The effects of the chorda tympani damage on submandibular glands: biometric changes Murat Cem Miman a, *, Ahmet Sigirci b , Orhan Ozturan a , Erkan Karatas a , Tamer Erdem a a Otorhinolaryngology Department, Medical Faculty, Inonu University, Malatya 44300, Turkey b Radiology Department, Medical Faculty, Inonu University, Malatya 44300, Turkey Received 12 February 2002; received in revised form 7 May 2002; accepted 24 May 2002 Abstract Objective: It was aimed to analyze the biometric changes in ipsilateral submandibular glands of patients with unilateral chorda tympani (ChT) section during otological operations, compared with change in size of the contralateral glands and with those of healthy subjects. Methods: 29 patients with unilateral complete ChT section and 29 healthy subjects with identical ages, genders, and weights to the patient group were examined ultrasonographically. The patients having a mean duration to follow-up examination of 32 months (2  /84 months) were subdivided into two groups by their time to follow-up as short-term patient group (2  /12 months, 14 patients) and long-term patient group (13 /84 months, 15 patients). The ultrasonographic dimensions and volumes of submandibular glands were compared statistically between the groups. Results: In the patient group, the glands on the contralateral, non-operated side were found to be greater than the ipsilateral, denervated glands in terms of both paramandibular depth dimension (P B/0.05) and volume (P B/0.01). The differences could be determined only in long-term patient group. When comparing the submandibular glands of the patient group with those of the control group, it was found that paramandibular depth dimension and volume of the submandibular glands on the contralateral, non-operated side were statistically greater (P B/0.01). There was no difference between submandibular glands on the operated side of the patient group and those of the control group (P /0.05). Conclusion: The late (13  /84 months) biometric results of ChT damage on submandibular gland were significant for increase in the size of the contralateral, non-denervated submandibular gland. An atrophying effect was not ascertained in the submandibular glands denervated parasympathetically due to the section of the ChT. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Chorda tympani damage; Biometric changes; Submandibular gland; Ultrasonography 1. Introduction The chorda tympani (ChT) is a mixed nerve transmit- ting afferent sensory and efferent secretory impulses. The latter component contains the preganglionic para- sympathetic axons that innervate the sublingual and submandibular glands [1]. The ChT is vulnerable to injury as it arises from the vertical portion of the facial nerve and travels exposed through the middle ear. Therefore, it may become compromised secondary to various disease processes affecting the middle ear [2] or iatrogenically during otological surgical procedures [3]. The effect of ChT damage on the submandibular gland function has been a subject of many animal model and human studies, each demonstrating decreased secretion due to lack of parasympathetic efferent stimulation [4,5]. These findings have led to trials of therapeutic ChT section in an attempt to treat excessive salivation in patients with central nervous system trauma and in children with cerebral paresis [3]. The atrophying effect of ChT damage on the submandibular gland has also been studied in experimental studies using animal models [6,7]. To the best of our knowledge, however, the submandibular gland’s biometric changes have never been studied in humans after ChT section. * Corresponding author. Tel.:  /90-422-3410-660x4606; fax:  /90- 422-3410-728 E-mail address: mcmiman@inonu.edu.tr (M.C. Miman). Auris, Nasus, Larynx 30 (2003) 21 /24 www.elsevier.com/locate/anl 0385-8146/02/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. PII:S0385-8146(02)00027-5