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Introduc tion: Restoration of function by dental implants follow ing complete tumor remova l has high priority in tumor surgery . Recur -rent squamous cell carcinoma (SCC) after this procedure led us tosearch for possible causes.

Method : 16 patients with primary oral SCC had undergone resec- tion, postop. radiotherap y, various reconstructi ve procedures and functional rehabilitat ion by endosseous mandibula r implants. Ineight patien ts a recurren ce was observed. The charts of these patients were examine d for possible causal factors.

Results : The primary SCC had always been located in the floor of the mouth and/or the mandibula r alveolar process, and had been removed with sound margins . The time interval between primary resection and the placem ent of implants was 18–118 months (mean 43 mos). The recurren t SCC occurre d in a similar area 1–69 months (mean34 mos) after implantat ion. This area was again resected in seven patients 23–95 month s after the first resectio n (mean 65 mos). Three patients died within 2–17 months (mean 7 mos) due to tumor pro- gression. One patient died after 4 months because of pulmonary embolism. The follow-up period of the other four patien ts (threetumor-free, one alive with disease) was 6–38 months (mean 26 mos).

Conclusi on: In our opinion the following factors may play a role:Close resection margins with remaining epithelia l dysplasia, fieldcanceriza tion, chronic inflammation due to poor oral hygiene, pas- sive smoking, loss of sensitivity in the mandible after continuity resection , clinical misinterpre tation of SCC as ‘‘granulation tissue’’,HPV infection etc.

The low number of patients does not allow unequ ivocal conclu- sions. We recommen d a small mucosal biopsy at the time of implant placemen t. Symptoms of periimplan titis in former tumor patients should be considered as a serious sign. Short-te rm controls are man- datory as patients may not suffer from discomfor t due to the loss ofsensitivit y.

doi:10.1016/j.oraloncolo gy.2013.03.386

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Metastases to the parotid gland from a medullary thyroid carci- noma (case report)Petros Zikos, Margarita Vafiadou, Nikolaos Kechagias,Konstantinos Vahtsevan os, Doxa Mangou di

Departme nt of Maxillofa cial Surgical Oncology, Theagenio Cancer Hospital, Thessaloniki , Greece

We present a rare case of a medullary thyroid carcinoma meta- static to the parotid gland and review the associat ed literature.

A 68 year old male presented with a right parotid mass for 6 months. He had a history of a medullary thyroid carcinoma diag- nosed ten years ago and treated with total thyroidectom y and para- tracheal neck dissection. Following surgery , he was monitored for recurren ce with periodic physical examina tions and laboratory test- ing of calcitonin and CEA levels.

Fine needle aspiration consistent with Warthin tumor. The CTneck examination demonstrate d the presence of a right paroti d mass but showed no cervical lymphadenop athy and chest CT scans showed no lesions .

The patient was managed surgically with a superficial parotidec -tomy and the final pathology confirmed a diagnosis of a medullary thyroid carcinoma metastat ic to the parotid gland. Two years from the time of surgery he remained free of clinical disease.

Knowled ge of this malignanc y’s potential for unusual and aggres- sive patterns of spread is essential to ensuring early identification ofrecurren t disease.

doi:10.1016/j.oraloncology.20 13.03.387

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Orbital preservati on in surgical manag ement of advanc ed max- illary cancer Jin Hwan Kim, Dong Jin Lee, Kee Hwan Kwon, Seung Woo Kim,Eun Jae Jungl, Il Seok Park, Young Soo Rho

Departme nt of Otolaryngo logy–Head and Neck Surgery, Ilsong Memorial Institute of Head and Neck Cancer, Hallym University College ofMedicin e, Seoul, Republic of Korea

Objectives: The decision whethe r or not to preserve orbital con- tents during surgical resecti on of malignant tumors involving the sinonasal tract and the orbit has been an issue of controversy . The purpos e of the study was to examine the oncolog ical and functional outcomes of multim odality therapy for patients with advanced max- illary cancer that invaded the orbit.

Materials and method s: Retrospective study was conducted using medica l records of 55 patients who underwent primary surgical manage ment with or without orbital exentration for maxillary can- cer abuttin g or eroding orbit.

Results: Among 55 cases of maxillary cancer, 26 patients (26/55,47%) were suspected to be invaded orbit in pre-opera tive radiologic studies. During surgery , 11 patients (11/26, 42%) had the tumor close to periosteu m without definite involveme nt and six patients (6/26,23%) had the tumor with periosteum involveme nt in frozen biopsy.These 17 patien ts (17/26, 63%) underwent maxillectom y without orbital exentra tion. And nine patients (9/26, 35%) had the tumor with orbital fat or muscle involveme nt in frozen biopsy and received orbital exentratio n. 19%(5/26) of the patients had local recurren ce.There were no statistical ly significant differences in recurrence rates (18% vs 22%) and 5-year disease free surviva l rate (55% vs 34%)between orbit preservation group and orbital exentra tion group. In11 patien ts (11/26, 42%), discrep ancy between pre-opera tive radio- logic studies and pathologic reports were found.

Conclusion: Control of the primary site and functional results are importan t in the curative treatment of maxillary cancer. Orbital pres- ervation procedure during radical maxillectom y for the patien ts with- out definite orbital fat or muscle invasion must be considered carefully . And proper pre-opera tive evaluation and frozen biopsy dur- ing surgery for orbital invasion is essential because of the high false positive rate of pre-opera tive radiologic studies for orbital invasion.

doi:10.1016/j.oraloncology.20 13.03.388

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Progno stic predictors in pathologica l node negative T2 lesions ofthe oral tongue squamous cell carcinoma Sharank umar Shetty, T. Krishnakum ar, B. Deepak,L.M. Chandrashek ar, D. Sriprak ash, Subrama nia Iyer

Head and Neck Institute, Amrita Institute of Medical Sciences, Kochi,India

Objective: Locoregiona l recurre nce in early tongue carcinoma after surgical treatment remain s a problem and has an impact on the sur- vival. The present study evaluate s the predictive factors for the recurre nces in patients with pathologica lly node negative T2 oral tongue carcinoma .

Asbtracts / Oral Oncology 49 (2013) S93–S156 S143