Thermography as a non-ionizing quantitative tool for diagnosing periapical inflammatory lesions.

BACKGROUND: Thermography is a contemporary imaging modality based on acquiring and analyzing thermal data using non-contact devices. The aim of the present study was to assess the validity of thermography, compared with that of the reference-standard, for the diagnosis of periapical inflammatory lesions and to evaluate the temperature ranges for acute pulpitis with apical periodontitis (AAP), acute periapical abscess (AA) and chronic periapical abscess (CA). METHODS: AAP, AA and CA were diagnosed based on clinical and radiographic criteria. Thermographic data were acquired using the FLIR E-5 Infrared Camera. Extraoral thermal images were taken from the front and right and left sides of patients whose mouths were closed, and one intraoral thermal image was taken from the palatal perspective. Agreement in the diagnoses based on the combination of clinical and radiographic assessments and the thermographic evaluation was calculated. The temperature ranges of the three diagnostic subgroups were also measured. RESULTS: A total of 80 patients were enrolled in this study. The mean intraoral thermal image temperature for AA was 37.26 ± 0.36, that for CA was 35.03 ± 0.63 and that for AAP was 36.07 ± 0.45. The differences between the mean intraoral thermal temperatures of the three diagnostic groups were statistically significant (P < 0.001). The result of the Kappa coefficient of agreement between the combination of clinical and radiographic assessments and the thermographic evaluation was significant (P < 0.001). CONCLUSIONS: Thermography is an effective, quantitative and nonionizing approach that can be used for the diagnosis of periapical inflammatory lesions. The results of the present study indicated that the highest thermal image temperatures were recorded for AA. Thermography might be able to detect inflammatory reactions during the preclinical stage, leading to early diagnosis.

Post COVID-19 lockdown: measures and practices for dental institutes.

Resuming regular clinical activities at dental premises after the COVID-19 lockdown period or post COVID-19 is likely to be a challenge for all dental institutes. When returning to the dental practice or training, staff and students alike should abide by the new rules and regulations. In the process of controlling viral spread, clinical dental facilities face a higher risk of disease transmission among patients as well as clinical and non-clinical staff. Aerosols formation and diffusion into the surrounding air can be a real concern of viral transmission, if no protective measures are established. We aim in this review to present the currently implemented measures and propose changes in clinical dental facilities to minimize the risk of transmission. Dental professionals should be prepared to treat every patient as a suspected COVID-19 carrier and be ready to receive and manage an overwhelming number of patients. We suggest that dental practices establish a sensible workforce shift schedule, improve ventilation levels, reduce dental aerosol generating procedures, and develop a comprehensive guidance to Healthcare Workers to reduce the risk of COVID-19 transmission.

Effect of different impression coping and scan body designs on the accuracy of conventional versus digital implant impressions: An in vitro study.

OBJECTIVES: This in vitro study compared the accuracy of conventional versus digital impression techniques for angulated and straight implants using two different impression coping and scan body designs. METHODS: Two implant systems were used: Straumann and Dentegris. Two implants were placed for each system, straight and angulated at 15 degrees mesiodistally. Conventional impressions were made using the splinted open-tray technique using narrow impression coping (NIC) and wide impression coping (WIC). The stone casts produced from the conventional impression were digitized with a lab scanner (3Shape D2000). Digital impressions were made using four intraoral scanners (IOS): 3Shape Trios 3, Medit i700, Cerec Omnicam, and Emerald Planmeca using short scanbodies (SSB) and long scanbodies (LSB). The scanning was repeated ten times to generate the Standard Tessellation Language (STL) files. The distance and angle deviations between impression copings and scanbodies were measured in reference to the master model. RESULTS: The trueness and precision of SSB and WIC were significantly better than LSB and NIC (p<0.001). The range trueness of the platform deviation was better with SSB (37.1 to 51.9) than LSB (89.6 to 127.9 µm) and for WIC than NIC in conventional impressions (58.2 and 75.1 µm, respectively). The trueness of the angle deviation of digital scans with SSB (0.11 to 0.25 degrees) was significantly better than scans with LSB (0.31 to 0.57 degrees) and for WIC than NIC (0.21 and 0.52 degrees, respectively). The precision of the platform deviation of digital scans with SSB (12.4 to 34.5 µm) was higher than other scans and conventional impressions (42.9 to 71.4 µm). The precision of the angle deviation of Medit i700 and Trios 3 with SSB (0.17 and 0.20 degrees, respectively) was higher than other scans with SSB and conventional impressions (0.54 to 1.63 degrees). CONCLUSIONS: Digital scans with SSB were more accurate than conventional splinted open-tray impressions. The type of impression coping and scanbody significantly affected the impression accuracy. CLINICAL SIGNIFICANCE: The use of a short scanbody can increase the accuracy of digital impressions, and wide impression coping can increase the accuracy of conventional impressions, resulting in improved clinical outcomes.

Applications of artificial intelligence in restorative dentistry: a scoping review.

OBJECTIVE: Artificial intelligence (AI) applications in restorative dentistry have remarkably increased in the past 5 years. This review outlines the applications, promises, and limitations of AI in the most performed procedures in restorative dentistry. METHOD AND MATERIALS: An electronic search was performed in four databases: MEDLINE/PubMed, Embase, Web of Science, and Scopus. The search included articles published in English language without date restriction. Two independent reviewers assessed the eligibility of the studies and performed data extraction. Any discrepancy was resolved by the consensus of a third reviewer. RESULTS: A total of 33 studies were included in this review. For AI applications in restorative dentistry, the included studies were classified into three main groups: (1) diagnosis, detection, and prediction of the disease, (2) detection and prediction of the longevity of dental restorations, and (3) teeth detection and treatments. For each study, the AI model, type of dataset, sample size, and main results (accuracy, precision, sensitivity, and specificity) were reported. CONCLUSIONS: AI systems are promising as advantageous aids for diagnosis, prediction, and treatment in dentistry, with a high degree of accuracy. Despite the AI promises, several limitations are still unresolved and must be addressed to bridge the gap between technology and clinical applications.

CO2 laser of oral dysplasia: clinicopathological features of recurrence and malignant transformation.

The use of the CO(2) laser in the management of oral dysplastic lesions has become a more common practice. Very few studies have evaluated recurrence, residual disease malignant transformation, and overall outcome in patients undergoing such a procedure. In this prospective study, a total of 123 oral dysplastic lesions from 77 consecutive patients were treated with the CO(2) laser (resection and/or ablation). The average age was 58 ± 4.8 years. The patients' recovery was uneventful and no complications were reported. Comparisons with the clinical and histopathological features and rate of recurrence as well as malignant transformation were made. The patients were followed-up for a mean of 6.4 years, and biopsies taken in case of changes suggestive of malignant development. Homogenous leukoplakias were identified in 31 patients, non-homogenous leukoplakias in 34 patients, whereas 12 patients had erythroplakias. Ex- and life-long smokers formed 88.3% of the recruited patients. While people who currently smoke and drink formed 55.8% of the cohort. Erythroplakias were solely identified in heavy life-long smokers. The most common identified primary anatomical locations were the lateral border of tongue, floor of mouth, and buccal mucosa. Moderate dysplasia was identified in 42 patients while 18 patients had severe dysplasia. Laser resection margins in selected cases (68 patients) were clear in 53 and showed mild-moderate dysplasia in the involved margins. The rate of recurrence had no significant association with the location but the severity of epithelial dysplasia. The rate of first recurrence after laser surgery was approximately 19.5%. Malignant transformation was observed in eight patients (10.4%), in the tongue and the floor of mouth. Recurrence and malignant transformation was mainly identified in erythroplakias and non-homogenous leukoplakias. Laser resection/ablation is recommended for oral dysplasia to prevent not only recurrence and malignant transformation but also postoperative oral dysfunction encountered by other conventional modalities.

Characteristics of Suture Materials Used in Oral Surgery: Systematic Review.

BACKGROUND: The aim of this review was to evaluate the most used suture materials with regards to their inflammatory response, their bacterial adhesion, and their physical properties when used to close oral wounds. METHODS: Four databases (PubMed, Scopus, Dentistry & Oral Sciences, and OVID) were searched to retrieve relevant studies from January 1, 2000, to January 31, 2020. RESULTS: Out of the 269 articles, only 13 studies were selected as they were relevant and met the systematic review's protocol. These studies showed that almost all suture materials studies (catgut, polyglycolic acid [PGA] sutures, nylon, expanded polytetrafluoroethylene, and silk sutures) caused bacterial adherence and tissue reaction. In nylon and chromic catgut, the number of bacteria accumulated was lowest. Silk and nylon were found to be more impacted than catgut and PGA in terms of physical characteristics such as tensile strength. PGA, on the other hand, was said to be the most susceptible to knot unwinding. CONCLUSIONS: Following an oral surgical operation, all sutures revealed varied degrees of irritation and microbial accumulation. Nonresorbable monofilament synthetic sutures, however, exhibited less tissue response and less microbial accumulation.

Photodynamic therapy outcome for T1/T2 N0 oral squamous cell carcinoma.

INTRODUCTION: This new prospective clinical study assessed the oncological outcomes following surface illumination mTHPC-photodynamic therapy of T1/T2 N0 oral squamous cell carcinoma (OSCC) patients. MATERIAL/METHODS: Thirty-eight patients participated in this study. Their mean age at the first diagnosis of OSCC was 58.0 years. Common clinical presentation was an ulcer mainly identified in the tongue, floor of mouth (FOM), or buccal mucosa. Current and ex-smokers represented 89.5% of the cohort; while current and ex-drinkers were 86.8%. Clinically nine patients had T1 disease while 29 had T2 disease. RESULTS: Pathological analysis revealed that 12 patients had well differentiated SCC, 16 moderately differentiated and 10 had poorly-differentiated cancer. All patients were discussed in a multidisciplinary meeting and, subsequently, underwent mTHPC-PDT. PDT was repeated in 6- to 7-month period following the first round when residual tumor was identified in the treated site. At last clinic review post-PDT, 26/38 patients showed complete normal clinical appearance of their oral mucosa in the primary tumor site. Recent surgical biopsies from the study cohort showed that 17 had normal mucosa, five with hyperkeratinization, 10 with dysplastic changes and six showed recurrent SCC. The overall recurrence was 15.8% and the 5-year survival was 84.2%. Death from loco-regional and distant disease spread was identified in three patients. The recurrence group comprised six patients. Most common presentation was an ulcer involving the buccal mucosa or retromolar area, identified in current or ex-smokers and current drinkers. The surgical margins in this group were also evaluated following laser or surgical excision and reconstruction. CONCLUSIONS: mTHPC-photodynamic therapy (up to three rounds) is a comparable modality to other traditional interventions in the management of low-risk tumors of the oral cavity. Although, sometimes, multiple rounds of the treatment is required, morbidity following PDT is far less when compared to the three conventional modalities: surgery, radiotherapy, and chemotherapy.

Photodynamic therapy outcome for oral dysplasia.

INTRODUCTION: Photodynamic therapy (PDT) is a minimally invasive surgical intervention used in the management of tissue disorders. It can be applied before, or after, any of the conventional modalities, without compromising these treatments or being compromised itself. MATERIALS AND METHODS: In this prospective study, a total of 147 consecutive patients with oral potentially malignant disorders were treated with surface illumination PDT, using 5-ALA or mTHPC as the photosensitizer. The average age was 53 ± 8.9 years. The patients' recovery was uneventful and no complications reported. Comparisons with the clinical and histopathological features and rate of recurrence as well as malignant transformation were made. The patients were followed-up for a mean of 7.3 years. ANALYSIS AND RESULTS: Homogenous leukoplakias were identified in 55 patients, non-homogenous leukoplakias in 73 patients, whereas 19 patients had erythroplakias. Ex- and current lifelong smokers formed 84.4% of the recruited patients. While people who currently smoke and drink formed 38.1% (56 patients) of the cohort. Erythroplakias were mainly identified in heavy lifelong smokers. The most common identified primary anatomical locations were the lateral border of tongue, floor of mouth and retromolar area. Moderate dysplasia was identified in 33 patients while 63 patients had severe dysplasias; and 32 patients had a histopathological diagnosis of carcinoma in situ. The rate of recurrence in laser surgery was approximately 11.6%. Malignant transformation was observed in 11 patients (7.5%), in the tongue, floor of mouth and retromolar area. Recurrence and malignant transformation was mainly identified in erythroplakias and non-homogenous leukoplakias. The final outcome of the cohort showed that 11 (7.5%) suffered from progressive disease, 5 (3.4%) had stable disease, 12 (8.2%) were considered partially responsive to the therapy. Complete response was identified in 119/147 patients (81%). CONCLUSION: 5-ALA-PDT and/or mTHPC-PDT offer an effective alternative treatment for oral potentially malignant disorders.

The consequences and outcomes associated with dental implants encroaching on adjacent teeth.

BACKGROUND: Dental implant placement carries a risk of iatrogenic damage to adjacent root surfaces. PURPOSE: To classify and understand different types of trauma to the tooth root body by dental implants. MATERIALS AND METHODS: This prospective case series included 43 implants placed between February 2017 and June 2020 that had primary stability and were in a position that accidentally invaded the adjacent teeth. The type and degree of the injury were evaluated clinically and radiographically. Tenderness, mobility, and sensitivity tests of the injured teeth were conducted at different visits. Implant failure was confirmed by the presence of implant mobility during the healing period. RESULTS: Overall, 43 patients had root injuries due to dental implant surgeries. Regarding the 43 injured roots, 32 developed transient tenderness to percussion, 16 developed variable degrees of resorption in the cementum, three lost pulp sensitivity and one had persistent tenderness to percussion. No injured teeth were lost. In three patients, implant periapical lesions were confirmed radiographically as radiolucency near the apex of the involved implants. Out of the 43 implants, 11 failed and were removed within 6 months, with an implant failure rate of (25%). CONCLUSIONS: Root damage after implant surgery varies depending on the type and severity of injury. Periodic clinical and radiographical examination is necessary to monitor root resorption and implant integration and to rule out pulp necrosis.

Evaluation of different surgical approaches to remove dental implants from the maxillary sinus.

Dental implant surgery on atrophied maxilla has many risks; in some patients, simultaneous sinus lifting with implant placement must be performed to increase the chances of successful implantation; this procedure can cause implant migration. Eleven patients were diagnosed with implant migration into the maxillary sinus in four anatomical areas: the sinus floor above the alveolar bone, near the junction of the sinus and nasal floor, near the floor of the orbit, and the most posterior aspect of the sinus. Surgical removal was performed through four different direct non-endoscopic transoral approaches depending on the location of the displaced implant. Surgical challenges, surgery duration and postoperative complications were reported. The least challenging surgical intervention was noted when removing the displaced implants from the floor of the sinus through the crestal approach. More challenges were experienced during the surgical removal of anteriorly displaced implants near the roof of the orbital floor due to surgical access and the proximity of vital anatomical structures. Bleeding from the pterygoid venous plexus was profound with the posterior lateral approach. The choice of an appropriate surgical approach to retrieve displaced dental implants from the maxillary sinus depends on the location of the implant and the surrounding vital anatomical structures.

Optical coherence tomography in the assessment of oral squamous cell carcinoma resection margins.

BACKGROUND: Incomplete surgical removal of cancer is believed to be the main cause of local recurrence and high mortality. This study assessed the use of optical technology (namely optical coherence tomography [OCT]) in examining oral squamous cell carcinoma (OSCC) resection margins to assess if this modality could guide the surgeon during surgical resections. MATERIALS AND METHODS: Twenty-eight T1-T2 N0M0 oral squamous cell carcinoma patients participated in this study. Nineteen patients were males and nine were females. The majority of lesions were in the ventro-lateral tongue, floor of mouth, retromolar trigone and the buccal mucosa. Following tumour resection, the specimen resection margins were optically scanned in the immediate ex vivo phase. Two independent assessors commented on the four resection margins of each specimen. The findings were then compared to the corresponding gold standard histopathology. The average epithelial thickness for both tumor-free and tumor-involved margins was also calculated. RESULTS: The pathology reports of the 112 margins revealed 90 tumor-free margins and 22 tumor-involved margins. Examining the data from both senior operating surgeons (assessors), the overall sensitivity and specificity was found to be 81.5% and 87%, respectively. Whilst the positive predictive value was 61.5% and the negative predictive value was 95%. OCT accuracy for the first assessor was 88% and for the second assessor 84%. The assessors' inter-observer agreement was "very good" for superior, inferior and medial margins; while agreement on the lateral surgical margin status was "good". Using OCT, the mean epithelial thickness at the tumor-free resection margins was 360 µm; while, it was 567 µm for the tumour-involved margins. CONCLUSION: OCT is a valuable tool in the assessment of surgical margins. Tumour-involved margins can be identified by architectural changes and increase in epithelial layer thickness on the OCT image. Further studies are required to assess tumour margins in vivo.

Skeletal and dental relapses after skeletal class III deformity correction surgery: single-jaw versus double-jaw procedures.

OBJECTIVE: In this prospective comparative study, we looked at the postoperative dental and skeletal relapses in patients undergoing orthognathic surgery for skeletal class III deformity. The surgical interventions were single-jaw versus double-jaw procedures. STUDY DESIGN: Twenty-four adult patients with skeletal class III deformity presented with functional and esthetic problems. Patients were randomized to receive single- or double-jaw corrective surgery. The assessment of outcome was by lateral cephalograms taken at different intervals and postoperative complications. RESULTS: At 1 year after surgery, no significant correlation was identified between surgical advancement and relapse regarding maxillary stability. The single-jaw procedure cohort had a significantly greater horizontal mandibular skeletal relapse. No differences were noted when examining the mandibular vertical stability. None of the patients reported any acute local neurology. CONCLUSIONS: Single-jaw procedure may lead to less stability, leading to skeletal relapse, than double-jaw procedure. A higher evidence-based study and larger cohort is required to prove this.

Solitary giant neurofibroma of the neck subjected to photodynamic therapy: case study.

Photodynamic therapy (PDT) - the fourth modality - has been successfully used in the management of early and advanced pathologies of the head and neck. We studied the effect of this modality on a giant solitary neurofibroma of the neck. A 70-year-old Caucasian female presented with left neck pain and disfigurement associated with slight shortness of breath and dysphagia. Examination revealed a large mass in the neck with no neurovascular compromise. Magnetic resonance imaging (MRI) reported a heterogeneously enhancing mass extending from the left angle of the mandible to the base of the neck. A core biopsy was performed and histopathological examination revealed a disorganised array of peripheral nerve fascicles. The patient elected to receive photodynamic therapy as the primary intervention. The multi-disciplinary meeting approved the treatment plan. The photosensitizing agent was mTHPC (0.15 mg/kg), which was systemically administered 96-hours prior to ultrasound (US)-guided light delivery to the mass, which was undertaken under general anaesthesia. Recovery was uneventful. Post-PDT follow-up showed that the patient's pain, dysphagia and shortness of breath issues had improved. The disfigurement of the neck caused by the mass was no longer a problem. Three months post-PDT, MRI revealed a significant reduction in the neurofibroma size. PDT was proven as a successful primary intervention for this pathology. However, higher evidence-based studies are required before this therapy can be proposed as a replacement to any of the other conventional therapies.

A patient with primary Burkitt's lymphoma of the postnasal space: case report.

INTRODUCTION: Burkitt's lymphoma is a highly aggressive lymphoma. The endemic form is present with Epstein - Barr virus. The most common sites are the mandible, facial bones, kidneys, gastrointestinal tract, ovaries, breast and extra-nodal sites. We present the first reported case of a primary Burkitt's lymphoma of the postnasal space occurring in an elderly Caucasian male. CASE PRESENTATION: A 72-year-old Caucasian male farmer presented with a 6-week history of a productive cough and a painless left sided cervical swelling. Examination of the neck revealed a 5 cm by 5 cm hard mass in the left anterior triangle. A CT scan of the head and neck showed a soft tissue swelling in the postnasal space. Histology of the postnasal space mass showed squamous mucosa infiltrated by a high grade lymphoma. Immunohistochemical staining and in situ hybridisation confirmed the tumour to be Epstein - Barr virus Ribonucleic acid negative suggesting this was a rare sporadic form of the tumour presenting in a location that is atypical for the clinical subtype and age of the patient. CONCLUSION: This is the first reported case of sporadic Burkitt's lymphoma of the postnasal space of an elderly Caucasian male in the absence of Epstein - Barr virus or human immunodeficiency virus infection and further serves to illustrate the diversity of histological subtypes of malignancies that may develop at this concealed site.

Prospective evaluation of outcome after transoral CO(2) laser resection of T1/T2 oral squamous cell carcinoma.

OBJECTIVE: Oral cancer is the sixth most common cancer in the world. The incidence of oral squamous cell carcinoma (OSCC) continues to be high, if not increasing. This prospective study assessed the oncological outcomes following transoral CO(2) laser resection of T1/T2 N0 OSCC. Patients' 3-year disease-specific survival and disease-free survival were evaluated. MATERIAL AND METHODS: The patients' data included a range of clinical, operative, and histopathological variables related to the status of the surgical margins. Data collection also included recurrence, cause of death, date of death, and last clinic review. Ninety patients (64 males and 26 females) participated in this study. Their mean age at the first diagnosis of OSCC was 63.5 years. Two thirds of the patients were Caucasians. Usually patients present with an ulcer of the tongue, floor of mouth, or buccal mucosa. Current and ex-smokers represented 82.2% of the cohort, whereas current and ex-drinkers were 78.9%. Comorbidities included history of oral lichen planus, oral submucous fibrosis, immunodeficiency, oral dysplasia, or OSCC. Clinically, 81 patients had T1N0 disease and 9 had T2N0 disease. RESULTS: Pathologic analysis revealed that nearly half of the patients had moderately differentiated OSCC, 18 moderately to poorly differentiated, and 19 poorly differentiated carcinoma. Study of the tumor margins was carried out and showed a mean of 5.7-mm depth of invasion; tumor clearance was primarily achieved in 73 patients. Recurrence was identified in 11 (12%) patients. The mean age of first diagnosis of the recurrence group was 76.4 years. The most common clinical presentation in the recurrence group was an ulcer involving the tongue or buccal mucosa; most commonly were identified in current or ex-smokers or drinkers. Recurrence was associated with clinical N-stage disease. The surgical margins in this group were also evaluated following relaser excision or surgical excision ± neck dissection. Follow-up resulted in a 3-year survival of 86.7%. Twelve patients died: 9 from noncancer-related causes, 2 from locoregional disease spread, and 1 from distant metastasis to the lungs. CONCLUSIONS: Squamous cell carcinoma of the oral cavity has a poor overall prognosis with a high tendency to recur at the primary site and extend to involve the locoregional lymph nodes. The overall results of this study suggest that CO(2) laser is a comparable modality to other traditional interventions (surgery) in the management of low-risk (T1/T2) tumors of the oral cavity.

Clinicopathological parameters, recurrence, locoregional and distant metastasis in 115 T1-T2 oral squamous cell carcinoma patients.

The incidence of oral squamous cell carcinoma remains high. Oral and oro-pharyngeal carcinomas are the sixth most common cancer in the world. Several clinicopathological parameters have been implicated in prognosis, recurrence and survival, following oral squamous cell carcinoma. In this retrospective analysis, clinicopathological parameters of 115 T1/T2 OSCC were studied and compared to recurrence and death from tumour-related causes. The study protocol was approved by the Joint UCL/UCLH committees of the ethics for human research. The patients' data was entered onto proformas, which were validated and checked by interval sampling. The fields included a range of clinical, operative and histopathological variables related to the status of the surgical margins. Data collection also included recurrence, cause of death, date of death and last clinic review. Causes of death were collated in 4 categories (1) death from locoregional spread, (2) death from distant metastasis, (3) death from bronchopulmonary pneumonia, and (4) death from any non-tumour event that lead to cardiorespiratory failure. The patients' population comprised 65 males and 50 females. Their mean age at the 1st diagnosis of OSCC was 61.7 years. Two-thirds of the patients were Caucasians. Primary sites were mainly identified in the tongue, floor of mouth (FOM), buccal mucosa and alveolus. Most of the identified OSCCs were low-risk (T1N0 and T2N0). All patients underwent primary resection +/- neck dissection and reconstruction when necessary. Twenty-two patients needed adjuvant radiotherapy. Pathological analysis revealed that half of the patients had moderately differentiated OSCC. pTNM slightly differed from the cTNM and showed that 70.4% of the patients had low-risk OSCC. Tumour clearance was ultimately achieved in 107 patients. Follow-up resulted in a 3-year survival of 74.8% and a 5-year survival of 72.2%. Recurrence was identified in 23 males and 20 females. The mean age of 1st diagnosis of the recurrence group was 59.53 years. Most common oral sites included the lateral border of tongue and floor of mouth. Recurrence was associated with clinical N-stage disease. The surgical margins in this group was evaluated and found that 17 had non-cohesive invasion, 30 had dysplasia at margin, 21 had vascular invasion, 9 had nerve invasion and 3 had bony invasion. Severe dysplasia was present in 37 patients. Tumour clearance was achieved in only 8 patients. The mean depth of tumour invasion in the recurrence group was 7.6 mm.An interesting finding was that 5/11 patients who died of distant metastasis had their primary disease in the tongue. Nodal disease comparison showed that 8/10 patients who died of locoregional metastasis and 8/11 patients who died from distant metastasis had clinical nodal involvement. Comparing this to pathological nodal disease (pTNM) showed that 10/10 patients and 10/11 patients who died from locoregional and distant metastasis, respectively, had nodal disease. All patients who died from locoregional and distant metastasis were shown to have recurrence after the primary tumour resection. Squamous cell carcinoma of the oral cavity has a poor overall prognosis with a high tendency to recur at the primary site and extend to involve the cervical lymph nodes. Several clinicopathological parameters can be employed to assess outcome, recurrence and overall survival.

Risk factors associated with injury to the inferior alveolar and lingual nerves following third molar surgery-revisited.

OBJECTIVE: Earlier reports, including a preliminary study within our unit, have shown that the surgeon's experience is one of the most influential factors in determining the likelihood of both permanent inferior alveolar nerve (IAN) and lingual nerve (LN) paresthesia, following third molar surgery. The effect of this and other factors influencing such prevalence are assessed in this study. STUDY DESIGN: This prospective study involved 3236 patients who underwent surgical removal of impacted third molars. Patients' demographics and radiological parameters were recorded along with the grade of the treating surgeon. The prevalence of inferior alveolar and lingual nerves paresthesia at 1 month, 6 months, and 18 to 24 months postoperatively were also traced. RESULTS: At 1 month postoperatively, the incidence of IAN paresthesia was 1.5% and the LN was 1.8%. These figures decreased over time and 18 to 24 months postoperatively, the incidence of permanent dysfunction of the IAN was 0.6% and LN was 1.1%. With regard to inferior alveolar nerve paresthesia, risk factors included the patient's age (26-30 years), horizontally impacted teeth, close radiographic proximity to the inferior alveolar canal (IAC), and treatment by trainee surgeons. With regard to the lingual nerve, risk factors included male patients, distoangular impactions, close radiographic proximity to the IAC, and treatment by trainee surgeons. CONCLUSION: One of the main risk factors of developing permanent sensory dysfunction in the distribution of these nerves is related to the surgical skills/experience of the operator. Other factors are associated with the type of impaction and the radiographic proximity of the tooth to the inferior alveolar nerve. Such long-term complications can affect the patient's quality of life; the impact on profession, education, and research is unknown.