reliability. Maximum in vitro measurement error was 0.54 mm and CV = 0.02. Overall, excellent intra-rater reliability (ICC > 0.90) for each variable, general excellent intra-rater reliability (ICC = 1.00) for all variables, and good reliability (ICC > 0.75) for inter-rater tests were obtained. A lower score was obtained for retrusion with “moderate reliability” (ICC = 0.557) in the inter-rater tests. Excellent repeatability and reliability in optical tracking of primary movements were observed using the tested portable tracking device and the developed workflow.

Bilateral mandibular condyle fractures: Should we open both?

Bilateral condylar fractures are common but are frequently undertreated. In most of the cases, only one side is surgically addressed and the other side is managed conservatively. Bilateral condylar fractures lead to loss of ramal height bilaterally, accentuated anterior open bite, disruption of articular surfaces, and disc and muscle attachments. In a mandibular bilateral condylar fracture, even though open reduction and internal fixation (ORIF) is done on one side, a patient still needs Inter Maxillary Fixation (IMF) for 2–4 weeks postoperatively to correct occlusion and deviation. The possibility of doing ORIF on the other is never explored. Here, we present two cases of bilateral condylar fracture treated both sides by ORIF. The article discusses the advantages and new approach to consider treating both sides.

Lateral Pterygoid Muscle Biometric Modifications in Pterygoid Process Fractures Associated With Mandibular Fractures

PURPOSE

Pterygoid process fractures (PPFs) are classically associated with Lefort fractures but can also be encountered in association with other facial fractures such as mandibular fractures. The aim of this study was to estimate the frequency of PPFs associated with mandibular fractures and identify factors associated with PPF.

MATERIALS AND METHODS

We conducted a retrospective cross-sectional study using computed tomography scanning of patients having a mandibular fracture between November 2018 and April 2020. PPFs were classified using the classification by An et al. Volume, length, and width of both lateral pterygoid muscles have been evaluated by using an image processing software. Study population has been divided into 2 groups: fracture of pterygoid process or the absence of PPF. To evaluate the implication of lateral pterygoid muscle in the pathophysiology of PPF, we compared lateral pterygoid muscle volume, its maximal length, and width between both groups. Patients with bilateral fractures were excluded from this analysis.

RESULTS

About 304 patients with at least 1 mandibular fracture have been included in this study. About 18 patients presenting an association of mandibular fracture and PPF were finally selected. About 83.33% of the patients were concerned by a fracture of the posterior part of the mandible. The PPF was classified as type IIA by the classification of An et al for 94.4% of patients. The lateral pterygoid muscle volumes were significantly larger on the side of the PPF (P = .02). However, there were no significant differences in the maximum length (P = .49) and width (P = .1) of lateral pterygoid muscle.

CONCLUSIONS

Our study showed an association between mandibular fractures (mainly ipsilateral posterior) and isolated PPF through a lateral pterygoid muscle volume increase.

Does Fracture Pattern Influence Functional Outcomes in the Management of Bilateral Mandibular Condylar Injuries?

The purpose of this study was to compare the functional outcomes of different types of bilateral mandibular condylar fractures. This was a retrospective study of patients with bilateral mandibular condylar fractures at a level-1 trauma center over a 15-year period. The primary predictor variable was fracture pattern, classified as type I (bilateral condylar), type II (condylar-subcondylar), or type III (bilateral subcondylar). Secondary predictor variables were demographic, injury-related, and treatment factors. Bivariate associations between the predictors and complication rates were computed; a multiple logistic regression model was utilized to adjust for confounders and effect modifiers. Thirty-eight subjects with bilateral condylar injuries met the inclusion criteria. The sample's mean age was 37.6 + 18.2 years, and 16% were female. The most common mechanisms of injury were motor vehicle collisions (53%) and falls (29%). Seventy-four percent had associated noncondylar mandibular fractures, and 32% of cases had concomitant midface fractures. Fifty-three percent of cases were classified as type I, 21% as type II, and 26% as type III. Ten subjects (26%) were managed with open reduction and internal fixation. The average length of follow-up was 4.5 + 6.3 months. After adjusting for confounders and effect modifiers, the type of fracture was a significant predictor of functional complications with type II injuries having the highest likelihood of a poor functional outcome (odds ratio: 7.77, 95% confidence interval: 1.45-41.53, p  = 0.02). Asymmetric bilateral mandibular condylar fractures may be associated with an increased risk of poor functional outcomes.

"Closed Reduction" Principles Can Manage Diverse Conditions of Temporomandibular Joint Vertical Height Loss: From Displaced Condylar Fractures to Idiopathic Condylar Resorption

PURPOSE

The aim of this case series was to describe a modification of the classic "closed reduction" technique to manage unilateral or anterior open bite owing to a loss in vertical height (LVH) caused by several disorders and pathologies other than displaced condylar fractures.

MATERIALS AND METHODS

The protocol included insertion of an occlusal appliance to increase the height of the premature contact and the width of the open bite, stabilization of the dental arches by rigid arches, and the use, during sleep, of rubber bands in the open bite region to pull the mandible cranially. In addition, when awake, the patient performed physiotherapy exercises to guide the mandible into maximum intercuspation. The increased open bite enhanced the effect of the rubber bands in guiding the mandible into the original habitual occlusion and the rigid arches served to minimize tooth eruption.

RESULTS

The present cases showed the favorable outcome of this low-risk treatment in the re-establishment of the original habitual occlusion within 1 to 4 weeks and without reconstruction of the LVH.

CONCLUSION

The efficacy of this complication-free approach to correct occlusion in various conditions of LVH suggests that this protocol should be applied before venturing into surgical intervention.

Impact of midface and upper face fracture on bite force, mandibular mobility, and electromyographic activity

This study evaluated the bite force, electromyographic activity, and mandibular mobility in patients undergoing surgery for facial fracture treatment that required a coronal approach. Ten men were divided into two groups: group I, coronal approach with pre-auricular extension (n=4, average age 34.5 years); group II, coronal approach (n=6, average age 24.8 years). The maximum bite force was measured using a dynamometer and mandibular mobility using a calliper. The electromyographic activity of the right masseter (RM), left masseter (LM), right temporal (RT), and left temporal (LT) muscles was evaluated using a Myosystem-Br1 apparatus. Patients were evaluated at 1, 2, 3, and 6 months after surgery. Data were analysed using the repeated measures test (SPSS 21.0; P≤0.05). Statistically significant differences were found for electromyographic activity at rest (group II: LM P=0.00), left laterality (group I: RT P=0.02; group II: RT P=0.04), and maximum voluntary contraction (group I: RM P=0.04 and RT P=0.04; group II: RM P=0.05, LM P=0.00, and LT P=0.01 and for maximum molar bite force in the right (group I, P=0.00; group II, P=0.01) and left (group II, P=0.01) molar regions. The subjects regained electromyographic activity, maximum bite force, and mandibular mobility throughout the period evaluated.

Functional evaluation in orthodontic surgical treatment: long-term stability and predictability

Background

The introduction of electromyographic and kinesiographic technology in orthodontics allows to obtain objective data regarding the functional aspects of the mandibular movements and the masticatory muscular activity. It is then important to be able to correlate the data obtained by instrumental activity with the clinical ones. The aim of this study consists to analyse the post ortodontic surgical stability through instrumental evaluation of the masticatory muscles and mandibular movements.

Method

30 patients undergo electromyographic and kinesiographic evaluations through all the surgical orthodontic iter and were than followed during other 4 years. JMP software was used to analyze and correlate the electromyographic and knesioographic data during treatment and during the follow up.

Results

A linear correlations between some functional objective values collected from the examinations at the beginning and during therapy and the follow up one has been demonstrated.

Conclusion

It is important to submit patients in surgical ortodontic treatment to instrumental analysis which can evidence how masticatory function and mandibular movements are performed. It is also important to highlight some functional values also from the beginning of the treatment because an alteration of such values can be related to a better or worse postsurgical rehabilitation.

Open versus closed reduction: diacapitular fractures of the mandibular condyle

PURPOSE

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle.

METHODS

An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions.

RESULTS

The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers.

CONCLUSIONS

The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical therapy. If conducted properly, surgical treatment of DFs is a safe and predictable procedure and yields good results.

Electromyographic analysis of anterior temporalis and superficial masseter muscles in mandibular angle fractures--a pilot study

INTRODUCTION

Fracture of the mandible occurs more frequently and the surgical anatomy of the mandible and adjacent structures is extremely important in understanding the pattern of fracture, the displacement of fractured fragments, and factors necessary for uncomplicated healing. In the field of dentistry, surface electromyography, electrokinesiography, and more recently, TMJ sound analysis have been particularly important developments. Previous electromyographic studies involving anterior temporalis and superficial masseter have been conducted in mandibular condylar fractures and in orthognathic and cosmetic procedures of the jaws.

MATERIALS AND METHODS

This experimental study was undertaken to measure the electrical activity of the anterior temporalis and superficial masseter muscles in mandibular angle fracture cases (n = 6) and the changes in the electrical activity over a period of 6 months.

RESULTS

The study shows that muscle activity increases significantly over a period of time but never matches the muscle activity of the normal subjects of same sex and age in a follow-up of 6 months post-trauma.

DISCUSSION

Electrodiagnostic testing is a potentially valuable tool for the management of patients who have suffered craniomaxillofacial trauma. Electromyography is being employed in clinical practice, and allows the inclusion of quantitative data on the qualitative aspects of a diagnosis. These data are often of significant importance in the correct management of therapy and patient follow-up, particularly if the subject is at risk of developing a different and/or more serious disease.

Functional outcomes of the retromaxillary-infratemporal fossa dissection for advanced head and neck/skull base lesions

The retromaxillary-infratemporal fossa (RM-ITF) dissection, using a preauricular incision, was initially popularized for the treatment of temporomandibular joint disorders, facial fractures, and orbital tumors. This approach has been expanded for the treatment of advanced head and neck and skull base tumors extending into the infratemporal fossa. We studied prospectively eight consecutive patients requiring a RM-ITF dissection. Pre- and postoperative functional outcomes measured were mastication, speech, swallowing, cranial nerve function, pain, and cosmesis. A significant reduction in pain was noted postoperatively in all patients studied. Limited changes were identified in mastication, speech, swallowing, vision, hearing, or cosmesis postoperatively. The RM-ITF dissection should be considered when resecting advanced head and neck/skull base lesions that extend into this region. We have found minimal morbidity associated with this dissection. This procedure may have a useful place in palliation of patients with incurable pain caused by tumor invasion into the infratemporal fossa.

Functional outcomes following surgical treatment of bilateral mandibular condylar fractures

Debate continues regarding unilateral or bilateral treatment for mandibular condylar fractures. This retrospective study evaluates the functional outcomes of bilateral condylar process fractures after surgical intervention. From May 1994 to December 2004, 51 adult patients with bilateral mandibular condylar process fractures were studied. There were 33 cases of bilateral condylar fractures (type I); 12 cases of condylar-subcondylar fractures (type II); and six cases of bilateral subcondylar fractures (type III). All patients underwent open reduction and internal fixation. Four patients had chin deviation, six had malocclusion, three had poor chewing function and eight had limited mouth opening. Type I patients had a significantly higher incidence of limited mouth opening (P=0.039) and associated maxillary fractures (n=12) and psychiatric disease (n=6) which yielded significantly poor functional outcomes. Complications included transient facial paresis (n=4), fracture and loosening of postoperative plates (n=3) and surgical wound infections (n=2). Open reduction with rigid fixation for bilateral condylar fractures provided satisfactory functional outcomes in this study. Concomitant maxillary fractures and underlying psychiatric problems are poor outcome factors. Aggressive rehabilitation in the first 9 months is important for early functional recovery.

Three-dimensional mandibular motion after closed and open reduction of unilateral mandibular condylar process fractures

OBJECTIVE

To detect the changes in 3D mandibular motion after two types of condylar fracture therapies.

MATERIALS AND METHODS

Using a 3D motion analyzer, free mandibular border movements were recorded in 21 patients successfully treated for unilateral fractures of the mandibular condylar process (nine patients: open reduction, rigid internal fixation, and functional treatment; 12 patients: closed reduction and functional treatment; follow-up: 6-66 months), and in 25 control subjects.

RESULTS

No differences were found among the groups at maximum mouth opening (MO), protrusion and in lateral excursions. During opening, the patients had a larger maximal deviation to the fractured side than the controls (controls 2.3 mm, open treatment 3.9 mm, closed treatment 4.2 mm; Kruskal-Wallis test, p=0.014; closed treatment vs. controls, p=0.004), with a larger coronal plane angle (controls 2.4°, open treatment 3.6°, closed treatment 4.4°; p=0.016; closed treatment vs. controls, p=0.013). In the closed treatment patients, a longer follow-up was related to increased maximum MO (p=0.04), sagittal plane angle (p=0.03), and reduced lateral mandibular deviation during MO (p=0.03).

CONCLUSION

Mandibular condylar fractures can recover good function; some kinematic variables of mandibular motion were more similar to the norm in the open treatment patients than in closed treatment patients.

The adaptive response of jaw muscles to varying functional demands

Jaw muscles are versatile entities that are able to adapt their anatomical characteristics, such as size, cross-sectional area, and fibre properties, to altered functional demands. The dynamic nature of muscle fibres allows them to change their phenotype to optimize the required contractile function while minimizing energy use. Changes in these anatomical parameters are associated with changes in neuromuscular activity as the pattern of muscle activation by the central nervous system plays an important role in the modulation of muscle properties. This review summarizes the adaptive response of jaw muscles to various stimuli or perturbations in the orofacial system and addresses general changes in muscles as they adapt, specific adaptive changes in jaw muscles under various physiologic and pathologic conditions, and their adaptive response to non-surgical and surgical therapeutic interventions. Although the jaw muscles are used concertedly in the masticatory system, their adaptive changes are not always uniform and vary with the nature, intensity, and duration of the stimulus. In general, stretch, increases neuromuscular activity, and resistance training result in hypertrophy, elicits increases in mitochondrial content and cross-sectional area of the fibres, and may change the fibre-type composition of the muscle towards a larger percentage of slow-type fibres. In contrast, changes in the opposite direction occur when neuromuscular activity is reduced, the muscle is immobilized in a shortened position, or paralysed. The broad range of stimuli that affect the properties of jaw muscles might help explain the large variability in the anatomical and physiological characteristics found among individuals, muscles, and muscle portions.

Closed reduction, open reduction, and endoscopic assistance: current thoughts on the management of mandibular condyle fractures

The management of fractures of the mandibular condyle continues to be controversial. This is in part attributable to a misinterpretation of the literature from decades prior, a lack of uniformity of classification of the various anatomical components of the mandibular condyle, and a perceived potential to cause harm through the open approach based in part on the surgeon's lack of a critical examination of the literature. This review explores the key historical articles that deal with the management of mandibular condyle fractures, and those modern-day contributions that represent the state of the art. The authors' intention was to provide the reader with an objective summary of the management of this form of injury, to place its management into a modern-day perspective, and perhaps to minimize the perception of controversy.

Prospective evaluation of a pragmatic treatment rationale: open reduction and internal fixation of displaced and dislocated condyle and condylar head fractures and closed reduction of non-displaced, non-dislocated fractures

This study prospectively evaluated closed reduction (CR) outcomes in non-displaced, non-dislocated high-condylar and condylar-head fractures (Class VI after Spiessl and Schroll) and open reduction and internal fixation (ORIF) of displaced (Class III) or dislocated (Class V) fractures. Thirty-eight patients with 54 fractures (16 (42%) with bilateral fractures, 14 (37%) CR, 24 (63%) ORIF) were enrolled in a 1 year follow-up that 18 patients with 33 fractures completed. Condylar translation in Class VI fractures recovered to 11 mm for vertical opening, 8mm for protrusion and 10 mm for mediotrusion; Class III synonymously 8 mm, 8 mm and 6 mm; and Class V 7 mm, 6mm and 7 mm; incisal movements recovered to 38 mm, 8 mm and 8 mm in Class VI; 55 mm, 7 mm and 10 mm in Class III with 1 (8%) malocclusion, 1 (8%) impaired vertical opening and 55 mm, 7 mm and 9 mm in Class V with 2 (18%) malocclusions. Fragment-reduction versus the non-fractured condyle was -0.3 mm to +1.3 mm and +3 degrees to +9 degrees in Class VI, -1 mm to -0.2 mm and +3 degrees to +2 degrees in Class III, -3.3 mm to +3.1 mm and -11.2 degrees to +1 degrees in Class V. Malocclusion and joint locking were unreliable determinants for a treatment decision, being forged by concomitant fractures. Joint movements were within normal range at 1-year follow-up except Classes III and V vertical opening translation. After predefined criteria, 92% successful outcomes were attained. Multiple factor analysis should be used to prospectively evaluate the unacceptable clinical outcomes. Class VI fractures with intact vertical support should prospectively be evaluated whether these benefit from ORIF.

Treatment of mandibular condylar process fractures: Biological considerations

The topic of condylar injury in adults has generated more discussion and controversy than any other in the field of maxillofacial trauma. It is an important subject because such injuries are common and complications of trauma to the temporomandibular joint (TMJ) are far-reaching in their effects. Why are there so many different methods to treat this injury? How can seemingly disparate treatment options all produce satisfactory outcomes in the majority of patients? The reason lies with the biological adaptations that occur within the masticatory system that are poorly understood, not readily quantifiable, and variable from one person to the next. This discussion presents our current understanding of the adaptations that must occur to provide the patient with a satisfactory outcome. The adaptations for patients treated open are different than for those treated closed. However, it is when these adaptations fail to occur that unsatisfactory outcomes occur, regardless of how they were treated.

Masticatory motion after surgical or nonsurgical treatment for unilateral fractures of the mandibular condylar process

PURPOSE

We sought to compare mandibular motion during mastication in patients treated in either an open or a closed fashion for unilateral fractures of the mandibular condylar process.

PATIENTS AND METHODS

Eighty-one male patients with unilateral condylar process fractures were treated either with (n = 37) or without (n = 44) surgical reduction and rigid fixation of their condylar process fractures. At 6 weeks, 6 months, 1 year, and 2 years after treatment, the subjects' chewing cycles were recorded using a magnetic sensor array (Sirognathograph; Siemens Corp, Bensheim, Germany) while chewing Gummi-Bears (HARIBO, Bonn, Germany) unilaterally on the same side as the fracture and on the opposite side. The chewing cycles were analyzed using a custom computer program, and the duration, excursive ranges, and 3-dimensional cycle shape were compared between the 2 treatment groups at each time interval using multilevel linear modeling statistics.

RESULTS

The 2 treatment groups did not differ significantly for any measure of cycle duration or any excursive range (except lateral excursions at 1 year post-treatment) at any of the time intervals. However, the 3-dimensional cycle shapes of the 2 groups did differ significantly at all time intervals.

CONCLUSION

Surgical correction of unilateral condylar process fractures has relatively little effect on the more standard measures (duration and excursive ranges) of masticatory function. However, surgical correction better normalizes opening incisor pathways during mastication on the side opposite the fracture.

Jaw kinematics during mastication after unilateral fractures of the mandibular condylar process

This study compared the mandibular kinematics during mastication of patients treated for unilateral fractures of the mandibular condylar process with those of control subjects. We used a Sirognathograph (Siemens, Bensheim, Germany) to record the chewing cycles of 81 male patients with unilateral condylar process fractures while they chewed a constant bolus unilaterally on the same side as the fracture and on the opposite side. Recordings were made at 6 weeks, 6 months, 1 year, and 2 years after treatment. Similar chewing cycles were recorded for 15 male controls (Class I dental and Class I skeletal occlusion) without fractures of the condylar process. The chewing cycles of both groups were analyzed with a custom computer program, and the duration, excursive ranges, and 3-dimensional cycle shape were compared at each time interval with multilevel linear modeling statistics. Fracture patients had significantly slower chewing cycles, with significantly less maximum excursion toward the working side during the closing phase and significantly greater excursion toward the balancing side during the opening phase than the controls. The opening pathway of the incisors showed greater differences between patients and controls than the closing pathways. Differences in chewing cycle shape persisted for up to 2 years, especially when chewing was on the side opposite the fracture. Unilateral condylar process fractures produce long-lasting changes in chewing cycle duration and chewing cycle shape of adults.

Assessment of patients treated for intracapsular fractures of the mandibular condyle by closed techniques

PURPOSE

The goals to study different lines of intracapsular fractures of the mandibular condyle and to evaluate their influence on the prognosis after closed treatment.

PATIENTS AND METHODS

Clinical, radiologic, and axiographic follow-up of 40 patients with 50 intracapsular fractures of the mandibular condyle was carried out after closed treatment. The examinations were performed an average of 22 weeks after treatment. Three types of intracapsular fractures were distinguished: type A, or fractures through the medial condylar pole; type B, or fractures through the lateral condylar pole with loss of vertical height of mandibular ramus, and type M, multiple fragments, comminuted fractures.

RESULTS

Moderate to serious dysfunction was observed in 33% of the cases. Radiologic examination of fracture types B and M revealed a reduction in the height of the mandibular ramus of up to 13% compared with the contralateral side. These 2 fracture types also resulted in the most prominent deformations of the condylar head. Axiography revealed irregular excursions and a limitation of condylar movement in comminuted fractures of up to 74% compared with the nonfractured side.

CONCLUSION

Lesions to the osseodiscoligamentous complex of the temporomandibular joint caused by intracapsular fractures of the mandibular condyle can be severe. The poor functional and radiologic results encountered in the fracture types B and M showed the limitations of closed functional treatment.