J Manipulative Physiol Ther 2000 (Nov); 23 (9): 615–618 ~ FULL TEXT
David P. Holtrop, DC, DICCP
4171 S. 15th Street,
Sheboygan, WI 53081;
OBJECTIVE: To discuss the management and resolution of suckling intolerance in a 6-month-old infant.
CLINICAL FEATURES: A 6-month-old boy with a 4(1/2)-month history of aversion to suckling was evaluated in a chiropractic office. Static and motion palpation and observation detected an abnormal inward dishing at the occipitoparietal junction, as well as upper cervical (C1-C2) asymmetry and fixation. These indicated the presence of cranial and upper cervical subluxations.
INTERVENTION AND OUTCOME: The patient was treated 5 times through use of cranial adjusting; 4 of these visits included atlas (C1) adjustment. The suckling intolerance resolved immediately after the first office visit and did not return.
CONCLUSION: It is possible that in the infant, a relationship between mechanical abnormalities of the cervicocranial junction and suckling dysfunction exists; further research in this area could be beneficial. Possible physiological etiologies of painful suckling are presented.
From the Full-Text Article:
The term cervicocraniomandibular syndrome denotes the potential of the TMJ, cranial articulations, and upper cervical spine to influence one another. In the infant, the cranial bones are more mobile than in the adult and are separated by wide strips of cartilage; their relative positions shift during vaginal birth. The birthing process also involves lateral flexion, rotation, and traction to the upper cervical spine, along with a great deal of axial compression followed by distraction.
In a clinical setting, the causes of chiropractic problems are often suspected of having occurred before the onset of resultant symptoms. In the absence of postnatal trauma, I believe that cranial and upper cervical subluxation, resulting from mechanical factors of birth, did not self-correct and gradually worsened. Such subluxation could theoretically result in pain that could be exacerbated by suckling efforts.
The scientific literature seems to be drawing more and more links between the function of the upper cervical spine and head and headache pain. [10-12] Pain fibers of the trigeminal nerve originate from receptors in the scalp, skull, meninges, and vessel walls within the brain. Traction on these fibers produces pain.  If preexisting cranial subluxation would be worsened by suckling efforts, suckling probably could result in headache pain for an infant.
Coordination between perioral muscles and TMJ function has been found to be important for proper suckling,  and tongue action and jaw lowering play primary roles in producing good suckling strength.  Hypertonicity of TMJ-related muscles, such as the temporalis, could result in spasm and thus in painful headache when suckling was attempted. Alternatively, pain might stem from the TMJ itself when suckling is attempted if TMJ alignment and function have been impaired, perhaps as a result of upper cervical and/or cranial subluxation.
Pulek and Horwitz  proposed in 1973 that obstruction of the eustachian tube lymphatics might be the mechanism for the production of serous otitis media. Lymph is moved along as a result of proper muscle activity and motion, and muscle relaxation, along with improved range of motion, is generally an immediate effect of chiropractic adjusting. Adult patients often mention a decrease in sinus pressure after cervical adjusting, and Fysh  theorizes that improved lymphatic drainage from the head and neck may explain alleviation of middle ear infection after chiropractic care. Perhaps congestion of sinuses and/or the middle ear could produce pain similar to that associated with flying and scuba diving—pain that could be exacerbated by the intraoral pressure changes of suckling.
Upledger  suggested that the hypoglossal nerve may be irritated by cranial subluxation. The nerve exits just lateral to the occipital condyles, in close proximity to the occipital bone and the atlantooccipital joint capsule. If such subluxation resulted in hypoglossal nerve dysfunction, impaired tongue function could lead to frustration on the part of an infant attempting to suckle.
This case report has some inherent weaknesses. By definition, it is not a report on a controlled study and has no statistical significance. Furthermore, the patient's condition may have coincidentally self-resolved at the time of the onset of chiropractic care. Therefore, a causal relationship cannot be drawn between the treatment rendered and the favorable outcome of the case. However, such a causal relationship was suspected by the patient's parents as well as by me, and chiropractic adjusting appears to have been effective in this case.
Chiropractic care of the infant is a topic that is in need of exploration in the scientific literature. Future case series and randomized comparative group clinical trials, as well as research comparing the outcomes of upper cervical and cranial adjusting, could shed valuable light on the appropriate role(s) of the chiropractor in managing certain neonatal feeding dysfunction cases.
In this case, a 6-month-old male infant had reportedly experienced significant discomfort while attempting to drink from a bottle over a period of 2 months. He drank freely and without fussing after the first of 5 chiropractic visits, which consisted of C1 and cranial adjusting.