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The inevitable sacrifice of the inferior alveolar nerve during oncologic resections results in substantial sensory impairment, impacting crucial functions such as speech, saliva retention, and mastication. This study investigated the feasibility of sensory restoration through cross-face reconstruction of the mental nerve via a contralateral mental nerve branch. The cross-face reconstruction procedure was simulated in five formalin-fixed cadavers in both sides to evaluate the anatomic fundamentals and the nerve gap between the mental nerve main trunk and transferred contralateral mental nerve branch. Furthermore, a histomorphometric analysis was performed to assess the cross-sectional area and axon counts. The mean gap distance between the main mental nerve trunk and transferred contralateral branch was 15.3 mm. End-to-end coaptation was achieved in nine out of ten simulations. The mean cross-sectional area was 0.996 mm2 at the main mental nerve trunk and 0.253 mm2 at the coaptation site of the nerve branch. The mean donor-to-recipient axon ratio was found to be 0.3:1. The cadaveric simulation demonstrates the feasibility of a cross-face reconstruction of the mental nerve with only minimal gapping. Advantages of the proposed technique include the use of shorter nerve grafts, to minimize donor site morbidity and enable fast reinnervation. This technique may offer a promising method to enhance the quality of life in patients by increasing survival rates and life expectancy. [ABSTRACT FROM AUTHOR]

This clinical report summarizes a workflow that introduces two approaches for fabricating a metal framework removable partial denture for a marginal mandibulectomy patient. First, the pre-existing denture was adjusted according to the piezographic technique to determine the optimal configuration for adhering to the available denture space. Second, computer-aided design-computer-aided manufacturing (CAD-CAM) technology was used to fabricate a new removable partial denture by digitally scanning the oral condition and the well-adjusted denture and then using the obtained data to design and fabricate the new denture. These two approaches can help to reduce chair time not only for maxillofacial prosthetic treatment but also for other denture cases. [ABSTRACT FROM AUTHOR]

Titanium plates have been used for primary reconstruction after mandibular resection in patients with oral cancer and mandibular osteomyelitis. However, complications—including plate fracture and screw breakage—have led to problems in the recovery of strength and aesthetics. Computer-assisted fabrication of custom-made plates has recently been developed, such as with Cosmofix®. Developed in Japan, it is a fully custom-made plate created by layered fabrication using three-dimensional (3D) printing technology after designing a plate that fits the mandibular defect based on the patient's computed tomography (CT) data. In this study, we treated two cases of medication-related osteonecrosis of the jaw (MRONJ) with mandibular dissection and primary reconstruction of the mandible with Cosmofix® using a self-made surgical guide made with PROPLAN CMF™ virtual planning software. Case 1: A 68-year-old female patient with stage 2 MRONJ underwent mandibular reconstruction using Cosmofix® after mandibular dissection from the┌4-centrum to the angle of the mandible. Case 2: A 78-year-old female patient with MRONJ stage 3 underwent mandibular dissection from 4┐to┌7, and her mandible was reconstructed using CosmofixⓇ. The patient was highly satisfied with the aesthetic result, as the preoperative facial appearance was almost restored. Long-term follow-up is needed to assess for plate fracture, screw breakage, and other issues. [ABSTRACT FROM AUTHOR]

Background: Ameloblastomas are a rare type of benign neoplastic tumors that are locally invasive and make up around 1% of all head-and-neck tumors. Mostly diagnosed in people between the ages of 30 and 60 years, it has a global incidence of about 0.5% of cases per million person years. Ameloblastomas are classified as multicystic, unicystic, peripheral, and desmoplastic variants. Unicystic ameloblastomas (UAs), accounting for about 6% of the cases, have a high recurrence rate. It is histologically divided into luminal, intraluminal, and mural types. As the mural variant is aggressive and has the highest chance of recurrence, radical resection of tumor is required. Case Presentation: A case of 47-year-old patient, diagnosed as unicystic mural variant of ameloblastoma presented to us in March 2023 at the department of head-and-neck surgery at a tertiary care setup in Karachi, Pakistan. Postoperatively, the patient is now on 6-month follow-up with no residual or recurrence report as of yet. Conclusion: We report a rare case of UA mural variant in the right mandible, which highlights the importance of prompt diagnosis and treatment of this type of ameloblastoma, particularly in a location where they can cause significant damage. [ABSTRACT FROM AUTHOR]

Canine acanthomatous ameloblastoma (CAA) has been reported to be the most prevalent odontogenic tumor in dogs. The most common location of this tumor is the rostral mandible. Symphyseal-sparing mandibulectomy has been shown to be an effective technique to maintain mandibular continuity and promote early return to function. In this retrospective study, 35 dogs with CAA associated with a mandibular canine tooth were evaluated following a symphyseal-sparing rostral mandibulectomy. Dogs with intraoperative transection of the canine tooth root and subsequent root fragment extraction were included. The objective of this study was to evaluate outcome following excision of CAA with mid-root transection. Data retrospectively evaluated in this study included the following: narrowest tumor margin, narrowest tumor margin at the border associated with the transected canine root, tumor size, and prevalence of local recurrence. This study showed that 82.86% of CAA were completely excised with tumor-free margins (N = 29). The median narrowest overall tumor-free margin was 3.5 mm (interquartile range [IQR] 2.0-6.5 mm) and the median tumor-free margin associated with the border of the transected canine root was 5.0 mm (IQR 3.1-7.0 mm). Follow-up data was obtained in 25 cases via phone interviews with referring veterinarians and clients. No local tumor recurrence was reported in cases with incomplete tumor excision (N = 5). All dogs with follow-up data survived at least 1 year following surgery. It was concluded that segmental or rostral mandibulectomy with wide margins to include the entire mandibular canine tooth with subsequent mandibular instability may not be warranted for dogs with CAA associated with this tooth. [ABSTRACT FROM AUTHOR]

Multilobular tumor of the bone is a rarely described neoplasia in the ferret. A 2-yr-old, male neutered ferret was presented for an oral swelling. On physical examination, a firm swelling was noted surrounding the base of tooth 409 with no discharge. The remainder of the physical examination was unremarkable. Differential diagnoses included oral neoplasia or abscess. A biopsy was recommended with possible extraction of the affected tooth. Medical management was initiated and a biopsy was scheduled. In surgery, the mass was determined to be firm. The initial biopsy results indicated a chondrosarcoma. A partial hemimandibulectomy was successfully performed without complications. The final histopathology report showed a multilobular tumor of bone. At 8 months postoperative and at the time of writing, no recurrence had been noted. This case reports an unusual presentation of a mandibular swelling in a ferret. Although rare, a multilobular tumor of bone should be considered as a differential for mandibular swelling in ferrets. Surgical intervention may be a viable treatment option. [ABSTRACT FROM AUTHOR]

Treatment for oral tumors in dogs may involve aggressive surgery, radiation therapy, and/or chemotherapy. It is of utmost importance that veterinarians can document the good quality of life (QoL) for patients during and after cancer treatment. In this retrospective study, medical records from 2 private practices during a 10-year period (2011-2020) were searched to identify dogs with confirmed histopathological diagnosis of an oral tumor. Owners of dogs who underwent surgery received a questionnaire to assess their perception of QoL before and after surgery, clinical signs from the oral tumor, pain before and after surgery, physical appearance, and drinking and eating ability after surgery. Forty-two of 45 (93%) owners answered the questionnaire. Thirty-eight owners (90%) perceived that their dog had not changed its appearance after surgery after the hair had regrown. Thirty owners (71%) reported that their dog prehended food and water normally within 4 weeks after surgery. Forty owners (95%) perceived that their dog had more "good" than ''bad" days after surgery. Thirty-eight owners (90%) would choose the same treatment again. Our results strongly support that dog owners perceived that their dogs had good QoL after partial mandibulectomy or maxillectomy. [ABSTRACT FROM AUTHOR]

Purpose: In the treatment of oral tumors, extensive jaw defects due to surgical resection can reduce masticatory performance. Herein, we aimed to clarify the factors related to masticatory performance in patients with jaw defects. Methods: In total, 76 patients (42 male and 34 female) underwent prosthetic treatment with a removable denture for a jaw defect following oral tumor surgery. Data on history of radiation therapy, period of time since surgery, period of use of the present denture, number of remaining teeth, and site of the jaw defect were collected. Masticatory performance was evaluated using test gummy jelly. In addition, maximum bite force, tongue pressure, tongue-lip motor function (oral diadochokinesis /pa/, /ta/, /ka/), and oral dryness were evaluated. Logistic regression analysis was performed with lower masticatory performance scores as the dependent variable. Since multicollinearity was suspected between the oral diadochokinesis /ta/ and /ka/ syllables, two logistic regression analyses were conducted: Model 1 with the /ta/ syllable as an explanatory variable, and Model 2 with the /ka/ syllable as an explanatory variable. Results: In Model 1, a history of radiation therapy, maximum bite force, number of remaining teeth, tongue pressure, and oral diadochokinesis /ta/ were significant explanatory variables. In Model 2, a history of radiation therapy, maximum bite force, number of remaining teeth, and tongue pressure were significant explanatory variables. Conclusions: A history of radiation therapy, maximum bite force, tongue pressure, number of remaining teeth, and motor function of the proglossis are related to decreased masticatory performance in patients with jaw defects. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the clinical outcomes of patients with stage 3 mandibular medication-related osteonecrosis of the jaw (MRONJ) treated using a submental island flap in combination with mylohyoid muscle reconstruction after rim mandibulectomy. The medical records of 12 patients treated between January 2019 and April 2022 were analysed retrospectively. Primary wound healing was assessed as the maintenance of full mucosal coverage without signs of infection at 6 months postoperatively. The follow-up period ranged from 7 to 38 months, with an average of 21.8 months. All 12 patients (100%) experienced primary wound healing, with normal mouth opening and occlusion, and without pathological mandibular fracture or facial aesthetic problems during the follow-up period. Postoperative panoramic images revealed new bone formation in the treated areas of the mandible in four patients. During the follow-up period, one patient continuing bevacizumab and zoledronate administration for the primary cancer developed MRONJ in the same area at 13 months postoperatively and finally died. Hence the total success rate was 91.7%. In summary, for patients with stage 3 mandibular MRONJ treated with rim mandibulectomy, the submental island flap combined with mylohyoid muscle is an effective reconstructive option for wound-healing and possible bone regeneration of denuded bone. [ABSTRACT FROM AUTHOR]

There remains a paucity of evidence with regards to functional outcomes following the reconstruction of segmental defects in the mandible. It is, however, well recognised that oral rehabilitation following head and neck surgery is a driver of improved quality of life outcomes. We present a prospective service review of functional outcomes of a consecutive cohort of patients following segmental mandibulectomy and virtual surgical planning (VSP) composite fibular free-flap reconstruction. Twenty-five patients, who were identified as having a complete dataset with a minimum of 12 months' follow up, ultimately met the inclusion criteria. Validated functional outcome measures were used primarily to assess speech, diet, and swallowing outcomes. The results demonstrate a decline in both speech and swallowing outcomes at three months postoperatively, with a decline of 37% in the Speech Handicap Index from the preoperative baseline, and a decline of 35% in the MD Anderson Dysphagia Inventory score over the same period. The MD Anderson Dysphagia Inventory score improved at 12 months, whereas the Speech Handicap Index did not. Fundamentally a collaborative approach is required between members of the multidisciplinary team (MDT) to enable optimal patient outcomes. [ABSTRACT FROM AUTHOR]

Diagnostic histopathology plays a key role in the management of oral cancer and timely reports are essential. The aim of this study was to retrospectively compare the time interval between receipt of the specimen and issue of the histopathology report (the 'turnaround time', TT) of two types of oral cancer resections (mandibulectomies and glossectomies) and incisional biopsies from the tongue (n = 100 of each). The information documented included the number of days from receipt of the specimen until the sample was ready for reporting, and the number of subsequent days until the report was authorised by the pathologist. The number of days mandibulectomies required decalcification, the number of blocks processed per sample, and pathological TNM stage were also recorded. Results showed that mandibulectomies had statistically significantly longer TT than glossectomies. Incisional biopsies had the shortest TT with 87% reported in seven days and 95% in ten. There were also statistically significantly longer TT for pT3/pT4 than for pT1/pT2 glossectomies, and between the number of blocks processed for the three main groups. Decalcification and the interval whilst the slides awaited the pathologists' attention were identified as 'bottlenecks'. Dentate mandibulectomies had the longest TT of all; extraction of teeth at operation and detachment of the lower border of the mandible at macroscopic sampling are thus potential means by which the decalcification delay might be reduced. Expectations of the multidisciplinary team managing the patient should be realistic when scheduling postoperative discussion. [ABSTRACT FROM AUTHOR]

Porcine mandibular defect models are commonly used for the preclinical evaluation of reconstruction techniques. Existing studies vary in technique, complexity, and postoperative outcomes. The procedures are complex and often described without sufficient detail. We describe in detail a simple and reproducible method for creating a critical-size mandibular defect in a porcine model. Seven hemimandibular critical size defects were created in five male Yorkshire-Landrace pigs, three with unilateral defects and two with bilateral defects. A transverse incision was made over the mandibular body. Periosteum was incised and elevated to expose the mandibular body and a critical-size defect of 30 × 20 mm created using an oscillating saw. The implant was inserted and fixed with a titanium reconstruction plate and bicortical locking screws, and the wound closed in layers with resorbable sutures. Intraoral contamination was avoided. Dentition was retained and the mental nerve and its branches preserved. The marginal mandibular nerve was not encountered during dissection. All pigs retained normal masticatory function, and there were no cases of infection, wound breakdown, haematoma, salivary leak, or implant-related complications. The procedure can be performed bilaterally on both hemimandibles without affecting load-bearing function. All pigs survived until the end point of three months. Postoperative computed tomographic scans and histology showed new bone formation, and a three-point bend test showed the restoration of biomechanical strength. Straight-segment mandibulectomy is a simple and reproducible method for the creation of critical-size mandibular defects in a porcine model, simulating a load-bearing situation. [ABSTRACT FROM AUTHOR]

Objectives: Temporomandibular joint ankylosis (TMJA) is the partial or complete inability to open the mouth due to intra- or extra-articular fibrous, bony or fibro-osseous tissue proliferation. Surgical procedures such as gap arthroplasty, condylectomy or wide extra-articular osteotomy have been recommended to treat this condition; these techniques are challenging, time-consuming and have been occasionally associated with postoperative recurrence, severe periarticular neurovascular iatrogenic trauma and death. Segmental mandibulectomy had previously been recommended as an alternative option for unilateral TMJA, but the location of mandibulectomy and extent of bone removal from the mandible region have not been mentioned in the literature. This study aimed to validate the area of the mandibular body (rostral, middle or caudal) and amount of bony tissue that should be osteotomized during a segmental mandibulectomy for treatment of unilateral TMJA in cats. Methods: In this block study, 30 cadaver heads of domestic shorthair cats were randomly divided into three groups of 10 specimens each based on the mandibular region that would undergo segmental mandibulectomy (rostral, middle and caudal). The size of the removed mandibular segment and pre- and postoperative vertical range of mandibular motion were compared for statistical purposes. Results: A significant statistical difference was observed between the pre- and postoperative vertical range of mandibular motion between the rostral, middle and caudal segmental mandibulectomies (P <0.001). The mean postoperative recovered range of mandibular motion for the rostral, middle and caudal segmental mandibulectomies was 50.4%, 81.9% and 90.4%, respectively. Conclusions and relevance: The caudal segmental mandibulectomy showed the highest postoperative vertical range of mandibular motion. The removal of a minimum of 1.2 cm of the caudal mandibular body was required to achieve nearly full recovery of presurgical mouth opening in the specimens of this study. The caudal segmental mandibulectomy may eliminate the risk of iatrogenic periarticular neurovascular damage inherent to more invasive surgeries performed at the temporomandibular joint area. When performed unilaterally, the caudal segmental mandibulectomy is a viable surgical alternative that may show a similar outcome to other surgical techniques. [ABSTRACT FROM AUTHOR]

In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide with the resection performed. Nine patients were included. The exact positions of the resection planes were planned virtually and a patient-specific cutting guide was designed and printed. After surgical placement of the cutting guide, intraoperative cone beam computed tomography (CBCT) was performed. Postoperative CT was used to obtain the final resection planes. Distances and yaw and pitch angles between the preoperative, intraoperative, and postoperative resection planes were calculated. Cutting guides were positioned on the mandible with millimetre accuracy. Anterior osteotomies were performed more accurately than posterior osteotomies (intraoperatively positioned and final resection planes differed by 1.2 ± 1.0 mm, 4.9 ± 6.6°, and 1.8 ± 1.5°, respectively, and by 2.2 ± 0.9 mm, 9.3 ± 9°, and 8.3 ± 6.5° respectively). Differences between intraoperatively planned and final resection planes imply a directional freedom of the saw through the saw slots. Since cutting guides are positioned with millimetre accuracy compared to the virtual plan, the design of the saw slots in the cutting guides needs improvement to allow more accurate resections. [ABSTRACT FROM AUTHOR]

Purpose: This study sought to geometrically evaluate the effect of a mandibular prosthesis on facial asymmetry in patients with one of two different types of mandibulectomy defect. Methods: Facial data from 20 participants (9 men and 11 women; mean age 68 years) with either a reconstructed segmental defect (segmental group, n = 10) or a marginal mandibulectomy defect (marginal group, n =10) were acquired with a non-contact three-dimensional (3D) digitizer. Facial asymmetry was evaluated by superimposing a facial scan onto its mirror scan using 3D evaluation software. Facial scans with and without the mandibular prosthesis in place were also superimposed to evaluate the effect of the mandibular prosthesis. Results: Facial asymmetry differed significantly between subjects with and without the prosthesis in the segmental group (P = 0.005) but not in the marginal group (P = 0.16). There was no significant difference in the effect of the prosthesis on facial appearance between the two groups (P = 0.052). The ratio of 3D deviation of facial asymmetry without the prosthesis and in the mirror scan with the prosthesis differed significantly between the two groups (P = 0.01). Conclusions: Placement of a mandibular prosthesis has a notable effect on facial asymmetry in patients with segmental mandibulectomy defects. [ABSTRACT FROM AUTHOR]

Lateral posterior segmental mandibular defects present a reconstructive challenge and an osseous flap would be the gold standard to reconstruct such a defect. However, combining a mandibular reconstruction plate (MRP) with a soft-tissue free flap (to restore mucosal integrity and provide durable coverage of the plate itself) offers an alternative option for posterior segmental mandibular defects in patients who are not suitable for osseous reconstruction, or do not choose it. We retrospectively reviewed 30 consecutive patients (19 male and 11 female) who underwent reconstruction of a segmental mandibulectomy defect using a bridging MRP and anterolateral thigh (ALT) free flap. The mean (range) age was 67 (31-87) years. The American Society of Anesthesiologists' (ASA) status of the study population comprised Grade 1 (n = 10), Grade 2 (n = 18), and Grade 3 (n = 2). The majority of patients had oral cavity squamous cell carcinoma (n = 26) involving the mandible, two had osteoradionecrosis, and two mucoepidermoid carcinoma. Four patients had complications specific to the reconstruction, and flap loss occurred in one (96.7% success rate). Metalwork infection occurred in three, including one plate extrusion and one plate fracture. The median length of stay was 10 days, and mean (range) duration of follow up 23.3 (1-96) months. This technique is an alternative reconstructive option for the non-tooth-bearing mandible. Reconstructing a posterolateral segmental mandibulectomy defect with a bridging MRP and ALT free flap offers a robust reconstructive alternative with a favourable complication profile. [ABSTRACT FROM AUTHOR]

Background and Aim: Oral cancer has been the second most common cancer in India. Mandibular cancer has been in raise due to the use of tobacco-related products. The influence of mandibular cancer before and after surgery has not been studied much. Hence, the current study aimed to evaluate the effect of mandibulectomy on mandibular stability through the assessment of diadochokinetic measurement. Materials and Methods: Thirty-nine subjects served as participants for the present study. Out of which, 30 normal (group 1) and 9 individuals of the mandibular lesion (group 2) as a clinical group. Study material included rapid repetition of bilabial /pa/, alveolar /ta/, velar /ka/ and /pataka/ sequence for 6 seconds duration. Three trials have been obtained from all participants. Data were analyzed using Praat software and an independent t-test and paired t-test was used for statistical analysis. Results: Results showed a reduced SMR rate as compared to the control group in the postoperative condition. AMR rate of only /pa/ syllable was found to be statistically significant at a lower rate in post-operative conditions. The acoustic parameters of syllable duration, inter syllable duration, and peak intensity of each consonant /p/, /t/, and /k/ did not vary across groups. Conclusion: The study indicated that the mandibular stability was found to be reduced following mandibulectomy. The reduced AMR rate of /pa/confirmed the effect of mandibular surgery on the production of anteriorly positioned speech sounds. The present study stresses the importance of incorporating the DDK parameters in speech assessment to understand mandibular stability. [ABSTRACT FROM AUTHOR]

Segmental defect areas in the mandible can change immediately following osteotomy due to muscular traction, impacting on accurate reconstruction. The purpose of this article is to introduce a new technique based on virtual surgery planning to record the position of the bony parts prior to mandibulectomy, for use in precise mandibular reconstruction after segmental osteotomy. The position information for the bony parts is transferred to a plate with complementary surface contact and locating holes with specific directions and angles. This technique was performed for six patients with segmental defects and the results were compared to those of six previous patients in whom the technique was not utilized. The design of the location holes shortened the average operation time from 406 minutes to 349 minutes (P = 0.033) and decreased the average, maximum, and minimum graft deviation from 1.21 mm to 0.88 mm (P = 0.015), 1.28 mm to 0.99 mm (P = 0.027), and −1.15 mm to −0.77 mm (P = 0.077), respectively. The design of the locating holes in multiple plates shortened the time taken for the bony repositioning step and hence significantly shortened the total operation time. More importantly, it also increased the reconstructive accuracy. [ABSTRACT FROM AUTHOR]

The purpose of this study was to identify the factors that impact the quality of life (QOL) scores of patients undergoing mandibulectomy. All patients with a diagnosis of an oral cavity neoplasm involving the mandible who underwent a mandibulectomy between January 1, 2000 and December 31, 2015 and completed a University of Washington QOL questionnaire (UW-QOL) were included in the study. Fifty-eight patients fulfilled all inclusion criteria and completed the UW-QOL questionnaire. Forty patients (69%) underwent a segmental mandibulectomy and 18 patients underwent a marginal mandibulectomy. Forty-eight patients (82.7%) had a free flap reconstruction. There was no significant difference in the QOL scores between patients who underwent a marginal or a segmental mandibulectomy. In contrast, patients who underwent symphysial resection reported significantly worse scores in various domains compared to patients with body or ramus segmental mandibulectomy. Patients who underwent a segmental mandibulectomy that included the symphysis had worse outcomes in chewing, recreation, health-related and social QOL domains compared to those whose mandibulectomy did not include the symphysis. [ABSTRACT FROM AUTHOR]

Surgery is the most well established mode of initial definitive treatment for the majority of oral cancers. The most important decision in terms of tumour ablation in oral cancers when the jaws are potentially involved is the management of the mandible. The aim of this study was to explore the differences in survival rate and disease control between patients undergoing marginal mandibulectomy and patients undergoing segmental mandibulectomy using a systematic review and meta-analysis approach. A total of 15 cohort studies, including 1672 participants, were identified. Meta-analysis provided weak evidence in favour of segmental mandibulectomy for local control. Segmental mandibulectomy gave 73% better disease-free survival than marginal mandibulectomy when the marrow was invaded ( P = 0.04). The overall survival rate was evaluated, and no statistically significant difference was found between the two different mandibulectomy approaches, although the results showed a trend in favour of segmental mandibulectomy which could increase the overall survival by 23%. Based on these findings regarding the survival rate and efficacy of disease control, this study indicates that a marginal mandibulectomy may be recommended for cases with no invasion or superficial invasion of the mandibular cortex, and a segmental mandibulectomy may be a more reasonable choice for patients with extensive mandibular cortex invasion or medullary invasion. [ABSTRACT FROM AUTHOR]

Objective Few studies evaluate condylar movement following mandibular reconstruction. The main objective of this study was to show that axial four-dimensional computed tomography (4DCT) could visualize bilateral protrusive condylar movement directly. We used axial 4DCT images to assess condylar protrusion in patients who underwent mandibular reconstruction. Methods We enrolled seven healthy volunteers (median age 30 years, range 27–38 years) and seven patients (median age 65 years, range 52–80 years), who underwent mandibulectomy (segmental in five, hemi in one, marginal in one) and free flap reconstruction (using the fibula in six and the radial forearm in one). Six study subjects were instructed to masticate a cookie during the 4DCT scan (the seventh made chewing motions). The distance between the most anterior and posterior positions of the bilateral condyles on 4DCT (axial view) images was then measured and compared between controls and patients using the Mann–Whitney U -test. Results The crosswise difference in the distances of condylar protrusion was significantly greater in patients than in the controls. Conclusion Axial 4DCT images can visualize a bilateral condylar protrusive path. Axial 4DCT images for patients who have undergone mandibulectomy and reconstruction may be useful for evaluation of functional movement of condyles. [ABSTRACT FROM AUTHOR]

Purpose This preliminary study examined whether the type of surgery performed for head and neck lesion was associated perceived chewing ability, objective masticatory function, and oral health-related quality of life (OHRQoL) in patients who required a dento-maxillary prosthesis postoperatively. Methods Thirty-eight patients with a dento-maxillary prosthesis were divided into three groups according to the type of surgery received: marginal mandibulectomy, segmental mandibulectomy with bony reconstruction, or glossectomy. Perceived chewing ability, objective mixing ability, and OHRQoL were evaluated using a food intake questionnaire, color-changeable chewing gum, and the Geriatric Oral Health Assessment Index (GOHAI), respectively. Differences in the scores obtained by the three measures were compared between the surgical groups using the Kruskal–Wallis test, and associations between the scores in each group were analyzed by Spearman's rank correlation analysis. Results Objective mixing ability was found to be significantly low only in patients who underwent glossectomy. No other measures differed significantly between the surgical groups. Perceived chewing ability and objective mixing ability were significantly associated in the marginal mandibulectomy and glossectomy groups but not in the segmental mandibulectomy group. Furthermore, GOHAI score was significantly associated with perceived chewing ability and objective mixing ability in the marginal mandibulectomy group. Conclusions Within the limitations of this study, the present findings suggest that the type of surgery received might influence food mixing ability. Associations among food mixing ability, perceived chewing and OHRQoL are not accountable depending on the type of surgery received, indicating the presence of other contributing factors to be considered. [ABSTRACT FROM AUTHOR]

The purpose of this study was to sequentially evaluate bone union of fibular grafts in mandibular reconstruction. Patients who underwent routine follow-up computed tomography (CT) and panoramic X-ray imaging during a period of ≥2 years were enrolled. On panoramic X-ray images, bone union was scored as 0 (absent callus formation) or 1 (complete callus formation). On CT images, a scale of 0 to 2 was used (0, absent callus formation; 1, complete callus formation only on the labial side; 2, complete callus formation on both the labial and lingual side). A total of 56 bone junctions were evaluated in 20 patients. Five of 56 junctions (9%) in four of 20 patients (20%) showed radiological non-union (panoramic X-ray score = 0, CT score = 0 or 1) at 2 years after surgery. All bone junctions with radiological non-union were located at the mandibular angle. No categorical values, including diabetes mellitus and radiation therapy, were significantly associated with radiological non-union. In conclusion, assessing at least two sides (i.e. labial and lingual sides) on CT images is adequate to evaluate bone union in transferred fibula flaps. Careful fixation at the mandibular angle may improve the rate of bone union. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate stomatognathic performance after mandibulectomy. Twenty-six subjects were classified into two groups: the mandibular continuity (MC) group were reconstructed and kept in MC, while the mandibular non-continuity (MNC) group lost MC. Stomatognathic performance was evaluated using the Oral Health Impact Profile in Japanese (OHIP-J), a colour-changing chewing gum, a gummy jelly, Sato's questionnaire, electromyography (EMG) of the masticatory muscles, and mandibular movement. The OHIP-J and modified Sato's questionnaire revealed that the physical and eating disability of the MNC group was significantly more severe than that of the MC group ( P < 0.05). The mean EMG activity of the anterior temporalis muscle in the relaxed state was significantly higher in the MNC group than in the MC group ( P < 0.05). The mean masticating/relaxing ratio of EMG activities for the masseter muscle was lower in the MNC group than in the MC group ( P < 0.05). The maximum mouth opening range of the MNC group was greater than that of the MC group ( P < 0.05). Accordingly, the MC group had good results for physical and eating ability. The MNC group suffered from muscle fatigue but had the advantage of a greater maximum mouth opening range. [ABSTRACT FROM AUTHOR]