Localization of ectopic maxillary canines -- is CBCT more accurate than conventional horizontal or vertical parallax?

OBJECTIVE: To compare the accuracy of cone-beam CT (CBCT) with conventional horizontal and vertical parallax for the localization of ectopic maxillary canines. DESIGN: Observational study. METHODS: A typodont was constructed using human teeth embedded in radio-dense impression material, containing a simulated ectopic canine. Image sets (vertical/horizontal parallax and CBCT scans) were obtained for nine positions. A photograph confirmed the true position of the canine. Six observers used horizontal (HP) and vertical (VP) parallax techniques with conventional radiographs and the axial, coronal and sagittal CBCT views to locate the canine tip. Images were manipulated as required using proprietary software (http://www.carestream.com and http://www.i-cat.com). Intra-observer reproducibility was calculated by one observer re-evaluating the image sets after 2 months. Individual observer validity was calculated in relation to the photographic position of the canine using weighted Kappa. Differences in the proportion of correct locations between CBCT and vertical/horizontal parallax were tested using McNemar tests (P<0·05). RESULTS: Intra- and inter-observer agreements were excellent (0·8985) and substantial (0·7528), respectively. Individual observer validity was substantial-excellent (0·7368-0·900). The canine position was correctly identified in 94% of cases located using CBCT, 83% using HP and 65% using VP. The differences between CBCT and vertical and horizontal parallax were highly statistically significant (P<0·01). CONCLUSION: CBCT is more accurate than either horizontal or vertical parallax for the localization of ectopic maxillary canine teeth.

The characteristics of bisphosphonate patients developing bisphosphonate-related osteonecrosis of the jaw attending an OMFS department.

UNLABELLED: This case series considers the incidence of patients taking bisphosphonate medication that suffer with bisphosphonate-related osteonecrosis of the jaw (BRONJ) following an exodontia procedure. Forty five such patients who attended the Wigan Royal Albert Edward Infirmary (RAEI) Oral and Maxillofacial Surgery (OMFS) department for an exodontia procedure were examined. A patient's age, gender, exodontia technique, bisphosphonate route (Oral/IV), smoking status and reason for taking the bisphosphonates, eg osteoporosis/cancer/ arthritis was considered. All of the patients that experienced BRONJ were smokers. CLINICAL RELEVANCE: Bisphosphonates are now widely accepted for the management of medical conditions, including arthritis, osteoporosis and various forms of cancer. Such patients are regularly referred to OMFS departments for dental extractions.

Mandibular advancement appliances for treating sleep apnoea/hypopnoea syndrome.

STUDY DESIGN: Randomised controlled crossover trial. INTERVENTION: Sixteen participants (13 men and three women) with mild to moderate OSAHS, diagnosed using polysomnography (PSG), were recruited from a sleep clinic. To be included, participants had to have 20 or more teeth (sufficient to provide retention for oral appliances), have had no previous OSAHS treatment, been unable to tolerate nasal continuous positive airway pressure and be free from caries, periodontal disease, temporomandibular joint (TMJ) pain or movement limitations. One-night mandibular advancement titration was carried out using a custom made temporary dental appliance to reach each individual's pre-determined maximum voluntary advancement value. Participants were given one week to acclimatise. Two different MAAs were made to this titrated value for each participant; the SILENT NITE (a two-piece MAA in flexible trays connected by two plastic bars to maintain mandibular advancement) and a one-piece resin-made activator appliance which was retained by posterior tooth clasps. Patients were 'randomly divided' into two groups and wore one or other appliance as allocated for three months. Following a two week washout period, they then wore the other appliance for a further three months. OUTCOME MEASURE: Subjective measures were recorded pre- and post treatment using Epworth's Sleepiness Scale and an unspecified Snoring Scale. Preferences, compliance and side effects were assessed through interviews with patients and their families. Pre- and post treatment objective measures were taken using a variety of PSG results which were manually scored by a blinded operator (these included EOG, ECG, supplemental EMG, nasal-oral airflow, abdominal and chest respiratory effort, ECG rhythm). Cephalometric radiographs taken pre- and post treatment were scored by a single examiner for upper airway space diameters. RESULTS: Baseline measures for both BMI and titrated distances for mandibular advancement were similar for both groups. Daytime performance (ESS) and snoring (SS) showed significant improvement for both MAAs during treatment but there were no significant differences between the appliances. Out of the 16 participants, seven preferred the monoblock appliance, two preferred the two-piece and seven had no preference. All patients finished treatment and stated full compliance despite some of the participants experiencing side effects; two had ulcers for several weeks at the start of treatment, four experienced TMJ pain, three complained of muscle discomfort and four felt some dental discomfort. PSG showed that total sleep time did not differ pre- and post treatment and sleep efficiency increased for the monoblock appliance only. Both appliances showed improvement in AHI, AI and Hypopnoea Index, but the monoblock had a more statistically important improvement for AHI and AI. Upper airway space diameters were increased with both MAAs but there were no significant differences between the appliances. CONCLUSIONS: Both the monoblock and the SILENT NITE appliances were effective at reducing the severity of symptoms of OSAHS. The monoblock, however, offered some advantages over the two-piece appliance in achieving a greater improvement in Apnoea Hypopnoea Index and Apnoea Index and being preferred by most patients.

Preoperative removal of lower third molars and bilateral sagittal split osteotomy in the UK.

To find out what consultants in Oral and Maxillofacial Surgery (OMFS) in the UK think about complications of bilateral sagittal split osteotomy (BSSO) in relation to lower third molars we organised a national postal questionnaire during 2012-13. Of 378 consultants, 192 practised orthognathic surgery of whom 132 replied (a 69% response rate). Eighty-one respondents routinely removed lower third molars before BSSO; 51 did not. Eighty-nine respondents thought that there was an increased risk of complications if third molars were present at the time of BSSO, mainly an increased risk of unfavourable fractures. Forty-three respondents did not think there was an increased risk of complications of BSSO when third molars were present. Of the 81 who routinely removed the lower third molars, 13 removed them within the six-month period before BSSO, 56 removed them 6-12 months before, and 11 removed them more than 12 months before. There seemed to be no difference in self-reported unfavourable fracture rates between those surgeons who routinely removed lower third molars and those who did not. The results of the questionnaire showed that there was considerable variation in surgical practice across the UK in the management of lower third molars before BSSO, both in terms of whether or not to remove these teeth at all, and if so, when to remove them.