Incidence of complicated healing and osteoradionecrosis following tooth extraction in patients receiving radiotherapy for treatment of nasopharyngeal carcinoma

A novel computationally engineered collagenase reduces the force required for tooth extraction in an ex-situ porcine jaw model

The currently employed tooth extraction methods in dentistry involve mechanical disruption of the periodontal ligament fibers, leading to inevitable trauma to the bundle bone comprising the socket walls. In our previous work, we have shown that a recombinantly expressed truncated version of clostridial collagenase G (ColG) purified from Escherichia coli efficiently reduced the force needed for tooth extraction in an ex-situ porcine jaw model, when injected into the periodontal ligament. Considering that enhanced thermostability often leads to higher enzymatic activity and to set the basis for additional rounds of optimization, we used a computational protein design approach to generate an enzyme to be more thermostable while conserving the key catalytic residues. This process generated a novel collagenase (ColG-variant) harboring sixteen mutations compared to ColG, with a nearly 4℃ increase in melting temperature. Herein, we explored the potential of ColG-variant to further decrease the physical effort required for tooth delivery using our established ex-situ porcine jaw model. An average reduction of 11% was recorded in the force applied to extract roots of mandibular split first and second premolar teeth treated with ColG-variant, relative to those treated with ColG. Our results show for the first time the potential of engineering enzyme properties for dental medicine and further contribute to minimally invasive tooth extraction.

Osteonecrosis of the Jaw

Osteonecrosis of the jaw is a condition in which bone cells die due to various causes. It is classified as drug-induced jaw osteonecrosis, osteoradionecrosis, traumatic, non-traumatic, and spontaneous osteonecrosis. Antiresorptive or antiangiogenic drugs cause drug-induced osteonecrosis. The combination of medications, microbial contamination, and local trauma induces this condition. Osteoradionecrosis is a severe radiation therapy side effect that can affect people with head and neck cancer. It is described as an exposed bone area that does not heal for longer than three months after the end of radiation treatment with the absence of any indications of an original tumor, recurrence, or metastasis. Trauma (tooth extraction), tumor site, radiation dose that the patient receives, the area of the bone which is irradiated, oral hygiene, and other factors are risk factors for the development of osteonecrosis. Less frequently, osteonecrosis can also be induced by non-traumatic and traumatic causes. Non-traumatic osteonecrosis is brought on by infections, acquired and congenital disorders, as well as the impact of chemicals. Traumatic osteonecrosis is brought on by thermal, mechanical, or chemical damage. The treatment of osteonecrosis can be conservative, which aims to be beneficial for the patient's quality of life, and surgical, which involves debridement of the necrotic bone.

Antibiotics in Dentoalveolar Surgery, a Closer Look at Infection, Alveolar Osteitis and Adverse Drug Reaction

PURPOSE

To execute an evidence-based review answering the following questions: "What antibiotic type and mode of delivery are most effective at reducing inflammatory complications in third molar and dental implant surgery? What are the types and rates of antibiotic-related adverse reactions in the context of third molar surgery, infective endocarditis, medication-related osteonecrosis of the jaw (MRONJ) and osteoradionecrosis (ORN)?"

MATERIAL AND METHODS

We performed a comprehensive literature review of peer-reviewed studies using MEDLINE/PubMed, Cochrane, Scopus/Elsevier, Google Scholar, and Wiley online library databases.

RESULTS

Twenty-five studies were reviewed for third molar surgery. Although there is some evidence that systemic antibiotics reduce inflammatory complications (infection and alveolar osteitis), routine use is not recommended for third molar surgery. For at-risk cases, a single preoperative dose of amoxicillin is preferred. Clindamycin, amoxicillin-clavulanic acid and erythromycin have a high adverse risk profile. Eight studies were reviewed for dental implant surgery. Antibiotics with dental implant placement showed little reduction in post surgery infection and minimal improvement in long-term success. A comprehensive search found limited data on antibiotic-related adverse effects in the context of infective endocarditis, MRONJ and ORN.

CONCLUSIONS

A set of clinical recommendations are presented to better guide evidence-based and standardized antibiotic usage on the basis of the literature discussed in this review. This review highlights the need for further research focusing on antibiotic type and timing of delivery with adverse drug reaction as a primary outcome measure when assessing treatment outcomes and complications in dentoalveolar surgery. This will better elucidate the risks vs benefits of antibiotic in dentoalveolar surgery.

Predictors of osteoradionecrosis following irradiated tooth extraction

Background

Tooth extraction post radiotherapy is one of the most important risk factors of osteoradionecrosis of the jawbones. The objective of this study was to determine the predictors of osteoradionecrosis (ORN) which were associated with a dental extraction post radiotherapy.

Methods

A retrospective analysis of medical records and dental panoramic tomogram (DPT) of patients with a history of head and neck radiotherapy who underwent dental extraction between August 2005 to October 2019 was conducted.

Results

Seventy-three patients fulfilled the inclusion criteria. 16 (21.9%) had ORN post dental extraction and 389 teeth were extracted. 33 sockets (8.5%) developed ORN. Univariate analyses showed significant associations with ORN for the following factors: tooth type, tooth pathology, surgical procedure, primary closure, target volume, total dose, timing of extraction post radiotherapy, bony changes at extraction site and visibility of lower and upper cortical line of mandibular canal. Using multivariate analysis, the odds of developing an ORN from a surgical procedure was 6.50 (CI 1.37–30.91, p = 0.02). Dental extraction of more than 5 years after radiotherapy and invisible upper cortical line of mandibular canal on the DPT have the odds of 0.06 (CI 0.01–0.25, p < 0.001) and 9.47 (CI 1.61–55.88, p = 0.01), respectively.

Conclusion

Extraction more than 5 years after radiotherapy, surgical removal procedure and invisible upper cortical line of mandibular canal on the DPT were the predictors of ORN.

Association between dental extraction after radiotherapy and osteoradionecrosis: A multi-centre retrospective study

OBJECTIVE

Radiotherapy (RT) carries a substantial risk for the development of osteoradionecrosis (ORN) of the jaw. This study was performed to investigate the relationship between dental extractions after RT and the development of ORN.

MATERIAL AND METHODS

Thirty-two patients with head and neck cancer who underwent tooth extraction after RT were investigated for correlations between the development of ORN and various factors.

RESULTS

Postextraction ORN was diagnosed in 12 (12.1%) teeth of 9 patients. The RT dose against the site of tooth extraction was 62.0 and 37.4 Gy in the ORN and Non-ORN groups, respectively (p < .001). The duration from RT to tooth extraction was 41.2 and 28.2 months in the ORN and Non-ORN groups, respectively (p = .025). Tooth extraction was significantly associated with ORN in patients with a high RT dose against the site (odds ratio = 1.231) and a longer duration of time from RT (odds ratio = 1.084).

CONCLUSIONS

Extraction of non-restorable teeth and those with a poor prognosis should not necessarily be postponed even when patients are undergoing RT. However, clinicians should pay special attention to postoperative management after tooth extraction in patients with a high RT dose and longer time from RT.

Timing of dental extractions in patients undergoing radiotherapy and the incidence of osteoradionecrosis: a systematic review and meta-analysis

This systematic review aimed to examine whether the incidence of osteonecrosis differed between patients who have dental extractions before or after radiotherapy (RT). The reported incidence of osteoradionecrosis (ORN) of the jaws following RT to the head and neck varies widely in the literature. Currently, for patients with head and neck cancer there are no universally accepted guidelines on the optimal timing of dental surgery relative to RT to minimise incident ORN. A literature review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) criteria. A search of PubMed, EMBASE, Evidence-Based Medicine, and Web of Science databases targeted literature published up to and including 10 April 2020. Two independent reviewers assessed studies for eligibility against inclusion criteria. An assessment of bias was conducted for each of the included studies and relevant data extracted. A meta-analysis was undertaken using the statistical methods described. Twenty-four of 708 studies were included. They were heterogeneous and included a wide variation of RT methods, head and neck malignancies, and comorbidities. While some concluded that the incidence of ORN was dependent on the timing of dental extractions in relation to RT, with regard to the risk of its development, others reported additional factors such as age, comorbidities, extent of surgical resection, and dose and field of radiation, as more important predictors than timing. In many there was consistent lack of detail around the timing of dental procedures in relation to the delivery of RT. From 21 studies including 36,294 patients, of whom 14,389 had extractions before RT, the pooled incidence of ORN was 5.5% (95% CI: 2.1% to 10.1%). Significant heterogeneity was found in Cochran's Q-test (p<0.001) and Higgins I²=98.0%. From 21 studies including 37,805 patients, of whom 6030 had extractions after RT, the pooled incidence of ORN was 5.3% (95% CI: 2.9% to 8.2%). Significant heterogeneity was found in Cochran's Q-test (p<0.001) and Higgins I²=80.0%. There was no statistically significant difference between these two groups (random-effects model Q=0.12, p=0.73). Large, longitudinal studies with a priori-specified methods are needed to identify, recruit, and prospectively follow patients with head and neck cancer for the onset of ORN after dental surgery. This will allow clinical guidelines to be established to assist clinicians to plan treatment when extractions are indicated in patients undergoing RT to the head and neck.

Preradiation tooth extraction and jaw osteoradionecrosis: Nationwide population-based retrospective study in Taiwan

OBJECTIVE

Radiotherapy (RT) for head and neck cancer (HNC) within 7 days of tooth extraction is contraindicated because it may increase the risk of osteoradionecrosis of the jaw (ORNJ). However, delayed RT could compromise survival in patients with HNC. By using a national healthcare database, we reviewed the contraindications and analysed other risk factors for ORNJ.

DESIGN

A retrospective cohort study.

SETTING

By using Taiwan's National Health Insurance Research Database, 5,062 HNC patients with at least one tooth extraction 1-21 days before the first RT day (index day) and without any extractions during or after RT from 2000 to 2013 were included. The patients were divided into two groups according to the time of tooth extraction before the index day: 1-7 days and 8-21 days.

PARTICIPANTS

Taiwanese patients with head and neck cancer.

MAIN OUTCOMES MEASURE

Univariate and multivariate Cox proportional hazard regression models were used to evaluate the risk factors of ORNJ.

RESULTS

The overall incidence of ORNJ in the included patients was 1.03% (mean follow-up duration, 4.07 ± 3.01 years; range, 1.00-13.99 years). Tooth extraction within 7 days before RT was not associated with increased ORNJ risk (hazard ratio [HR] =0.734; P = .312). Significant risk factors for ORNJ included oral cancer (adjusted HR = 3.961), tumour excision surgery within 3 months before RT (adjusted HR = 3.488) and mandibulectomy within 3 months before RT (adjusted HR = 5.985; all P < .001).

CONCLUSION

In a mean follow-up of 4 years, tooth extraction within 7 days before RT for HNC treatment did not increase the ORNJ risk compared with tooth extraction 7-21 days before RT.

Photobiomodulation for mucosal repair in patients submitted to dental extraction after head and neck radiation therapy: a double-blind randomized pilot study

OBJECTIVE

The aim of this study was to evaluate the efficacy of photobiomodulation therapy (PBMT) on the mucosal healing of patients submitted to simple dental extractions after head and neck radiation therapy (HNRT).

METHODS

Forty surgical procedures were randomly assigned into two groups: G1: dental extraction + PBMT (n = 19) and G2: dental extraction + sham-PBMT (n = 21). All patients received antibiotic therapy and the surgical alveolotomy to promote primary closure of the surgical site. Group 1 was submitted to PMBT according to the following parameters: 808 nm, 40 mW, 100 J/cm², 70 s, 2.8 J/point, 14 J/session, and area of 0.028cm². The primary outcome was complete mucosal lining at 14 days, and the secondary outcomes were the presence of infection, postoperative pain, and analgesics intake at 7 days. The patients were evaluated every 7 days until 28 days.

RESULTS

Alveolar mucosal lining was faster in G1, and at 14 postoperative days, 94.7% patients evolved with complete alveolar mucosal lining compared to no patient from G2 (p < 0.001). Patients from G1 reported postoperative pain less frequently (G1 = 4, 21.1% × G2 = 14, 66.7%, p = 0.005), and also reported lower intake of analgesic pills at D7 (21.1% × 66.7%, p = 0.005%). PBMT had a significant positive impact on both postoperative pain (NNT = 2.192, CI95% = 1.372-5.445) and mucosal healing (NNT = 1.056, CI95% = 0.954-1.181).

CONCLUSIONS

This preliminary study strongly supports the use of PMBT to promote surgical alveolar mucosal lining in a shorter time and with less postoperative pain.

Research Frontiers in Oral Toxicities of Cancer Therapies: Osteoradionecrosis of the Jaws

The deleterious effects of head and neck radiation on bone, with osteoradionecrosis (ORN) as the major disabling side effect of head and neck cancer treatment, are difficult to prevent and hard to treat. This review focuses on the current state of the science regarding the pathobiology, clinical impact, and management of ORN. With regard to the pathobiology underlying ORN, it is not yet confirmed whether the current radiation schedules by 3-dimensional conformal radiotherapy and intensity modified radiotherapy result in an unchanged, decreased, or increased risk of developing ORN when compared with conventional radiation treatment, the main risk factor being the total radiation dose delivered on any clinically significant surface of the mandible.

With regard to the prevention of ORN, a thorough, early pre-irradiation dental assessment is still considered the first step to reduce the hazard of developing ORN post-radiotherapy, and hyperbaric oxygen (HBO) treatment reduces the risk of developing ORN in case of dental surgery in an irradiated field.

With regard to the treatment of ORN, the focus is bidirectional: elimination of the necrotic bone and improving the vascularity of the normal tissues that were included in the radiation portal. The cure rate of limited ORN by conservative therapy is approximately 50%, and the cure rate of surgical approaches when conservative therapy has failed is approximately 40%.

Whether it is effective to support conservative or surgical treatment with HBO as an adjuvant is not set. HBO treatment is shown to increase the vascularity of hard and soft tissues and has been reported to be beneficial in selected cases. However, in randomized clinical trials comparing the preventive effect of HBO on developing ORN with, eg, antibiotic coverage in patients needing dental surgery, the preventive effect of HBO was not shown to surpass that of a more conservative approach.

More recently, pharmacologic management was introduced in the treatment of ORN with success, but its efficacy has to be confirmed in randomized clinical trials. The major problem of performing well-designed randomized clinical trials in ORN is having access to large numbers of patients with well-defined, comparable cases of ORN. Because many institutions will not have large numbers of such ORN cases, national and international scientific societies must be approached to join multicenter trials. Fortunately, the interest of funding organizations and the number researchers with an interest in healthy aging is growing. Research aimed at prevention and reduction of the morbidity of cancer treatment fits well within these programs.

HOPON (Hyperbaric Oxygen for the Prevention of Osteoradionecrosis): a randomised controlled trial of hyperbaric oxygen to prevent osteoradionecrosis of the irradiated mandible: study protocol for a randomised controlled trial

BACKGROUND

Osteoradionecrosis of the mandible is the most common serious complication of radiotherapy for head and neck malignancy. For decades, hyperbaric oxygen has been employed in efforts to prevent those cases of osteoradionecrosis that are precipitated by dental extractions or implant placement. The evidence for using hyperbaric oxygen remains poor and current clinical practice varies greatly. We describe a protocol for a clinical trial to assess the benefit of hyperbaric oxygen in the prevention of osteoradionecrosis during surgery on the irradiated mandible.

METHODS/DESIGN

The HOPON trial is a phase III, randomised controlled, multi-centre trial. It employs an unblinded trial design, but the assessment of the primary endpoint, i.e. the diagnosis of osteoradionecrosis, is assessed on anonymised clinical photographs and radiographs by a blinded expert panel. Eligibility is through the need for a high-risk dental procedure in the mandible where at least 50-Gy radiotherapy has been received. Patients are randomised 1:1 to hyperbaric oxygen arm (Marx protocol) : control arm, but both groups receive antibiotics and chlorhexidine mouthwash. The primary endpoint is the presence of osteoradionecrosis at 6 months following surgery, but secondary endpoints include other time points, acute symptoms and pain, quality of life, and where implants are placed, their successful retention.

DISCUSSION

The protocol presented has evolved through feasibility stages and through analysis of interim data. The classification of osteoradionecrosis has undergone technical refinement to ensure that robust definitions are employed. The HOPON trial is the only multi-centre RCT conducted in this clinical setting despite decades of use of hyperbaric oxygen for the prevention of osteoradionecrosis.

TRIAL REGISTRATION

European Clinical Trials Database, ID: EudraCT200700622527 . First registered on 5 November 2007.

Upper aerodigestive tract cancer and oral health status before radiotherapy: A cross-sectional study of 154 patients

OBJECTIVES

We aimed to determine primarily the oral health status of patients with upper aerodigestive tract cancer before radiotherapy, and secondarily the prevalence of risk factors for poor oral status.

METHODS

A cross-sectional study was conducted in Marseille University hospital. Assessment criteria were the Decay, Missing and Filled (DMF) Index and periodontal status.

RESULTS

One hundred and fifty-four patients, mean age 60.9years, were included. The most common sites of primary tumors were the larynx (28.6%) and oral cavity (26.6%). Current or past smokers accounted for 80.5% of patients and 67% were alcohol abusers. Most patients (83.8%) did not have xerostomia. They ate three meals a day (61%), with sugar consumption in 40%. The median number of daily tooth brushings was 2, with a manual toothbrush (81.2%). Few patients used dental floss or interproximal brushes. Individual DMF index was 17.6 (D=2.3, M=9.3, F=6.0) and was higher in patients with xerostomia and alcohol abusers (P=0.01). Osseous level was 62.3% and 57.8% of patients had osseous infections, which were more common with poor hygiene (P=0.04). Most patients (85.7%) had periodontal disease, but incidence did not significantly differ according to risk factors.

DISCUSSION

The DMF index was higher in presence of periodontal disease and osseous infections. Alcohol and xerostomia were associated with a high individual DMF index and osseous infections were more frequent in patients with poor hygiene. Patients with upper aerodigestive tract cancer are at high risk of osteoradionecrosis if they do not receive dental treatment before radiotherapy.

Concomitant-chemoradiotherapy-associated oral lesions in patients with oral squamous-cell carcinoma

OBJECTIVE

: Oral squamous-cell carcinoma (OSCC) accounts for >90% of oral cancers affecting adults mostly between the fourth to seventh decades of life. The most common OSCC treatment is concomitant chemoradiotherapy (CCRT) having both loco-regional and distant control, but CCRT has acute and chronic toxic effects on adjacent normal tissue. This study aimed to determine the side effects of CCRT on the oral mucosa and to characterize the clinicopathology of oral lesions in patients with OSCC.

METHODS

This descriptive, cross-sectional study was certified by the Ethical Review Committee (UHS/Education/126-12/2728) of the University of Health Sciences, Lahore, Pakistan. OSSC patients (n=81) with various histological subtypes, grades, and stages were recruited, and findings on their oral examination were recorded. These patients received 70, 90, and 119 Gy of radiotherapy dosages in combination with the chemotherapy drugs cisplatin and 5-fluorouracil. Data were analyzed using SPSS 20.0.

RESULTS

: The most common presentation of OSCC was a nonhealing ulcer (63%) involving tongue (55.6%). Clinical findings included mucositis (92.6%) and xerostomia of mild, moderate, and severe degrees in 11.1%, 46.9%, and 35.8% cases, respectively. Ulcers (87.7%), palpable lymph nodes (64.2%), limited mouth opening (64.2%) and fistula (40.7%) were also observed. In females, the association of radiotherapy dosage with limited mouth opening, xerostomia, and histological grading was statistically significant (P<0.05). The association of chemotherapy drugs with xerostomia (P=0.003) was also statistically significant.

CONCLUSIONS

: CCRT induced mucositis, xerostomia, and trismus in patients with OSCC.

Hyperbaric oxygen therapy for maxillary bone radiation-induced injury: A 15-year single-center experience

BACKGROUND

Although hyperbaric oxygen therapy (HBOT) is used to treat chronic radiation tissue injury, clinical evidence supporting its use in maxillary bone osteoradionecrosis (ORN) is lacking. Therefore, the purpose of this study was to report our results of collected patient outcomes from a single center's large experience using HBOT to treat maxillary bone ORN.

METHODS

From 1999 to 2015, 21 patients received treatment for maxillary bone ORN at our center. The medical records were retrospectively reviewed for the following variables: age, sex, comorbidities, tumor stage and site, previous surgery, previous radiotherapy or chemoradiation therapy, HBOT data, response to treatment and further management.

RESULTS

A positive clinical outcome from HBOT occurred in 85.7% of patients with ORN and was proven radiologically in 14 of 15 patients (93.3%). In 5 patients, reconstructive surgery was required thereafter.

CONCLUSION

Controversy exists regarding the management of ORN of the maxillofacial skeleton. Our large, single-center experience probably supports the efficacy of HBOT for maxillary bone ORN. © 2016 Wiley Periodicals, Inc. Head Neck 39: 275-278, 2017.

Jaw osteoradionecrosis and dental extraction after head and neck radiotherapy: A nationwide population-based retrospective study in Taiwan

OBJECTIVES

Osteoradionecrosis of the jaws (ORNJ) is painful for patients and relatively difficult to treat clinically. The high risk of ORNJ for post radiotherapy R/T dental extraction is known; however, many patients still have to have teeth extracted after head and neck R/T. The objective of the present study is to review post R/T dental extraction and determine the ORNJ risk.

MATERIALS AND METHODS

We preformed a retrospective cohort study of 1759 patients with head and neck cancer s/p R/T from a random sample of 1,000,000 insurants in the National Health Insurance Research Database during 2000-2013 in Taiwan. Statistical methods included two-proportion Z-test.

RESULTS

We evaluated two cohorts: 522 patients with post R/T dental extraction and 1237 patients without post R/T extraction. Overall moderate-to-severe ORNJ after R/T was 2.22% (39/1759), and a total of 39 ORNJ cases were noted during an average of 3.02years (range: 0.62-8.89years, ±2.07). ORNJ prevalence in the overall post R/T extraction-exposed cohort (5.17%, 27/522) was significantly greater than that in the unexposed cohort (0.97%, 12/1237). In a group of patients with ⩽5 post R/T dental extractions (n=373), the ORNJ risk was 2.4% (ORNJ case n=9); in a group of patients with >5 dental extractions (n=149), the ORNJ risk was 12.1% (ORNJ case n=18) (Z-score=4.5062; p-value<0.0001). In the extraction-exposed cohort, the ORNJ risk is higher if the index day to first extraction day was ⩽0.5year (n=103) compared with the group with the index day to first extraction day >0.5year (n=419) (Z-score=-2.1506; p-value=0.0315).

CONCLUSION

A tooth extraction time less than half a year after R/T or during the head and neck R/T period, and extraction tooth number ⩽5 would significant lower the ORNJ prevalence.

Surgical extraction of impacted teeth in elderly patients. A retrospective analysis of perioperative complications - the experience of a single institution

OBJECTIVE

The aim of this retrospective study was to investigate the most frequent complications and assess their overall rate associated with the surgical extraction of impacted teeth in an elderly patient population.

BACKGROUND

Oral health needs of the elders are often associated with surgical procedures for the creation of appropriate conditions for any further prosthetic treatment. One such process is the removal of severely decayed, fractured or impacted teeth detrimental to the fit or appearance of dentures. While broken and decayed teeth leave little doubt for their removal, impacted teeth divide opinion, some extreme regarding their prophylactic removal and the appropriate age for the procedure.

MATERIAL AND METHODS

Material was selected from the archives of an Out-Patient Dental Surgery Clinic of the Regional Centre of Dentistry in Szczecin, from 2002 to 2013. The database was independently screened by two investigators according to inclusion and exclusion criteria. After selection process, all included records were screened using a data extraction form to obtain the necessary data.

RESULTS

The total number of impacted teeth was 73, of which 29% were partially impacted. The overall complication rate was 24.6%. The most common complications were as follows: haematoma, nerve disturbances and local infections.

CONCLUSION

Surgical extraction in patients above 60 years of age is fraught with a high risk of possible complications.

Late Toxicities after Conventional Radiotherapy for Nasopharyngeal Carcinoma: Incidence and Risk Factors

Background. To determine the incidence and analyze the factors affecting late toxicity for nasopharyngeal carcinoma patients treated with conventional radiotherapy. Patients and Methods. Retrospective analysis was performed on 239 NPC patients treated between 1993 and 2004 in our institution. One hundred and fifty-seven patients were treated with conventional fractionation (2 Gy per fraction, 5 fractions per week) and eighty-two patients with hyperfractionated radiotherapy (1.6 Gy per fraction twice a day, 5 days per week). One hundred fifty nine patients underwent neoadjuvant cisplatin based chemotherapy. Late toxicity was evaluated according to the RTOG/EORTC score. Results. Xerostomia was the most common related complication (98.7%). Neoadjuvant chemotherapy and hyperfractionated radiotherapy did not increase late toxicities. Multivariate analyses showed that radiation dose was a significant factor for hearing impairment, younger age for trismus, initial node status for neck fibrosis, and initial dental hygiene for dental complications. Female gender was associated with significantly higher incidence of trismus and hearing impairment. Conclusion. Conventional radiotherapy was associated with a high rate of late toxicities which affect patients’ quality of life. With the development of three-dimensional conformal radiotherapy and intensity modulated radiotherapy, a reduced incidence of radiation related complications could be expected.

Expertise regarding dental management of oral cancer patients receiving radiation therapy among Western Australian dentists

OBJECTIVES

Dental care forms an important part of the multidisciplinary management of oral cancer patients. The aim of this study was to examine actual and self-perceived knowledge and clinical expertise regarding dental management of oral cancer patients receiving radiation therapy among Western Australian general dentists.

MATERIALS AND METHODS

An invitation to participate in a web-based questionnaire was emailed to 1095 dentists registered with the Australian Dental Association (ADA), WA branch. To assess dentists' knowledge and expertise, actual and perceived knowledge was investigated. Information regarding type of practice, practice location, year of graduation and number of oral cancer patients treated in the preceding 12 months was also obtained.

RESULTS

One hundred and ninety one dentists responded to the survey. General dentists who took part in the study appeared to possess some knowledge regarding dental management of oral cancer patients treated with radiation therapy. The majority of responders however identified deficiencies in their knowledge and willingness to participate in continuing education programs.

CONCLUSION

In view of the rising incidence of oral cancer in Western Australia, efforts should be made to provide more clinically relevant training to dentists in this area.

The diagnosis and treatment of oral cavity cancer

BACKGROUND

About 10,000 persons are diagnosed as having carcinoma of the oral cavity or the throat in Germany every year. Squamous-cell carcinoma accounts for 95% of cases.

METHODS

We systematically reviewed the pertinent literature on predefined key questions about these tumors (which were agreed upon by a consensus of the investigators), concerning imaging, the removal of cervical lymph nodes, and resection of the primary tumor.

RESULTS

246 clinical trials were selected for review on the basis of 3014 abstracts. There was only one randomized, controlled trial (evidence level 1-); the remaining trials reached evidence levels 2++ to 3. Patients with mucosal changes of an unclear nature persisting for more than two weeks should be examined by a specialist without delay. The diagnosis is made by computed tomography or magnetic resonance imaging along with biopsy and a standardized histopathological examination. Occult metastases are present in 20% to 40% of cases. Advanced disease (stages T3 and T4) should be treated by surgery followed by radiotherapy, with or without chemotherapy. 20% of the patients overall go on to have a recurrence, usually within 2 to 3 years of the initial treatment. The 5-year survival rate is somewhat above 50%. Depending on the radicality of surgery and radiotherapy, there may be functional deficits, osteoradionecrosis, and xerostomia. The rate of loss of implants in irradiated bone is about 10% in 3 years.

CONCLUSION

The interdisciplinary planning and implementation of treatment, based on the patient's individual constellation of findings and personal wishes, are prerequisites for therapeutic success. Reconstructive measures, particularly microsurgical ones, have proven their usefulness and are an established component of surgical treatment.

Osteoradionecrosis of the mandible and mastoiditis after radiotherapy for parotid mucoepidermoid carcinoma

Osteoradionecrosis of the mandible in conjunction with mastoiditis is an extremely rare occurrence following irradiation of salivary gland malignancy in the orofacial region. We report one such case of a patient who presented to us with trismus, jaw pain, and ear discharge. Imaging of the jaws revealed classical features of osteoradionecrosis and mastoiditis. This case is important because presenting features like trismus and dental infection led us to investigative procedures that revealed extensive bone involvement including mastoiditis. Trismus progressively increased over a period of 8 years. In this case, we would like to emphasize the importance of good oral hygiene in the postradiotherapy stage for head and neck cancer.

Efficacy of pre- and postirradiation hyperbaric oxygen therapy in the prevention of postextraction osteoradionecrosis: a systematic review

PURPOSE

There is still considerable controversy regarding whether hyperbaric oxygen (HBO) therapy used preoperatively and postoperatively will prevent osteoradionecrosis in previously irradiated patients undergoing tooth extraction. The purpose of this systematic review was to evaluate the best evidence available in an attempt to find an answer to this question.

MATERIALS AND METHODS

The literature search on Medline covered the period from January 1948 to March 2008. Included were randomized clinical trials, prospective studies without randomization, case-control studies, retrospective studies, and observational studies with and without control groups. This search retrieved 696 citations, which was reduced to 14 acceptable publications based on an assessment of methodologic quality. They included 1 randomized clinical trial, 8 cohort-controlled studies, and 5 observational studies. These were analyzed for radiation dose, type of radiation, use of adjunctive cancer treatments, number and location of extractions, method of extraction, HBO protocol, and use of adjunctive therapy besides HBO.

RESULTS

Most of the studies had a small sample size, lacked specific inclusion and exclusion criteria, did not report the interval between radiation and extraction, and provided limited information on the method of extraction. There was also variation in HBO protocols, radiation dosage, the use of antibiotics, and the use of adjunctive cancer therapy.

CONCLUSION

On the basis of the best available evidence, there is currently insufficient information to show that the use of HBO reduces the incidence of osteoradionecrosis in irradiated patients requiring tooth extraction.

Osteoradionecrosis of the jaws--a current overview--Part 2: dental management and therapeutic options for treatment

PURPOSE

The aim of this paper is to explore the current theories about pretreatment assessment and dental management of patients receiving head and neck radiotherapy, and the therapeutic options to treat osteoradionecrosis of the jaws, based on the literature review.

DISCUSSION

Osteoradionecrosis is one of the most serious oral complications of head and neck cancer treatment. Osteoradionecrosis is a severe delayed radiation-induced injury, characterized by bone tissue necrosis and failure to heal. Osteoradionecrosis either stabilizes or gradually worsens and is notoriously difficult to manage. Because most cases occur in patients who were dentulous in the mandible at tumor onset, proper dental management is the single most important factor in prevention.

CONCLUSIONS

Complete dental clearance before treatment is no longer necessary. Controversy exists regarding the management of osteoradionecrosis of the maxillofacial skeleton because of the variability of this condition. The treatment of osteoradionecrosis has included local wound care, antibiotic therapy, surgical procedures, and the administration of hyperbaric oxygenation. Recently, new methods of treatment were introduced, according to the new theory about its pathophysiology.

Osteoradionecrosis of the jaws--a current overview--part 1: Physiopathology and risk and predisposing factors

PURPOSE

The aim of this paper is to explore the current theories about definition, classification, incidence and physiopathology of osteoradionecrosis (ORN) of the jaws. Moreover, it is discussed the predisposing and risk factors for the development of osteoradionecrosis based on the literature review.

DISCUSSION

Osteoradionecrosis is one of the most serious oral complications of head and neck cancer treatment. Osteoradionecrosis is a severe delayed radiation-induced injury, characterised by bone tissue necrosis and failure to heal. Osteoradionecrosis either stabilises or gradually worsens and is notoriously difficult to manage. The most widely accepted theory to explain its cause until recently was the theory of hypoxia, hypovascularity and hypocellularity. A new theory for the pathogenesis of osteoradionecrosis was proposed. The clinical presentations of osteoradionecrosis are pain, drainage and fistulation of the mucosa or skin that is related to exposed bone in an area that has been irradiated. The tumour size and location, radiation dose, local trauma, dental extractions, infection, immune defects and malnutrition can predispose its development.

CONCLUSIONS

A better understanding of risk factors for the development ORN and of the underlying pathophysiology may improve our ability to prevent this complication and help to improve the prognosis for those being treated for osteoradionecrosis.

Dental extractions and radiotherapy in head and neck oncology: review of the literature

Management of irradiated patients with cancer in the head and neck region represents a challenge for multidisciplinary teams. Radiotherapy promotes cellular and vascular decrease that results in a low response rate in the healing. Consequently, surgical procedures in irradiated tissues present high rates of complication. Osteoradionecrosis (ORN) is the most severe sequelae caused by radiotherapy. It is associated with previous extractions especially those carried out post-irradiation. The management of this side effect is difficult and can result in bone or soft tissue loss, affecting the quality of life. The literature regarding dental extractions performed before and after head and neck radiotherapy was evaluated, focusing on indications, criteria, surgical techniques and adjunctive therapies such as antibiotics and hyperbaric oxygen. Osteoradionecrosis can be minimized by oral evaluation and care prior to irradiation and healing time which allows tissue repair until the commencement of radiotherapy. In dental extractions realized after irradiation, minimal trauma, alveolectomy, primary alveolar closure and adjunctive therapies are recommended. Patients must be evaluated before radiation therapy and at that time all unrestorable teeth and/or teeth with periodontal problems must be extracted to reduce the post-radiotherapy exodontias that contribute to ORN. Once dental extractions become unavoidable after irradiation, additional care is needed.

The effect of prior radiation therapy for treatment of nasopharyngeal cancer on wound healing following extractions: incidence of complications and risk factors

This is a prospective study of wound healing after extractions in patients who had radiation therapy for nasopharyngeal cancer. From 40 patients who fulfilled all the study criteria were extracted a total of 155 teeth. The demographic data were analysed, checking for factors that might affect the healing process after extraction. Wound healing was divided into three groups: normal wound healing, delayed healing and osteoradionecrosis. Logistic regression was used to analyse possible relationships. There was a low complication rate: 5.8% and 1.9% of extractions showed delayed healing and osteoradionecrosis, respectively. The age of the patient at time of extraction was the only significant factor that influenced the occurrence of delayed healing. It was observed that localized radiation absorption was considerably different from the total radiation dose. In conclusion, postradiation extractions have a low risk of complications and the results point to age as a factor that may influence wound healing.

Osteoradionecrosis prevention myths

PURPOSE

To critically analyze controversial osteoradionecrosis (ORN) prevention techniques, including preradiation extractions of healthy or restorable teeth and the use of prophylactic antibiotics or hyperbaric oxygen (HBO) treatments for preradiation and postradiation extractions.

METHODS

The author reviewed ORN studies found on PubMed and in other article references, including studies on overall ORN incidence and pre- and postradiation incidence, with and without prophylactic HBO or antibiotics.

RESULTS

Owing in part to more efficient radiation techniques, the incidence of ORN has been declining in radiation patients over the last 2 decades, but the prevention of ORN remains controversial. A review of the available literature does not support the preradiation extraction of restorable or healthy teeth. There is also insufficient evidence to support the use of prophylactic HBO treatments or prophylactic antibiotics before extractions or other oral surgical procedures in radiation patients.

CONCLUSIONS

To prevent ORN, irradiated dental patients should maintain a high level of oral health. A preradiation referral for a dental evaluation and close collaboration by a multidisciplinary team can be invaluable for radiation patients. As with most other dental patients, restorable and healthy teeth should be retained in irradiated patients. The use of prophylactic HBO or antibiotics should be reconsidered for preradiation and postradiation extractions.

Are Sterile Gloves Necessary in Nonsurgical Dental Extractions?

PURPOSE

The aim of the study was to compare the incidence of healing complications of extraction socket with the use of sterile or clean nonsterile gloves during nonsurgical dental extractions.

MATERIAL AND METHODS

This was a randomized prospective study conducted at the exodontia clinic of the Department of Oral and Maxillofacial Surgery of the Lagos University Teaching Hospital (Nigeria), between October 2002 and January 2003. Patients who were referred for nonsurgical extractions of permanent teeth and who satisfied the inclusion criteria into the study were randomly allocated into 2 groups. One group had their extractions performed with the surgeon wearing a pair of sterile gloves and the second group had their extractions performed with the surgeon wearing a pair of clean nonsterile gloves. Two hundred sixty-nine patients who had 301 teeth extracted and satisfied the inclusion criteria for socket healing assessment were assessed for postoperative socket healing.

RESULTS

Three different types of socket healing complications were identified (dry socket, acutely inflamed socket, and acutely infected socket). A total of 32 patients (11.9%) developed socket healing complications. Nineteen of 122 patients in the sterile glove group and 13 of 147 patients in the clean nonsterile glove group developed socket healing complications (P = .09).

CONCLUSION

The study confirmed that the use of sterile surgical gloves offers no advantage over clean nonsterile gloves in minimizing extraction socket healing complications following dental extraction. Therefore, nonsurgical dental extraction can be safely performed with the surgeon wearing clean nonsterile gloves.

Dental extractions in the irradiated head and neck patient: a retrospective analysis of memorial sloan-kettering cancer center protocols, criteria, and end results

BACKGROUND

This study was designed to use our institutional experience with irradiated head and neck patients to evaluate 1) dental extraction incidence and sequelae; 2) those patients who developed osteoradionecrosis via extraction and the efficacy of hyperbaric oxygen therapy; and 3) guidelines for extraction protocols in this population. Materials and methods A group of 1,194 patients with a history of radiation to the head and neck, who were evaluated and treated in the Dental Service at Memorial Sloan-Kettering Cancer Center, were reviewed. The 187 who required dental extractions were analyzed using patient demographics, tumor location, staging, histopathology, radiation dosage, field, and timing, dental extraction indications, location, surgical methods, and sequelae.

RESULTS

Almost 85% of the patients reviewed did not require extraction. Only 4 of those who underwent extractions at Memorial Sloan-Kettering Cancer Center developed osteoradionecrosis.

CONCLUSIONS

The use of multidisciplinary team communications and careful extraction selection by prognosis and symptomatology regardless of preexisting dental pathologies, atraumatic extraction procedures, and meticulous follow-up can lower both extraction and osteoradionecrosis rates.

Oral health condition in southern Chinese after radiotherapy for nasopharyngeal carcinoma: extent and nature of the problem

OBJECTIVE

To measure the oral health status of southern Chinese nasopharyngeal carcinoma (NPC) survivors 1-4 years after radiotherapy.

SUBJECTS AND METHODS

A total of 109 subjects participated in this cross-sectional study. Thirty-eight subjects were NPC survivors, 40 subjects were patients newly diagnosed with NPC and 31 were healthy subjects. Verified clinical examination techniques were used to assess limitation of jaw opening, the presence of mucositis, candidiasis, dental caries, periodontal disease [community periodontal index (CPI)] including attachment loss (ALoss) and prosthetic status/need. Differences among three groups were tested by chi-squared and Kruskal-Wallis tests. Relationships between selected clinical variables and radiation parameters were analysed using Spearman's rank correlation coefficients.

RESULTS

The NPC survivors attended for dental treatment more frequently than the other groups (P < 0.01). NPC survivors had significant xerostomia (92%, P < 0.01), trismus (29%, P < 0.01), a higher prevalence of clinical candidiasis (24%, P < 0.01), a greater DMFT (16.4 +/- 7.0, P < 0.01), more decay/filled roots (2.1 +/- 2.9, P = 0.01) compared with new NPC patients and controls. No difference was found in CPI, ALoss, prosthetic status and need between groups. Dry mouth and tooth hypersensitivity were the most common oral problems perceived by the NPC survivors.

CONCLUSION

Despite having regular dental follow-ups, oral health was compromised in NPC survivors 1-4 years postradiotherapy.

Prevention and treatment of the consequences of head and neck radiotherapy

The location of the primary tumor or lymph node metastases dictates the inclusion of the oral cavity, salivary glands, and jaws in the radiation treatment portals for patients who have head and neck cancer. The clinical sequelae of the radiation treatment include mucositis, hyposalivation, loss of taste, osteoradionecrosis, radiation caries, and trismus. These sequelae may be dose-limiting and have a tremendous effect on the patient's quality of life. Most treatment protocols to prevent these sequelae are still based on clinical experience, but alternatives based on fundamental basic and clinical research are becoming more and more available. Many of these alternatives either need further study before they can be incorporated into the protocols commonly used to prevent and treat the radiation-related oral sequelae or await implementation of these protocols. In this review, the various possibilities for prevention and/or treatment of radiation-induced changes in healthy oral tissues and their consequences are discussed.

Oral sequelae of head and neck radiotherapy

In addition to anti-tumor effects, ionizing radiation causes damage in normal tissues located in the radiation portals. Oral complications of radiotherapy in the head and neck region are the result of the deleterious effects of radiation on, e.g., salivary glands, oral mucosa, bone, dentition, masticatory musculature, and temporomandibular joints. The clinical consequences of radiotherapy include mucositis, hyposalivation, taste loss, osteoradionecrosis, radiation caries, and trismus. Mucositis and taste loss are reversible consequences that usually subside early post-irradiation, while hyposalivation is normally irreversible. Furthermore, the risk of developing radiation caries and osteoradionecrosis is a life-long threat. All these consequences form a heavy burden for the patients and have a tremendous impact on their quality of life during and after radiotherapy. In this review, the radiation-induced changes in healthy oral tissues and the resulting clinical consequences are discussed.

Early detection of radiation-induced structural changes in rat trabecular bone

OBJECTIVE

Early detection of bone changes following radiotherapy is very important. The aim of this study is to establish a radiographic image analysis method for early detection of radiation-induced trabecular bone changes.

METHODS

Thirty-five Wistar rats were used for the experimental model of trabecular bone changes, which were induced by X-ray irradiation with 30 Gy to develop simulated osteomyelitis. Standardized 2.2 x direct magnification radiography was performed immediately prior to X-ray irradiation and once a week for 4 weeks following irradiation. The latent X-ray images were scanned using a computed radiography (CR) system. Mathematical morphological processing was then applied to the CR image data, which allowed the bone trabecular pattern features to be extracted as skeletal binary images. The sensitivity and specificity for detecting early trabecular bone changes in CR images and in skeletal binary images were evaluated. Quantitative analyses with quantum level value (QL value), skeletal pixel percentage (SKP) and star volume analysis (skeletal volume (Vsk), skeletal space volume (Vsp)) were performed. Histopathological examination was also conducted for confirmation of physical changes in the bone.

RESULTS

Visual observation of the skeletal binary images provided a higher sensitivity than the CR images. In the quantitative analysis, SKP, Vsk and Vsp values provided higher sensitivity than QL values.

CONCLUSION

The results of the present study suggest that a combined radiographic image analysis method using CR, mathematical morphological processing, SKP, Vsk and Vsp can be useful for the early detection of radiation-induced trabecular bone changes.

Antibiotic prophylaxis for endocarditis, prosthetic joints, and surgery

It would seem from a review of the evidence that the need for antibiotic prophylaxis in dentistry is overstated. In simple mathematic terms, the risk for providing coverage is greater than the outcomes that could arise if coverage is withheld. In addition, there is the increasing problem of the development of resistant strains and their impact on medicine and dentistry. Yet despite these observations, the profession continues to put their patients at this greater risk. Medico-legal issues do cloud judgments in this area and many dentists err on the side of caution. The profession does require clear, uniform guidelines that are evidence-based. At present, there is still significant debate as to who is at risk from dental-induced bacteremia and what procedures require chemoprophylaxis.

A survey of antibiotic prescribing by maxillofacial consultants for dental extractions following radiotherapy to the oral cavity

OBJECTIVES

To analyse the antibiotic prescribing trends for exodontia and minor oral surgery in patients with a history of radiotherapy. Also, to evaluate the use of hyperbaric oxygen as a separate modality in the prevention of osteoradionecrosis.

DESIGN

A survey of antibiotic prescribing involving the analysis of a questionnaire which included the management of three patients with a history of head and neck malignancy.

METHOD

The heads of the departments in each unit in the UK were sent a closed-response questionnaire. Antibiotic prescribing was assessed in three case scenarios. Case one referred to a patient that had surgery alone as part of the management of head and neck cancer, who needed the surgical removal of second molar roots. Case two referred to a patient that had surgery and adjuvant radiotherapy as part of the management of head and neck cancer, and needed the same procedure as in case one. Case three included a patient with a history of surgery and adjuvant radiotherapy, who required the extraction of three mobile and periodontally-involved lower incisors. Consultants were also asked about the use of hyperbaric oxygen in the patients who had radiotherapy as part of their treatment strategy.

RESULTS

A total of 109 questionnaires were sent to all the Maxillofacial Units in the UK. The response rate was 73%. In patients with a history of radical surgery alone for the management of head and neck cancer, 20% of the surgeons advocated pre-operative antibiotics for the surgical removal of lower posterior teeth. In contrast, in the patient with a history of adjuvant radiotherapy 86% supported pre-operative antimicrobial use for the surgical removal of the same teeth. In the extraction of mobile and periodontally involved lower incisors in the previously irradiated patient, 63% of the clinicians supported pre-extraction antibiotics. Postoperative antibiotics were advocated in 52% in the first case, 89% in the second case and 71% in the third case. 34% of the clinicians advocated hyperbaric oxygen for surgical removal of posterior teeth and 15% for the extraction of mobile anterior teeth.

CONCLUSIONS

The use of peri-extraction antibiotics was favoured among oral and maxillofacial surgeons. There was little enthusiasm towards the use of hyperbaric oxygen as a prophylactic measure, alone or in conjunction with an antimicrobial regime. Control randomised trials that will measure the effectiveness of hyperbaric oxygen and the appropriate use of antibiotics for prophylaxis in pre- and post-operative regimes are necessary to evaluate the use of these modalities.