A longitudinal evaluation of psychosocial changes throughout orthognathic surgery.

BACKGROUND: Jaw correction surgery can cause significant psychosocial impacts on patients. This prospective study investigated the longitudinal changes of psychosocial characteristics of patients with dentofacial deformities after jaw correction surgery and the factors that predict the psychological resilience in Hong Kong Chinese undergoing jaw correction surgery. METHODS: A longitudinal cohort study was conducted on 92 Hong Kong Chinese patients (32 males, 60 females; mean age = 24.75 ± 5.65 years), who had jaw correction surgery as treatment for their dentofacial deformities, from 1st June 2011 to 30th June 2015. Self-completed psychological inventories including Brief Symptom Inventory, Life Orientation Test, and the Adult Trait Hope Scale were used to measure distress, optimism, and hope levels respectively. Patients completed the inventories in five time points: the surgical consent signing day (usually two to three months before the surgery) (T1); one day before operation (T2), first to second post-operative week (T3), third post-operative month (T4) and sixth post-operative month (T5). RESULTS: Latent class growth analysis revealed two outcome trajectory classes: a resilience trajectory (n = 45, 48.9%) and a chronic dysfunction trajectory (n = 14, 15.2%). Another 33 (35.9%) showed erratic trajectory patterns that would not be classified into any categories. The psychological distress levels of patients in the resilience trajectory group, on average, were below the clinical threshold of the Brief Symptom Inventory at all time points. However, the opposite result was obtained for patients in the chronic dysfunctional group. Patients exhibiting a resilience trajectory pattern, when compared to those showing a chronic dysfunction pattern, had higher optimism (t(57) = 3.69, p < .0001) and hope (t(57) = 2.46, p < .05) levels at T1. Logistic regression analyses were conducted to compare the relative power of optimism and hope levels at T1 to predict resilience or chronic dysfunctional group membership. A test of the full model against a constant only model was statistically significant (χ2(2) = 24.096, p < .01). Preoperative baseline optimism (B = -.276, p < .05) but not hope (B = -.25, ns) was a significant variable to classify the outcome trajectories for psychological distress. CONCLUSIONS: Most patients were resilient to dentofacial deformities jaw correction surgery. About 15% exhibited a chronic distress pattern. An optimistic view about the surgery may enhance resilience. Pre-surgical counselling or educational sessions to facilitate a realistic positive outlook about the operation would be beneficial.

Orbit Segmentation by Surface Reconstruction With Automatic Sliced Vertex Screening.

GOAL: The purpose of this paper is to develop a computational approach to the segmentation of human orbits. METHODS: The first step is to perform Hounsfield units thresholding to segment the bony structure around the orbit. Then, a three-dimensional mesh model is generated. Poisson surface reconstruction is applied to a set of automatically screened vertices, which are facing the inner orbital walls. These procedures effectively close orbital fissures; various nerves foramina; and interpolate the broken surfaces due to thin bone structures around the orbit. We also developed validation models with five dried skulls, where the orbits were filled with dental impression. Validations on the proposed algorithm were performed with the corresponding CT images and verified by experienced radiographer. RESULTS: The mean volume differences are less than 0.3%. Surface differences are within 0.3 mm of root mean square. Both differences are not clinically significant. SIGNIFICANCE: Traditional approaches are slice-by-slice manual editing or shape interpolation with selected slices interactively. It is not only time consuming, but also inefficient, exhibits interoperator variability, and repeatability problems. In the proposed method, most of the manual processes are eliminated with adjustable vertex screening parameters. It makes the proposed method repeatable.

Distraction osteogenesis as a treatment of obstructive sleep apnea syndrome: A systematic review.

BACKGROUND: To conduct a systematic review to answer the clinical question "What are the effectiveness of mandibular distraction osteogenesis (MDO) and its complications to treat patients with obstructive sleep apnea syndrome (OSAS)?". METHODS: A systematic search including a computer search with specific keywords, reference list search, and manual search were done. Relevant articles on MDO were assessed and selected in 3 rounds for final review based on 5 predefined inclusion criteria and followed by a round of critical appraisal. Different types of distraction and their treatment outcomes of OSAS were recorded with standardized form and analyzed. RESULTS: Twelve articles were included in the final review. A total of 256 patients aged 7 days to 60 years were treated with either external or internal MDO, with a mean follow-up period of 6 to 37 months. The average distraction distance of 12 to 29 mm was achieved with various distraction protocols. The success rate for adult patients was 100%, and cure rates were ranged from 82% to 100%. The definition of success or cure for OSAS in children or infants was not defined. Therefore, there were no clearly reported success or cure rates for children/infants in the included studies. However, all studies reported that these patients showed significant improvement in OSAS, with many of them who avoided tracheostomy or had the tracheostomy decannulated. The complication rates were ranged from 0% to 21.4%, with most being from local wound infections or neurosensory disturbances. CONCLUSION: This systematic review showed that MDO was effective in resolving OSAS in adults with retrognathic mandible. MDO also showed promising results in infants or children with OSAS. From the results of this systematic review, we recommend to define the criteria of success or cure for OSAS surgery in children and infants. We also recommend setting up randomized controlled trials to compare MDO with traditional maxillomandibular advancement surgery for OSAS patients and to provide a better evidence on the success and complication rates of the techniques.

Longitudinal Treatment Outcomes of Microsurgical Treatment of Neurosensory Deficit after Lower Third Molar Surgery: A Prospective Case Series.

OBJECTIVE: To prospectively evaluate the longitudinal subjective and objective outcomes of the microsurgical treatment of lingual nerve (LN) and inferior alveolar nerve (IAN) injury after third molar surgery. MATERIALS AND METHODS: A 1-year longitudinal observational study was conducted on patients who received LN or IAN repair after third molar surgery-induced nerve injury. Subjective assessments ("numbness", "hyperaesthesia", "pain", "taste disturbance", "speech" and "social life impact") and objective assessments (light touch threshold, two-point discrimination, pain threshold, and taste discrimination) were recorded. RESULTS: 12 patients (10 females) with 10 LN and 2 IAN repairs were recruited. The subjective outcomes at post-operative 12 months for LN and IAN repair were improved. "Pain" and "hyperaesthesia" were most drastically improved. Light touch threshold improved from 44.7 g to 1.2 g for LN repair and 2 g to 0.5 g for IAN repair. CONCLUSION: Microsurgical treatment of moderate to severe LN injury after lower third molar surgery offered significant subjective and objective sensory improvements. 100% FSR was achieved at post-operative 6 months.

Long-term morbidities of coronectomy on lower third molar.

OBJECTIVE: To monitor the long-term morbidity of retained roots up to 5 years following lower third molars coronectomy with close proximity to the inferior alveolar nerve (IAN). STUDY DESIGN: A prospective study on long-term morbidities after lower third molar coronectomy. RESULTS: This study included 612 lower third molar coronectomies in 458 patients. The prevalence of IAN injury was 0.16% (1/612) and was temporary. Long-term postoperative infection occurred in 1 case at 6 months following surgery and another at 12 months. No infection was found after 12 months. The incidence rates of pain at 6 months, 12 months, 24 months after surgery were 0.50% (3/596), 0.38% (2/529), 0.49% (2/411), respectively. Root exposure was noted in 2.3% of cases (14/612). Reoperation to remove the exposed root did not cause any IAN deficit. CONCLUSIONS: Lower third molar coronectomy is safe in the long term.

Monobloc Le Fort III Distraction Osteogenesis for Correction of Severe Fronto-orbital and Midface Hypoplasia in Pediatric Crouzon Syndrome.

In severe syndromic craniosynostosis, distraction osteogenesis (DO) provides superior segmental advancement and allows progressive clinical monitoring to ensure that adequate skeletal expansion is achieved. We report two cases of Crouzon syndrome involving a 3-year-old boy and a 4-year-old girl, who were both treated with monobloc Le Fort III DO using a combination of external and internal distraction devices (Synthes, Oberdorf, Switzerland) to treat severe orbital proptosis and obstructed nasopharyngeal airway secondary to severe hypoplastic craniofacial skeletal components. Their skeletal segments were advanced in daily increments by 27 mm and 23 mm, respectively. Results at 18 months postoperatively showed successful outcomes, as evidenced by adequate eye protection, tracheostomy tube decannulation following objective evidence of patent nasopharyngeal airway, and acceptable facial appearance. Monobloc Le Fort III DO using a combination of external and internal devices produces favorable functional and clinical outcomes for the treatment of severe orbital and airway discrepancy in Crouzon syndrome.

Effect of Fluoride-Modified Titanium Surface on Early Adhesion of Irradiated Osteoblasts.

OBJECTIVE: The present study aimed to investigate the effect of fluoride-modified titanium surface on adhesion of irradiated osteoblasts. MATERIALS AND METHODS: Fluoride-modified surface was obtained and the morphology, roughness, and chemical composition of the surface were evaluated by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. The adhesion of irradiated osteoblast-like cells, in terms of number, area, and fluorescence intensity on the titanium surface, was evaluated using immunofluorescence staining. RESULTS: Numerous nanosize pits were seen only in the F-TiO surface. The pits were more remarkable and uniform on F-TiO surface than on TiO surface; however, the amplitude of peaks and bottoms on F-TiO surface appeared to be smaller than on TiO surface. The Sa value and Sdr percentage of TiO surfaces were significantly higher than those of F-TiO surface. The concentrations of main elements such as titanium, oxygen, and carbon were similar on both surfaces. The number of irradiated osteoblasts adhered on the control surface was larger than on fluoride-modified surface. Meanwhile, the cells on the fluoride-modified surface formed more actin filaments. CONCLUSIONS: The fluoride-modified titanium surface alters the adhesion of irradiated osteoblasts. Further studies are needed to investigate the proliferation, differentiation, maturation, gene expression, and cytokine production of irradiated osteoblasts on fluoride-modified titanium surface.

Automatic Detection and Reproduction of Natural Head Position in Stereo-Photogrammetry.

UNLABELLED: The aim of this study was to develop an automatic orientation calibration and reproduction method for recording the natural head position (NHP) in stereo-photogrammetry (SP). A board was used as the physical reference carrier for true verticals and NHP alignment mirror orientation. Orientation axes were detected and saved from the digital mesh model of the board. They were used for correcting the pitch, roll and yaw angles of the subsequent captures of patients' facial surfaces, which were obtained without any markings or sensors attached onto the patient. We tested the proposed method on two commercial active (3dMD) and passive (DI3D) SP devices. The reliability of the pitch, roll and yaw for the board placement were within ±0.039904°, ±0.081623°, and ±0.062320°; where standard deviations were 0.020234°, 0.045645° and 0.027211° respectively. CONCLUSION: Orientation-calibrated stereo-photogrammetry is the most accurate method (angulation deviation within ±0.1°) reported for complete NHP recording with insignificant clinical error.

Effects of calcium phosphate nanocrystals on osseointegration of titanium implant in irradiated bone.

Radiotherapy may compromise the integration of implant and cause implant loss. Implant surface modifications have the possibility of promoting cell attachment, cell growth, and bone formation which ultimately enhance the osseointegration process. The present study aimed to investigate the effects of calcium phosphate nanocrystals on implant osseointegration in irradiated bone. Sixteen rabbits were randomly assigned into control and nano-CaP groups, receiving implants with dual acid-etched surface or dual acid-etched surface discretely deposited of nanoscale calcium-phosphate crystals, respectively. The left leg of all the rabbits received 15 Gy radiation, followed by implants placement one week after. Four animals in each group were sacrificed after 4 and 12 weeks, respectively. Implant stability quotient (ISQ), ratio of bone volume to total volume (BV/TV), bone growth rate, and bone-to-implant contact (BIC) were evaluated. The nano-CaP group showed significantly higher ISQ (week 12, P = 0.031) and bone growth rate (week 6, P = 0.021; week 9, P = 0.001) than that in control group. No significant differences in BV/TV and BIC were found between two groups. Titanium implant surface modified with CaP nanocrystals provides a potential alternative to improve bone healing around implant in irradiated bone.

A Rare Orbital Complication of Eye Exodeviation With Limited Abduction During Monobloc Le Fort III Distraction Osteogenesis.

Monobloc Le Fort III distraction osteogenesis allows superior skeletal advancement in treating severe syndromic craniosynostosis. We report a rare orbital complication in a 3-year-old boy with Crouzon syndrome who developed right-eye exodeviation with limited abduction during the intradistraction period following this surgery. Images from a computed tomography scan confirmed direct impingement of the distracted right lateral orbital wall to the lateral rectus muscle. The impingement was surgically relieved via lateral orbital wall osteotomy. Ten months postdistraction, a review showed normal eye movement. A lateral orbital osteotomy cut for a monobloc Le Fort III distraction should be designed near the rim to prevent this complication.

Psychosocial and quality of life outcomes of prosthetic auricular rehabilitation with CAD/CAM technology.

Introduction. The psychosocial and quality of life (QoL) of patients with deformed or missing ears are frequently compromised. The aim of this study is to develop innovative techniques using CAD/CAM technology in prosthetic auricular rehabilitation and provide improvement in the treatment outcomes, including their psychology and QoL. Methods. This is a preliminary clinical cohort study. Six patients requesting for auricular reconstruction were recruited and rehabilitated with implant-supported prosthesis using CAD/CAM technology. Different treatment outcomes including QoL and psychological changes were assessed at different time points. Results. A significant reduction in severity of depressive symptoms (P = 0.038) and an improving trend of satisfaction with life were found at 1 year postoperatively when compared with the preoperative findings. The domain scores in ''Body image", ''Family/friends/strangers", and ''Mood" were also significantly higher (P < 0.05) at 1 year postoperatively than 1 week postoperatively. However, only 50% of the patients wear their auricular prosthesis regularly. Conclusion. This preliminary study has confirmed that implant-supported auricular prosthesis could induce improvement in the psychology and QoL with statistically significant differences in the domains of the body image, social interaction, and mood. Our present findings can inform research design and hypotheses generation of future studies.

Recording of natural head position using stereophotogrammetry: a new technique and reliability study.

The purpose of this study was to develop a technique to record physical references and orient digital mesh models to a natural head position using stereophotogrammetry (SP). The first step was to record the digital mesh model of a hanging reference board placed at the capturing position of the SP machine. The board was aligned to true vertical using a plumb bob. It also was aligned with a laser plane parallel to a hanging mirror, which was located at the center of the machine. The parameter derived from the digital mesh model of the board was used to adjust the roll, pitch, and yaw of the subsequent captures of patients' facial images. This information was valid until the next machine calibration. The board placement was repeatable, with standard deviations less than 0.1° for pitch and yaw angles and 0.15° for roll angles.

Dose-dependent effect of radiation on titanium implants: a quantitative study in rabbits.

OBJECTIVES: The aim of the study was to investigate the dose-dependent effect of radiation on dental implant stability and osseointegration using a series of quantitative analyses. MATERIAL AND METHODS: Six rabbits were randomly assigned to 15 and 30 Gy radiation groups. Each rabbit received radiation at the tibial and femoral metaphyseal region of left hind leg. The right leg was used as control. Implant surgery was performed on tibial and femoral metaphyses after 1 week. Totally 24 implants were inserted. The animals were killed at postoperative week four. Implant stability was measured using resonance frequency analysis. Ratio of bone volume to total volume (BV/TV), rate of bone growth, and bone-to-implant contact (BIC) were assessed using micro-computed tomography (micro-CT), fluorochrome labeling analysis, and histomorphometric analysis, respectively. RESULTS: After 4 weeks of healing, all implants were integrated (n = 6). Implant stability was significantly compromised by 15 Gy (P = 0.010) and 30 Gy (P = 0.025) of radiation. Radiation decreased BV/TV, and the significant effect was detected at the dose of 15 Gy (P = 0.008) and 30 Gy (P < 0.001). Bone growth in osseointegration was impaired by radiation. In 15 Gy group, the radiation side showed significant lower rate of bone growth than the control side at week 3 (P = 0.001), while the undistinguishable signals on 30 Gy radiation side suggested the low rate of new bone formation at each time point. Histomorphological BIC had no significant difference between 15 Gy control side and 15 Gy radiation side. 30 Gy radiation side showed a significantly lower BIC than 30 Gy control side (P < 0.001) as well as 15 Gy radiation side (P < 0.001). CONCLUSIONS: Implant stability and osseointegration were compromised by radiation. Radiation compromised osseointegration in a dose-dependent manner.

Quantitative analysis of titanium-induced artifacts and correlated factors during micro-CT scanning.

OBJECTIVES: To investigate the impact of cover screw, resin embedment, and implant angulation on artifact of microcomputed tomography (micro-CT) scanning for implant. MATERIALS AND METHODS: A total of twelve implants were randomly divided into 4 groups: (i) implant only; (ii) implant with cover screw; (iii) implant with resin embedment; and (iv) implants with cover screw and resin embedment. Implants angulation at 0°, 45°, and 90° were scanned by micro-CT. Images were assessed, and the ratio of artifact volume to total volume (AV/TV) was calculated. A multiple regression analysis in stepwise model was used to determine the significance of different factors. One-way ANOVA was performed to identify which combination of factors could minimize the artifact. RESULTS: In the regression analysis, implant angulation was identified as the best predictor for artifact among the factors (P < 0.001). Resin embedment also had significant effect on artifact volume (P = 0.028), while cover screw had not (P > 0.05). Non-embedded implants with the axis parallel to X-ray source of micro-CT produced minimal artifact. CONCLUSIONS: Implant angulation and resin embedment affected the artifact volume of micro-CT scanning for implant, while cover screw did not.

Trigeminal neurosensory deficit and patient reported outcome measures: the effect on quality of life.

OBJECTIVES: To investigate the effect of persistent neurosensory disturbance of the lingual nerve (LN) or inferior alveolar nerve (IAN) on general health and oral health- related quality of life (QoL). METHODS: The study design was a case-control study. Patients with persistent neurosensory deficit of LN or IAN after lower third molar surgery (for 12 months or more) were the study group. The control group was an age and gender matched sample of patients who had dental extractions or lower third molar surgeries without trigeminal neurosensory deficit. The outcome variables were the general health and oral health-related QoL. General health-related QoL was assessed using the 36-item Short Form Health Survey (SF-36) and oral health-related QoL using the 14-item Short Form Oral Health Impact Profile (OHIP-14). Differences in SF-36 scores and OHIP-14 scores between the groups were compared. RESULTS: Forty-eight subjects (24 cases and 24 controls) were recruited. When compared to the control group, patients with neurosensory deficits had poorer Mental-Health Component Scores (MCS) (p = 0.005), General Health (p = 0.023), Vitality (p = 0.048), Social Functioning (p = 0.003), Role-emotion (p = 0.008) and Mental Health (p = 0.022). The OHIP-14 scores were also significantly worse in this patients with neurosensory deficits compared with the control group (p = 0.002). When compared within the study group, older patient with neurosensory deficit was found to correlate with worse Physical Health Component Scores (PCS) (p = 0.02) and OHIP-14 scores (p = 0.02), while more severe visualized analog scaling rating of numbness was correlated with a worse PCS (p = 0.034). CONCLUSIONS: Patients with persistent LN or IAN deficit after lower third molar surgery have poorer health-related QoL and poorer oral health-related QoL than those without such deficits.

Trigeminal neurosensory deficit and patient reported outcome measures: the effect on life satisfaction and depression symptoms.

OBJECTIVES: To investigate the effect of persistent neurosensory disturbance of the lingual nerve (LN) or inferior alveolar nerve (IAN) on life satisfaction and depression symptoms. METHODS: This study recruited patients with persistent LN or IAN deficit as a consequence of lower third molar surgery for 12 months or more to form the study group. A control group was formed by matching age and gender of recruited subjects in the study group with patients without the neurosensory complications. Life satisfaction was assessed with Satisfaction With Life Scale (SWLS) and depression symptoms were assessed with 20-item Center for Epidemiological Studies Depression scale (CESD-20). RESULTS: Fourty-eight participants (24 cases and 24 controls) were recruited. Patients with LN or IAN deficits after lower third molar surgery were less satisfied with their lives when compared to the control group (p<0.001). They were presenting with more depression symptoms (p = 0.001). 45.8% of the study group subjects had a CESD-20 score of 16 or above. Older patients presented with more depression symptoms among the subjects with neurosensory disturbance after lower third molar surgery (p = 0.02). CONCLUSIONS: Individuals with permanent trigeminal neurosensory deficit after lower third molar surgery have worse life satisfaction and more depressive symptoms when compared to those who did not suffer from the surgical complication.

Alveolar distraction osteogenesis for dental implant rehabilitation following fibular reconstruction: a case series.

OBJECTIVE: Alveolar distraction osteogenesis (ADO), a novel bone augmentation technique, is gaining acceptance in restoring the vertical bone discrepancy between the transplanted graft and the residual alveolar bone after mandibular reconstruction. This case series presents the outcomes of ADO in fibula-reconstructed mandibles rehabilitated with dental implants, with an emphasis on clinical indications, surgical protocol, clinical outcomes, histologic evidence, and complications. MATERIALS AND METHODS: Five patients underwent fibula distraction procedures after undergoing mandibular reconstruction with a vascularized fibula bone graft. The indication for the application of ADO was for the correction of the vertical discrepancy between the top of the reconstructed fibula and the adjacent alveolar crest to achieve adequate vertical bone height before implant placement. RESULTS: The mean vertical bone height achieved was 13.58 mm. Twenty-two dental implants were placed in 5 patients. All patients were rehabilitated with implant-supported prostheses. Bone biopsies showed the distracted area was filled with newly formed, bony trabeculae between the transported fibula and the basal segments. The most common complication was transient infection around the distractor rod. CONCLUSIONS: ADO can be performed on fibula-reconstructed mandibles to achieve the restoration of alveolar height, which then can be rehabilitated with dental implant-supported prostheses. The procedure has a minor risk of infection associated with the distractor rod, which does not compromise the bone regeneration from distraction. Patients with mandibles reconstructed with fibulas can attain dental implant rehabilitation with ADO, achieving good esthetic and occlusal outcomes.

Biomechanical properties of novel biodegradable poly ε-caprolactone-chitosan scaffolds.

AIM: To investigate the biomechanical properties of poly ε-caprolactone (PCL)-chitosan (CS) scaffolds fabricated by the melt stretching and multilayer deposition technique. METHODS: The PCL-CS scaffolds containing CS at 0% (pure PCL), 10%, and 20% by weight were prepared. For the monolayer scaffolds, shear and blending tests simulating the reconstruction of orbital floor defects (situation A) and mandibular defects (situation B) were conducted. For the 3-D scaffolds, compression tests of their superior and lateral aspects were done. RESULTS: For the monolayer scaffolds, the pure PCL group had remarkably lower shear strength than the other groups (P > 0.05). In situation A, all groups withstood the forces without any significant difference. In situation B, the pure PCL group could withstand the forces remarkably lower than those of the other group (P < 0.05). The 3-D scaffolds of all groups could withstand compressive forces directed towards their superior aspects. However, they could not withstand the forces directed towards their lateral aspects at the limited strain. CONCLUSIONS: The monolayer scaffolds were suitable for reconstruction of the orbital floor and mandibular defects under light load-bearing conditions. The 3-D scaffolds could be used in the high load bearing-areas only if the forces were directed at their superior aspects.

The comparison of psychological adjustment of patients with cleft lip and palate after maxillary distraction osteogenesis and conventional orthognathic surgery.

OBJECTIVE: The objective of this study was to compare the psychological changes of patients with cleft lip and palate (CLP) undergoing maxillary Le Fort I advancement by distraction osteogenesis (DO) and conventional orthognathic surgery (CO). STUDY DESIGN: Prospective randomized controlled study. Participants completed a set of questionnaires to measure their psychological states preoperatively and postoperatively. RESULT: When compared with CO, CLP patients treated with DO had lower social self-esteem and higher social avoidance and distress levels during the first 3 postoperative months. Their self-esteem, social avoidance, and distress levels improved after the distractors were removed. Both CO and DO patients had similar levels of self-esteem, social avoidance, and distress levels 2 years postoperatively. The CLP patients treated with DO were more satisfied with their lives after 2 years. CONCLUSIONS: DO may induce short-term distress to patients up to 3 months but CLP patients who received DO were more satisfied with their lives in the long term.

Expression of MMP-1 and TIMP-1 in irradiated mandibles during distraction osteogenesis.

OBJECTIVES: The study aimed to evaluate the expression of MMP-1 and TIMP-1 in irradiated mandibles during distraction osteogenesis. STUDY DESIGN: Rabbits in the experimental group received preoperative radiation of 9 Gy for 5 fractions. After 1 month, all rabbits underwent osteotomy and distraction osteogenesis with 7 days of latency. Three rabbits in the control and experimental groups were killed at days 7, 12, 18, and 25. Specimens were subjected to immunohistochemical examination and real-time polymerase chain reaction analysis. RESULTS: At day 7, expression of MMP-1 and TIMP-1 was significantly suppressed in the radiotherapy group in contrast to the control group. At day 12, expression of MMP-1 was significantly higher in the control group. At day 18, expression of MMP-1 and TIMP-1 was significantly higher in the control than in the radiotherapy group. CONCLUSIONS: Radiotherapy changes the expression pattern of MMP-1 and TIMP-1.